Add simple investment requests/responses

This is lacking (at least) parsing the list of securities frequently
sent with investment statements

investments.go

@@ -0,0 +1,111 @@
+package ofxgo
+
+import (
+	"errors"
+	"github.com/golang/go/src/encoding/xml"
+)
+
+type InvStatementRequest struct {
+	XMLName   xml.Name `xml:"INVSTMTTRNRQ"`
+	TrnUID    UID      `xml:"TRNUID"`
+	CltCookie String   `xml:"CLTCOOKIE,omitempty"`
+	TAN       String   `xml:"TAN,omitempty"` // Transaction authorization number
+	// TODO `xml:"OFXEXTENSION,omitempty"`
+	InvAcctFrom      InvAcct `xml:"INVSTMTRQ>INVACCTFROM"`
+	DtStart          Date    `xml:"INVSTMTRQ>INCTRAN>DTSTART,omitempty"`
+	DtEnd            Date    `xml:"INVSTMTRQ>INCTRAN>DTEND,omitempty"`
+	Include          Boolean `xml:"INVSTMTRQ>INCTRAN>INCLUDE"`         // Include transactions (instead of just balance)
+	IncludeOO        Boolean `xml:"INVSTMTRQ>INCOO"`                   // Include open orders
+	PosDtAsOf        Date    `xml:"INVSTMTRQ>INCPOS>DTASOF,omitempty"` // Date that positions should be sent down for, if present
+	IncludePos       Boolean `xml:"INVSTMTRQ>INCPOS>INCLUDE"`          // Include position data in response
+	IncludeBalance   Boolean `xml:"INVSTMTRQ>INCBAL"`                  // Include investment balance in response
+	Include401K      Boolean `xml:"INVSTMTRQ>INC401K,omitempty"`       // Include 401k information
+	Include401KBal   Boolean `xml:"INVSTMTRQ>INC401KBAL,omitempty"`    // Include 401k balance information
+	IncludeTranImage Boolean `xml:"INVSTMTRQ>INCTRANIMAGE,omitempty"`  // Include transaction images
+}
+
+func (r *InvStatementRequest) Name() string {
+	return "INVSTMTTRNRQ"
+}
+
+func (r *InvStatementRequest) Valid() (bool, error) {
+	if ok, err := r.TrnUID.Valid(); !ok {
+		return false, err
+	}
+	return true, nil
+}
+
+type InvBankTransaction struct {
+	XMLName      xml.Name      `xml:"INVBANKTRAN"`
+	Transactions []Transaction `xml:"STMTTRN,omitempty"`
+	SubAcctFund  String        `xml:"SUBACCTFUND"` // Where did the money for the transaction come from or go to? CASH, MARGIN, SHORT, OTHER
+}
+
+type InvTransactionList struct {
+	XMLName      xml.Name             `xml:"INVTRANLIST"`
+	DtStart      Date                 `xml:"DTSTART"`
+	DtEnd        Date                 `xml:"DTEND"`
+	Transactions []InvBankTransaction `xml:"INVBANKTRAN,omitempty"`
+}
+
+type InvBalance struct {
+	XMLName       xml.Name  `xml:"INVBAL"`
+	AvailCash     Amount    `xml:"AVAILCASH"`     // Available cash across all sub-accounts, including sweep funds
+	MarginBalance Amount    `xml:"MARGINBALANCE"` // Negative means customer has borrowed funds
+	ShortBalance  Amount    `xml:"SHORTBALANCE"`  // Always positive, market value of all short positions
+	BuyPower      Amount    `xml:"BUYPOWER"`
+	BalList       []Balance `xml:"BALLIST>BAL,omitempty"`
+}
+
+type InvStatementResponse struct {
+	XMLName   xml.Name `xml:"INVSTMTTRNRS"`
+	TrnUID    UID      `xml:"TRNUID"`
+	Status    Status   `xml:"STATUS"`
+	CltCookie String   `xml:"CLTCOOKIE,omitempty"`
+	// TODO OFXEXTENSION
+	DtAsOf      Date               `xml:"INVSTMTRS>DTASOF"`
+	CurDef      String             `xml:"INVSTMTRS>CURDEF"`
+	InvAcctFrom InvAcct            `xml:"INVSTMTRS>INVACCTFROM"`
+	InvTranList InvTransactionList `xml:"INVSTMTRS>INVTRANLIST,omitempty"`
+	// TODO INVPOSLIST
+	InvBal InvBalance `xml:"INVSTMTRS>INVBAL,omitempty"`
+	// TODO INVOOLIST
+	MktgInfo String `xml:"INVSTMTRS>MKTGINFO,omitempty"` // Marketing information
+	// TODO INV401K
+	// TODO INV401KBAL
+}
+
+func (sr InvStatementResponse) Name() string {
+	return "INVSTMTTRNRS"
+}
+
+func (sr InvStatementResponse) Valid() (bool, error) {
+	//TODO implement
+	return true, nil
+}
+
+func DecodeInvestmentsMessageSet(d *xml.Decoder, start xml.StartElement) ([]Message, error) {
+	var msgs []Message
+	for {
+		tok, err := nextNonWhitespaceToken(d)
+		if err != nil {
+			return nil, err
+		} else if end, ok := tok.(xml.EndElement); ok && end.Name.Local == start.Name.Local {
+			// If we found the end of our starting element, we're done parsing
+			return msgs, nil
+		} else if startElement, ok := tok.(xml.StartElement); ok {
+			switch startElement.Name.Local {
+			case "INVSTMTTRNRS":
+				var info InvStatementResponse
+				if err := d.DecodeElement(&info, &startElement); err != nil {
+					return nil, err
+				}
+				msgs = append(msgs, Message(info))
+			default:
+				return nil, errors.New("Unsupported investments response tag: " + startElement.Name.Local)
+			}
+		} else {
+			return nil, errors.New("Didn't find an opening element")
+		}
+	}
+}