First pass at reorganizing go code into sub-packages

internal/handlers/Makefile

@@ -0,0 +1,9 @@
+all: security_templates.go
+
+security_templates.go: cusip_list.csv scripts/gen_security_list.py
+	./scripts/gen_security_list.py > security_templates.go
+
+cusip_list.csv:
+	./scripts/gen_cusip_csv.sh > cusip_list.csv
+
+.PHONY = all

internal/handlers/accounts.go

@@ -0,0 +1,561 @@
+package handlers
+
+import (
+	"encoding/json"
+	"errors"
+	"gopkg.in/gorp.v1"
+	"log"
+	"net/http"
+	"regexp"
+	"strings"
+)
+
+type AccountType int64
+
+const (
+	Bank       AccountType = 1 // start at 1 so that the default (0) is invalid
+	Cash                   = 2
+	Asset                  = 3
+	Liability              = 4
+	Investment             = 5
+	Income                 = 6
+	Expense                = 7
+	Trading                = 8
+	Equity                 = 9
+	Receivable             = 10
+	Payable                = 11
+)
+
+var AccountTypes = []AccountType{
+	Bank,
+	Cash,
+	Asset,
+	Liability,
+	Investment,
+	Income,
+	Expense,
+	Trading,
+	Equity,
+	Receivable,
+	Payable,
+}
+
+func (t AccountType) String() string {
+	switch t {
+	case Bank:
+		return "Bank"
+	case Cash:
+		return "Cash"
+	case Asset:
+		return "Asset"
+	case Liability:
+		return "Liability"
+	case Investment:
+		return "Investment"
+	case Income:
+		return "Income"
+	case Expense:
+		return "Expense"
+	case Trading:
+		return "Trading"
+	case Equity:
+		return "Equity"
+	case Receivable:
+		return "Receivable"
+	case Payable:
+		return "Payable"
+	}
+	return ""
+}
+
+type Account struct {
+	AccountId         int64
+	ExternalAccountId string
+	UserId            int64
+	SecurityId        int64
+	ParentAccountId   int64 // -1 if this account is at the root
+	Type              AccountType
+	Name              string
+
+	// monotonically-increasing account transaction version number. Used for
+	// allowing a client to ensure they have a consistent version when paging
+	// through transactions.
+	AccountVersion int64 `json:"Version"`
+
+	// Optional fields specifying how to fetch transactions from a bank via OFX
+	OFXURL       string
+	OFXORG       string
+	OFXFID       string
+	OFXUser      string
+	OFXBankID    string // OFX BankID (BrokerID if AcctType == Investment)
+	OFXAcctID    string
+	OFXAcctType  string // ofxgo.acctType
+	OFXClientUID string
+	OFXAppID     string
+	OFXAppVer    string
+	OFXVersion   string
+	OFXNoIndent  bool
+}
+
+type AccountList struct {
+	Accounts *[]Account `json:"accounts"`
+}
+
+var accountTransactionsRE *regexp.Regexp
+var accountImportRE *regexp.Regexp
+
+func init() {
+	accountTransactionsRE = regexp.MustCompile(`^/account/[0-9]+/transactions/?$`)
+	accountImportRE = regexp.MustCompile(`^/account/[0-9]+/import/[a-z]+/?$`)
+}
+
+func (a *Account) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(a)
+}
+
+func (a *Account) Read(json_str string) error {
+	dec := json.NewDecoder(strings.NewReader(json_str))
+	return dec.Decode(a)
+}
+
+func (al *AccountList) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(al)
+}
+
+func GetAccount(db *DB, accountid int64, userid int64) (*Account, error) {
+	var a Account
+
+	err := db.SelectOne(&a, "SELECT * from accounts where UserId=? AND AccountId=?", userid, accountid)
+	if err != nil {
+		return nil, err
+	}
+	return &a, nil
+}
+
+func GetAccountTx(transaction *gorp.Transaction, accountid int64, userid int64) (*Account, error) {
+	var a Account
+
+	err := transaction.SelectOne(&a, "SELECT * from accounts where UserId=? AND AccountId=?", userid, accountid)
+	if err != nil {
+		return nil, err
+	}
+
+	return &a, nil
+}
+
+func GetAccounts(db *DB, userid int64) (*[]Account, error) {
+	var accounts []Account
+
+	_, err := db.Select(&accounts, "SELECT * from accounts where UserId=?", userid)
+	if err != nil {
+		return nil, err
+	}
+	return &accounts, nil
+}
+
+// Get (and attempt to create if it doesn't exist). Matches on UserId,
+// SecurityId, Type, Name, and ParentAccountId
+func GetCreateAccountTx(transaction *gorp.Transaction, a Account) (*Account, error) {
+	var accounts []Account
+	var account Account
+
+	// Try to find the top-level trading account
+	_, err := transaction.Select(&accounts, "SELECT * from accounts where UserId=? AND SecurityId=? AND Type=? AND Name=? AND ParentAccountId=? ORDER BY AccountId ASC LIMIT 1", a.UserId, a.SecurityId, a.Type, a.Name, a.ParentAccountId)
+	if err != nil {
+		return nil, err
+	}
+	if len(accounts) == 1 {
+		account = accounts[0]
+	} else {
+		account.UserId = a.UserId
+		account.SecurityId = a.SecurityId
+		account.Type = a.Type
+		account.Name = a.Name
+		account.ParentAccountId = a.ParentAccountId
+
+		err = transaction.Insert(&account)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &account, nil
+}
+
+// Get (and attempt to create if it doesn't exist) the security/currency
+// trading account for the supplied security/currency
+func GetTradingAccount(transaction *gorp.Transaction, userid int64, securityid int64) (*Account, error) {
+	var tradingAccount Account
+	var account Account
+
+	user, err := GetUserTx(transaction, userid)
+	if err != nil {
+		return nil, err
+	}
+
+	tradingAccount.UserId = userid
+	tradingAccount.Type = Trading
+	tradingAccount.Name = "Trading"
+	tradingAccount.SecurityId = user.DefaultCurrency
+	tradingAccount.ParentAccountId = -1
+
+	// Find/create the top-level trading account
+	ta, err := GetCreateAccountTx(transaction, tradingAccount)
+	if err != nil {
+		return nil, err
+	}
+
+	security, err := GetSecurityTx(transaction, securityid, userid)
+	if err != nil {
+		return nil, err
+	}
+
+	account.UserId = userid
+	account.Name = security.Name
+	account.ParentAccountId = ta.AccountId
+	account.SecurityId = securityid
+	account.Type = Trading
+
+	a, err := GetCreateAccountTx(transaction, account)
+	if err != nil {
+		return nil, err
+	}
+
+	return a, nil
+}
+
+// Get (and attempt to create if it doesn't exist) the security/currency
+// imbalance account for the supplied security/currency
+func GetImbalanceAccount(transaction *gorp.Transaction, userid int64, securityid int64) (*Account, error) {
+	var imbalanceAccount Account
+	var account Account
+	xxxtemplate := FindSecurityTemplate("XXX", Currency)
+	if xxxtemplate == nil {
+		return nil, errors.New("Couldn't find XXX security template")
+	}
+	xxxsecurity, err := ImportGetCreateSecurity(transaction, userid, xxxtemplate)
+	if err != nil {
+		return nil, errors.New("Couldn't create XXX security")
+	}
+
+	imbalanceAccount.UserId = userid
+	imbalanceAccount.Name = "Imbalances"
+	imbalanceAccount.ParentAccountId = -1
+	imbalanceAccount.SecurityId = xxxsecurity.SecurityId
+	imbalanceAccount.Type = Bank
+
+	// Find/create the top-level trading account
+	ia, err := GetCreateAccountTx(transaction, imbalanceAccount)
+	if err != nil {
+		return nil, err
+	}
+
+	security, err := GetSecurityTx(transaction, securityid, userid)
+	if err != nil {
+		return nil, err
+	}
+
+	account.UserId = userid
+	account.Name = security.Name
+	account.ParentAccountId = ia.AccountId
+	account.SecurityId = securityid
+	account.Type = Bank
+
+	a, err := GetCreateAccountTx(transaction, account)
+	if err != nil {
+		return nil, err
+	}
+
+	return a, nil
+}
+
+type ParentAccountMissingError struct{}
+
+func (pame ParentAccountMissingError) Error() string {
+	return "Parent account missing"
+}
+
+func insertUpdateAccount(db *DB, a *Account, insert bool) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	if a.ParentAccountId != -1 {
+		existing, err := transaction.SelectInt("SELECT count(*) from accounts where AccountId=?", a.ParentAccountId)
+		if err != nil {
+			transaction.Rollback()
+			return err
+		}
+		if existing != 1 {
+			transaction.Rollback()
+			return ParentAccountMissingError{}
+		}
+	}
+
+	if insert {
+		err = transaction.Insert(a)
+		if err != nil {
+			transaction.Rollback()
+			return err
+		}
+	} else {
+		oldacct, err := GetAccountTx(transaction, a.AccountId, a.UserId)
+		if err != nil {
+			transaction.Rollback()
+			return err
+		}
+
+		a.AccountVersion = oldacct.AccountVersion + 1
+
+		count, err := transaction.Update(a)
+		if err != nil {
+			transaction.Rollback()
+			return err
+		}
+		if count != 1 {
+			transaction.Rollback()
+			return errors.New("Updated more than one account")
+		}
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func InsertAccount(db *DB, a *Account) error {
+	return insertUpdateAccount(db, a, true)
+}
+
+func UpdateAccount(db *DB, a *Account) error {
+	return insertUpdateAccount(db, a, false)
+}
+
+func DeleteAccount(db *DB, a *Account) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	if a.ParentAccountId != -1 {
+		// Re-parent splits to this account's parent account if this account isn't a root account
+		_, err = transaction.Exec("UPDATE splits SET AccountId=? WHERE AccountId=?", a.ParentAccountId, a.AccountId)
+		if err != nil {
+			transaction.Rollback()
+			return err
+		}
+	} else {
+		// Delete splits if this account is a root account
+		_, err = transaction.Exec("DELETE FROM splits WHERE AccountId=?", a.AccountId)
+		if err != nil {
+			transaction.Rollback()
+			return err
+		}
+	}
+
+	// Re-parent child accounts to this account's parent account
+	_, err = transaction.Exec("UPDATE accounts SET ParentAccountId=? WHERE ParentAccountId=?", a.ParentAccountId, a.AccountId)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	count, err := transaction.Delete(a)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+	if count != 1 {
+		transaction.Rollback()
+		return errors.New("Was going to delete more than one account")
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func AccountHandler(w http.ResponseWriter, r *http.Request, db *DB) {
+	user, err := GetUserFromSession(db, r)
+	if err != nil {
+		WriteError(w, 1 /*Not Signed In*/)
+		return
+	}
+
+	if r.Method == "POST" {
+		// if URL looks like /account/[0-9]+/import, use the account
+		// import handler
+		if accountImportRE.MatchString(r.URL.Path) {
+			var accountid int64
+			var importtype string
+			n, err := GetURLPieces(r.URL.Path, "/account/%d/import/%s", &accountid, &importtype)
+
+			if err != nil || n != 2 {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+			AccountImportHandler(db, w, r, user, accountid, importtype)
+			return
+		}
+
+		account_json := r.PostFormValue("account")
+		if account_json == "" {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		var account Account
+		err := account.Read(account_json)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		account.AccountId = -1
+		account.UserId = user.UserId
+		account.AccountVersion = 0
+
+		security, err := GetSecurity(db, account.SecurityId, user.UserId)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+		if security == nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		err = InsertAccount(db, &account)
+		if err != nil {
+			if _, ok := err.(ParentAccountMissingError); ok {
+				WriteError(w, 3 /*Invalid Request*/)
+			} else {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+			}
+			return
+		}
+
+		w.WriteHeader(201 /*Created*/)
+		err = account.Write(w)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	} else if r.Method == "GET" {
+		var accountid int64
+		n, err := GetURLPieces(r.URL.Path, "/account/%d", &accountid)
+
+		if err != nil || n != 1 {
+			//Return all Accounts
+			var al AccountList
+			accounts, err := GetAccounts(db, user.UserId)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+			al.Accounts = accounts
+			err = (&al).Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else {
+			// if URL looks like /account/[0-9]+/transactions, use the account
+			// transaction handler
+			if accountTransactionsRE.MatchString(r.URL.Path) {
+				AccountTransactionsHandler(db, w, r, user, accountid)
+				return
+			}
+
+			// Return Account with this Id
+			account, err := GetAccount(db, accountid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = account.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		}
+	} else {
+		accountid, err := GetURLID(r.URL.Path)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		if r.Method == "PUT" {
+			account_json := r.PostFormValue("account")
+			if account_json == "" {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			var account Account
+			err := account.Read(account_json)
+			if err != nil || account.AccountId != accountid {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+			account.UserId = user.UserId
+
+			security, err := GetSecurity(db, account.SecurityId, user.UserId)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+			if security == nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = UpdateAccount(db, &account)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			err = account.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else if r.Method == "DELETE" {
+			account, err := GetAccount(db, accountid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = DeleteAccount(db, account)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			WriteSuccess(w)
+		}
+	}
+}

internal/handlers/accounts_lua.go

@@ -0,0 +1,217 @@
+package handlers
+
+import (
+	"context"
+	"errors"
+	"github.com/yuin/gopher-lua"
+	"math/big"
+	"strings"
+)
+
+const luaAccountTypeName = "account"
+
+func luaContextGetAccounts(L *lua.LState) (map[int64]*Account, error) {
+	var account_map map[int64]*Account
+
+	ctx := L.Context()
+
+	db, ok := ctx.Value(dbContextKey).(*DB)
+	if !ok {
+		return nil, errors.New("Couldn't find DB in lua's Context")
+	}
+
+	account_map, ok = ctx.Value(accountsContextKey).(map[int64]*Account)
+	if !ok {
+		user, ok := ctx.Value(userContextKey).(*User)
+		if !ok {
+			return nil, errors.New("Couldn't find User in lua's Context")
+		}
+
+		accounts, err := GetAccounts(db, user.UserId)
+		if err != nil {
+			return nil, err
+		}
+
+		account_map = make(map[int64]*Account)
+		for i := range *accounts {
+			account_map[(*accounts)[i].AccountId] = &(*accounts)[i]
+		}
+
+		ctx = context.WithValue(ctx, accountsContextKey, account_map)
+		L.SetContext(ctx)
+	}
+
+	return account_map, nil
+}
+
+func luaGetAccounts(L *lua.LState) int {
+	account_map, err := luaContextGetAccounts(L)
+	if err != nil {
+		panic("luaGetAccounts couldn't fetch accounts")
+	}
+
+	table := L.NewTable()
+
+	for accountid := range account_map {
+		table.RawSetInt(int(accountid), AccountToLua(L, account_map[accountid]))
+	}
+
+	L.Push(table)
+	return 1
+}
+
+func luaRegisterAccounts(L *lua.LState) {
+	mt := L.NewTypeMetatable(luaAccountTypeName)
+	L.SetGlobal("account", mt)
+	L.SetField(mt, "__index", L.NewFunction(luaAccount__index))
+	L.SetField(mt, "__tostring", L.NewFunction(luaAccount__tostring))
+	L.SetField(mt, "__eq", L.NewFunction(luaAccount__eq))
+	L.SetField(mt, "__metatable", lua.LString("protected"))
+
+	for _, accttype := range AccountTypes {
+		L.SetField(mt, accttype.String(), lua.LNumber(float64(accttype)))
+	}
+
+	getAccountsFn := L.NewFunction(luaGetAccounts)
+	L.SetField(mt, "get_all", getAccountsFn)
+	// also register the get_accounts function as a global in its own right
+	L.SetGlobal("get_accounts", getAccountsFn)
+}
+
+func AccountToLua(L *lua.LState, account *Account) *lua.LUserData {
+	ud := L.NewUserData()
+	ud.Value = account
+	L.SetMetatable(ud, L.GetTypeMetatable(luaAccountTypeName))
+	return ud
+}
+
+// Checks whether the first lua argument is a *LUserData with *Account and returns this *Account.
+func luaCheckAccount(L *lua.LState, n int) *Account {
+	ud := L.CheckUserData(n)
+	if account, ok := ud.Value.(*Account); ok {
+		return account
+	}
+	L.ArgError(n, "account expected")
+	return nil
+}
+
+func luaAccount__index(L *lua.LState) int {
+	a := luaCheckAccount(L, 1)
+	field := L.CheckString(2)
+
+	switch field {
+	case "AccountId", "accountid":
+		L.Push(lua.LNumber(float64(a.AccountId)))
+	case "Security", "security":
+		security_map, err := luaContextGetSecurities(L)
+		if err != nil {
+			panic("account.security couldn't fetch securities")
+		}
+		if security, ok := security_map[a.SecurityId]; ok {
+			L.Push(SecurityToLua(L, security))
+		} else {
+			panic("SecurityId not in lua security_map")
+		}
+	case "SecurityId", "securityid":
+		L.Push(lua.LNumber(float64(a.SecurityId)))
+	case "Parent", "parent", "ParentAccount", "parentaccount":
+		if a.ParentAccountId == -1 {
+			L.Push(lua.LNil)
+		} else {
+			account_map, err := luaContextGetAccounts(L)
+			if err != nil {
+				panic("account.parent couldn't fetch accounts")
+			}
+			if parent, ok := account_map[a.ParentAccountId]; ok {
+				L.Push(AccountToLua(L, parent))
+			} else {
+				panic("ParentAccountId not in lua account_map")
+			}
+		}
+	case "Name", "name":
+		L.Push(lua.LString(a.Name))
+	case "Type", "type":
+		L.Push(lua.LNumber(float64(a.Type)))
+	case "TypeName", "Typename":
+		L.Push(lua.LString(a.Type.String()))
+	case "typename":
+		L.Push(lua.LString(strings.ToLower(a.Type.String())))
+	case "Balance", "balance":
+		L.Push(L.NewFunction(luaAccountBalance))
+	default:
+		L.ArgError(2, "unexpected account attribute: "+field)
+	}
+
+	return 1
+}
+
+func luaAccountBalance(L *lua.LState) int {
+	a := luaCheckAccount(L, 1)
+
+	ctx := L.Context()
+	db, ok := ctx.Value(dbContextKey).(*DB)
+	if !ok {
+		panic("Couldn't find DB in lua's Context")
+	}
+	user, ok := ctx.Value(userContextKey).(*User)
+	if !ok {
+		panic("Couldn't find User in lua's Context")
+	}
+	security_map, err := luaContextGetSecurities(L)
+	if err != nil {
+		panic("account.security couldn't fetch securities")
+	}
+	security, ok := security_map[a.SecurityId]
+	if !ok {
+		panic("SecurityId not in lua security_map")
+	}
+	date := luaWeakCheckTime(L, 2)
+	var b Balance
+	var rat *big.Rat
+	if date != nil {
+		end := luaWeakCheckTime(L, 3)
+		if end != nil {
+			rat, err = GetAccountBalanceDateRange(db, user, a.AccountId, date, end)
+		} else {
+			rat, err = GetAccountBalanceDate(db, user, a.AccountId, date)
+		}
+	} else {
+		rat, err = GetAccountBalance(db, user, a.AccountId)
+	}
+	if err != nil {
+		panic("Failed to GetAccountBalance:" + err.Error())
+	}
+	b.Amount = rat
+	b.Security = security
+	L.Push(BalanceToLua(L, &b))
+
+	return 1
+}
+
+func luaAccount__tostring(L *lua.LState) int {
+	a := luaCheckAccount(L, 1)
+
+	account_map, err := luaContextGetAccounts(L)
+	if err != nil {
+		panic("luaGetAccounts couldn't fetch accounts")
+	}
+
+	full_name := a.Name
+	for a.ParentAccountId != -1 {
+		a = account_map[a.ParentAccountId]
+		full_name = a.Name + "/" + full_name
+	}
+
+	L.Push(lua.LString(full_name))
+
+	return 1
+}
+
+func luaAccount__eq(L *lua.LState) int {
+	a := luaCheckAccount(L, 1)
+	b := luaCheckAccount(L, 2)
+
+	L.Push(lua.LBool(a.AccountId == b.AccountId))
+
+	return 1
+}

internal/handlers/balance_lua.go

@@ -0,0 +1,224 @@
+package handlers
+
+import (
+	"github.com/yuin/gopher-lua"
+	"math/big"
+)
+
+type Balance struct {
+	Security *Security
+	Amount   *big.Rat
+}
+
+const luaBalanceTypeName = "balance"
+
+func luaRegisterBalances(L *lua.LState) {
+	mt := L.NewTypeMetatable(luaBalanceTypeName)
+	L.SetGlobal("balance", mt)
+	L.SetField(mt, "__index", L.NewFunction(luaBalance__index))
+	L.SetField(mt, "__tostring", L.NewFunction(luaBalance__tostring))
+	L.SetField(mt, "__eq", L.NewFunction(luaBalance__eq))
+	L.SetField(mt, "__lt", L.NewFunction(luaBalance__lt))
+	L.SetField(mt, "__le", L.NewFunction(luaBalance__le))
+	L.SetField(mt, "__add", L.NewFunction(luaBalance__add))
+	L.SetField(mt, "__sub", L.NewFunction(luaBalance__sub))
+	L.SetField(mt, "__mul", L.NewFunction(luaBalance__mul))
+	L.SetField(mt, "__div", L.NewFunction(luaBalance__div))
+	L.SetField(mt, "__unm", L.NewFunction(luaBalance__unm))
+	L.SetField(mt, "__metatable", lua.LString("protected"))
+}
+
+func BalanceToLua(L *lua.LState, balance *Balance) *lua.LUserData {
+	ud := L.NewUserData()
+	ud.Value = balance
+	L.SetMetatable(ud, L.GetTypeMetatable(luaBalanceTypeName))
+	return ud
+}
+
+// Checks whether the first lua argument is a *LUserData with *Balance and returns this *Balance.
+func luaCheckBalance(L *lua.LState, n int) *Balance {
+	ud := L.CheckUserData(n)
+	if balance, ok := ud.Value.(*Balance); ok {
+		return balance
+	}
+	L.ArgError(n, "balance expected")
+	return nil
+}
+
+func luaWeakCheckBalance(L *lua.LState, n int) *Balance {
+	v := L.Get(n)
+	if ud, ok := v.(*lua.LUserData); ok {
+		if balance, ok := ud.Value.(*Balance); ok {
+			return balance
+		}
+		L.ArgError(n, "balance expected")
+	}
+	return nil
+}
+
+func luaGetBalanceOperands(L *lua.LState, n int, m int) (*Balance, *Balance) {
+	bn := luaWeakCheckBalance(L, n)
+	bm := luaWeakCheckBalance(L, m)
+
+	if bn != nil && bm != nil {
+		return bn, bm
+	} else if bn != nil {
+		nm := L.CheckNumber(m)
+		var balance Balance
+		var rat big.Rat
+		balance.Security = bn.Security
+		balance.Amount = rat.SetFloat64(float64(nm))
+		if balance.Amount == nil {
+			L.ArgError(n, "non-finite float invalid for operand to balance arithemetic")
+			return nil, nil
+		}
+		return bn, &balance
+	} else if bm != nil {
+		nn := L.CheckNumber(n)
+		var balance Balance
+		var rat big.Rat
+		balance.Security = bm.Security
+		balance.Amount = rat.SetFloat64(float64(nn))
+		if balance.Amount == nil {
+			L.ArgError(n, "non-finite float invalid for operand to balance arithemetic")
+			return nil, nil
+		}
+		return bm, &balance
+	}
+	L.ArgError(n, "balance expected")
+	return nil, nil
+}
+
+func luaBalance__index(L *lua.LState) int {
+	a := luaCheckBalance(L, 1)
+	field := L.CheckString(2)
+
+	switch field {
+	case "Security", "security":
+		L.Push(SecurityToLua(L, a.Security))
+	case "Amount", "amount":
+		float, _ := a.Amount.Float64()
+		L.Push(lua.LNumber(float))
+	default:
+		L.ArgError(2, "unexpected balance attribute: "+field)
+	}
+
+	return 1
+}
+
+func luaBalance__tostring(L *lua.LState) int {
+	b := luaCheckBalance(L, 1)
+
+	L.Push(lua.LString(b.Security.Symbol + " " + b.Amount.FloatString(b.Security.Precision)))
+
+	return 1
+}
+
+func luaBalance__eq(L *lua.LState) int {
+	a := luaCheckBalance(L, 1)
+	b := luaCheckBalance(L, 2)
+
+	L.Push(lua.LBool(a.Security.SecurityId == b.Security.SecurityId && a.Amount.Cmp(b.Amount) == 0))
+
+	return 1
+}
+
+func luaBalance__lt(L *lua.LState) int {
+	a := luaCheckBalance(L, 1)
+	b := luaCheckBalance(L, 2)
+	if a.Security.SecurityId != b.Security.SecurityId {
+		L.ArgError(2, "Can't compare balances with different securities")
+	}
+
+	L.Push(lua.LBool(a.Amount.Cmp(b.Amount) < 0))
+
+	return 1
+}
+
+func luaBalance__le(L *lua.LState) int {
+	a := luaCheckBalance(L, 1)
+	b := luaCheckBalance(L, 2)
+	if a.Security.SecurityId != b.Security.SecurityId {
+		L.ArgError(2, "Can't compare balances with different securities")
+	}
+
+	L.Push(lua.LBool(a.Amount.Cmp(b.Amount) <= 0))
+
+	return 1
+}
+
+func luaBalance__add(L *lua.LState) int {
+	a, b := luaGetBalanceOperands(L, 1, 2)
+
+	if a.Security.SecurityId != b.Security.SecurityId {
+		L.ArgError(2, "Can't add balances with different securities")
+	}
+
+	var balance Balance
+	var rat big.Rat
+	balance.Security = a.Security
+	balance.Amount = rat.Add(a.Amount, b.Amount)
+	L.Push(BalanceToLua(L, &balance))
+
+	return 1
+}
+
+func luaBalance__sub(L *lua.LState) int {
+	a, b := luaGetBalanceOperands(L, 1, 2)
+
+	if a.Security.SecurityId != b.Security.SecurityId {
+		L.ArgError(2, "Can't subtract balances with different securities")
+	}
+
+	var balance Balance
+	var rat big.Rat
+	balance.Security = a.Security
+	balance.Amount = rat.Sub(a.Amount, b.Amount)
+	L.Push(BalanceToLua(L, &balance))
+
+	return 1
+}
+
+func luaBalance__mul(L *lua.LState) int {
+	a, b := luaGetBalanceOperands(L, 1, 2)
+
+	if a.Security.SecurityId != b.Security.SecurityId {
+		L.ArgError(2, "Can't multiply balances with different securities")
+	}
+
+	var balance Balance
+	var rat big.Rat
+	balance.Security = a.Security
+	balance.Amount = rat.Mul(a.Amount, b.Amount)
+	L.Push(BalanceToLua(L, &balance))
+
+	return 1
+}
+
+func luaBalance__div(L *lua.LState) int {
+	a, b := luaGetBalanceOperands(L, 1, 2)
+
+	if a.Security.SecurityId != b.Security.SecurityId {
+		L.ArgError(2, "Can't divide balances with different securities")
+	}
+
+	var balance Balance
+	var rat big.Rat
+	balance.Security = a.Security
+	balance.Amount = rat.Quo(a.Amount, b.Amount)
+	L.Push(BalanceToLua(L, &balance))
+
+	return 1
+}
+
+func luaBalance__unm(L *lua.LState) int {
+	b := luaCheckBalance(L, 1)
+
+	var balance Balance
+	var rat big.Rat
+	balance.Security = b.Security
+	balance.Amount = rat.Neg(b.Amount)
+	L.Push(BalanceToLua(L, &balance))
+
+	return 1
+}

internal/handlers/date_lua.go

@@ -0,0 +1,169 @@
+package handlers
+
+import (
+	"github.com/yuin/gopher-lua"
+	"time"
+)
+
+const luaDateTypeName = "date"
+const timeFormat = "2006-01-02"
+
+func luaRegisterDates(L *lua.LState) {
+	mt := L.NewTypeMetatable(luaDateTypeName)
+	L.SetGlobal("date", mt)
+	L.SetField(mt, "new", L.NewFunction(luaDateNew))
+	L.SetField(mt, "now", L.NewFunction(luaDateNow))
+	L.SetField(mt, "__index", L.NewFunction(luaDate__index))
+	L.SetField(mt, "__tostring", L.NewFunction(luaDate__tostring))
+	L.SetField(mt, "__eq", L.NewFunction(luaDate__eq))
+	L.SetField(mt, "__lt", L.NewFunction(luaDate__lt))
+	L.SetField(mt, "__le", L.NewFunction(luaDate__le))
+	L.SetField(mt, "__add", L.NewFunction(luaDate__add))
+	L.SetField(mt, "__sub", L.NewFunction(luaDate__sub))
+	L.SetField(mt, "__metatable", lua.LString("protected"))
+}
+
+func TimeToLua(L *lua.LState, date *time.Time) *lua.LUserData {
+	ud := L.NewUserData()
+	ud.Value = date
+	L.SetMetatable(ud, L.GetTypeMetatable(luaDateTypeName))
+	return ud
+}
+
+// Checks whether the first lua argument is a *LUserData with *Time and returns this *Time.
+func luaCheckTime(L *lua.LState, n int) *time.Time {
+	ud := L.CheckUserData(n)
+	if date, ok := ud.Value.(*time.Time); ok {
+		return date
+	}
+	L.ArgError(n, "date expected")
+	return nil
+}
+
+func luaWeakCheckTime(L *lua.LState, n int) *time.Time {
+	v := L.Get(n)
+	if ud, ok := v.(*lua.LUserData); ok {
+		if date, ok := ud.Value.(*time.Time); ok {
+			return date
+		}
+	}
+	return nil
+}
+
+func luaWeakCheckTableFieldInt(L *lua.LState, T *lua.LTable, n int, name string, def int) int {
+	lv := T.RawGetString(name)
+	if lv == lua.LNil {
+		return def
+	}
+	if i, ok := lv.(lua.LNumber); ok {
+		return int(i)
+	}
+	L.ArgError(n, "table field '"+name+"' expected to be int")
+	return def
+}
+
+func luaDateNew(L *lua.LState) int {
+	v := L.Get(1)
+	if s, ok := v.(lua.LString); ok {
+		date, err := time.Parse(timeFormat, s.String())
+		if err != nil {
+			L.ArgError(1, "error parsing date string: "+err.Error())
+			return 0
+		}
+		L.Push(TimeToLua(L, &date))
+		return 1
+	}
+	var year, month, day int
+	if t, ok := v.(*lua.LTable); ok {
+		year = luaWeakCheckTableFieldInt(L, t, 1, "year", 0)
+		month = luaWeakCheckTableFieldInt(L, t, 1, "month", 1)
+		day = luaWeakCheckTableFieldInt(L, t, 1, "day", 1)
+	} else {
+		year = L.CheckInt(1)
+		month = L.CheckInt(2)
+		day = L.CheckInt(3)
+	}
+	date := time.Date(year, time.Month(month), day, 0, 0, 0, 0, time.Local)
+	L.Push(TimeToLua(L, &date))
+	return 1
+}
+
+func luaDateNow(L *lua.LState) int {
+	now := time.Now()
+	date := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
+	L.Push(TimeToLua(L, &date))
+	return 1
+}
+
+func luaDate__index(L *lua.LState) int {
+	d := luaCheckTime(L, 1)
+	field := L.CheckString(2)
+
+	switch field {
+	case "Year", "year":
+		L.Push(lua.LNumber(d.Year()))
+	case "Month", "month":
+		L.Push(lua.LNumber(float64(d.Month())))
+	case "Day", "day":
+		L.Push(lua.LNumber(float64(d.Day())))
+	default:
+		L.ArgError(2, "unexpected date attribute: "+field)
+	}
+
+	return 1
+}
+
+func luaDate__tostring(L *lua.LState) int {
+	a := luaCheckTime(L, 1)
+
+	L.Push(lua.LString(a.Format(timeFormat)))
+
+	return 1
+}
+
+func luaDate__eq(L *lua.LState) int {
+	a := luaCheckTime(L, 1)
+	b := luaCheckTime(L, 2)
+
+	L.Push(lua.LBool(a.Equal(*b)))
+
+	return 1
+}
+
+func luaDate__lt(L *lua.LState) int {
+	a := luaCheckTime(L, 1)
+	b := luaCheckTime(L, 2)
+
+	L.Push(lua.LBool(a.Before(*b)))
+
+	return 1
+}
+
+func luaDate__le(L *lua.LState) int {
+	a := luaCheckTime(L, 1)
+	b := luaCheckTime(L, 2)
+
+	L.Push(lua.LBool(a.Equal(*b) || a.Before(*b)))
+
+	return 1
+}
+
+func luaDate__add(L *lua.LState) int {
+	a := luaCheckTime(L, 1)
+	b := luaCheckTime(L, 2)
+
+	date := a.AddDate(b.Year(), int(b.Month()), b.Day())
+	L.Push(TimeToLua(L, &date))
+
+	return 1
+}
+
+func luaDate__sub(L *lua.LState) int {
+	a := luaCheckTime(L, 1)
+	b := luaCheckTime(L, 2)
+
+	date := a.AddDate(-b.Year(), -int(b.Month()), -b.Day())
+	L.Push(TimeToLua(L, &date))
+
+	return 1
+}

internal/handlers/errors.go

@@ -0,0 +1,37 @@
+package handlers
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+)
+
+type Error struct {
+	ErrorId     int
+	ErrorString string
+}
+
+var error_codes = map[int]string{
+	1: "Not Signed In",
+	2: "Unauthorized Access",
+	3: "Invalid Request",
+	4: "User Exists",
+	//  5:   "Connection Failed", //reserved for client-side error
+	6:   "Import Error",
+	999: "Internal Error",
+}
+
+func WriteError(w http.ResponseWriter, error_code int) {
+	msg, ok := error_codes[error_code]
+	if !ok {
+		log.Printf("Error: WriteError received error code of %d", error_code)
+		msg = error_codes[999]
+	}
+	e := Error{error_code, msg}
+
+	enc := json.NewEncoder(w)
+	err := enc.Encode(e)
+	if err != nil {
+		log.Fatal(err)
+	}
+}

internal/handlers/gnucash.go

@@ -0,0 +1,493 @@
+package handlers
+
+import (
+	"bufio"
+	"compress/gzip"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"math"
+	"math/big"
+	"net/http"
+	"time"
+)
+
+type GnucashXMLCommodity struct {
+	Name        string `xml:"http://www.gnucash.org/XML/cmdty id"`
+	Description string `xml:"http://www.gnucash.org/XML/cmdty name"`
+	Type        string `xml:"http://www.gnucash.org/XML/cmdty space"`
+	Fraction    int    `xml:"http://www.gnucash.org/XML/cmdty fraction"`
+	XCode       string `xml:"http://www.gnucash.org/XML/cmdty xcode"`
+}
+
+type GnucashCommodity struct{ Security }
+
+func (gc *GnucashCommodity) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	var gxc GnucashXMLCommodity
+	if err := d.DecodeElement(&gxc, &start); err != nil {
+		return err
+	}
+
+	gc.Name = gxc.Name
+	gc.Symbol = gxc.Name
+	gc.Description = gxc.Description
+	gc.AlternateId = gxc.XCode
+
+	gc.Security.Type = Stock // assumed default
+	if gxc.Type == "ISO4217" {
+		gc.Security.Type = Currency
+		// Get the number from our templates for the AlternateId because
+		// Gnucash uses 'id' (our Name) to supply the string ISO4217 code
+		template := FindSecurityTemplate(gxc.Name, Currency)
+		if template == nil {
+			return errors.New("Unable to find security template for Gnucash ISO4217 commodity")
+		}
+		gc.AlternateId = template.AlternateId
+		gc.Precision = template.Precision
+	} else {
+		if gxc.Fraction > 0 {
+			gc.Precision = int(math.Ceil(math.Log10(float64(gxc.Fraction))))
+		} else {
+			gc.Precision = 0
+		}
+	}
+	return nil
+}
+
+type GnucashTime struct{ time.Time }
+
+func (g *GnucashTime) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	var s string
+	if err := d.DecodeElement(&s, &start); err != nil {
+		return fmt.Errorf("date should be a string")
+	}
+	t, err := time.Parse("2006-01-02 15:04:05 -0700", s)
+	g.Time = t
+	return err
+}
+
+type GnucashDate struct {
+	Date GnucashTime `xml:"http://www.gnucash.org/XML/ts date"`
+}
+
+type GnucashPrice struct {
+	Id        string           `xml:"http://www.gnucash.org/XML/price id"`
+	Commodity GnucashCommodity `xml:"http://www.gnucash.org/XML/price commodity"`
+	Currency  GnucashCommodity `xml:"http://www.gnucash.org/XML/price currency"`
+	Date      GnucashDate      `xml:"http://www.gnucash.org/XML/price time"`
+	Source    string           `xml:"http://www.gnucash.org/XML/price source"`
+	Type      string           `xml:"http://www.gnucash.org/XML/price type"`
+	Value     string           `xml:"http://www.gnucash.org/XML/price value"`
+}
+
+type GnucashPriceDB struct {
+	Prices []GnucashPrice `xml:"price"`
+}
+
+type GnucashAccount struct {
+	Version         string              `xml:"version,attr"`
+	accountid       int64               // Used to map Gnucash guid's to integer ones
+	AccountId       string              `xml:"http://www.gnucash.org/XML/act id"`
+	ParentAccountId string              `xml:"http://www.gnucash.org/XML/act parent"`
+	Name            string              `xml:"http://www.gnucash.org/XML/act name"`
+	Description     string              `xml:"http://www.gnucash.org/XML/act description"`
+	Type            string              `xml:"http://www.gnucash.org/XML/act type"`
+	Commodity       GnucashXMLCommodity `xml:"http://www.gnucash.org/XML/act commodity"`
+}
+
+type GnucashTransaction struct {
+	TransactionId string              `xml:"http://www.gnucash.org/XML/trn id"`
+	Description   string              `xml:"http://www.gnucash.org/XML/trn description"`
+	Number        string              `xml:"http://www.gnucash.org/XML/trn num"`
+	DatePosted    GnucashDate         `xml:"http://www.gnucash.org/XML/trn date-posted"`
+	DateEntered   GnucashDate         `xml:"http://www.gnucash.org/XML/trn date-entered"`
+	Commodity     GnucashXMLCommodity `xml:"http://www.gnucash.org/XML/trn currency"`
+	Splits        []GnucashSplit      `xml:"http://www.gnucash.org/XML/trn splits>split"`
+}
+
+type GnucashSplit struct {
+	SplitId   string `xml:"http://www.gnucash.org/XML/split id"`
+	Status    string `xml:"http://www.gnucash.org/XML/split reconciled-state"`
+	AccountId string `xml:"http://www.gnucash.org/XML/split account"`
+	Memo      string `xml:"http://www.gnucash.org/XML/split memo"`
+	Amount    string `xml:"http://www.gnucash.org/XML/split quantity"`
+	Value     string `xml:"http://www.gnucash.org/XML/split value"`
+}
+
+type GnucashXMLImport struct {
+	XMLName      xml.Name             `xml:"gnc-v2"`
+	Commodities  []GnucashCommodity   `xml:"http://www.gnucash.org/XML/gnc book>commodity"`
+	PriceDB      GnucashPriceDB       `xml:"http://www.gnucash.org/XML/gnc book>pricedb"`
+	Accounts     []GnucashAccount     `xml:"http://www.gnucash.org/XML/gnc book>account"`
+	Transactions []GnucashTransaction `xml:"http://www.gnucash.org/XML/gnc book>transaction"`
+}
+
+type GnucashImport struct {
+	Securities   []Security
+	Accounts     []Account
+	Transactions []Transaction
+	Prices       []Price
+}
+
+func ImportGnucash(r io.Reader) (*GnucashImport, error) {
+	var gncxml GnucashXMLImport
+	var gncimport GnucashImport
+
+	// Perform initial parsing of xml into structs
+	decoder := xml.NewDecoder(r)
+	err := decoder.Decode(&gncxml)
+	if err != nil {
+		return nil, err
+	}
+
+	// Fixup securities, making a map of them as we go
+	securityMap := make(map[string]Security)
+	for i := range gncxml.Commodities {
+		s := gncxml.Commodities[i].Security
+		s.SecurityId = int64(i + 1)
+		securityMap[s.Name] = s
+
+		// Ignore gnucash's "template" commodity
+		if s.Name != "template" ||
+			s.Description != "template" ||
+			s.AlternateId != "template" {
+			gncimport.Securities = append(gncimport.Securities, s)
+		}
+	}
+
+	// Create prices, setting security and currency IDs from securityMap
+	for i := range gncxml.PriceDB.Prices {
+		price := gncxml.PriceDB.Prices[i]
+		var p Price
+		security, ok := securityMap[price.Commodity.Name]
+		if !ok {
+			return nil, fmt.Errorf("Unable to find commodity '%s' for price '%s'", price.Commodity.Name, price.Id)
+		}
+		currency, ok := securityMap[price.Currency.Name]
+		if !ok {
+			return nil, fmt.Errorf("Unable to find currency '%s' for price '%s'", price.Currency.Name, price.Id)
+		}
+		if currency.Type != Currency {
+			return nil, fmt.Errorf("Currency for imported price isn't actually a currency\n")
+		}
+		p.PriceId = int64(i + 1)
+		p.SecurityId = security.SecurityId
+		p.CurrencyId = currency.SecurityId
+		p.Date = price.Date.Date.Time
+
+		var r big.Rat
+		_, ok = r.SetString(price.Value)
+		if ok {
+			p.Value = r.FloatString(currency.Precision)
+		} else {
+			return nil, fmt.Errorf("Can't set price value: %s", price.Value)
+		}
+
+		p.RemoteId = "gnucash:" + price.Id
+		gncimport.Prices = append(gncimport.Prices, p)
+	}
+
+	//find root account, while simultaneously creating map of GUID's to
+	//accounts
+	var rootAccount GnucashAccount
+	accountMap := make(map[string]GnucashAccount)
+	for i := range gncxml.Accounts {
+		gncxml.Accounts[i].accountid = int64(i + 1)
+		if gncxml.Accounts[i].Type == "ROOT" {
+			rootAccount = gncxml.Accounts[i]
+		} else {
+			accountMap[gncxml.Accounts[i].AccountId] = gncxml.Accounts[i]
+		}
+	}
+
+	//Translate to our account format, figuring out parent relationships
+	for guid := range accountMap {
+		ga := accountMap[guid]
+		var a Account
+
+		a.AccountId = ga.accountid
+		if ga.ParentAccountId == rootAccount.AccountId {
+			a.ParentAccountId = -1
+		} else {
+			parent, ok := accountMap[ga.ParentAccountId]
+			if ok {
+				a.ParentAccountId = parent.accountid
+			} else {
+				a.ParentAccountId = -1 // Ugly, but assign to top-level if we can't find its parent
+			}
+		}
+		a.Name = ga.Name
+		if security, ok := securityMap[ga.Commodity.Name]; ok {
+			a.SecurityId = security.SecurityId
+		} else {
+			return nil, fmt.Errorf("Unable to find security: %s", ga.Commodity.Name)
+		}
+
+		//TODO find account types
+		switch ga.Type {
+		default:
+			a.Type = Bank
+		case "ASSET":
+			a.Type = Asset
+		case "BANK":
+			a.Type = Bank
+		case "CASH":
+			a.Type = Cash
+		case "CREDIT", "LIABILITY":
+			a.Type = Liability
+		case "EQUITY":
+			a.Type = Equity
+		case "EXPENSE":
+			a.Type = Expense
+		case "INCOME":
+			a.Type = Income
+		case "PAYABLE":
+			a.Type = Payable
+		case "RECEIVABLE":
+			a.Type = Receivable
+		case "MUTUAL", "STOCK":
+			a.Type = Investment
+		case "TRADING":
+			a.Type = Trading
+		}
+
+		gncimport.Accounts = append(gncimport.Accounts, a)
+	}
+
+	//Translate transactions to our format
+	for i := range gncxml.Transactions {
+		gt := gncxml.Transactions[i]
+
+		t := new(Transaction)
+		t.Description = gt.Description
+		t.Date = gt.DatePosted.Date.Time
+		for j := range gt.Splits {
+			gs := gt.Splits[j]
+			s := new(Split)
+
+			switch gs.Status {
+			default: // 'n', or not present
+				s.Status = Imported
+			case "c":
+				s.Status = Cleared
+			case "y":
+				s.Status = Reconciled
+			}
+
+			account, ok := accountMap[gs.AccountId]
+			if !ok {
+				return nil, fmt.Errorf("Unable to find account: %s", gs.AccountId)
+			}
+			s.AccountId = account.accountid
+
+			security, ok := securityMap[account.Commodity.Name]
+			if !ok {
+				return nil, fmt.Errorf("Unable to find security: %s", account.Commodity.Name)
+			}
+			s.SecurityId = -1
+
+			s.RemoteId = "gnucash:" + gs.SplitId
+			s.Number = gt.Number
+			s.Memo = gs.Memo
+
+			var r big.Rat
+			_, ok = r.SetString(gs.Amount)
+			if ok {
+				s.Amount = r.FloatString(security.Precision)
+			} else {
+				return nil, fmt.Errorf("Can't set split Amount: %s", gs.Amount)
+			}
+
+			t.Splits = append(t.Splits, s)
+		}
+		gncimport.Transactions = append(gncimport.Transactions, *t)
+	}
+
+	return &gncimport, nil
+}
+
+func GnucashImportHandler(w http.ResponseWriter, r *http.Request, db *DB) {
+	user, err := GetUserFromSession(db, r)
+	if err != nil {
+		WriteError(w, 1 /*Not Signed In*/)
+		return
+	}
+
+	if r.Method != "POST" {
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	multipartReader, err := r.MultipartReader()
+	if err != nil {
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	// Assume there is only one 'part' and it's the one we care about
+	part, err := multipartReader.NextPart()
+	if err != nil {
+		if err == io.EOF {
+			WriteError(w, 3 /*Invalid Request*/)
+		} else {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+		}
+		return
+	}
+
+	bufread := bufio.NewReader(part)
+	gzHeader, err := bufread.Peek(2)
+	if err != nil {
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+
+	// Does this look like a gzipped file?
+	var gnucashImport *GnucashImport
+	if gzHeader[0] == 0x1f && gzHeader[1] == 0x8b {
+		gzr, err := gzip.NewReader(bufread)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+		gnucashImport, err = ImportGnucash(gzr)
+	} else {
+		gnucashImport, err = ImportGnucash(bufread)
+	}
+
+	if err != nil {
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	sqltransaction, err := db.Begin()
+	if err != nil {
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+
+	// Import securities, building map from Gnucash security IDs to our
+	// internal IDs
+	securityMap := make(map[int64]int64)
+	for _, security := range gnucashImport.Securities {
+		securityId := security.SecurityId // save off because it could be updated
+		s, err := ImportGetCreateSecurity(sqltransaction, user.UserId, &security)
+		if err != nil {
+			sqltransaction.Rollback()
+			WriteError(w, 6 /*Import Error*/)
+			log.Print(err)
+			log.Print(security)
+			return
+		}
+		securityMap[securityId] = s.SecurityId
+	}
+
+	// Import prices, setting security and currency IDs from securityMap
+	for _, price := range gnucashImport.Prices {
+		price.SecurityId = securityMap[price.SecurityId]
+		price.CurrencyId = securityMap[price.CurrencyId]
+		price.PriceId = 0
+
+		err := CreatePriceIfNotExist(sqltransaction, &price)
+		if err != nil {
+			sqltransaction.Rollback()
+			WriteError(w, 6 /*Import Error*/)
+			log.Print(err)
+			return
+		}
+	}
+
+	// Get/create accounts in the database, building a map from Gnucash account
+	// IDs to our internal IDs as we go
+	accountMap := make(map[int64]int64)
+	accountsRemaining := len(gnucashImport.Accounts)
+	accountsRemainingLast := accountsRemaining
+	for accountsRemaining > 0 {
+		for _, account := range gnucashImport.Accounts {
+
+			// If the account has already been added to the map, skip it
+			_, ok := accountMap[account.AccountId]
+			if ok {
+				continue
+			}
+
+			// If it hasn't been added, but its parent has, add it to the map
+			_, ok = accountMap[account.ParentAccountId]
+			if ok || account.ParentAccountId == -1 {
+				account.UserId = user.UserId
+				if account.ParentAccountId != -1 {
+					account.ParentAccountId = accountMap[account.ParentAccountId]
+				}
+				account.SecurityId = securityMap[account.SecurityId]
+				a, err := GetCreateAccountTx(sqltransaction, account)
+				if err != nil {
+					sqltransaction.Rollback()
+					WriteError(w, 999 /*Internal Error*/)
+					log.Print(err)
+					return
+				}
+				accountMap[account.AccountId] = a.AccountId
+				accountsRemaining--
+			}
+		}
+		if accountsRemaining == accountsRemainingLast {
+			//We didn't make any progress in importing the next level of accounts, so there must be a circular parent-child relationship, so give up and tell the user they're wrong
+			sqltransaction.Rollback()
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(fmt.Errorf("Circular account parent-child relationship when importing %s", part.FileName()))
+			return
+		}
+		accountsRemainingLast = accountsRemaining
+	}
+
+	// Insert transactions, fixing up account IDs to match internal ones from
+	// above
+	for _, transaction := range gnucashImport.Transactions {
+		var already_imported bool
+		for _, split := range transaction.Splits {
+			acctId, ok := accountMap[split.AccountId]
+			if !ok {
+				sqltransaction.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(fmt.Errorf("Error: Split's AccountID Doesn't exist: %d\n", split.AccountId))
+				return
+			}
+			split.AccountId = acctId
+
+			exists, err := split.AlreadyImportedTx(sqltransaction)
+			if err != nil {
+				sqltransaction.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print("Error checking if split was already imported:", err)
+				return
+			} else if exists {
+				already_imported = true
+			}
+		}
+		if !already_imported {
+			err := InsertTransactionTx(sqltransaction, &transaction, user)
+			if err != nil {
+				sqltransaction.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		}
+	}
+
+	err = sqltransaction.Commit()
+	if err != nil {
+		sqltransaction.Rollback()
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+
+	WriteSuccess(w)
+}

internal/handlers/handlers.go

@@ -0,0 +1,31 @@
+package handlers
+
+import (
+	"gopkg.in/gorp.v1"
+	"net/http"
+)
+
+// Create a closure over db, allowing the handlers to look like a
+// http.HandlerFunc
+type DB = gorp.DbMap
+type DBHandler func(http.ResponseWriter, *http.Request, *DB)
+
+func DBHandlerFunc(h DBHandler, db *DB) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		h(w, r, db)
+	}
+}
+
+func GetHandler(db *DB) *http.ServeMux {
+	servemux := http.NewServeMux()
+	servemux.HandleFunc("/session/", DBHandlerFunc(SessionHandler, db))
+	servemux.HandleFunc("/user/", DBHandlerFunc(UserHandler, db))
+	servemux.HandleFunc("/security/", DBHandlerFunc(SecurityHandler, db))
+	servemux.HandleFunc("/securitytemplate/", SecurityTemplateHandler)
+	servemux.HandleFunc("/account/", DBHandlerFunc(AccountHandler, db))
+	servemux.HandleFunc("/transaction/", DBHandlerFunc(TransactionHandler, db))
+	servemux.HandleFunc("/import/gnucash", DBHandlerFunc(GnucashImportHandler, db))
+	servemux.HandleFunc("/report/", DBHandlerFunc(ReportHandler, db))
+
+	return servemux
+}

internal/handlers/imports.go

@@ -0,0 +1,409 @@
+package handlers
+
+import (
+	"encoding/json"
+	"github.com/aclindsa/ofxgo"
+	"io"
+	"log"
+	"math/big"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type OFXDownload struct {
+	OFXPassword string
+	StartDate   time.Time
+	EndDate     time.Time
+}
+
+func (od *OFXDownload) Read(json_str string) error {
+	dec := json.NewDecoder(strings.NewReader(json_str))
+	return dec.Decode(od)
+}
+
+func ofxImportHelper(db *DB, r io.Reader, w http.ResponseWriter, user *User, accountid int64) {
+	itl, err := ImportOFX(r)
+
+	if err != nil {
+		//TODO is this necessarily an invalid request (what if it was an error on our end)?
+		WriteError(w, 3 /*Invalid Request*/)
+		log.Print(err)
+		return
+	}
+
+	if len(itl.Accounts) != 1 {
+		WriteError(w, 3 /*Invalid Request*/)
+		log.Printf("Found %d accounts when importing OFX, expected 1", len(itl.Accounts))
+		return
+	}
+
+	sqltransaction, err := db.Begin()
+	if err != nil {
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+
+	// Return Account with this Id
+	account, err := GetAccountTx(sqltransaction, accountid, user.UserId)
+	if err != nil {
+		sqltransaction.Rollback()
+		WriteError(w, 3 /*Invalid Request*/)
+		log.Print(err)
+		return
+	}
+
+	importedAccount := itl.Accounts[0]
+
+	if len(account.ExternalAccountId) > 0 &&
+		account.ExternalAccountId != importedAccount.ExternalAccountId {
+		sqltransaction.Rollback()
+		WriteError(w, 3 /*Invalid Request*/)
+		log.Printf("OFX import has \"%s\" as ExternalAccountId, but the account being imported to has\"%s\"",
+			importedAccount.ExternalAccountId,
+			account.ExternalAccountId)
+		return
+	}
+
+	// Find matching existing securities or create new ones for those
+	// referenced by the OFX import. Also create a map from placeholder import
+	// SecurityIds to the actual SecurityIDs
+	var securitymap = make(map[int64]Security)
+	for _, ofxsecurity := range itl.Securities {
+		// save off since ImportGetCreateSecurity overwrites SecurityId on
+		// ofxsecurity
+		oldsecurityid := ofxsecurity.SecurityId
+		security, err := ImportGetCreateSecurity(sqltransaction, user.UserId, &ofxsecurity)
+		if err != nil {
+			sqltransaction.Rollback()
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+		securitymap[oldsecurityid] = *security
+	}
+
+	if account.SecurityId != securitymap[importedAccount.SecurityId].SecurityId {
+		sqltransaction.Rollback()
+		WriteError(w, 3 /*Invalid Request*/)
+		log.Printf("OFX import account's SecurityId (%d) does not match this account's (%d)", securitymap[importedAccount.SecurityId].SecurityId, account.SecurityId)
+		return
+	}
+
+	// TODO Ensure all transactions have at least one split in the account
+	// we're importing to?
+
+	var transactions []Transaction
+	for _, transaction := range itl.Transactions {
+		transaction.UserId = user.UserId
+
+		if !transaction.Valid() {
+			sqltransaction.Rollback()
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print("Unexpected invalid transaction from OFX import")
+			return
+		}
+
+		// Ensure that either AccountId or SecurityId is set for this split,
+		// and fixup the SecurityId to be a valid one for this user's actual
+		// securities instead of a placeholder from the import
+		for _, split := range transaction.Splits {
+			split.Status = Imported
+			if split.AccountId != -1 {
+				if split.AccountId != importedAccount.AccountId {
+					sqltransaction.Rollback()
+					WriteError(w, 999 /*Internal Error*/)
+					log.Print("Imported split's AccountId wasn't -1 but also didn't match the account")
+					return
+				}
+				split.AccountId = account.AccountId
+			} else if split.SecurityId != -1 {
+				if sec, ok := securitymap[split.SecurityId]; ok {
+					// TODO try to auto-match splits to existing accounts based on past transactions that look like this one
+					if split.ImportSplitType == TradingAccount {
+						// Find/make trading account if we're that type of split
+						trading_account, err := GetTradingAccount(sqltransaction, user.UserId, sec.SecurityId)
+						if err != nil {
+							sqltransaction.Rollback()
+							WriteError(w, 999 /*Internal Error*/)
+							log.Print("Couldn't find split's SecurityId in map during OFX import")
+							return
+						}
+						split.AccountId = trading_account.AccountId
+						split.SecurityId = -1
+					} else if split.ImportSplitType == SubAccount {
+						subaccount := &Account{
+							UserId:          user.UserId,
+							Name:            sec.Name,
+							ParentAccountId: account.AccountId,
+							SecurityId:      sec.SecurityId,
+							Type:            account.Type,
+						}
+						subaccount, err := GetCreateAccountTx(sqltransaction, *subaccount)
+						if err != nil {
+							sqltransaction.Rollback()
+							WriteError(w, 999 /*Internal Error*/)
+							log.Print(err)
+							return
+						}
+						split.AccountId = subaccount.AccountId
+						split.SecurityId = -1
+					} else {
+						split.SecurityId = sec.SecurityId
+					}
+				} else {
+					sqltransaction.Rollback()
+					WriteError(w, 999 /*Internal Error*/)
+					log.Print("Couldn't find split's SecurityId in map during OFX import")
+					return
+				}
+			} else {
+				sqltransaction.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print("Neither Split.AccountId Split.SecurityId was set during OFX import")
+				return
+			}
+		}
+
+		imbalances, err := transaction.GetImbalancesTx(sqltransaction)
+		if err != nil {
+			sqltransaction.Rollback()
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+
+		// Fixup any imbalances in transactions
+		var zero big.Rat
+		for imbalanced_security, imbalance := range imbalances {
+			if imbalance.Cmp(&zero) != 0 {
+				imbalanced_account, err := GetImbalanceAccount(sqltransaction, user.UserId, imbalanced_security)
+				if err != nil {
+					sqltransaction.Rollback()
+					WriteError(w, 999 /*Internal Error*/)
+					log.Print(err)
+					return
+				}
+
+				// Add new split to fixup imbalance
+				split := new(Split)
+				r := new(big.Rat)
+				r.Neg(&imbalance)
+				security, err := GetSecurityTx(sqltransaction, imbalanced_security, user.UserId)
+				if err != nil {
+					sqltransaction.Rollback()
+					WriteError(w, 999 /*Internal Error*/)
+					log.Print(err)
+					return
+				}
+				split.Amount = r.FloatString(security.Precision)
+				split.SecurityId = -1
+				split.AccountId = imbalanced_account.AccountId
+				transaction.Splits = append(transaction.Splits, split)
+			}
+		}
+
+		// Move any splits with SecurityId but not AccountId to Imbalances
+		// accounts. In the same loop, check to see if this transaction/split
+		// has been imported before
+		var already_imported bool
+		for _, split := range transaction.Splits {
+			if split.SecurityId != -1 || split.AccountId == -1 {
+				imbalanced_account, err := GetImbalanceAccount(sqltransaction, user.UserId, split.SecurityId)
+				if err != nil {
+					sqltransaction.Rollback()
+					WriteError(w, 999 /*Internal Error*/)
+					log.Print(err)
+					return
+				}
+
+				split.AccountId = imbalanced_account.AccountId
+				split.SecurityId = -1
+			}
+
+			exists, err := split.AlreadyImportedTx(sqltransaction)
+			if err != nil {
+				sqltransaction.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print("Error checking if split was already imported:", err)
+				return
+			} else if exists {
+				already_imported = true
+			}
+		}
+
+		if !already_imported {
+			transactions = append(transactions, transaction)
+		}
+	}
+
+	for _, transaction := range transactions {
+		err := InsertTransactionTx(sqltransaction, &transaction, user)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	}
+
+	err = sqltransaction.Commit()
+	if err != nil {
+		sqltransaction.Rollback()
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+
+	WriteSuccess(w)
+}
+
+func OFXImportHandler(db *DB, w http.ResponseWriter, r *http.Request, user *User, accountid int64) {
+	download_json := r.PostFormValue("ofxdownload")
+	if download_json == "" {
+		log.Print("download_json")
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	var ofxdownload OFXDownload
+	err := ofxdownload.Read(download_json)
+	if err != nil {
+		log.Print("ofxdownload.Read")
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	account, err := GetAccount(db, accountid, user.UserId)
+	if err != nil {
+		log.Print("GetAccount")
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	ofxver := ofxgo.OfxVersion203
+	if len(account.OFXVersion) != 0 {
+		ofxver, err = ofxgo.NewOfxVersion(account.OFXVersion)
+		if err != nil {
+			log.Print("NewOfxVersion")
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+	}
+
+	var client = ofxgo.Client{
+		AppID:       account.OFXAppID,
+		AppVer:      account.OFXAppVer,
+		SpecVersion: ofxver,
+		NoIndent:    account.OFXNoIndent,
+	}
+
+	var query ofxgo.Request
+	query.URL = account.OFXURL
+	query.Signon.ClientUID = ofxgo.UID(account.OFXClientUID)
+	query.Signon.UserID = ofxgo.String(account.OFXUser)
+	query.Signon.UserPass = ofxgo.String(ofxdownload.OFXPassword)
+	query.Signon.Org = ofxgo.String(account.OFXORG)
+	query.Signon.Fid = ofxgo.String(account.OFXFID)
+
+	transactionuid, err := ofxgo.RandomUID()
+	if err != nil {
+		WriteError(w, 999 /*Internal Error*/)
+		log.Println("Error creating uid for transaction:", err)
+		return
+	}
+
+	if account.Type == Investment {
+		// Investment account
+		statementRequest := ofxgo.InvStatementRequest{
+			TrnUID: *transactionuid,
+			InvAcctFrom: ofxgo.InvAcct{
+				BrokerID: ofxgo.String(account.OFXBankID),
+				AcctID:   ofxgo.String(account.OFXAcctID),
+			},
+			Include:        true,
+			IncludeOO:      true,
+			IncludePos:     true,
+			IncludeBalance: true,
+			Include401K:    true,
+			Include401KBal: true,
+		}
+		query.InvStmt = append(query.InvStmt, &statementRequest)
+	} else if account.OFXAcctType == "CC" {
+		// Import credit card transactions
+		statementRequest := ofxgo.CCStatementRequest{
+			TrnUID: *transactionuid,
+			CCAcctFrom: ofxgo.CCAcct{
+				AcctID: ofxgo.String(account.OFXAcctID),
+			},
+			Include: true,
+		}
+		query.CreditCard = append(query.CreditCard, &statementRequest)
+	} else {
+		// Import generic bank transactions
+		acctTypeEnum, err := ofxgo.NewAcctType(account.OFXAcctType)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		statementRequest := ofxgo.StatementRequest{
+			TrnUID: *transactionuid,
+			BankAcctFrom: ofxgo.BankAcct{
+				BankID:   ofxgo.String(account.OFXBankID),
+				AcctID:   ofxgo.String(account.OFXAcctID),
+				AcctType: acctTypeEnum,
+			},
+			Include: true,
+		}
+		query.Bank = append(query.Bank, &statementRequest)
+	}
+
+	response, err := client.RequestNoParse(&query)
+	if err != nil {
+		// TODO this could be an error talking with the OFX server...
+		WriteError(w, 3 /*Invalid Request*/)
+		log.Print(err)
+		return
+	}
+	defer response.Body.Close()
+
+	ofxImportHelper(db, response.Body, w, user, accountid)
+}
+
+func OFXFileImportHandler(db *DB, w http.ResponseWriter, r *http.Request, user *User, accountid int64) {
+	multipartReader, err := r.MultipartReader()
+	if err != nil {
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	// assume there is only one 'part'
+	part, err := multipartReader.NextPart()
+	if err != nil {
+		if err == io.EOF {
+			WriteError(w, 3 /*Invalid Request*/)
+			log.Print("Encountered unexpected EOF")
+		} else {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+		}
+		return
+	}
+
+	ofxImportHelper(db, part, w, user, accountid)
+}
+
+/*
+ * Assumes the User is a valid, signed-in user, but accountid has not yet been validated
+ */
+func AccountImportHandler(db *DB, w http.ResponseWriter, r *http.Request, user *User, accountid int64, importtype string) {
+
+	switch importtype {
+	case "ofx":
+		OFXImportHandler(db, w, r, user, accountid)
+	case "ofxfile":
+		OFXFileImportHandler(db, w, r, user, accountid)
+	default:
+		WriteError(w, 3 /*Invalid Request*/)
+	}
+}

internal/handlers/prices.go

@@ -0,0 +1,113 @@
+package handlers
+
+import (
+	"gopkg.in/gorp.v1"
+	"time"
+)
+
+type Price struct {
+	PriceId    int64
+	SecurityId int64
+	CurrencyId int64
+	Date       time.Time
+	Value      string // String representation of decimal price of Security in Currency units, suitable for passing to big.Rat.SetString()
+	RemoteId   string // unique ID from source, for detecting duplicates
+}
+
+func InsertPriceTx(transaction *gorp.Transaction, p *Price) error {
+	err := transaction.Insert(p)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func CreatePriceIfNotExist(transaction *gorp.Transaction, price *Price) error {
+	if len(price.RemoteId) == 0 {
+		// Always create a new price if we can't match on the RemoteId
+		err := InsertPriceTx(transaction, price)
+		if err != nil {
+			return err
+		}
+		return nil
+	}
+
+	var prices []*Price
+
+	_, err := transaction.Select(&prices, "SELECT * from prices where SecurityId=? AND CurrencyId=? AND Date=? AND Value=?", price.SecurityId, price.CurrencyId, price.Date, price.Value)
+	if err != nil {
+		return err
+	}
+
+	if len(prices) > 0 {
+		return nil // price already exists
+	}
+
+	err = InsertPriceTx(transaction, price)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Return the latest price for security in currency units before date
+func GetLatestPrice(transaction *gorp.Transaction, security, currency *Security, date *time.Time) (*Price, error) {
+	var p Price
+	err := transaction.SelectOne(&p, "SELECT * from prices where SecurityId=? AND CurrencyId=? AND Date <= ? ORDER BY Date DESC LIMIT 1", security.SecurityId, currency.SecurityId, date)
+	if err != nil {
+		return nil, err
+	}
+	return &p, nil
+}
+
+// Return the earliest price for security in currency units after date
+func GetEarliestPrice(transaction *gorp.Transaction, security, currency *Security, date *time.Time) (*Price, error) {
+	var p Price
+	err := transaction.SelectOne(&p, "SELECT * from prices where SecurityId=? AND CurrencyId=? AND Date >= ? ORDER BY Date ASC LIMIT 1", security.SecurityId, currency.SecurityId, date)
+	if err != nil {
+		return nil, err
+	}
+	return &p, nil
+}
+
+// Return the price for security in currency closest to date
+func GetClosestPriceTx(transaction *gorp.Transaction, security, currency *Security, date *time.Time) (*Price, error) {
+	earliest, _ := GetEarliestPrice(transaction, security, currency, date)
+	latest, err := GetLatestPrice(transaction, security, currency, date)
+
+	// Return early if either earliest or latest are invalid
+	if earliest == nil {
+		return latest, err
+	} else if err != nil {
+		return earliest, nil
+	}
+
+	howlate := earliest.Date.Sub(*date)
+	howearly := date.Sub(latest.Date)
+	if howearly < howlate {
+		return latest, nil
+	} else {
+		return earliest, nil
+	}
+}
+
+func GetClosestPrice(db *DB, security, currency *Security, date *time.Time) (*Price, error) {
+	transaction, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+
+	price, err := GetClosestPriceTx(transaction, security, currency, date)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	return price, nil
+}

internal/handlers/prices_lua.go

@@ -0,0 +1,91 @@
+package handlers
+
+import (
+	"github.com/yuin/gopher-lua"
+)
+
+const luaPriceTypeName = "price"
+
+func luaRegisterPrices(L *lua.LState) {
+	mt := L.NewTypeMetatable(luaPriceTypeName)
+	L.SetGlobal("price", mt)
+	L.SetField(mt, "__index", L.NewFunction(luaPrice__index))
+	L.SetField(mt, "__tostring", L.NewFunction(luaPrice__tostring))
+	L.SetField(mt, "__metatable", lua.LString("protected"))
+}
+
+func PriceToLua(L *lua.LState, price *Price) *lua.LUserData {
+	ud := L.NewUserData()
+	ud.Value = price
+	L.SetMetatable(ud, L.GetTypeMetatable(luaPriceTypeName))
+	return ud
+}
+
+// Checks whether the first lua argument is a *LUserData with *Price and returns this *Price.
+func luaCheckPrice(L *lua.LState, n int) *Price {
+	ud := L.CheckUserData(n)
+	if price, ok := ud.Value.(*Price); ok {
+		return price
+	}
+	L.ArgError(n, "price expected")
+	return nil
+}
+
+func luaPrice__index(L *lua.LState) int {
+	p := luaCheckPrice(L, 1)
+	field := L.CheckString(2)
+
+	switch field {
+	case "PriceId", "priceid":
+		L.Push(lua.LNumber(float64(p.PriceId)))
+	case "Security", "security":
+		security_map, err := luaContextGetSecurities(L)
+		if err != nil {
+			panic("luaContextGetSecurities couldn't fetch securities")
+		}
+		s, ok := security_map[p.SecurityId]
+		if !ok {
+			panic("Price's security not found for user")
+		}
+		L.Push(SecurityToLua(L, s))
+	case "Currency", "currency":
+		security_map, err := luaContextGetSecurities(L)
+		if err != nil {
+			panic("luaContextGetSecurities couldn't fetch securities")
+		}
+		c, ok := security_map[p.CurrencyId]
+		if !ok {
+			panic("Price's currency not found for user")
+		}
+		L.Push(SecurityToLua(L, c))
+	case "Value", "value":
+		amt, err := GetBigAmount(p.Value)
+		if err != nil {
+			panic(err)
+		}
+		float, _ := amt.Float64()
+		L.Push(lua.LNumber(float))
+	default:
+		L.ArgError(2, "unexpected price attribute: "+field)
+	}
+
+	return 1
+}
+
+func luaPrice__tostring(L *lua.LState) int {
+	p := luaCheckPrice(L, 1)
+
+	security_map, err := luaContextGetSecurities(L)
+	if err != nil {
+		panic("luaContextGetSecurities couldn't fetch securities")
+	}
+	s, ok1 := security_map[p.SecurityId]
+	c, ok2 := security_map[p.CurrencyId]
+	if !ok1 || !ok2 {
+		panic("Price's currency or security not found for user")
+	}
+
+	L.Push(lua.LString(p.Value + " " + c.Symbol + " (" + s.Symbol + ")"))
+
+	return 1
+}

internal/handlers/reports.go

@@ -0,0 +1,354 @@
+package handlers
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/yuin/gopher-lua"
+	"log"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+)
+
+var reportTabulationRE *regexp.Regexp
+
+func init() {
+	reportTabulationRE = regexp.MustCompile(`^/report/[0-9]+/tabulation/?$`)
+}
+
+//type and value to store user in lua's Context
+type key int
+
+const (
+	userContextKey key = iota
+	accountsContextKey
+	securitiesContextKey
+	balanceContextKey
+	dbContextKey
+)
+
+const luaTimeoutSeconds time.Duration = 30 // maximum time a lua request can run for
+
+type Report struct {
+	ReportId int64
+	UserId   int64
+	Name     string
+	Lua      string
+}
+
+func (r *Report) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(r)
+}
+
+func (r *Report) Read(json_str string) error {
+	dec := json.NewDecoder(strings.NewReader(json_str))
+	return dec.Decode(r)
+}
+
+type ReportList struct {
+	Reports *[]Report `json:"reports"`
+}
+
+func (rl *ReportList) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(rl)
+}
+
+type Series struct {
+	Values []float64
+	Series map[string]*Series
+}
+
+type Tabulation struct {
+	ReportId int64
+	Title    string
+	Subtitle string
+	Units    string
+	Labels   []string
+	Series   map[string]*Series
+}
+
+func (r *Tabulation) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(r)
+}
+
+func GetReport(db *DB, reportid int64, userid int64) (*Report, error) {
+	var r Report
+
+	err := db.SelectOne(&r, "SELECT * from reports where UserId=? AND ReportId=?", userid, reportid)
+	if err != nil {
+		return nil, err
+	}
+	return &r, nil
+}
+
+func GetReports(db *DB, userid int64) (*[]Report, error) {
+	var reports []Report
+
+	_, err := db.Select(&reports, "SELECT * from reports where UserId=?", userid)
+	if err != nil {
+		return nil, err
+	}
+	return &reports, nil
+}
+
+func InsertReport(db *DB, r *Report) error {
+	err := db.Insert(r)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func UpdateReport(db *DB, r *Report) error {
+	count, err := db.Update(r)
+	if err != nil {
+		return err
+	}
+	if count != 1 {
+		return errors.New("Updated more than one report")
+	}
+	return nil
+}
+
+func DeleteReport(db *DB, r *Report) error {
+	count, err := db.Delete(r)
+	if err != nil {
+		return err
+	}
+	if count != 1 {
+		return errors.New("Deleted more than one report")
+	}
+	return nil
+}
+
+func runReport(db *DB, user *User, report *Report) (*Tabulation, error) {
+	// Create a new LState without opening the default libs for security
+	L := lua.NewState(lua.Options{SkipOpenLibs: true})
+	defer L.Close()
+
+	// Create a new context holding the current user with a timeout
+	ctx := context.WithValue(context.Background(), userContextKey, user)
+	ctx = context.WithValue(ctx, dbContextKey, db)
+	ctx, cancel := context.WithTimeout(ctx, luaTimeoutSeconds*time.Second)
+	defer cancel()
+	L.SetContext(ctx)
+
+	for _, pair := range []struct {
+		n string
+		f lua.LGFunction
+	}{
+		{lua.LoadLibName, lua.OpenPackage}, // Must be first
+		{lua.BaseLibName, lua.OpenBase},
+		{lua.TabLibName, lua.OpenTable},
+		{lua.StringLibName, lua.OpenString},
+		{lua.MathLibName, lua.OpenMath},
+	} {
+		if err := L.CallByParam(lua.P{
+			Fn:      L.NewFunction(pair.f),
+			NRet:    0,
+			Protect: true,
+		}, lua.LString(pair.n)); err != nil {
+			return nil, errors.New("Error initializing Lua packages")
+		}
+	}
+
+	luaRegisterAccounts(L)
+	luaRegisterSecurities(L)
+	luaRegisterBalances(L)
+	luaRegisterDates(L)
+	luaRegisterTabulations(L)
+	luaRegisterPrices(L)
+
+	err := L.DoString(report.Lua)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if err := L.CallByParam(lua.P{
+		Fn:      L.GetGlobal("generate"),
+		NRet:    1,
+		Protect: true,
+	}); err != nil {
+		return nil, err
+	}
+
+	value := L.Get(-1)
+	if ud, ok := value.(*lua.LUserData); ok {
+		if tabulation, ok := ud.Value.(*Tabulation); ok {
+			return tabulation, nil
+		} else {
+			return nil, fmt.Errorf("generate() for %s (Id: %d) didn't return a tabulation", report.Name, report.ReportId)
+		}
+	} else {
+		return nil, fmt.Errorf("generate() for %s (Id: %d) didn't even return LUserData", report.Name, report.ReportId)
+	}
+}
+
+func ReportTabulationHandler(db *DB, w http.ResponseWriter, r *http.Request, user *User, reportid int64) {
+	report, err := GetReport(db, reportid, user.UserId)
+	if err != nil {
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	tabulation, err := runReport(db, user, report)
+	if err != nil {
+		// TODO handle different failure cases differently
+		log.Print("runReport returned:", err)
+		WriteError(w, 3 /*Invalid Request*/)
+		return
+	}
+
+	tabulation.ReportId = reportid
+
+	err = tabulation.Write(w)
+	if err != nil {
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+}
+
+func ReportHandler(w http.ResponseWriter, r *http.Request, db *DB) {
+	user, err := GetUserFromSession(db, r)
+	if err != nil {
+		WriteError(w, 1 /*Not Signed In*/)
+		return
+	}
+
+	if r.Method == "POST" {
+		report_json := r.PostFormValue("report")
+		if report_json == "" {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		var report Report
+		err := report.Read(report_json)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		report.ReportId = -1
+		report.UserId = user.UserId
+
+		err = InsertReport(db, &report)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+
+		w.WriteHeader(201 /*Created*/)
+		err = report.Write(w)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	} else if r.Method == "GET" {
+		if reportTabulationRE.MatchString(r.URL.Path) {
+			var reportid int64
+			n, err := GetURLPieces(r.URL.Path, "/report/%d/tabulation", &reportid)
+			if err != nil || n != 1 {
+				WriteError(w, 999 /*InternalError*/)
+				log.Print(err)
+				return
+			}
+			ReportTabulationHandler(db, w, r, user, reportid)
+			return
+		}
+
+		var reportid int64
+		n, err := GetURLPieces(r.URL.Path, "/report/%d", &reportid)
+		if err != nil || n != 1 {
+			//Return all Reports
+			var rl ReportList
+			reports, err := GetReports(db, user.UserId)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+			rl.Reports = reports
+			err = (&rl).Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else {
+			// Return Report with this Id
+			report, err := GetReport(db, reportid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = report.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		}
+	} else {
+		reportid, err := GetURLID(r.URL.Path)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		if r.Method == "PUT" {
+			report_json := r.PostFormValue("report")
+			if report_json == "" {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			var report Report
+			err := report.Read(report_json)
+			if err != nil || report.ReportId != reportid {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+			report.UserId = user.UserId
+
+			err = UpdateReport(db, &report)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			err = report.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else if r.Method == "DELETE" {
+			report, err := GetReport(db, reportid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = DeleteReport(db, report)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			WriteSuccess(w)
+		}
+	}
+}

internal/handlers/reports/asset_allocation.lua

@@ -0,0 +1,42 @@
+function generate()
+    accounts = get_accounts()
+    securities = get_securities()
+    default_currency = get_default_currency()
+    series_map = {}
+    totals_map = {}
+
+    t = tabulation.new(1)
+    t:title("Current Asset Allocation")
+
+    t:label(1, "Assets")
+
+    for id, security in pairs(securities) do
+        totals_map[id] = 0
+        series_map[id] = t:series(tostring(security))
+    end
+
+    for id, acct in pairs(accounts) do
+        if acct.type == account.Asset or acct.type == account.Investment or acct.type == account.Bank or acct.type == account.Cash then
+            balance = acct:balance()
+            multiplier = 1
+            if acct.security ~= default_currency and balance.amount ~= 0 then
+                price = acct.security:closestprice(default_currency, date.now())
+                if price == nil then
+                    --[[
+                    -- This should contain code to warn the user that their report is missing some information
+                    --]]
+                    multiplier = 0
+                else
+                    multiplier = price.value
+                end
+            end
+            totals_map[acct.security.SecurityId] = balance.amount * multiplier + totals_map[acct.security.SecurityId]
+        end
+    end
+
+    for id, series in pairs(series_map) do
+        series:value(1, totals_map[id])
+    end
+
+    return t
+end

internal/handlers/reports/monthly_cash_flow.lua

@@ -0,0 +1,26 @@
+function generate()
+    year = date.now().year
+
+    accounts = get_accounts()
+    t = tabulation.new(12)
+    t:title(year .. " Monthly Cash Flow")
+    series = t:series("Income minus expenses")
+
+    for month=1,12 do
+        begin_date = date.new(year, month, 1)
+        end_date = date.new(year, month+1, 1)
+
+        t:label(month, tostring(begin_date))
+        cash_flow = 0
+
+        for id, acct in pairs(accounts) do
+            if acct.type == account.Expense or acct.type == account.Income then
+                balance = acct:balance(begin_date, end_date)
+                cash_flow = cash_flow - balance.amount
+            end
+        end
+        series:value(month, cash_flow)
+    end
+
+    return t
+end

internal/handlers/reports/monthly_expenses.lua

@@ -0,0 +1,49 @@
+function account_series_map(accounts, tabulation)
+    map = {}
+
+    for i=1,100 do -- we're not messing with accounts more than 100 levels deep
+        all_handled = true
+        for id, acct in pairs(accounts) do
+            if not map[id] then
+                all_handled = false
+                if not acct.parent then
+                    map[id] = tabulation:series(acct.name)
+                elseif map[acct.parent.accountid] then
+                    map[id] = map[acct.parent.accountid]:series(acct.name)
+                end
+            end
+        end
+        if all_handled then
+            return map
+        end
+    end
+
+    error("Accounts nested (at least) 100 levels deep")
+end
+
+function generate()
+    year = date.now().year
+    account_type = account.Expense
+
+    accounts = get_accounts()
+    t = tabulation.new(12)
+    t:title(year .. " Monthly Expenses")
+    series_map = account_series_map(accounts, t)
+
+    for month=1,12 do
+        begin_date = date.new(year, month, 1)
+        end_date = date.new(year, month+1, 1)
+
+        t:label(month, tostring(begin_date))
+
+        for id, acct in pairs(accounts) do
+            series = series_map[id]
+            if acct.type == account_type then
+                balance = acct:balance(begin_date, end_date)
+                series:value(month, balance.amount)
+            end
+        end
+    end
+
+    return t
+end

internal/handlers/reports/monthly_net_worth.lua

@@ -0,0 +1,60 @@
+function account_series_map(accounts, tabulation)
+    map = {}
+
+    for i=1,100 do -- we're not messing with accounts more than 100 levels deep
+        all_handled = true
+        for id, acct in pairs(accounts) do
+            if not map[id] then
+                all_handled = false
+                if not acct.parent then
+                    map[id] = tabulation:series(acct.name)
+                elseif map[acct.parent.accountid] then
+                    map[id] = map[acct.parent.accountid]:series(acct.name)
+                end
+            end
+        end
+        if all_handled then
+            return map
+        end
+    end
+
+    error("Accounts nested (at least) 100 levels deep")
+end
+
+function generate()
+    year = date.now().year
+
+    accounts = get_accounts()
+    t = tabulation.new(12)
+    t:title(year .. " Monthly Net Worth")
+    series_map = account_series_map(accounts, t)
+    default_currency = get_default_currency()
+
+    for month=1,12 do
+        end_date = date.new(year, month+1, 1)
+
+        t:label(month, tostring(end_date))
+
+        for id, acct in pairs(accounts) do
+            series = series_map[id]
+            if acct.type ~= account.Expense and acct.type ~= account.Income and acct.type ~= account.Trading then
+                balance = acct:balance(end_date)
+                multiplier = 1
+                if acct.security ~= default_currency and balance.amount ~= 0 then
+                    price = acct.security:closestprice(default_currency, end_date)
+                    if price == nil then
+                        --[[
+                        -- This should contain code to warn the user that their report is missing some information
+                        --]]
+                        multiplier = 0
+                    else
+                        multiplier = price.value
+                    end
+                end
+                series:value(month, balance.amount * multiplier)
+            end
+        end
+    end
+
+    return t
+end

internal/handlers/reports/monthly_net_worth_change.lua

@@ -0,0 +1,61 @@
+function account_series_map(accounts, tabulation)
+    map = {}
+
+    for i=1,100 do -- we're not messing with accounts more than 100 levels deep
+        all_handled = true
+        for id, acct in pairs(accounts) do
+            if not map[id] then
+                all_handled = false
+                if not acct.parent then
+                    map[id] = tabulation:series(acct.name)
+                elseif map[acct.parent.accountid] then
+                    map[id] = map[acct.parent.accountid]:series(acct.name)
+                end
+            end
+        end
+        if all_handled then
+            return map
+        end
+    end
+
+    error("Accounts nested (at least) 100 levels deep")
+end
+
+function generate()
+    year = date.now().year
+
+    accounts = get_accounts()
+    t = tabulation.new(12)
+    t:title(year .. " Monthly Net Worth")
+    series_map = account_series_map(accounts, t)
+    default_currency = get_default_currency()
+
+    for month=1,12 do
+        begin_date = date.new(year, month, 1)
+        end_date = date.new(year, month+1, 1)
+
+        t:label(month, tostring(begin_date))
+
+        for id, acct in pairs(accounts) do
+            series = series_map[id]
+            if acct.type ~= account.Expense and acct.type ~= account.Income and acct.type ~= account.Trading then
+                balance = acct:balance(begin_date, end_date)
+                multiplier = 1
+                if acct.security ~= default_currency then
+                    price = acct.security:closestprice(default_currency, end_date)
+                    if price == nil then
+                        --[[
+                        -- This should contain code to warn the user that their report is missing some information
+                        --]]
+                        multiplier = 0
+                    else
+                        multiplier = price.value
+                    end
+                end
+                series:value(month, balance.amount * multiplier)
+            end
+        end
+    end
+
+    return t
+end

internal/handlers/reports/quarterly_net_worth.lua

@@ -0,0 +1,60 @@
+function account_series_map(accounts, tabulation)
+    map = {}
+
+    for i=1,100 do -- we're not messing with accounts more than 100 levels deep
+        all_handled = true
+        for id, acct in pairs(accounts) do
+            if not map[id] then
+                all_handled = false
+                if not acct.parent then
+                    map[id] = tabulation:series(acct.name)
+                elseif map[acct.parent.accountid] then
+                    map[id] = map[acct.parent.accountid]:series(acct.name)
+                end
+            end
+        end
+        if all_handled then
+            return map
+        end
+    end
+
+    error("Accounts nested (at least) 100 levels deep")
+end
+
+function generate()
+    year = date.now().year-4
+
+    accounts = get_accounts()
+    t = tabulation.new(20)
+    t:title(year .. "-" .. date.now().year .. " Quarterly Net Worth")
+    series_map = account_series_map(accounts, t:series("Net Worth"))
+    default_currency = get_default_currency()
+
+    for month=1,20 do
+        end_date = date.new(year, month*3-2, 1)
+
+        t:label(month, tostring(end_date))
+
+        for id, acct in pairs(accounts) do
+            series = series_map[id]
+            if acct.type ~= account.Expense and acct.type ~= account.Income and acct.type ~= account.Trading then
+                balance = acct:balance(end_date)
+                multiplier = 1
+                if acct.security ~= default_currency then
+                    price = acct.security:closestprice(default_currency, end_date)
+                    if price == nil then
+                        --[[
+                        -- This should contain code to warn the user that their report is missing some information
+                        --]]
+                        multiplier = 0
+                    else
+                        multiplier = price.value
+                    end
+                end
+                series:value(month, balance.amount * multiplier)
+            end
+        end
+    end
+
+    return t
+end

internal/handlers/reports/years_income.lua

@@ -0,0 +1,47 @@
+function account_series_map(accounts, tabulation)
+    map = {}
+
+    for i=1,100 do -- we're not messing with accounts more than 100 levels deep
+        all_handled = true
+        for id, acct in pairs(accounts) do
+            if not map[id] then
+                all_handled = false
+                if not acct.parent then
+                    map[id] = tabulation:series(acct.name)
+                elseif map[acct.parent.accountid] then
+                    map[id] = map[acct.parent.accountid]:series(acct.name)
+                end
+            end
+        end
+        if all_handled then
+            return map
+        end
+    end
+
+    error("Accounts nested (at least) 100 levels deep")
+end
+
+function generate()
+    year = date.now().year
+    account_type = account.Income
+
+    accounts = get_accounts()
+    t = tabulation.new(1)
+    t:title(year .. " Income")
+    series_map = account_series_map(accounts, t)
+
+    begin_date = date.new(year, 1, 1)
+    end_date = date.new(year+1, 1, 1)
+
+    t:label(1, year .. " Income")
+
+    for id, acct in pairs(accounts) do
+        series = series_map[id]
+        if acct.type == account_type then
+            balance = acct:balance(begin_date, end_date)
+            series:value(1, balance.amount)
+        end
+    end
+
+    return t
+end

internal/handlers/reports_lua.go

@@ -0,0 +1,187 @@
+package handlers
+
+import (
+	"github.com/yuin/gopher-lua"
+)
+
+const luaTabulationTypeName = "tabulation"
+const luaSeriesTypeName = "series"
+
+func luaRegisterTabulations(L *lua.LState) {
+	mtr := L.NewTypeMetatable(luaTabulationTypeName)
+	L.SetGlobal("tabulation", mtr)
+	L.SetField(mtr, "new", L.NewFunction(luaTabulationNew))
+	L.SetField(mtr, "__index", L.NewFunction(luaTabulation__index))
+	L.SetField(mtr, "__metatable", lua.LString("protected"))
+
+	mts := L.NewTypeMetatable(luaSeriesTypeName)
+	L.SetGlobal("series", mts)
+	L.SetField(mts, "__index", L.NewFunction(luaSeries__index))
+	L.SetField(mts, "__metatable", lua.LString("protected"))
+}
+
+// Checks whether the first lua argument is a *LUserData with *Tabulation and returns *Tabulation
+func luaCheckTabulation(L *lua.LState, n int) *Tabulation {
+	ud := L.CheckUserData(n)
+	if tabulation, ok := ud.Value.(*Tabulation); ok {
+		return tabulation
+	}
+	L.ArgError(n, "tabulation expected")
+	return nil
+}
+
+// Checks whether the first lua argument is a *LUserData with *Series and returns *Series
+func luaCheckSeries(L *lua.LState, n int) *Series {
+	ud := L.CheckUserData(n)
+	if series, ok := ud.Value.(*Series); ok {
+		return series
+	}
+	L.ArgError(n, "series expected")
+	return nil
+}
+
+func luaTabulationNew(L *lua.LState) int {
+	numvalues := L.CheckInt(1)
+	ud := L.NewUserData()
+	ud.Value = &Tabulation{
+		Labels: make([]string, numvalues),
+		Series: make(map[string]*Series),
+	}
+	L.SetMetatable(ud, L.GetTypeMetatable(luaTabulationTypeName))
+	L.Push(ud)
+	return 1
+}
+
+func luaTabulation__index(L *lua.LState) int {
+	field := L.CheckString(2)
+
+	switch field {
+	case "Label", "label":
+		L.Push(L.NewFunction(luaTabulationLabel))
+	case "Series", "series":
+		L.Push(L.NewFunction(luaTabulationSeries))
+	case "Title", "title":
+		L.Push(L.NewFunction(luaTabulationTitle))
+	case "Subtitle", "subtitle":
+		L.Push(L.NewFunction(luaTabulationSubtitle))
+	case "Units", "units":
+		L.Push(L.NewFunction(luaTabulationUnits))
+	default:
+		L.ArgError(2, "unexpected tabulation attribute: "+field)
+	}
+
+	return 1
+}
+
+func luaTabulationLabel(L *lua.LState) int {
+	tabulation := luaCheckTabulation(L, 1)
+	labelnumber := L.CheckInt(2)
+	label := L.CheckString(3)
+
+	if labelnumber > cap(tabulation.Labels) || labelnumber < 1 {
+		L.ArgError(2, "Label index must be between 1 and the number of data points, inclusive")
+	}
+	tabulation.Labels[labelnumber-1] = label
+	return 0
+}
+
+func luaTabulationSeries(L *lua.LState) int {
+	tabulation := luaCheckTabulation(L, 1)
+	name := L.CheckString(2)
+	ud := L.NewUserData()
+
+	s, ok := tabulation.Series[name]
+	if ok {
+		ud.Value = s
+	} else {
+		tabulation.Series[name] = &Series{
+			Series: make(map[string]*Series),
+			Values: make([]float64, cap(tabulation.Labels)),
+		}
+		ud.Value = tabulation.Series[name]
+	}
+	L.SetMetatable(ud, L.GetTypeMetatable(luaSeriesTypeName))
+	L.Push(ud)
+	return 1
+}
+
+func luaTabulationTitle(L *lua.LState) int {
+	tabulation := luaCheckTabulation(L, 1)
+
+	if L.GetTop() == 2 {
+		tabulation.Title = L.CheckString(2)
+		return 0
+	}
+	L.Push(lua.LString(tabulation.Title))
+	return 1
+}
+
+func luaTabulationSubtitle(L *lua.LState) int {
+	tabulation := luaCheckTabulation(L, 1)
+
+	if L.GetTop() == 2 {
+		tabulation.Subtitle = L.CheckString(2)
+		return 0
+	}
+	L.Push(lua.LString(tabulation.Subtitle))
+	return 1
+}
+
+func luaTabulationUnits(L *lua.LState) int {
+	tabulation := luaCheckTabulation(L, 1)
+
+	if L.GetTop() == 2 {
+		tabulation.Units = L.CheckString(2)
+		return 0
+	}
+	L.Push(lua.LString(tabulation.Units))
+	return 1
+}
+
+func luaSeries__index(L *lua.LState) int {
+	field := L.CheckString(2)
+
+	switch field {
+	case "Value", "value":
+		L.Push(L.NewFunction(luaSeriesValue))
+	case "Series", "series":
+		L.Push(L.NewFunction(luaSeriesSeries))
+	default:
+		L.ArgError(2, "unexpected series attribute: "+field)
+	}
+
+	return 1
+}
+
+func luaSeriesValue(L *lua.LState) int {
+	series := luaCheckSeries(L, 1)
+	valuenumber := L.CheckInt(2)
+	value := float64(L.CheckNumber(3))
+
+	if valuenumber > cap(series.Values) || valuenumber < 1 {
+		L.ArgError(2, "value index must be between 1 and the number of data points, inclusive")
+	}
+	series.Values[valuenumber-1] = value
+
+	return 0
+}
+
+func luaSeriesSeries(L *lua.LState) int {
+	parent := luaCheckSeries(L, 1)
+	name := L.CheckString(2)
+	ud := L.NewUserData()
+
+	s, ok := parent.Series[name]
+	if ok {
+		ud.Value = s
+	} else {
+		parent.Series[name] = &Series{
+			Series: make(map[string]*Series),
+			Values: make([]float64, cap(parent.Values)),
+		}
+		ud.Value = parent.Series[name]
+	}
+	L.SetMetatable(ud, L.GetTypeMetatable(luaSeriesTypeName))
+	L.Push(ud)
+	return 1
+}

internal/handlers/scripts/gen_cusip_csv.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+QUARTER=2017q1
+
+function get_ticker() {
+	local cusip=$1
+
+	local tmpfile=$tmpdir/curl_tmpfile
+	curl -s -d "sopt=cusip&tickersymbol=${cusip}" http://quantumonline.com/search.cfm > $tmpfile
+	local quantum_name=$(sed -rn 's@<font size="\+1"><center><b>(.+)</b><br></center></font>\s*$@\1@p' $tmpfile | head -n1)
+	local quantum_ticker=$(sed -rn 's@^.*Ticker Symbol: ([A-Z\.0-9\-]+) &nbsp;&nbsp;&nbsp;&nbsp;CUSIP.*$@\1@p' $tmpfile | head -n1)
+
+	if [[ -z $quantum_ticker ]] || [[ -z $quantum_name ]]; then
+		curl -s -d "reqforlookup=REQUESTFORLOOKUP&productid=mmnet&isLoggedIn=mmnet&rows=50&for=stock&by=cusip&criteria=${cusip}&submit=Search" http://quotes.fidelity.com/mmnet/SymLookup.phtml > $tmpfile
+		fidelity_name=$(sed -rn 's@<tr><td height="20" nowrap><font class="smallfont">(.+)</font></td>\s*@\1@p' $tmpfile | sed -r 's/\&amp;/\&/')
+		fidelity_ticker=$(sed -rn 's@\s+<td align="center" width="20%"><font><a href="/webxpress/get_quote\?QUOTE_TYPE=\&SID_VALUE_ID=(.+)">(.+)</a></td>\s*@\1@p' $tmpfile | head -n1)
+		if [[ -z $fidelity_ticker ]] || [[ -z $fidelity_name ]]; then
+			echo $cusip >> $tmpdir/${QUARTER}_bad_cusips.csv
+		else
+			echo "$cusip,$fidelity_ticker,$fidelity_name"
+		fi
+	else
+		echo "$cusip,$quantum_ticker,$quantum_name"
+	fi
+}
+
+tmpdir=$(mktemp -d -p $PWD)
+
+# Get the list of CUSIPs from the SEC and generate a nicer format of it
+wget -q http://www.sec.gov/divisions/investment/13f/13flist${QUARTER}.pdf -O $tmpdir/13flist${QUARTER}.pdf
+pdftotext -layout $tmpdir/13flist${QUARTER}.pdf - > $tmpdir/13flist${QUARTER}.txt
+sed -rn 's/^([A-Z0-9]{6}) ([A-Z0-9]{2}) ([A-Z0-9]) .*$/\1\2\3/p' $tmpdir/13flist${QUARTER}.txt > $tmpdir/${QUARTER}_cusips
+
+# Find tickers and names for all the CUSIPs we can and print them out
+for cusip in $(cat $tmpdir/${QUARTER}_cusips); do
+	get_ticker $cusip
+done
+
+rm -rf $tmpdir

internal/handlers/scripts/gen_security_list.py

@@ -0,0 +1,114 @@
+#!/usr/bin/env python
+
+import csv
+from xml.dom import minidom
+import sys
+
+if sys.version_info[0] < 3:
+    from urllib2 import urlopen
+
+    # Allow writing utf-8 to stdout
+    import codecs
+    UTF8Writer = codecs.getwriter('utf8')
+    sys.stdout = UTF8Writer(sys.stdout)
+else:
+    from urllib.request import urlopen
+
+    # This is absent, but also unneeded in python3, so just return the string
+    def unicode(s, encoding):
+        return s
+
+class Security(object):
+    def __init__(self, name, description, number, _type, precision):
+        self.name = name
+        self.description = description
+        self.number = number
+        self.type = _type
+        self.precision = precision
+    def unicode(self):
+        s = """\tSecurity{
+\t\tName: \"%s\",
+\t\tDescription: \"%s\",
+\t\tSymbol: \"%s\",
+\t\tPrecision: %d,
+\t\tType: %s,
+\t\tAlternateId: \"%s\"},\n""" % (self.name, self.description, self.name, self.precision, self.type, str(self.number))
+        try:
+            return unicode(s, 'utf_8')
+        except TypeError:
+            return s
+
+class SecurityList(object):
+    def __init__(self, comment):
+        self.comment = comment
+        self.currencies = {}
+    def add(self, currency):
+        self.currencies[currency.number] = currency
+    def unicode(self):
+        string = "\t// "+self.comment+"\n"
+        for key in sorted(self.currencies.keys()):
+            string += self.currencies[key].unicode()
+        return string
+
+def process_ccyntry(currency_list, node):
+    name = ""
+    nameSet = False
+    number = 0
+    numberSet = False
+    description = ""
+    precision = 0
+    for n in node.childNodes:
+        if n.nodeName == "Ccy":
+            name = n.firstChild.nodeValue
+            nameSet = True
+        elif n.nodeName == "CcyNm":
+            description = n.firstChild.nodeValue
+        elif n.nodeName == "CcyNbr":
+            number = int(n.firstChild.nodeValue)
+            numberSet = True
+        elif n.nodeName == "CcyMnrUnts":
+            if n.firstChild.nodeValue == "N.A.":
+                precision = 0
+            else:
+                precision = int(n.firstChild.nodeValue)
+    if nameSet and numberSet:
+        currency_list.add(Security(name, description, number, "Currency", precision))
+
+def get_currency_list():
+    currency_list = SecurityList("ISO 4217, from http://www.currency-iso.org/en/home/tables/table-a1.html")
+
+    f = urlopen('http://www.currency-iso.org/dam/downloads/lists/list_one.xml')
+    xmldoc = minidom.parse(f)
+    for isonode in xmldoc.childNodes:
+        if isonode.nodeName == "ISO_4217":
+            for ccytblnode in isonode.childNodes:
+                if ccytblnode.nodeName == "CcyTbl":
+                    for ccyntrynode in ccytblnode.childNodes:
+                        if ccyntrynode.nodeName == "CcyNtry":
+                            process_ccyntry(currency_list, ccyntrynode)
+    f.close()
+    return currency_list
+
+def get_cusip_list(filename):
+    cusip_list = SecurityList("")
+    with open(filename) as csvfile:
+        csvreader = csv.reader(csvfile, delimiter=',')
+        for row in csvreader:
+            cusip = row[0]
+            name = row[1]
+            description = ",".join(row[2:])
+            cusip_list.add(Security(name, description, cusip, "Stock", 5))
+    return cusip_list
+
+def main():
+    currency_list = get_currency_list()
+    cusip_list = get_cusip_list('cusip_list.csv')
+
+    print("package handlers\n")
+    print("var SecurityTemplates = []Security{")
+    print(currency_list.unicode())
+    print(cusip_list.unicode())
+    print("}")
+
+if __name__ == "__main__":
+    main()

internal/handlers/securities.go

@@ -0,0 +1,442 @@
+package handlers
+
+//go:generate make
+
+import (
+	"encoding/json"
+	"errors"
+	"gopkg.in/gorp.v1"
+	"log"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+const (
+	Currency int64 = 1
+	Stock          = 2
+)
+
+func GetSecurityType(typestring string) int64 {
+	if strings.EqualFold(typestring, "currency") {
+		return Currency
+	} else if strings.EqualFold(typestring, "stock") {
+		return Stock
+	} else {
+		return 0
+	}
+}
+
+type Security struct {
+	SecurityId  int64
+	UserId      int64
+	Name        string
+	Description string
+	Symbol      string
+	// Number of decimal digits (to the right of the decimal point) this
+	// security is precise to
+	Precision int
+	Type      int64
+	// AlternateId is CUSIP for Type=Stock, ISO4217 for Type=Currency
+	AlternateId string
+}
+
+type SecurityList struct {
+	Securities *[]*Security `json:"securities"`
+}
+
+func (s *Security) Read(json_str string) error {
+	dec := json.NewDecoder(strings.NewReader(json_str))
+	return dec.Decode(s)
+}
+
+func (s *Security) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(s)
+}
+
+func (sl *SecurityList) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(sl)
+}
+
+func SearchSecurityTemplates(search string, _type int64, limit int64) []*Security {
+	upperSearch := strings.ToUpper(search)
+	var results []*Security
+	for i, security := range SecurityTemplates {
+		if strings.Contains(strings.ToUpper(security.Name), upperSearch) ||
+			strings.Contains(strings.ToUpper(security.Description), upperSearch) ||
+			strings.Contains(strings.ToUpper(security.Symbol), upperSearch) {
+			if _type == 0 || _type == security.Type {
+				results = append(results, &SecurityTemplates[i])
+				if limit != -1 && int64(len(results)) >= limit {
+					break
+				}
+			}
+		}
+	}
+	return results
+}
+
+func FindSecurityTemplate(name string, _type int64) *Security {
+	for _, security := range SecurityTemplates {
+		if name == security.Name && _type == security.Type {
+			return &security
+		}
+	}
+	return nil
+}
+
+func FindCurrencyTemplate(iso4217 int64) *Security {
+	iso4217string := strconv.FormatInt(iso4217, 10)
+	for _, security := range SecurityTemplates {
+		if security.Type == Currency && security.AlternateId == iso4217string {
+			return &security
+		}
+	}
+	return nil
+}
+
+func GetSecurity(db *DB, securityid int64, userid int64) (*Security, error) {
+	var s Security
+
+	err := db.SelectOne(&s, "SELECT * from securities where UserId=? AND SecurityId=?", userid, securityid)
+	if err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+func GetSecurityTx(transaction *gorp.Transaction, securityid int64, userid int64) (*Security, error) {
+	var s Security
+
+	err := transaction.SelectOne(&s, "SELECT * from securities where UserId=? AND SecurityId=?", userid, securityid)
+	if err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+func GetSecurities(db *DB, userid int64) (*[]*Security, error) {
+	var securities []*Security
+
+	_, err := db.Select(&securities, "SELECT * from securities where UserId=?", userid)
+	if err != nil {
+		return nil, err
+	}
+	return &securities, nil
+}
+
+func InsertSecurity(db *DB, s *Security) error {
+	err := db.Insert(s)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func InsertSecurityTx(transaction *gorp.Transaction, s *Security) error {
+	err := transaction.Insert(s)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func UpdateSecurity(db *DB, s *Security) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	user, err := GetUserTx(transaction, s.UserId)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	} else if user.DefaultCurrency == s.SecurityId && s.Type != Currency {
+		transaction.Rollback()
+		return errors.New("Cannot change security which is user's default currency to be non-currency")
+	}
+
+	count, err := transaction.Update(s)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+	if count != 1 {
+		transaction.Rollback()
+		return errors.New("Updated more than one security")
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func DeleteSecurity(db *DB, s *Security) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	// First, ensure no accounts are using this security
+	accounts, err := transaction.SelectInt("SELECT count(*) from accounts where UserId=? and SecurityId=?", s.UserId, s.SecurityId)
+
+	if accounts != 0 {
+		transaction.Rollback()
+		return errors.New("One or more accounts still use this security")
+	}
+
+	user, err := GetUserTx(transaction, s.UserId)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	} else if user.DefaultCurrency == s.SecurityId {
+		transaction.Rollback()
+		return errors.New("Cannot delete security which is user's default currency")
+	}
+
+	// Remove all prices involving this security (either of this security, or
+	// using it as a currency)
+	_, err = transaction.Exec("DELETE * FROM prices WHERE SecurityId=? OR CurrencyId=?", s.SecurityId, s.SecurityId)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	count, err := transaction.Delete(s)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+	if count != 1 {
+		transaction.Rollback()
+		return errors.New("Deleted more than one security")
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func ImportGetCreateSecurity(transaction *gorp.Transaction, userid int64, security *Security) (*Security, error) {
+	security.UserId = userid
+	if len(security.AlternateId) == 0 {
+		// Always create a new local security if we can't match on the AlternateId
+		err := InsertSecurityTx(transaction, security)
+		if err != nil {
+			return nil, err
+		}
+		return security, nil
+	}
+
+	var securities []*Security
+
+	_, err := transaction.Select(&securities, "SELECT * from securities where UserId=? AND Type=? AND AlternateId=? AND Precision=?", userid, security.Type, security.AlternateId, security.Precision)
+	if err != nil {
+		return nil, err
+	}
+
+	// First try to find a case insensitive match on the name or symbol
+	upperName := strings.ToUpper(security.Name)
+	upperSymbol := strings.ToUpper(security.Symbol)
+	for _, s := range securities {
+		if (len(s.Name) > 0 && strings.ToUpper(s.Name) == upperName) ||
+			(len(s.Symbol) > 0 && strings.ToUpper(s.Symbol) == upperSymbol) {
+			return s, nil
+		}
+	}
+	//		if strings.Contains(strings.ToUpper(security.Name), upperSearch) ||
+
+	// Try to find a partial string match on the name or symbol
+	for _, s := range securities {
+		sUpperName := strings.ToUpper(s.Name)
+		sUpperSymbol := strings.ToUpper(s.Symbol)
+		if (len(upperName) > 0 && len(s.Name) > 0 && (strings.Contains(upperName, sUpperName) || strings.Contains(sUpperName, upperName))) ||
+			(len(upperSymbol) > 0 && len(s.Symbol) > 0 && (strings.Contains(upperSymbol, sUpperSymbol) || strings.Contains(sUpperSymbol, upperSymbol))) {
+			return s, nil
+		}
+	}
+
+	// Give up and return the first security in the list
+	if len(securities) > 0 {
+		return securities[0], nil
+	}
+
+	// If there wasn't even one security in the list, make a new one
+	err = InsertSecurityTx(transaction, security)
+	if err != nil {
+		return nil, err
+	}
+
+	return security, nil
+}
+
+func SecurityHandler(w http.ResponseWriter, r *http.Request, db *DB) {
+	user, err := GetUserFromSession(db, r)
+	if err != nil {
+		WriteError(w, 1 /*Not Signed In*/)
+		return
+	}
+
+	if r.Method == "POST" {
+		security_json := r.PostFormValue("security")
+		if security_json == "" {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		var security Security
+		err := security.Read(security_json)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		security.SecurityId = -1
+		security.UserId = user.UserId
+
+		err = InsertSecurity(db, &security)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+
+		w.WriteHeader(201 /*Created*/)
+		err = security.Write(w)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	} else if r.Method == "GET" {
+		var securityid int64
+		n, err := GetURLPieces(r.URL.Path, "/security/%d", &securityid)
+
+		if err != nil || n != 1 {
+			//Return all securities
+			var sl SecurityList
+
+			securities, err := GetSecurities(db, user.UserId)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			sl.Securities = securities
+			err = (&sl).Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else {
+			security, err := GetSecurity(db, securityid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = security.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		}
+	} else {
+		securityid, err := GetURLID(r.URL.Path)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		if r.Method == "PUT" {
+			security_json := r.PostFormValue("security")
+			if security_json == "" {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			var security Security
+			err := security.Read(security_json)
+			if err != nil || security.SecurityId != securityid {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+			security.UserId = user.UserId
+
+			err = UpdateSecurity(db, &security)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			err = security.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else if r.Method == "DELETE" {
+			security, err := GetSecurity(db, securityid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = DeleteSecurity(db, security)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			WriteSuccess(w)
+		}
+	}
+}
+
+func SecurityTemplateHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method == "GET" {
+		var sl SecurityList
+
+		query, _ := url.ParseQuery(r.URL.RawQuery)
+
+		var limit int64 = -1
+		search := query.Get("search")
+		_type := GetSecurityType(query.Get("type"))
+
+		limitstring := query.Get("limit")
+		if limitstring != "" {
+			limitint, err := strconv.ParseInt(limitstring, 10, 0)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+			limit = limitint
+		}
+
+		securities := SearchSecurityTemplates(search, _type, limit)
+
+		sl.Securities = &securities
+		err := (&sl).Write(w)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	} else {
+		WriteError(w, 3 /*Invalid Request*/)
+	}
+}

internal/handlers/securities_lua.go

@@ -0,0 +1,188 @@
+package handlers
+
+import (
+	"context"
+	"errors"
+	"github.com/yuin/gopher-lua"
+)
+
+const luaSecurityTypeName = "security"
+
+func luaContextGetSecurities(L *lua.LState) (map[int64]*Security, error) {
+	var security_map map[int64]*Security
+
+	ctx := L.Context()
+
+	db, ok := ctx.Value(dbContextKey).(*DB)
+	if !ok {
+		return nil, errors.New("Couldn't find DB in lua's Context")
+	}
+
+	security_map, ok = ctx.Value(securitiesContextKey).(map[int64]*Security)
+	if !ok {
+		user, ok := ctx.Value(userContextKey).(*User)
+		if !ok {
+			return nil, errors.New("Couldn't find User in lua's Context")
+		}
+
+		securities, err := GetSecurities(db, user.UserId)
+		if err != nil {
+			return nil, err
+		}
+
+		security_map = make(map[int64]*Security)
+		for i := range *securities {
+			security_map[(*securities)[i].SecurityId] = (*securities)[i]
+		}
+
+		ctx = context.WithValue(ctx, securitiesContextKey, security_map)
+		L.SetContext(ctx)
+	}
+
+	return security_map, nil
+}
+
+func luaContextGetDefaultCurrency(L *lua.LState) (*Security, error) {
+	security_map, err := luaContextGetSecurities(L)
+	if err != nil {
+		return nil, err
+	}
+
+	ctx := L.Context()
+
+	user, ok := ctx.Value(userContextKey).(*User)
+	if !ok {
+		return nil, errors.New("Couldn't find User in lua's Context")
+	}
+
+	if security, ok := security_map[user.DefaultCurrency]; ok {
+		return security, nil
+	} else {
+		return nil, errors.New("DefaultCurrency not in lua security_map")
+	}
+}
+
+func luaGetDefaultCurrency(L *lua.LState) int {
+	defcurrency, err := luaContextGetDefaultCurrency(L)
+	if err != nil {
+		panic("luaGetDefaultCurrency couldn't fetch default currency")
+	}
+
+	L.Push(SecurityToLua(L, defcurrency))
+	return 1
+}
+
+func luaGetSecurities(L *lua.LState) int {
+	security_map, err := luaContextGetSecurities(L)
+	if err != nil {
+		panic("luaGetSecurities couldn't fetch securities")
+	}
+
+	table := L.NewTable()
+
+	for securityid := range security_map {
+		table.RawSetInt(int(securityid), SecurityToLua(L, security_map[securityid]))
+	}
+
+	L.Push(table)
+	return 1
+}
+
+func luaRegisterSecurities(L *lua.LState) {
+	mt := L.NewTypeMetatable(luaSecurityTypeName)
+	L.SetGlobal("security", mt)
+	L.SetField(mt, "__index", L.NewFunction(luaSecurity__index))
+	L.SetField(mt, "__tostring", L.NewFunction(luaSecurity__tostring))
+	L.SetField(mt, "__eq", L.NewFunction(luaSecurity__eq))
+	L.SetField(mt, "__metatable", lua.LString("protected"))
+	getSecuritiesFn := L.NewFunction(luaGetSecurities)
+	L.SetField(mt, "get_all", getSecuritiesFn)
+	getDefaultCurrencyFn := L.NewFunction(luaGetDefaultCurrency)
+	L.SetField(mt, "get_default", getDefaultCurrencyFn)
+
+	// also register the get_securities and get_default functions as globals in
+	// their own right
+	L.SetGlobal("get_securities", getSecuritiesFn)
+	L.SetGlobal("get_default_currency", getDefaultCurrencyFn)
+}
+
+func SecurityToLua(L *lua.LState, security *Security) *lua.LUserData {
+	ud := L.NewUserData()
+	ud.Value = security
+	L.SetMetatable(ud, L.GetTypeMetatable(luaSecurityTypeName))
+	return ud
+}
+
+// Checks whether the first lua argument is a *LUserData with *Security and returns this *Security.
+func luaCheckSecurity(L *lua.LState, n int) *Security {
+	ud := L.CheckUserData(n)
+	if security, ok := ud.Value.(*Security); ok {
+		return security
+	}
+	L.ArgError(n, "security expected")
+	return nil
+}
+
+func luaSecurity__index(L *lua.LState) int {
+	a := luaCheckSecurity(L, 1)
+	field := L.CheckString(2)
+
+	switch field {
+	case "SecurityId", "securityid":
+		L.Push(lua.LNumber(float64(a.SecurityId)))
+	case "Name", "name":
+		L.Push(lua.LString(a.Name))
+	case "Description", "description":
+		L.Push(lua.LString(a.Description))
+	case "Symbol", "symbol":
+		L.Push(lua.LString(a.Symbol))
+	case "Precision", "precision":
+		L.Push(lua.LNumber(float64(a.Precision)))
+	case "Type", "type":
+		L.Push(lua.LNumber(float64(a.Type)))
+	case "ClosestPrice", "closestprice":
+		L.Push(L.NewFunction(luaClosestPrice))
+	default:
+		L.ArgError(2, "unexpected security attribute: "+field)
+	}
+
+	return 1
+}
+
+func luaClosestPrice(L *lua.LState) int {
+	s := luaCheckSecurity(L, 1)
+	c := luaCheckSecurity(L, 2)
+	date := luaCheckTime(L, 3)
+
+	ctx := L.Context()
+	db, ok := ctx.Value(dbContextKey).(*DB)
+	if !ok {
+		panic("Couldn't find DB in lua's Context")
+	}
+
+	p, err := GetClosestPrice(db, s, c, date)
+	if err != nil {
+		L.Push(lua.LNil)
+	} else {
+		L.Push(PriceToLua(L, p))
+	}
+
+	return 1
+}
+
+func luaSecurity__tostring(L *lua.LState) int {
+	s := luaCheckSecurity(L, 1)
+
+	L.Push(lua.LString(s.Name + " - " + s.Description + " (" + s.Symbol + ")"))
+
+	return 1
+}
+
+func luaSecurity__eq(L *lua.LState) int {
+	a := luaCheckSecurity(L, 1)
+	b := luaCheckSecurity(L, 2)
+
+	L.Push(lua.LBool(a.SecurityId == b.SecurityId))
+
+	return 1
+}

internal/handlers/sessions.go

@@ -0,0 +1,139 @@
+package handlers
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"time"
+)
+
+type Session struct {
+	SessionId     int64
+	SessionSecret string `json:"-"`
+	UserId        int64
+}
+
+func (s *Session) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(s)
+}
+
+func GetSession(db *DB, r *http.Request) (*Session, error) {
+	var s Session
+
+	cookie, err := r.Cookie("moneygo-session")
+	if err != nil {
+		return nil, fmt.Errorf("moneygo-session cookie not set")
+	}
+	s.SessionSecret = cookie.Value
+
+	err = db.SelectOne(&s, "SELECT * from sessions where SessionSecret=?", s.SessionSecret)
+	if err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+func DeleteSessionIfExists(db *DB, r *http.Request) {
+	// TODO do this in one transaction
+	session, err := GetSession(db, r)
+	if err == nil {
+		db.Delete(session)
+	}
+}
+
+func NewSessionCookie() (string, error) {
+	bits := make([]byte, 128)
+	if _, err := io.ReadFull(rand.Reader, bits); err != nil {
+		return "", err
+	}
+	return base64.StdEncoding.EncodeToString(bits), nil
+}
+
+func NewSession(db *DB, w http.ResponseWriter, r *http.Request, userid int64) (*Session, error) {
+	s := Session{}
+
+	session_secret, err := NewSessionCookie()
+	if err != nil {
+		return nil, err
+	}
+
+	cookie := http.Cookie{
+		Name:     "moneygo-session",
+		Value:    session_secret,
+		Path:     "/",
+		Domain:   r.URL.Host,
+		Expires:  time.Now().AddDate(0, 1, 0), // a month from now
+		Secure:   true,
+		HttpOnly: true,
+	}
+	http.SetCookie(w, &cookie)
+
+	s.SessionSecret = session_secret
+	s.UserId = userid
+
+	err = db.Insert(&s)
+	if err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+func SessionHandler(w http.ResponseWriter, r *http.Request, db *DB) {
+	if r.Method == "POST" || r.Method == "PUT" {
+		user_json := r.PostFormValue("user")
+		if user_json == "" {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		user := User{}
+		err := user.Read(user_json)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		dbuser, err := GetUserByUsername(db, user.Username)
+		if err != nil {
+			WriteError(w, 2 /*Unauthorized Access*/)
+			return
+		}
+
+		user.HashPassword()
+		if user.PasswordHash != dbuser.PasswordHash {
+			WriteError(w, 2 /*Unauthorized Access*/)
+			return
+		}
+
+		DeleteSessionIfExists(db, r)
+
+		session, err := NewSession(db, w, r, dbuser.UserId)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			return
+		}
+
+		err = session.Write(w)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	} else if r.Method == "GET" {
+		s, err := GetSession(db, r)
+		if err != nil {
+			WriteError(w, 1 /*Not Signed In*/)
+			return
+		}
+
+		s.Write(w)
+	} else if r.Method == "DELETE" {
+		DeleteSessionIfExists(db, r)
+		WriteSuccess(w)
+	}
+}

internal/handlers/transactions.go

@@ -0,0 +1,945 @@
+package handlers
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"gopkg.in/gorp.v1"
+	"log"
+	"math/big"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Split.Status
+const (
+	Imported   int64 = 1
+	Entered          = 2
+	Cleared          = 3
+	Reconciled       = 4
+	Voided           = 5
+)
+
+// Split.ImportSplitType
+const (
+	Default         int64 = 0
+	ImportAccount         = 1 // This split belongs to the main account being imported
+	SubAccount            = 2 // This split belongs to a sub-account of that being imported
+	ExternalAccount       = 3
+	TradingAccount        = 4
+	Commission            = 5
+	Taxes                 = 6
+	Fees                  = 7
+	Load                  = 8
+	IncomeAccount         = 9
+	ExpenseAccount        = 10
+)
+
+type Split struct {
+	SplitId         int64
+	TransactionId   int64
+	Status          int64
+	ImportSplitType int64
+
+	// One of AccountId and SecurityId must be -1
+	// In normal splits, AccountId will be valid and SecurityId will be -1. The
+	// only case where this is reversed is for transactions that have been
+	// imported and not yet associated with an account.
+	AccountId  int64
+	SecurityId int64
+
+	RemoteId string // unique ID from server, for detecting duplicates
+	Number   string // Check or reference number
+	Memo     string
+	Amount   string // String representation of decimal, suitable for passing to big.Rat.SetString()
+}
+
+func GetBigAmount(amt string) (*big.Rat, error) {
+	var r big.Rat
+	_, success := r.SetString(amt)
+	if !success {
+		return nil, errors.New("Couldn't convert string amount to big.Rat via SetString()")
+	}
+	return &r, nil
+}
+
+func (s *Split) GetAmount() (*big.Rat, error) {
+	return GetBigAmount(s.Amount)
+}
+
+func (s *Split) Valid() bool {
+	if (s.AccountId == -1) == (s.SecurityId == -1) {
+		return false
+	}
+	_, err := s.GetAmount()
+	return err == nil
+}
+
+func (s *Split) AlreadyImportedTx(transaction *gorp.Transaction) (bool, error) {
+	count, err := transaction.SelectInt("SELECT COUNT(*) from splits where RemoteId=? and AccountId=?", s.RemoteId, s.AccountId)
+	return count == 1, err
+}
+
+type Transaction struct {
+	TransactionId int64
+	UserId        int64
+	Description   string
+	Date          time.Time
+	Splits        []*Split `db:"-"`
+}
+
+type TransactionList struct {
+	Transactions *[]Transaction `json:"transactions"`
+}
+
+type AccountTransactionsList struct {
+	Account           *Account
+	Transactions      *[]Transaction
+	TotalTransactions int64
+	BeginningBalance  string
+	EndingBalance     string
+}
+
+func (t *Transaction) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(t)
+}
+
+func (t *Transaction) Read(json_str string) error {
+	dec := json.NewDecoder(strings.NewReader(json_str))
+	return dec.Decode(t)
+}
+
+func (tl *TransactionList) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(tl)
+}
+
+func (atl *AccountTransactionsList) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(atl)
+}
+
+func (t *Transaction) Valid() bool {
+	for i := range t.Splits {
+		if !t.Splits[i].Valid() {
+			return false
+		}
+	}
+	return true
+}
+
+// Return a map of security ID's to big.Rat's containing the amount that
+// security is imbalanced by
+func (t *Transaction) GetImbalancesTx(transaction *gorp.Transaction) (map[int64]big.Rat, error) {
+	sums := make(map[int64]big.Rat)
+
+	if !t.Valid() {
+		return nil, errors.New("Transaction invalid")
+	}
+
+	for i := range t.Splits {
+		securityid := t.Splits[i].SecurityId
+		if t.Splits[i].AccountId != -1 {
+			var err error
+			var account *Account
+			account, err = GetAccountTx(transaction, t.Splits[i].AccountId, t.UserId)
+			if err != nil {
+				return nil, err
+			}
+			securityid = account.SecurityId
+		}
+		amount, _ := t.Splits[i].GetAmount()
+		sum := sums[securityid]
+		(&sum).Add(&sum, amount)
+		sums[securityid] = sum
+	}
+	return sums, nil
+}
+
+// Returns true if all securities contained in this transaction are balanced,
+// false otherwise
+func (t *Transaction) Balanced(transaction *gorp.Transaction) (bool, error) {
+	var zero big.Rat
+
+	sums, err := t.GetImbalancesTx(transaction)
+	if err != nil {
+		return false, err
+	}
+
+	for _, security_sum := range sums {
+		if security_sum.Cmp(&zero) != 0 {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
+func GetTransaction(db *DB, transactionid int64, userid int64) (*Transaction, error) {
+	var t Transaction
+
+	transaction, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+
+	err = transaction.SelectOne(&t, "SELECT * from transactions where UserId=? AND TransactionId=?", userid, transactionid)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	_, err = transaction.Select(&t.Splits, "SELECT * from splits where TransactionId=?", transactionid)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	return &t, nil
+}
+
+func GetTransactions(db *DB, userid int64) (*[]Transaction, error) {
+	var transactions []Transaction
+
+	transaction, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = transaction.Select(&transactions, "SELECT * from transactions where UserId=?", userid)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := range transactions {
+		_, err := transaction.Select(&transactions[i].Splits, "SELECT * from splits where TransactionId=?", transactions[i].TransactionId)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	return &transactions, nil
+}
+
+func incrementAccountVersions(transaction *gorp.Transaction, user *User, accountids []int64) error {
+	for i := range accountids {
+		account, err := GetAccountTx(transaction, accountids[i], user.UserId)
+		if err != nil {
+			return err
+		}
+		account.AccountVersion++
+		count, err := transaction.Update(account)
+		if err != nil {
+			return err
+		}
+		if count != 1 {
+			return errors.New("Updated more than one account")
+		}
+	}
+	return nil
+}
+
+type AccountMissingError struct{}
+
+func (ame AccountMissingError) Error() string {
+	return "Account missing"
+}
+
+func InsertTransactionTx(transaction *gorp.Transaction, t *Transaction, user *User) error {
+	// Map of any accounts with transaction splits being added
+	a_map := make(map[int64]bool)
+	for i := range t.Splits {
+		if t.Splits[i].AccountId != -1 {
+			existing, err := transaction.SelectInt("SELECT count(*) from accounts where AccountId=?", t.Splits[i].AccountId)
+			if err != nil {
+				return err
+			}
+			if existing != 1 {
+				return AccountMissingError{}
+			}
+			a_map[t.Splits[i].AccountId] = true
+		} else if t.Splits[i].SecurityId == -1 {
+			return AccountMissingError{}
+		}
+	}
+
+	//increment versions for all accounts
+	var a_ids []int64
+	for id := range a_map {
+		a_ids = append(a_ids, id)
+	}
+	// ensure at least one of the splits is associated with an actual account
+	if len(a_ids) < 1 {
+		return AccountMissingError{}
+	}
+	err := incrementAccountVersions(transaction, user, a_ids)
+	if err != nil {
+		return err
+	}
+
+	t.UserId = user.UserId
+	err = transaction.Insert(t)
+	if err != nil {
+		return err
+	}
+
+	for i := range t.Splits {
+		t.Splits[i].TransactionId = t.TransactionId
+		t.Splits[i].SplitId = -1
+		err = transaction.Insert(t.Splits[i])
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func InsertTransaction(db *DB, t *Transaction, user *User) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	err = InsertTransactionTx(transaction, t, user)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func UpdateTransactionTx(transaction *gorp.Transaction, t *Transaction, user *User) error {
+	var existing_splits []*Split
+
+	_, err := transaction.Select(&existing_splits, "SELECT * from splits where TransactionId=?", t.TransactionId)
+	if err != nil {
+		return err
+	}
+
+	// Map of any accounts with transaction splits being added
+	a_map := make(map[int64]bool)
+
+	// Make a map with any existing splits for this transaction
+	s_map := make(map[int64]bool)
+	for i := range existing_splits {
+		s_map[existing_splits[i].SplitId] = true
+	}
+
+	// Insert splits, updating any pre-existing ones
+	for i := range t.Splits {
+		t.Splits[i].TransactionId = t.TransactionId
+		_, ok := s_map[t.Splits[i].SplitId]
+		if ok {
+			count, err := transaction.Update(t.Splits[i])
+			if err != nil {
+				return err
+			}
+			if count != 1 {
+				return errors.New("Updated more than one transaction split")
+			}
+			delete(s_map, t.Splits[i].SplitId)
+		} else {
+			t.Splits[i].SplitId = -1
+			err := transaction.Insert(t.Splits[i])
+			if err != nil {
+				return err
+			}
+		}
+		if t.Splits[i].AccountId != -1 {
+			a_map[t.Splits[i].AccountId] = true
+		}
+	}
+
+	// Delete any remaining pre-existing splits
+	for i := range existing_splits {
+		_, ok := s_map[existing_splits[i].SplitId]
+		if existing_splits[i].AccountId != -1 {
+			a_map[existing_splits[i].AccountId] = true
+		}
+		if ok {
+			_, err := transaction.Delete(existing_splits[i])
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	// Increment versions for all accounts with modified splits
+	var a_ids []int64
+	for id := range a_map {
+		a_ids = append(a_ids, id)
+	}
+	err = incrementAccountVersions(transaction, user, a_ids)
+	if err != nil {
+		return err
+	}
+
+	count, err := transaction.Update(t)
+	if err != nil {
+		return err
+	}
+	if count != 1 {
+		return errors.New("Updated more than one transaction")
+	}
+
+	return nil
+}
+
+func DeleteTransaction(db *DB, t *Transaction, user *User) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	var accountids []int64
+	_, err = transaction.Select(&accountids, "SELECT DISTINCT AccountId FROM splits WHERE TransactionId=? AND AccountId != -1", t.TransactionId)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	_, err = transaction.Exec("DELETE FROM splits WHERE TransactionId=?", t.TransactionId)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	count, err := transaction.Delete(t)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+	if count != 1 {
+		transaction.Rollback()
+		return errors.New("Deleted more than one transaction")
+	}
+
+	err = incrementAccountVersions(transaction, user, accountids)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func TransactionHandler(w http.ResponseWriter, r *http.Request, db *DB) {
+	user, err := GetUserFromSession(db, r)
+	if err != nil {
+		WriteError(w, 1 /*Not Signed In*/)
+		return
+	}
+
+	if r.Method == "POST" {
+		transaction_json := r.PostFormValue("transaction")
+		if transaction_json == "" {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		var transaction Transaction
+		err := transaction.Read(transaction_json)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		transaction.TransactionId = -1
+		transaction.UserId = user.UserId
+
+		sqltx, err := db.Begin()
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+
+		balanced, err := transaction.Balanced(sqltx)
+		if err != nil {
+			sqltx.Rollback()
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+		if !transaction.Valid() || !balanced {
+			sqltx.Rollback()
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		for i := range transaction.Splits {
+			transaction.Splits[i].SplitId = -1
+			_, err := GetAccountTx(sqltx, transaction.Splits[i].AccountId, user.UserId)
+			if err != nil {
+				sqltx.Rollback()
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+		}
+
+		err = InsertTransactionTx(sqltx, &transaction, user)
+		if err != nil {
+			if _, ok := err.(AccountMissingError); ok {
+				WriteError(w, 3 /*Invalid Request*/)
+			} else {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+			}
+			sqltx.Rollback()
+			return
+		}
+
+		err = sqltx.Commit()
+		if err != nil {
+			sqltx.Rollback()
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+
+		err = transaction.Write(w)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	} else if r.Method == "GET" {
+		transactionid, err := GetURLID(r.URL.Path)
+
+		if err != nil {
+			//Return all Transactions
+			var al TransactionList
+			transactions, err := GetTransactions(db, user.UserId)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+			al.Transactions = transactions
+			err = (&al).Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else {
+			//Return Transaction with this Id
+			transaction, err := GetTransaction(db, transactionid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+			err = transaction.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		}
+	} else {
+		transactionid, err := GetURLID(r.URL.Path)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		if r.Method == "PUT" {
+			transaction_json := r.PostFormValue("transaction")
+			if transaction_json == "" {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			var transaction Transaction
+			err := transaction.Read(transaction_json)
+			if err != nil || transaction.TransactionId != transactionid {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+			transaction.UserId = user.UserId
+
+			sqltx, err := db.Begin()
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			balanced, err := transaction.Balanced(sqltx)
+			if err != nil {
+				sqltx.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+			if !transaction.Valid() || !balanced {
+				sqltx.Rollback()
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			for i := range transaction.Splits {
+				_, err := GetAccountTx(sqltx, transaction.Splits[i].AccountId, user.UserId)
+				if err != nil {
+					sqltx.Rollback()
+					WriteError(w, 3 /*Invalid Request*/)
+					return
+				}
+			}
+
+			err = UpdateTransactionTx(sqltx, &transaction, user)
+			if err != nil {
+				sqltx.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			err = sqltx.Commit()
+			if err != nil {
+				sqltx.Rollback()
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			err = transaction.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else if r.Method == "DELETE" {
+			transactionid, err := GetURLID(r.URL.Path)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			transaction, err := GetTransaction(db, transactionid, user.UserId)
+			if err != nil {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			err = DeleteTransaction(db, transaction, user)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			WriteSuccess(w)
+		}
+	}
+}
+
+func TransactionsBalanceDifference(transaction *gorp.Transaction, accountid int64, transactions []Transaction) (*big.Rat, error) {
+	var pageDifference, tmp big.Rat
+	for i := range transactions {
+		_, err := transaction.Select(&transactions[i].Splits, "SELECT * FROM splits where TransactionId=?", transactions[i].TransactionId)
+		if err != nil {
+			return nil, err
+		}
+
+		// Sum up the amounts from the splits we're returning so we can return
+		// an ending balance
+		for j := range transactions[i].Splits {
+			if transactions[i].Splits[j].AccountId == accountid {
+				rat_amount, err := GetBigAmount(transactions[i].Splits[j].Amount)
+				if err != nil {
+					return nil, err
+				}
+				tmp.Add(&pageDifference, rat_amount)
+				pageDifference.Set(&tmp)
+			}
+		}
+	}
+	return &pageDifference, nil
+}
+
+func GetAccountBalance(db *DB, user *User, accountid int64) (*big.Rat, error) {
+	var splits []Split
+	transaction, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+
+	sql := "SELECT DISTINCT splits.* FROM splits INNER JOIN transactions ON transactions.TransactionId = splits.TransactionId WHERE splits.AccountId=? AND transactions.UserId=?"
+	_, err = transaction.Select(&splits, sql, accountid, user.UserId)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	var balance, tmp big.Rat
+	for _, s := range splits {
+		rat_amount, err := GetBigAmount(s.Amount)
+		if err != nil {
+			transaction.Rollback()
+			return nil, err
+		}
+		tmp.Add(&balance, rat_amount)
+		balance.Set(&tmp)
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	return &balance, nil
+}
+
+// Assumes accountid is valid and is owned by the current user
+func GetAccountBalanceDate(db *DB, user *User, accountid int64, date *time.Time) (*big.Rat, error) {
+	var splits []Split
+	transaction, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+
+	sql := "SELECT DISTINCT splits.* FROM splits INNER JOIN transactions ON transactions.TransactionId = splits.TransactionId WHERE splits.AccountId=? AND transactions.UserId=? AND transactions.Date < ?"
+	_, err = transaction.Select(&splits, sql, accountid, user.UserId, date)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	var balance, tmp big.Rat
+	for _, s := range splits {
+		rat_amount, err := GetBigAmount(s.Amount)
+		if err != nil {
+			transaction.Rollback()
+			return nil, err
+		}
+		tmp.Add(&balance, rat_amount)
+		balance.Set(&tmp)
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	return &balance, nil
+}
+
+func GetAccountBalanceDateRange(db *DB, user *User, accountid int64, begin, end *time.Time) (*big.Rat, error) {
+	var splits []Split
+	transaction, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+
+	sql := "SELECT DISTINCT splits.* FROM splits INNER JOIN transactions ON transactions.TransactionId = splits.TransactionId WHERE splits.AccountId=? AND transactions.UserId=? AND transactions.Date >= ? AND transactions.Date < ?"
+	_, err = transaction.Select(&splits, sql, accountid, user.UserId, begin, end)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	var balance, tmp big.Rat
+	for _, s := range splits {
+		rat_amount, err := GetBigAmount(s.Amount)
+		if err != nil {
+			transaction.Rollback()
+			return nil, err
+		}
+		tmp.Add(&balance, rat_amount)
+		balance.Set(&tmp)
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	return &balance, nil
+}
+
+func GetAccountTransactions(db *DB, user *User, accountid int64, sort string, page uint64, limit uint64) (*AccountTransactionsList, error) {
+	var transactions []Transaction
+	var atl AccountTransactionsList
+
+	transaction, err := db.Begin()
+	if err != nil {
+		return nil, err
+	}
+
+	var sqlsort, balanceLimitOffset string
+	var balanceLimitOffsetArg uint64
+	if sort == "date-asc" {
+		sqlsort = " ORDER BY transactions.Date ASC"
+		balanceLimitOffset = " LIMIT ?"
+		balanceLimitOffsetArg = page * limit
+	} else if sort == "date-desc" {
+		numSplits, err := transaction.SelectInt("SELECT count(*) FROM splits")
+		if err != nil {
+			transaction.Rollback()
+			return nil, err
+		}
+		sqlsort = " ORDER BY transactions.Date DESC"
+		balanceLimitOffset = fmt.Sprintf(" LIMIT %d OFFSET ?", numSplits)
+		balanceLimitOffsetArg = (page + 1) * limit
+	}
+
+	var sqloffset string
+	if page > 0 {
+		sqloffset = fmt.Sprintf(" OFFSET %d", page*limit)
+	}
+
+	account, err := GetAccountTx(transaction, accountid, user.UserId)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+	atl.Account = account
+
+	sql := "SELECT DISTINCT transactions.* FROM transactions INNER JOIN splits ON transactions.TransactionId = splits.TransactionId WHERE transactions.UserId=? AND splits.AccountId=?" + sqlsort + " LIMIT ?" + sqloffset
+	_, err = transaction.Select(&transactions, sql, user.UserId, accountid, limit)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+	atl.Transactions = &transactions
+
+	pageDifference, err := TransactionsBalanceDifference(transaction, accountid, transactions)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	count, err := transaction.SelectInt("SELECT count(DISTINCT transactions.TransactionId) FROM transactions INNER JOIN splits ON transactions.TransactionId = splits.TransactionId WHERE transactions.UserId=? AND splits.AccountId=?", user.UserId, accountid)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+	atl.TotalTransactions = count
+
+	security, err := GetSecurityTx(transaction, atl.Account.SecurityId, user.UserId)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+	if security == nil {
+		transaction.Rollback()
+		return nil, errors.New("Security not found")
+	}
+
+	// Sum all the splits for all transaction splits for this account that
+	// occurred before the page we're returning
+	var amounts []string
+	sql = "SELECT splits.Amount FROM splits WHERE splits.AccountId=? AND splits.TransactionId IN (SELECT DISTINCT transactions.TransactionId FROM transactions INNER JOIN splits ON transactions.TransactionId = splits.TransactionId WHERE transactions.UserId=? AND splits.AccountId=?" + sqlsort + balanceLimitOffset + ")"
+	_, err = transaction.Select(&amounts, sql, accountid, user.UserId, accountid, balanceLimitOffsetArg)
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	var tmp, balance big.Rat
+	for _, amount := range amounts {
+		rat_amount, err := GetBigAmount(amount)
+		if err != nil {
+			transaction.Rollback()
+			return nil, err
+		}
+		tmp.Add(&balance, rat_amount)
+		balance.Set(&tmp)
+	}
+	atl.BeginningBalance = balance.FloatString(security.Precision)
+	atl.EndingBalance = tmp.Add(&balance, pageDifference).FloatString(security.Precision)
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return nil, err
+	}
+
+	return &atl, nil
+}
+
+// Return only those transactions which have at least one split pertaining to
+// an account
+func AccountTransactionsHandler(db *DB, w http.ResponseWriter, r *http.Request,
+	user *User, accountid int64) {
+
+	var page uint64 = 0
+	var limit uint64 = 50
+	var sort string = "date-desc"
+
+	query, _ := url.ParseQuery(r.URL.RawQuery)
+
+	pagestring := query.Get("page")
+	if pagestring != "" {
+		p, err := strconv.ParseUint(pagestring, 10, 0)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		page = p
+	}
+
+	limitstring := query.Get("limit")
+	if limitstring != "" {
+		l, err := strconv.ParseUint(limitstring, 10, 0)
+		if err != nil || l > 100 {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		limit = l
+	}
+
+	sortstring := query.Get("sort")
+	if sortstring != "" {
+		if sortstring != "date-asc" && sortstring != "date-desc" {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		sort = sortstring
+	}
+
+	accountTransactions, err := GetAccountTransactions(db, user, accountid, sort, page, limit)
+	if err != nil {
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+
+	err = accountTransactions.Write(w)
+	if err != nil {
+		WriteError(w, 999 /*Internal Error*/)
+		log.Print(err)
+		return
+	}
+}

internal/handlers/users.go

@@ -0,0 +1,291 @@
+package handlers
+
+import (
+	"crypto/sha256"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"gopkg.in/gorp.v1"
+	"io"
+	"log"
+	"net/http"
+	"strings"
+)
+
+type User struct {
+	UserId          int64
+	DefaultCurrency int64 // SecurityId of default currency, or ISO4217 code for it if creating new user
+	Name            string
+	Username        string
+	Password        string `db:"-"`
+	PasswordHash    string `json:"-"`
+	Email           string
+}
+
+const BogusPassword = "password"
+
+type UserExistsError struct{}
+
+func (ueu UserExistsError) Error() string {
+	return "User exists"
+}
+
+func (u *User) Write(w http.ResponseWriter) error {
+	enc := json.NewEncoder(w)
+	return enc.Encode(u)
+}
+
+func (u *User) Read(json_str string) error {
+	dec := json.NewDecoder(strings.NewReader(json_str))
+	return dec.Decode(u)
+}
+
+func (u *User) HashPassword() {
+	password_hasher := sha256.New()
+	io.WriteString(password_hasher, u.Password)
+	u.PasswordHash = fmt.Sprintf("%x", password_hasher.Sum(nil))
+	u.Password = ""
+}
+
+func GetUser(db *DB, userid int64) (*User, error) {
+	var u User
+
+	err := db.SelectOne(&u, "SELECT * from users where UserId=?", userid)
+	if err != nil {
+		return nil, err
+	}
+	return &u, nil
+}
+
+func GetUserTx(transaction *gorp.Transaction, userid int64) (*User, error) {
+	var u User
+
+	err := transaction.SelectOne(&u, "SELECT * from users where UserId=?", userid)
+	if err != nil {
+		return nil, err
+	}
+	return &u, nil
+}
+
+func GetUserByUsername(db *DB, username string) (*User, error) {
+	var u User
+
+	err := db.SelectOne(&u, "SELECT * from users where Username=?", username)
+	if err != nil {
+		return nil, err
+	}
+	return &u, nil
+}
+
+func InsertUser(db *DB, u *User) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	security_template := FindCurrencyTemplate(u.DefaultCurrency)
+	if security_template == nil {
+		transaction.Rollback()
+		return errors.New("Invalid ISO4217 Default Currency")
+	}
+
+	existing, err := transaction.SelectInt("SELECT count(*) from users where Username=?", u.Username)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+	if existing > 0 {
+		transaction.Rollback()
+		return UserExistsError{}
+	}
+
+	err = transaction.Insert(u)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	// Copy the security template and give it our new UserId
+	var security Security
+	security = *security_template
+	security.UserId = u.UserId
+
+	err = InsertSecurityTx(transaction, &security)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	// Update the user's DefaultCurrency to our new SecurityId
+	u.DefaultCurrency = security.SecurityId
+	count, err := transaction.Update(u)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	} else if count != 1 {
+		transaction.Rollback()
+		return errors.New("Would have updated more than one user")
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func GetUserFromSession(db *DB, r *http.Request) (*User, error) {
+	s, err := GetSession(db, r)
+	if err != nil {
+		return nil, err
+	}
+	return GetUser(db, s.UserId)
+}
+
+func UpdateUser(db *DB, u *User) error {
+	transaction, err := db.Begin()
+	if err != nil {
+		return err
+	}
+
+	security, err := GetSecurityTx(transaction, u.DefaultCurrency, u.UserId)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	} else if security.UserId != u.UserId || security.SecurityId != u.DefaultCurrency {
+		transaction.Rollback()
+		return errors.New("UserId and DefaultCurrency don't match the fetched security")
+	} else if security.Type != Currency {
+		transaction.Rollback()
+		return errors.New("New DefaultCurrency security is not a currency")
+	}
+
+	count, err := transaction.Update(u)
+	if err != nil {
+		transaction.Rollback()
+		return err
+	} else if count != 1 {
+		transaction.Rollback()
+		return errors.New("Would have updated more than one user")
+	}
+
+	err = transaction.Commit()
+	if err != nil {
+		transaction.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func UserHandler(w http.ResponseWriter, r *http.Request, db *DB) {
+	if r.Method == "POST" {
+		user_json := r.PostFormValue("user")
+		if user_json == "" {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		var user User
+		err := user.Read(user_json)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+		user.UserId = -1
+		user.HashPassword()
+
+		err = InsertUser(db, &user)
+		if err != nil {
+			if _, ok := err.(UserExistsError); ok {
+				WriteError(w, 4 /*User Exists*/)
+			} else {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+			}
+			return
+		}
+
+		w.WriteHeader(201 /*Created*/)
+		err = user.Write(w)
+		if err != nil {
+			WriteError(w, 999 /*Internal Error*/)
+			log.Print(err)
+			return
+		}
+	} else {
+		user, err := GetUserFromSession(db, r)
+		if err != nil {
+			WriteError(w, 1 /*Not Signed In*/)
+			return
+		}
+
+		userid, err := GetURLID(r.URL.Path)
+		if err != nil {
+			WriteError(w, 3 /*Invalid Request*/)
+			return
+		}
+
+		if userid != user.UserId {
+			WriteError(w, 2 /*Unauthorized Access*/)
+			return
+		}
+
+		if r.Method == "GET" {
+			err = user.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else if r.Method == "PUT" {
+			user_json := r.PostFormValue("user")
+			if user_json == "" {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			// Save old PWHash in case the new password is bogus
+			old_pwhash := user.PasswordHash
+
+			err = user.Read(user_json)
+			if err != nil || user.UserId != userid {
+				WriteError(w, 3 /*Invalid Request*/)
+				return
+			}
+
+			// If the user didn't create a new password, keep their old one
+			if user.Password != BogusPassword {
+				user.HashPassword()
+			} else {
+				user.Password = ""
+				user.PasswordHash = old_pwhash
+			}
+
+			err = UpdateUser(db, user)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			err = user.Write(w)
+			if err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+		} else if r.Method == "DELETE" {
+			count, err := db.Delete(&user)
+			if count != 1 || err != nil {
+				WriteError(w, 999 /*Internal Error*/)
+				log.Print(err)
+				return
+			}
+
+			WriteSuccess(w)
+		}
+	}
+}

internal/handlers/util.go

@@ -0,0 +1,23 @@
+package handlers
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+func GetURLID(url string) (int64, error) {
+	pieces := strings.Split(strings.Trim(url, "/"), "/")
+	return strconv.ParseInt(pieces[len(pieces)-1], 10, 0)
+}
+
+func GetURLPieces(url string, format string, a ...interface{}) (int, error) {
+	url = strings.Replace(url, "/", " ", -1)
+	format = strings.Replace(format, "/", " ", -1)
+	return fmt.Sscanf(url, format, a...)
+}
+
+func WriteSuccess(w http.ResponseWriter) {
+	fmt.Fprint(w, "{}")
+}