paginate large playlists

lib/sc/init.go

@@ -468,36 +468,21 @@ func (p Playlist) FormatDescription() string {
 	return desc
 }
 
-type missingtrack struct {
+type MissingTrack struct {
 	ID    int64
 	Index int
 }
 
-func (p *Playlist) GetMissingTracks() error {
+func GetTracks(ids string) ([]Track, error) {
 	cid, err := GetClientID()
 	if err != nil {
-		return err
-	}
-
-	missing := []missingtrack{}
-	for i, track := range p.Tracks {
-		if track.Title == "" {
-			missing = append(missing, missingtrack{ID: track.ID, Index: i})
-		}
-	}
-
-	var st string
-	for i, track := range missing {
-		st += strconv.FormatInt(track.ID, 10)
-		if i != len(missing)-1 {
-			st += ","
-		}
+		return nil, err
 	}
 
 	req := fasthttp.AcquireRequest()
 	defer fasthttp.ReleaseRequest(req)
 
-	req.SetRequestURI("https://api-v2.soundcloud.com/tracks?ids=" + st + "&client_id=" + cid)
+	req.SetRequestURI("https://api-v2.soundcloud.com/tracks?ids=" + ids + "&client_id=" + cid)
 	req.Header.Set("User-Agent", cfg.UserAgent)
 	req.Header.Set("Accept-Encoding", "gzip, deflate, br, zstd")
 
@@ -506,7 +491,7 @@ func (p *Playlist) GetMissingTracks() error {
 
 	err = DoWithRetry(req, resp)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	data, err := resp.BodyUncompressed()
@@ -516,6 +501,49 @@ func (p *Playlist) GetMissingTracks() error {
 
 	var res []Track
 	err = cfg.JSON.Unmarshal(data, &res)
+	return res, err
+}
+
+func JoinMissingTracks(missing []MissingTrack) (st string) {
+	for i, track := range missing {
+		st += strconv.FormatInt(track.ID, 10)
+		if i != len(missing)-1 {
+			st += ","
+		}
+	}
+	return
+}
+
+func GetMissingTracks(missing []MissingTrack) (res []Track, next []MissingTrack, err error) {
+	if len(missing) > 50 {
+		next = missing[50:]
+		missing = missing[:50]
+	}
+
+	res, err = GetTracks(JoinMissingTracks(missing))
+	return
+}
+
+func GetNextMissingTracks(raw string) (res []Track, next []string, err error) {
+	missing := strings.Split(raw, ",")
+	if len(missing) > 50 {
+		next = missing[50:]
+		missing = missing[:50]
+	}
+
+	res, err = GetTracks(strings.Join(missing, ","))
+	return
+}
+
+func (p *Playlist) GetMissingTracks() error {
+	missing := []MissingTrack{}
+	for i, track := range p.Tracks {
+		if track.Title == "" {
+			missing = append(missing, MissingTrack{ID: track.ID, Index: i})
+		}
+	}
+
+	res, next, err := GetMissingTracks(missing)
 	if err != nil {
 		return err
 	}
@@ -528,5 +556,7 @@ func (p *Playlist) GetMissingTracks() error {
 		}
 	}
 
+	p.MissingTracks = JoinMissingTracks(next)
+
 	return nil
 }

lib/sc/structs.go

@@ -98,4 +98,6 @@ type Playlist struct {
 	Album   bool    `json:"is_album"`
 	Author  User    `json:"user"`
 	Tracks  []Track `json:"tracks"`
+
+	MissingTracks string `json:"-"`
 }

main.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"net/url"
+	"strings"
 
 	"github.com/gofiber/fiber/v2"
 	"github.com/gofiber/fiber/v2/middleware/compress"
@@ -112,6 +113,18 @@ func main() {
 			return err
 		}
 
+		p := c.Query("pagination")
+		if p != "" {
+			tracks, next, err := sc.GetNextMissingTracks(p)
+			if err != nil {
+				fmt.Printf("error getting %s playlist tracks from %s: %s\n", c.Params("playlist"), c.Params("user"), err)
+				return err
+			}
+
+			playlist.Tracks = tracks
+			playlist.MissingTracks = strings.Join(next, ",")
+		}
+
 		c.Set("Content-Type", "text/html")
 		return templates.Base(playlist.Title+" by "+playlist.Author.Username, templates.Playlist(playlist), templates.PlaylistEmbed(playlist)).Render(context.Background(), c)
 	})

templates/playlist.templ

@@ -4,6 +4,7 @@ import (
     "github.com/maid-zone/soundcloak/lib/sc"
     "strings"
     "strconv"
+	"net/url"
 )
 
 templ PlaylistEmbed(p sc.Playlist) {
@@ -29,6 +30,9 @@ templ Playlist(p sc.Playlist) {
             }
         }
     </div>
+    if len(p.MissingTracks) != 0 {
+        <a href={templ.URL("?pagination="+url.QueryEscape(p.MissingTracks))} rel="noreferrer">more tracks</a>
+    }
 
     <div>
         if p.TagList != "" {

templates/searchPlaylists.templ

@@ -14,5 +14,5 @@ templ SearchPlaylists(p *sc.Paginated[sc.Playlist]) {
         <h1><a href={ templ.URL("/" + playlist.Author.Permalink + "/sets/" + playlist.Permalink) }>{ playlist.Title }</a></h1>
     }
 
-    <a href={ templ.URL("?type=playlists&pagination=" + url.QueryEscape(strings.Split(p.Next, "/playlists")[1])) }>more playlists</a>
+    <a href={ templ.URL("?type=playlists&pagination=" + url.QueryEscape(strings.Split(p.Next, "/playlists")[1])) } rel="noreferrer">more playlists</a>
 }

templates/searchTracks.templ

@@ -13,5 +13,5 @@ templ SearchTracks(p *sc.Paginated[sc.Track]) {
         <h1><a href={ templ.URL("/" + track.Author.Permalink + "/" + track.Permalink) }>{ track.Title }</a></h1>
     }
 
-    <a href={ templ.URL("?type=tracks&pagination=" + url.QueryEscape(strings.Split(p.Next, "/tracks")[1])) }>more tracks</a>
+    <a href={ templ.URL("?type=tracks&pagination=" + url.QueryEscape(strings.Split(p.Next, "/tracks")[1])) } rel="noreferrer">more tracks</a>
 }

templates/searchUsers.templ

@@ -13,5 +13,5 @@ templ SearchUsers(p *sc.Paginated[sc.User]) {
 		<h1><a href={ templ.URL("/" + user.Permalink) }>{ user.Username }</a></h1>
 	}
 
-    <a href={ templ.URL("?type=users&pagination=" + url.QueryEscape(strings.Split(p.Next, "/users")[1])) }>more users</a>
+    <a href={ templ.URL("?type=users&pagination=" + url.QueryEscape(strings.Split(p.Next, "/users")[1])) } rel="noreferrer">more users</a>
 }

templates/user.templ

@@ -45,7 +45,7 @@ templ User(u sc.User, p *sc.Paginated[sc.Track]) {
 				</div>
 			}
 		</div>
-		<a href={ templ.URL("?pagination=" + url.QueryEscape(strings.Split(p.Next, "/tracks")[1])) }>more tracks</a>
+		<a href={ templ.URL("?pagination=" + url.QueryEscape(strings.Split(p.Next, "/tracks")[1])) } rel="noreferrer">more tracks</a>
 	} else {
 		<h1>no more tracks</h1>
 	}