add support for returning playlist urls

Author: topi314

common/src/main/java/dev/lavalink/youtube/YoutubeAudioPlaylist.java

@@ -0,0 +1,24 @@
+package dev.lavalink.youtube;
+
+import com.sedmelluq.discord.lavaplayer.track.AudioTrack;
+import com.sedmelluq.discord.lavaplayer.track.BasicAudioPlaylist;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+
+public class YoutubeAudioPlaylist extends BasicAudioPlaylist {
+
+    @Nullable
+    protected final String url;
+
+    public YoutubeAudioPlaylist(String name, List<AudioTrack> tracks, AudioTrack selectedTrack, boolean isSearchResult, @Nullable String url) {
+        super(name, tracks, selectedTrack, isSearchResult);
+        this.url = url;
+    }
+
+    @Nullable
+    public String getUrl() {
+        return url;
+    }
+
+}

common/src/main/java/dev/lavalink/youtube/clients/skeleton/NonMusicClient.java

@@ -7,6 +7,7 @@
 import com.sedmelluq.discord.lavaplayer.track.*;
 import dev.lavalink.youtube.CannotBeLoaded;
 import dev.lavalink.youtube.OptionDisabledException;
+import dev.lavalink.youtube.YoutubeAudioPlaylist;
 import dev.lavalink.youtube.YoutubeAudioSourceManager;
 import dev.lavalink.youtube.cipher.SignatureCipher;
 import dev.lavalink.youtube.cipher.SignatureCipherManager;
@@ -429,6 +430,12 @@ public AudioItem loadMix(@NotNull YoutubeAudioSourceManager source,
         JsonBrowser titleElement = playlist.get("title");
         String title = titleElement.isNull() ? "YouTube mix" : titleElement.text();
 
+        String playlistUrl = "https://www.youtube.com/watch?";
+        if (selectedVideoId != null) {
+            playlistUrl += "v=" + selectedVideoId + "&";
+        }
+        playlistUrl += "list=" + mixId;
+
         List<AudioTrack> tracks = playlist.get("contents").values().stream()
             .map(item -> extractAudioTrack(item.get("playlistPanelVideoRenderer"), source))
             .filter(Objects::nonNull)
@@ -440,7 +447,7 @@ public AudioItem loadMix(@NotNull YoutubeAudioSourceManager source,
             throw new FriendlyException("Could not find tracks from mix.", SUSPICIOUS, null);
         }
 
-        return new BasicAudioPlaylist(title, tracks, findSelectedTrack(tracks, selectedVideoId), false);
+        return new YoutubeAudioPlaylist(title, tracks, findSelectedTrack(tracks, selectedVideoId), false, playlistUrl);
     }
 
     @Override
@@ -466,6 +473,13 @@ public AudioItem loadPlaylist(@NotNull YoutubeAudioSourceManager source,
                 new RuntimeException("Playlist name was not found, JSON: " + json.format()));
         }
 
+        String playlistUrl;
+        if (selectedVideoId == null) {
+            playlistUrl = "https://www.youtube.com/playlist?list=" + playlistId;
+        } else {
+            playlistUrl = "https://www.youtube.com/watch?v=" + selectedVideoId + "&list=" + playlistId;
+        }
+
         JsonBrowser playlistVideoList = extractPlaylistVideoList(json);
 
         List<AudioTrack> tracks = new ArrayList<>();
@@ -498,7 +512,7 @@ public AudioItem loadPlaylist(@NotNull YoutubeAudioSourceManager source,
             throw new FriendlyException("Could not find tracks from playlist.", SUSPICIOUS, new RuntimeException("JSON: " + json.format()));
         }
 
-        return new BasicAudioPlaylist(playlistName, tracks, findSelectedTrack(tracks, selectedVideoId), false);
+        return new YoutubeAudioPlaylist(playlistName, tracks, findSelectedTrack(tracks, selectedVideoId), false, playlistUrl);
     }
 
     @Override

plugin/src/main/java/dev/lavalink/youtube/plugin/YoutubeAudioPluginInfoModifier.java

@@ -0,0 +1,26 @@
+package dev.lavalink.youtube.plugin;
+
+import com.sedmelluq.discord.lavaplayer.track.AudioPlaylist;
+import dev.arbjerg.lavalink.api.AudioPluginInfoModifier;
+import dev.lavalink.youtube.YoutubeAudioPlaylist;
+import kotlinx.serialization.json.JsonElementKt;
+import kotlinx.serialization.json.JsonObject;
+import org.jetbrains.annotations.NotNull;
+import org.springframework.stereotype.Component;
+
+import java.util.Map;
+
+@Component
+public class YoutubeAudioPluginInfoModifier implements AudioPluginInfoModifier {
+
+  @Override
+  public JsonObject modifyAudioPlaylistPluginInfo(@NotNull AudioPlaylist playlist) {
+    if (playlist instanceof YoutubeAudioPlaylist extendedPlaylist) {
+      return new JsonObject(Map.of(
+        "url", JsonElementKt.JsonPrimitive(extendedPlaylist.getUrl())
+      ));
+    }
+    return null;
+  }
+
+}