import transaction from GnuCash database

pkg/converters/gnucash/gnucash_data_reader.go

@@ -0,0 +1,55 @@
+package gnucash
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/xml"
+
+	"github.com/mayswind/ezbookkeeping/pkg/core"
+	"github.com/mayswind/ezbookkeeping/pkg/errs"
+	"github.com/mayswind/ezbookkeeping/pkg/utils"
+)
+
+// gnucashDatabaseReader defines the structure of gnucash database reader
+type gnucashDatabaseReader struct {
+	xmlDecoder *xml.Decoder
+}
+
+// read returns the imported gnucash data
+func (r *gnucashDatabaseReader) read(ctx core.Context) (*gnucashDatabase, error) {
+	database := &gnucashDatabase{}
+
+	err := r.xmlDecoder.Decode(&database)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return database, nil
+}
+
+func createNewGnuCashDatabaseReader(data []byte) (*gnucashDatabaseReader, error) {
+	if len(data) > 2 && data[0] == 0x1F && data[1] == 0x8B { // gzip magic number
+		gzipReader, err := gzip.NewReader(bytes.NewReader(data))
+
+		if err != nil {
+			return nil, err
+		}
+
+		xmlDecoder := xml.NewDecoder(gzipReader)
+		xmlDecoder.CharsetReader = utils.IdentReader
+
+		return &gnucashDatabaseReader{
+			xmlDecoder: xmlDecoder,
+		}, nil
+	} else if len(data) > 5 && data[0] == 0x3C && data[1] == 0x3F && data[2] == 0x78 && data[3] == 0x6D && data[4] == 0x6C { // <?xml
+		xmlDecoder := xml.NewDecoder(bytes.NewReader(data))
+		xmlDecoder.CharsetReader = utils.IdentReader
+
+		return &gnucashDatabaseReader{
+			xmlDecoder: xmlDecoder,
+		}, nil
+	}
+
+	return nil, errs.ErrInvalidGnuCashFile
+}