feat: read the songs in QQ Music playlists

internal/adapter/out/qq/playlist.go

@@ -0,0 +1,60 @@
+package qq
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/url"
+
+	"github.com/dihemoe/alisten/internal/app/port"
+)
+
+const playlistDetailAPI = "https://i.y.qq.com/qzone-music/fcg-bin/fcg_ucc_getcdinfo_byids_cp.fcg"
+
+type playlistDetailResponse struct {
+	Code   int `json:"code"`
+	Cdlist []struct {
+		Songlist []struct {
+			SongMID   string   `json:"songmid"`
+			SongName  string   `json:"songname"`
+			AlbumName string   `json:"albumname"`
+			AlbumMID  string   `json:"albummid"`
+			Interval  int64    `json:"interval"`
+			Singer    []singer `json:"singer"`
+		} `json:"songlist"`
+	} `json:"cdlist"`
+}
+
+func (r playlistDetailResponse) check() error {
+	if r.Code != 0 {
+		return fmt.Errorf("QQ 音乐返回错误码 %d", r.Code)
+	}
+	return nil
+}
+
+func (c *Client) PlaylistTracks(ctx context.Context, playlistID string) ([]port.Song, error) {
+	return cached(c, "playlist_tracks "+playlistID, func() ([]port.Song, error) {
+		var resp playlistDetailResponse
+		query := url.Values{
+			"type": {"1"}, "json": {"1"}, "utf8": {"1"}, "onlysong": {"0"}, "disstid": {playlistID},
+			"format": {"json"}, "g_tk": {"5381"}, "loginUin": {"0"}, "hostUin": {"0"},
+			"inCharset": {"utf8"}, "outCharset": {"utf-8"}, "notice": {"0"}, "platform": {"yqq"}, "needNewCode": {"0"},
+		}
+		if err := c.get(ctx, "qq", "playlist_tracks", playlistDetailAPI, query, desktopHeader, &resp); err != nil {
+			return nil, err
+		}
+		if len(resp.Cdlist) == 0 {
+			return nil, errors.New("QQ 音乐的歌单不存在或不可见")
+		}
+		// 这个接口一次返回全部曲目，实测 1137 首的歌单也完整，不需要翻页。
+		songs := make([]port.Song, 0, len(resp.Cdlist[0].Songlist))
+		for _, s := range resp.Cdlist[0].Songlist {
+			// 没有 songmid 的条目是下架等不可用的歌，丢弃但保持其余歌曲的原顺序。
+			if s.SongMID == "" {
+				continue
+			}
+			songs = append(songs, song(s.SongMID, s.SongName, s.Singer, s.AlbumName, s.AlbumMID, s.Interval))
+		}
+		return songs, nil
+	})
+}

internal/adapter/out/qq/playlist_test.go

@@ -0,0 +1,69 @@
+package qq
+
+import (
+	"net/http"
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/dihemoe/alisten/internal/app/port"
+	"github.com/dihemoe/alisten/internal/domain/track"
+)
+
+func TestPlaylistTracks(t *testing.T) {
+	c, obs := serve(t, map[string]http.HandlerFunc{
+		"/qzone-music/fcg-bin/fcg_ucc_getcdinfo_byids_cp.fcg": func(w http.ResponseWriter, r *http.Request) {
+			if got := r.URL.Query().Get("disstid"); got != "7382629476" {
+				t.Errorf("歌单 ID = %q，期望与搜索返回的 dissid 一致", got)
+			}
+			fixture(t, "playlist-tracks.json")(w, r)
+		},
+	})
+	want := []port.Song{
+		{
+			Track: track.Track{Source: track.QQ, ID: "mid1"},
+			Meta: track.Meta{
+				Title: "第一首", Artist: "歌手甲, 歌手乙", Album: "专辑一",
+				CoverURL: "https://y.gtimg.cn/music/photo_new/T002R300x300M000album1.jpg",
+				PageURL:  "https://y.qq.com/n/ryqq/songDetail/mid1",
+				Duration: 200 * time.Second,
+			},
+		},
+		{
+			Track: track.Track{Source: track.QQ, ID: "mid2"},
+			Meta: track.Meta{
+				Title: "第二首", Artist: "歌手丙", Album: "专辑二",
+				CoverURL: "https://y.gtimg.cn/music/photo_new/T002R300x300M000album2.jpg",
+				PageURL:  "https://y.qq.com/n/ryqq/songDetail/mid2",
+				Duration: 100 * time.Second,
+			},
+		},
+	}
+	// 缓存命中时第二次调用不再发请求。
+	for range 2 {
+		got, err := c.PlaylistTracks(t.Context(), "7382629476")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !reflect.DeepEqual(got, want) {
+			t.Fatalf("歌单内的歌曲 = %#v\n期望 %#v", got, want)
+		}
+	}
+	obs.check(t, "qq playlist_tracks")
+}
+
+func TestPlaylistTracksUnavailable(t *testing.T) {
+	for name, file := range map[string]string{
+		"接口返回错误码":   "playlist-tracks-missing.json",
+		"cdlist 为空": "playlist-tracks-empty.json",
+	} {
+		t.Run(name, func(t *testing.T) {
+			c, _ := serve(t, map[string]http.HandlerFunc{
+				"/qzone-music/fcg-bin/fcg_ucc_getcdinfo_byids_cp.fcg": fixture(t, file),
+			})
+			if _, err := c.PlaylistTracks(t.Context(), "999999999999"); err == nil {
+				t.Error("不存在或不可见的歌单没有返回错误")
+			}
+		})
+	}
+}

internal/adapter/out/qq/testdata/playlist-tracks-empty.json

@@ -0,0 +1 @@
+{"code":0,"subcode":0,"cdnum":0,"cdlist":[]}

internal/adapter/out/qq/testdata/playlist-tracks-missing.json

@@ -0,0 +1 @@
+{"code":10,"subcode":0,"cdnum":0,"cdlist":[]}

internal/adapter/out/qq/testdata/playlist-tracks.json

@@ -0,0 +1 @@
+{"code":0,"subcode":0,"cdnum":1,"cdlist":[{"dissname":"测试歌单","songlist":[{"songmid":"mid1","songname":"第一首","albumname":"专辑一","albummid":"album1","interval":200,"singer":[{"name":"歌手甲"},{"name":"歌手乙"}]},{"songmid":"","songname":"已下架的歌","albumname":"","albummid":"","interval":0,"singer":[]},{"songmid":"mid2","songname":"第二首","albumname":"专辑二","albummid":"album2","interval":100,"singer":[{"name":"歌手丙"}]}]}]}