From a92ea82090ad41c930840ef2423b601a371e7c2b Mon Sep 17 00:00:00 2001
From: Emmm Monster <58943012+emmmx@users.noreply.github.com>
Date: Sat, 26 Dec 2020 02:53:28 +0800
Subject: [PATCH] Update NCM, QMC Decoder

---
 algo/common/common.go |  2 +-
 algo/ncm/ncm.go       | 42 +++++++++++++++++++++---------------------
 algo/qmc/qmc.go       | 15 +++++++--------
 3 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/algo/common/common.go b/algo/common/common.go
index 1b8bea9..c25f2f5 100644
--- a/algo/common/common.go
+++ b/algo/common/common.go
@@ -1,7 +1,7 @@
 package common
 
 type Decoder interface {
-	Validate() bool
+	Validate() error
 	Decode() error
 	GetCoverImage() []byte
 	GetAudioData() []byte
diff --git a/algo/ncm/ncm.go b/algo/ncm/ncm.go
index 2687bc6..07592e0 100644
--- a/algo/ncm/ncm.go
+++ b/algo/ncm/ncm.go
@@ -42,10 +42,10 @@ type Decoder struct {
 
 	metaRaw  []byte
 	metaType string
-	Meta     RawMeta
+	meta     RawMeta
 
-	Cover []byte
-	Audio []byte
+	cover []byte
+	audio []byte
 
 	offsetKey   uint32
 	offsetMeta  uint32
@@ -53,16 +53,16 @@ type Decoder struct {
 	offsetAudio uint32
 }
 
-func (d *Decoder) Validate() bool {
+func (d *Decoder) Validate() error {
 	if !bytes.Equal(magicHeader, d.file[:len(magicHeader)]) {
-		return false
+		return errors.New("ncm magic header not match")
 	}
 
 	/*if status.IsDebug {
 		logging.Log().Info("the unknown field of the header is: \n" + spew.Sdump(d.file[8:10]))
 	}*/
 	d.offsetKey = 8 + 2
-	return true
+	return nil
 }
 
 //todo: 读取前进行检查长度，防止越界
@@ -141,11 +141,11 @@ func (d *Decoder) buildKeyBox() {
 func (d *Decoder) parseMeta() error {
 	switch d.metaType {
 	case "music":
-		d.Meta = new(RawMetaMusic)
-		return json.Unmarshal(d.metaRaw, d.Meta)
+		d.meta = new(RawMetaMusic)
+		return json.Unmarshal(d.metaRaw, d.meta)
 	case "dj":
-		d.Meta = new(RawMetaDJ)
-		return json.Unmarshal(d.metaRaw, d.Meta)
+		d.meta = new(RawMetaDJ)
+		return json.Unmarshal(d.metaRaw, d.meta)
 	default:
 		return errors.New("unknown ncm meta type: " + d.metaType)
 	}
@@ -173,7 +173,7 @@ func (d *Decoder) readCoverData() error {
 	if iCoverLen == 0 {
 		return errors.New("no any cover file found")
 	}
-	d.Cover = d.file[coverLenStart+4 : 4+coverLenStart+iCoverLen]
+	d.cover = d.file[coverLenStart+4 : 4+coverLenStart+iCoverLen]
 	return nil
 }
 
@@ -183,9 +183,9 @@ func (d *Decoder) readAudioData() error {
 	}
 	audioRaw := d.file[d.offsetAudio:]
 	audioLen := len(audioRaw)
-	d.Audio = make([]byte, audioLen)
+	d.audio = make([]byte, audioLen)
 	for i := uint32(0); i < uint32(audioLen); i++ {
-		d.Audio[i] = d.box[i&0xff] ^ audioRaw[i]
+		d.audio[i] = d.box[i&0xff] ^ audioRaw[i]
 	}
 	return nil
 }
@@ -213,23 +213,23 @@ func (d *Decoder) Decode() error {
 }
 
 func (d Decoder) GetAudioExt() string {
-	if d.Meta != nil {
-		return d.Meta.GetFormat()
+	if d.meta != nil {
+		return d.meta.GetFormat()
 	}
 	return ""
 }
 
 func (d Decoder) GetAudioData() []byte {
-	return d.Audio
+	return d.audio
 }
 
 func (d Decoder) GetCoverImage() []byte {
-	if d.Cover != nil {
-		return d.Cover
+	if d.cover != nil {
+		return d.cover
 	}
 	{
-		imgURL := d.Meta.GetAlbumImageURL()
-		if d.Meta != nil && !strings.HasPrefix(imgURL, "http") {
+		imgURL := d.meta.GetAlbumImageURL()
+		if d.meta != nil && !strings.HasPrefix(imgURL, "http") {
 			return nil
 		}
 		resp, err := http.Get(imgURL)
@@ -253,5 +253,5 @@ func (d Decoder) GetCoverImage() []byte {
 }
 
 func (d Decoder) GetMeta() common.Meta {
-	return d.Meta
+	return d.meta
 }
diff --git a/algo/qmc/qmc.go b/algo/qmc/qmc.go
index 45da8a8..a5d88f1 100644
--- a/algo/qmc/qmc.go
+++ b/algo/qmc/qmc.go
@@ -5,8 +5,6 @@ import (
 	"encoding/binary"
 	"errors"
 	"github.com/umlock-music/cli/algo/common"
-	"github.com/umlock-music/cli/internal/logging"
-	"go.uber.org/zap"
 )
 
 var (
@@ -36,18 +34,19 @@ func NewMgg256Decoder(data []byte) *Decoder {
 	return &Decoder{file: data, maskDetector: detectMgg256Mask, audioExt: "ogg"}
 }
 
-func (d *Decoder) Validate() bool {
+func (d *Decoder) Validate() error {
 	if nil != d.mask {
-		return true
+		return nil
 	}
 	if nil != d.maskDetector {
 		if err := d.validateKey(); err != nil {
-			logging.Log().Error("detect file failed", zap.Error(err))
-			return false
+			return err
 		}
-		d.mask, _ = d.maskDetector(d.file)
+		var err error
+		d.mask, err = d.maskDetector(d.file)
+		return err
 	}
-	return d.mask != nil
+	return errors.New("no mask or mask detector found")
 }
 
 func (d *Decoder) validateKey() error {