Simplify tmd parsing

tmd.go

@@ -0,0 +1,50 @@
+package wiiudownloader
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+)
+
+type TMD struct {
+	TitleVersion uint16
+	ContentCount uint16
+	Contents     []Content
+}
+
+func parseTMD(data []byte) (*TMD, error) {
+	tmd := &TMD{}
+	reader := bytes.NewReader(data)
+
+	reader.Seek(476, io.SeekStart)
+
+	if err := binary.Read(reader, binary.BigEndian, &tmd.TitleVersion); err != nil {
+		return nil, err
+	}
+
+	if err := binary.Read(reader, binary.BigEndian, &tmd.ContentCount); err != nil {
+		return nil, err
+	}
+
+	tmd.Contents = make([]Content, tmd.ContentCount)
+
+	for i := 0; i < int(tmd.ContentCount); i++ {
+		offset := 0xB04 + (0x30 * i)
+
+		reader.Seek(int64(offset), io.SeekStart)
+		if err := binary.Read(reader, binary.BigEndian, &tmd.Contents[i].ID); err != nil {
+			return nil, err
+		}
+
+		reader.Seek(2, io.SeekCurrent)
+
+		if err := binary.Read(reader, binary.BigEndian, &tmd.Contents[i].Type); err != nil {
+			return nil, err
+		}
+
+		if err := binary.Read(reader, binary.BigEndian, &tmd.Contents[i].Size); err != nil {
+			return nil, err
+		}
+	}
+	return tmd, nil
+}