library

pom.xml

@@ -90,6 +90,15 @@
                                     <include>de.themoep:inventorygui</include>
                                 </includes>
                             </artifactSet>
+                            <filters>
+                                <filter>
+                                    <artifact>*</artifact>
+                                    <excludes>
+                                        <exclude>META-INF/MANIFEST.MF</exclude>
+                                        <exclude>META-INF/maven/**</exclude>
+                                    </excludes>
+                                </filter>
+                            </filters>
                         </configuration>
                     </execution>
                 </executions>

src/main/java/eu/m724/music_plugin/MusicPlugin.java

@@ -8,6 +8,7 @@ import eu.m724.music_plugin.audio.storage.Downloader;
 import eu.m724.music_plugin.item.ItemEvents;
 import eu.m724.music_plugin.item.PmpCommand;
 import eu.m724.music_plugin.item.speaker.BlockChecker;
+import eu.m724.music_plugin.library.LibraryStorage;
 import net.bramp.ffmpeg.FFmpeg;
 import org.bukkit.NamespacedKey;
 import org.bukkit.plugin.java.JavaPlugin;
@@ -23,6 +24,7 @@ public final class MusicPlugin extends JavaPlugin {
     private static AudioFileStorage AUDIO_FILE_STORAGE;
     private static Converter CONVERTER;
     private static Downloader DOWNLOADER;
+    private static LibraryStorage LIBRARY_STORAGE;
 
     @Override
     public void onEnable() {
@@ -41,14 +43,19 @@ public final class MusicPlugin extends JavaPlugin {
         service.registerPlugin(new MyVoicechatPlugin(api -> VOICECHAT_API = api));
 
         var storagePath = getDataFolder().toPath().resolve("storage");
+        var audioStoragePath = storagePath.resolve("audio");
+        var libraryStoragePath = storagePath.resolve("library");
+
         try {
-            Files.createDirectories(storagePath);
+            Files.createDirectories(audioStoragePath);
+            Files.createDirectories(libraryStoragePath);
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
 
-        AUDIO_FILE_STORAGE = new AudioFileStorage(storagePath);
+        AUDIO_FILE_STORAGE = new AudioFileStorage(audioStoragePath);
-        DOWNLOADER = new Downloader(storagePath);
+        DOWNLOADER = new Downloader(audioStoragePath);
+        LIBRARY_STORAGE = new LibraryStorage(libraryStoragePath);
 
         try {
             CONVERTER = new Converter(new FFmpeg());
@@ -91,6 +98,10 @@ public final class MusicPlugin extends JavaPlugin {
         return DOWNLOADER;
     }
 
+    public static LibraryStorage getLibraryStorage() {
+        return LIBRARY_STORAGE;
+    }
+
     public static NamespacedKey getNamespacedKey(String key) {
         return new NamespacedKey(INSTANCE, key);
     }

src/main/java/eu/m724/music_plugin/TestCommand.java

@@ -60,26 +60,21 @@ public class TestCommand implements CommandExecutor {
     }
 
     private void testConvert(Player player, String hash, int bitrate) {
-        try {
+        player.sendMessage("Converting...");
-            player.sendMessage("Converting...");
+        MusicPlugin.getStorage().convert(MusicPlugin.getConverter(), hash, bitrate).handle((f, ex) -> {
-            MusicPlugin.getStorage().convert(MusicPlugin.getConverter(), hash, bitrate).handle((f, ex) -> {
+            if (ex != null) {
-                if (ex != null) {
+                ex.printStackTrace();
-                    ex.printStackTrace();
+                player.sendMessage("Error converting. See console for details.");
-                    player.sendMessage("Error converting. See console for details.");
+            } else {
-                } else {
+                player.spigot().sendMessage(
-                    player.spigot().sendMessage(
+                        new ComponentBuilder("Converted " + hash.substring(0, 7) + "... to " + bitrate + "bps! Click to play")
-                            new ComponentBuilder("Converted " + hash.substring(0, 7) + "... to " + bitrate + "bps! Click to play")
+                                .event(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new Text("Click to play")))
-                                    .event(new HoverEvent(HoverEvent.Action.SHOW_TEXT, new Text("Click to play")))
+                                .event(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/test play " + hash + " " + bitrate))
-                                    .event(new ClickEvent(ClickEvent.Action.RUN_COMMAND, "/test play " + hash + " " + bitrate))
+                                .create()
-                                    .create()
+                );
-                    );
+            }
-                }
+            return null;
-                return null;
+        });
-            });
-        } catch (IOException e) {
-            e.printStackTrace();
-            player.sendMessage("Error");
-        }
     }
 
     private void testPlay(Player player, String hash, int bitrate) {

src/main/java/eu/m724/music_plugin/audio/storage/AudioFileStorage.java

@@ -41,7 +41,10 @@ public class AudioFileStorage {
     }
 
     /**
-     * Get an audio file of given original hash and bitrate
+     * Get an audio file of given original hash and bitrate<br>
+     * <br>
+     * <strong>WARNING</strong> Whether the file exists is not checked.<br>
+     * Do it yourself - simply check if the file exists.
      *
      * @param hash the hex sha256 hash of the original
      * @param bitrate the bitrate in bps like 32000
@@ -77,13 +80,18 @@ public class AudioFileStorage {
      * @param bitrate the target bitrate in bps
      * @return the future with the new file
      */
-    public CompletableFuture<Path> convert(Converter converter, String hash, int bitrate) throws IOException {
+    public CompletableFuture<Path> convert(Converter converter, String hash, int bitrate) {
         var file = get(hash, bitrate);
         if (Files.exists(file)) return CompletableFuture.completedFuture(file);
 
         var og = getOriginal(hash);
         if (!Files.exists(og)) return null;
 
-        return converter.convert(og, file, bitrate).thenApply(v -> file);
+        // TODO maybe do that in Converter?
+        try {
+            return converter.convert(og, file, bitrate);
+        } catch (IOException e) {
+            return CompletableFuture.failedFuture(e);
+        }
     }
 }

src/main/java/eu/m724/music_plugin/audio/storage/Downloader.java

@@ -34,7 +34,7 @@ public class Downloader {
     public CompletableFuture<String> download(URI uri) {
         DebugLogger.fine("About to download from %s", uri);
 
-        // TODO fix this. Yes this is the only way. sendAsync doesn't block for some reason. I don't know why.
+        // TODO sendAsync doesn't block for some reason
         return CompletableFuture.supplyAsync(() -> {
             try (
                     var client = HttpClient.newBuilder().followRedirects(HttpClient.Redirect.ALWAYS).build()

src/main/java/eu/m724/music_plugin/item/ItemEvents.java

@@ -20,7 +20,7 @@ public class ItemEvents implements Listener {
 
         if (event.getItem() == null) return;
 
-        var player = PortableMediaPlayers.get(event.getItem());
+        var player = PortableMediaPlayers.fromItemStack(event.getItem());
         if (player == null) return;
 
         System.out.println("A  player used");
@@ -31,7 +31,7 @@ public class ItemEvents implements Listener {
                 player.next();
             } else {
                 System.out.println("no shift + lmb: rpevous song");
-                player.prev();
+                player.previous();
             }
         } else {
             if (right) {
@@ -65,7 +65,7 @@ public class ItemEvents implements Listener {
 
     @EventHandler
     public void onDrop(PlayerDropItemEvent event) {
-        var player = PortableMediaPlayers.get(event.getItemDrop().getItemStack());
+        var player = PortableMediaPlayers.fromItemStack(event.getItemDrop().getItemStack());
         if (player == null) return;
 
         System.out.println("A playe rdropped");
@@ -75,7 +75,7 @@ public class ItemEvents implements Listener {
 
     @EventHandler
     public void onPickup(EntityPickupItemEvent event) {
-        var player = PortableMediaPlayers.get(event.getItem().getItemStack());
+        var player = PortableMediaPlayers.fromItemStack(event.getItem().getItemStack());
         if (player == null) return;
 
         System.out.println("A player puckuperd");
@@ -86,7 +86,7 @@ public class ItemEvents implements Listener {
     @EventHandler
     public void onMove(InventoryMoveItemEvent event) {
         if (event.getDestination().getType() == InventoryType.PLAYER) {
-            var player = PortableMediaPlayers.get(event.getItem());
+            var player = PortableMediaPlayers.fromItemStack(event.getItem());
             if (player == null) return;
 
             System.out.println("A player storaged :((");

src/main/java/eu/m724/music_plugin/item/PmpCommand.java

@@ -1,20 +1,19 @@
 package eu.m724.music_plugin.item;
 
-import eu.m724.music_plugin.MusicPlugin;
+import eu.m724.music_plugin.library.Track;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 
-import java.io.IOException;
 import java.util.Arrays;
 
 public class PmpCommand implements CommandExecutor {
     @Override
     public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] args) {
         var player = (Player) sender;
-        var pmp = PortableMediaPlayers.get(player.getInventory().getItemInMainHand());
+        var pmp = PortableMediaPlayers.fromItemStack(player.getInventory().getItemInMainHand());
 
         var action = args.length > 0 ? args[0] : null;
 
@@ -22,18 +21,7 @@ public class PmpCommand implements CommandExecutor {
             if (pmp != null) {
                 sender.sendMessage("ID: " + pmp.id);
                 sender.sendMessage("Premium: " + pmp.premium);
-
+                sender.sendMessage("Capacity: " + secondsToHms(pmp.storageSeconds));
-                var capacityStr = "";
-                var h = pmp.storageSeconds % 3600;
-                var m = (pmp.storageSeconds - (h * 3600)) % 60;
-                var s = pmp.storageSeconds - (h * 3600) - (m * 60);
-                if (h > 0) {
-                    capacityStr += h + "h ";
-                }
-                capacityStr += m + "m " + s + "s ";
-
-                sender.sendMessage("Capacity: " + capacityStr);
-
                 sender.sendMessage("Bitrate: %d Kbps".formatted(pmp.audioBitrate / 1000));
             }
         }
@@ -41,23 +29,57 @@ public class PmpCommand implements CommandExecutor {
         if ("create".equals(action)) {
             pmp = PortableMediaPlayer.create(args[1].equals("yes"), String.join(" ", Arrays.asList(args).subList(2, args.length)));
             player.getInventory().addItem(pmp.getItemStack());
-        } else if ("play".equals(action)) {
+        } else if ("add".equals(action)) {
             if (pmp != null) {
-                var storage = MusicPlugin.getStorage();
+                var library = pmp.getLibrary();
+                library.addTrack(new Track(args[1]));
+
+                player.sendMessage("Added track");
+
+                /*var storage = MusicPlugin.getStorage();
                 var path = storage.get(args[1], Integer.parseInt(args[2]));
 
                 try {
                     pmp.play(path.toFile());
                 } catch (IOException e) {
                     throw new RuntimeException(e);
-                }
+                }*/
+            } else {
+                player.sendMessage("You must hold a Portable Music Player");
+            }
+        } else if ("play".equals(action)) {
+            if (pmp != null) {
+                pmp.play();
+                player.sendMessage("Started");
+            } else {
+                player.sendMessage("You must hold a Portable Music Player");
+            }
+        } else if ("skip".equals(action)) {
+            if (pmp != null) {
+                pmp.next();
+                player.sendMessage("Skipped");
             } else {
                 player.sendMessage("You must hold a Portable Music Player");
             }
         } else {
-            player.sendMessage("create | play");
+            player.sendMessage("create | add | play | skip");
         }
 
         return true;
     }
+
+    private String secondsToHms(int seconds) {
+        var sb = new StringBuilder();
+
+        var hours = seconds / 3600;
+        if (hours > 0) {
+            sb.append(hours).append("h ");
+            seconds = seconds % 3600;
+        }
+
+        sb.append(seconds / 60).append("m ");
+        sb.append(seconds % 60).append("s");
+
+        return sb.toString();
+    }
 }

src/main/java/eu/m724/music_plugin/item/PortableMediaPlayer.java

@@ -5,37 +5,28 @@ import eu.m724.music_plugin.MusicPlugin;
 import eu.m724.music_plugin.audio.player.OpusFilePlayer;
 import eu.m724.music_plugin.audio.player.TrackEvent;
 import eu.m724.music_plugin.item.speaker.Speaker;
-import net.md_5.bungee.api.ChatColor;
+import eu.m724.music_plugin.library.Library;
-import org.bukkit.Material;
-import org.bukkit.NamespacedKey;
-import org.bukkit.enchantments.Enchantment;
-import org.bukkit.inventory.ItemFlag;
 import org.bukkit.inventory.ItemStack;
-import org.bukkit.persistence.PersistentDataType;
 
-import java.awt.*;
 import java.io.File;
 import java.io.IOException;
-import java.nio.ByteBuffer;
+import java.util.concurrent.CompletionException;
-import java.nio.charset.StandardCharsets;
-import java.util.List;
 import java.util.concurrent.ThreadLocalRandom;
 
 public class PortableMediaPlayer {
-    static final NamespacedKey idKey = MusicPlugin.getNamespacedKey("player_id");
+    // TODO getters for all that
-    static final NamespacedKey dataKey = MusicPlugin.getNamespacedKey("player_data");
-
     public final int id;
 
-    // TODO configurable
+    // TODO make those two configurable
     public final int storageSeconds;
     public final int audioBitrate;
 
     public final boolean premium;
     public final String engraving;
 
+    private final Library library;
     private OpusFilePlayer player; // TODO rename?
-    private Speaker<?> speaker;
+    private Speaker<?> linkedSpeaker;
 
     PortableMediaPlayer(int id, int storageSeconds, int audioBitrate, boolean premium, String engraving) {
         this.id = id;
@@ -43,55 +34,45 @@ public class PortableMediaPlayer {
         this.audioBitrate = audioBitrate;
         this.premium = premium;
         this.engraving = engraving;
+
+        // TODO there should be a better way. Like load if needed?
+        this.library = MusicPlugin.getLibraryStorage().load(id);
     }
 
     public static PortableMediaPlayer create(boolean premium, String engraving) {
         return new PortableMediaPlayer(ThreadLocalRandom.current().nextInt(), 600, 32000, premium, engraving);
     }
 
-    public void setSpeaker(Speaker<?> speaker) {
+    public void play() {
-        if (speaker.equals(this.speaker))
+        DebugLogger.fine("play() called");
-            return;
+        library.getPlaying().getPath(audioBitrate).thenAccept(p -> {
-
+            DebugLogger.finer("accepted");
-        if (this.speaker != null) {
+            try {
-            // no need to pause if no need to pause
+                play(p.toAbsolutePath().toFile());
-            this.speaker.setDestroyCallback(c -> {});
+            } catch (IOException e) {
-            this.speaker.destroy();
+                e.printStackTrace();
-        }
+                throw new CompletionException(e);
-
+            }
-        speaker.setDestroyCallback(v -> {
-            System.out.println("spekar rip");
-            if (player != null)
-                player.pause();
-            this.speaker = null;
         });
-
-        this.speaker = speaker;
-        if (player != null)
-            player.setChannel(speaker.getChannel().getAudioChannel());
     }
 
-    public void play(File file) throws IOException {
+    private void play(File file) throws IOException {
-        DebugLogger.finer("pmp play");
+        DebugLogger.finer("playing a file: %s", file.toString());
-        if (speaker == null) return;
+        if (linkedSpeaker == null) return;
 
-        //played = new Track(audioFile);
         if (player != null)
             player.stop();
 
-        this.player = new OpusFilePlayer(file, speaker.getChannel().getAudioChannel());
+        this.player = new OpusFilePlayer(file, linkedSpeaker.getChannel().getAudioChannel());
 
         player.setOnTrackEvent(event -> {
             if (event == TrackEvent.START) {
                 DebugLogger.finer("I detected track START");
-                //played.unpause();
             } else if (event == TrackEvent.STOP) {
                 DebugLogger.finer("I detected track STOP");
-                //played.pause();
-                //played.hint(played.file.getEncoder().getFrame());
             } else if (event == TrackEvent.END) {
                 DebugLogger.finer("I detected track END");
-                //next();
+                next();
             }
         });
 
@@ -119,58 +100,46 @@ public class PortableMediaPlayer {
             player.stop();
     }
 
-    // TODO
+    void previous() {
-    void prev() {
+        // TODO seek to beginning
-        DebugLogger.fine("pmp previous (does nothing)");
+        if (library.previous() != null)
+            play();
     }
 
-    // TODO
     void next() {
-        System.out.println("pmp next (does nothing)");
+        if (library.next() != null)
+            play();
     }
 
-    /* Item functions */
+    /* Getters / Setters */
 
-    public ItemStack getItemStack() {
+    public void setSpeaker(Speaker<?> speaker) {
-        var is = new ItemStack(premium ? Material.GOLD_INGOT : Material.IRON_INGOT);
+        if (speaker.equals(this.linkedSpeaker))
-        var meta = is.getItemMeta();
+            return;
 
-        if (premium) {
+        if (this.linkedSpeaker != null) {
-            var hue = (id & 0xFFFFFF) / (float) 0xFFFFFF;
+            // no need to pause if no need to pause
-            var saturation = (id >> 24) & 0xF;
+            this.linkedSpeaker.setDestroyCallback(c -> {});
-            var color = Color.getHSBColor(hue, 0.84f + saturation / 15.0f, 1.0f);
+            this.linkedSpeaker.destroy();
-            meta.setItemName(ChatColor.of(color) + "Portable Music Player");
-
-            if (engraving != null)
-                meta.setLore(List.of(ChatColor.of(color.darker()) + engraving));
-        } else {
-            meta.setItemName("Portable Music Player");
-
-            if (engraving != null)                       // custom colors only in premium
-                meta.setLore(List.of(ChatColor.GRAY + ChatColor.stripColor(engraving)));
         }
 
-        meta.addEnchant(Enchantment.UNBREAKING, 1, false);
+        speaker.setDestroyCallback(v -> {
-        meta.addItemFlags(ItemFlag.HIDE_ENCHANTS);
+            DebugLogger.finer("linked speaker destroyed");
-        meta.getPersistentDataContainer().set(idKey, PersistentDataType.INTEGER, id);
+            if (player != null)
-        meta.getPersistentDataContainer().set(dataKey, PersistentDataType.BYTE_ARRAY, getData());
+                player.pause();
+            this.linkedSpeaker = null;
+        });
 
-        is.setItemMeta(meta);
+        this.linkedSpeaker = speaker;
-
+        if (player != null)
-        return is;
+            player.setChannel(speaker.getChannel().getAudioChannel());
     }
 
-    private byte[] getData() {
+    public ItemStack getItemStack() {
-        var buffer = ByteBuffer.allocate(11 + engraving.length());
+        return PortableMediaPlayers.getItemStack(this);
-        buffer.put((byte) 0); // data format version
+    }
-        buffer.put((byte) (premium ? 1 : 0));
 
-        buffer.putShort((short) storageSeconds); // make int if 18 hours is not enough. or store as minutes
+    public Library getLibrary() {
-        buffer.put((byte) (audioBitrate / 1000));
+        return this.library;
-
-        buffer.put((byte) engraving.length());
-        buffer.put(engraving.getBytes(StandardCharsets.UTF_8));
-
-        return buffer.array();
     }
 }

src/main/java/eu/m724/music_plugin/item/PortableMediaPlayers.java

@@ -1,26 +1,36 @@
 package eu.m724.music_plugin.item;
 
+import eu.m724.music_plugin.MusicPlugin;
+import net.md_5.bungee.api.ChatColor;
+import org.bukkit.Material;
+import org.bukkit.NamespacedKey;
+import org.bukkit.enchantments.Enchantment;
+import org.bukkit.inventory.ItemFlag;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.persistence.PersistentDataType;
 
+import java.awt.*;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
-// This class stores PortableMediaPlayer instances so that there's no hassle of working with a new one every time
 public class PortableMediaPlayers {
-    private static Map<Integer, PortableMediaPlayer> players = new HashMap<>();
+    static final NamespacedKey idKey = MusicPlugin.getNamespacedKey("player_id");
+    static final NamespacedKey dataKey = MusicPlugin.getNamespacedKey("player_data");
 
-    public static PortableMediaPlayer get(Integer id) {
+    private static final Map<Integer, PortableMediaPlayer> players = new HashMap<>();
+
+    public static PortableMediaPlayer fromId(Integer id) {
         return players.get(id);
     }
 
-    public static PortableMediaPlayer get(ItemStack itemStack) {
+    public static PortableMediaPlayer fromItemStack(ItemStack itemStack) {
         var meta = itemStack.getItemMeta();
         if (meta == null) return null;
 
-        var id = meta.getPersistentDataContainer().get(PortableMediaPlayer.idKey, PersistentDataType.INTEGER);
+        var id = meta.getPersistentDataContainer().get(idKey, PersistentDataType.INTEGER);
         if (id == null) return null;
 
         // check cache
@@ -30,7 +40,7 @@ public class PortableMediaPlayers {
 
         // if not cached
 
-        var data = meta.getPersistentDataContainer().get(PortableMediaPlayer.dataKey, PersistentDataType.BYTE_ARRAY);
+        var data = meta.getPersistentDataContainer().get(dataKey, PersistentDataType.BYTE_ARRAY);
         if (data == null) return null;
 
         player = fromData(id, data);
@@ -57,4 +67,47 @@ public class PortableMediaPlayers {
 
         return new PortableMediaPlayer(id, storageSeconds, audioBitrate, premium, engraving);
     }
+
+    private static byte[] getData(PortableMediaPlayer player) {
+        var buffer = ByteBuffer.allocate(11 + player.engraving.length());
+        buffer.put((byte) 0); // data format version
+        buffer.put((byte) (player.premium ? 1 : 0));
+
+        buffer.putShort((short) player.storageSeconds); // make int if 18 hours is not enough. or store as minutes
+        buffer.put((byte) (player.audioBitrate / 1000));
+
+        buffer.put((byte) player.engraving.length());
+        buffer.put(player.engraving.getBytes(StandardCharsets.UTF_8));
+
+        return buffer.array();
+    }
+
+    public static ItemStack getItemStack(PortableMediaPlayer player) {
+        var is = new ItemStack(player.premium ? Material.GOLD_INGOT : Material.IRON_INGOT);
+        var meta = is.getItemMeta();
+
+        if (player.premium) {
+            var hue = (player.id & 0xFFFFFF) / (float) 0xFFFFFF;
+            var saturation = (player.id >> 24) & 0xF;
+            var color = Color.getHSBColor(hue, 0.84f + saturation / 15.0f, 1.0f);
+            meta.setItemName(ChatColor.of(color) + "Portable Music Player");
+
+            if (player.engraving != null)
+                meta.setLore(java.util.List.of(ChatColor.of(color.darker()) + player.engraving));
+        } else {
+            meta.setItemName("Portable Music Player");
+
+            if (player.engraving != null)                       // custom colors only in premium
+                meta.setLore(List.of(ChatColor.GRAY + ChatColor.stripColor(player.engraving)));
+        }
+
+        meta.addEnchant(Enchantment.UNBREAKING, 1, false);
+        meta.addItemFlags(ItemFlag.HIDE_ENCHANTS);
+        meta.getPersistentDataContainer().set(idKey, PersistentDataType.INTEGER, player.id);
+        meta.getPersistentDataContainer().set(dataKey, PersistentDataType.BYTE_ARRAY, getData(player));
+
+        is.setItemMeta(meta);
+
+        return is;
+    }
 }

src/main/java/eu/m724/music_plugin/library/Library.java

@@ -1,13 +1,21 @@
 package eu.m724.music_plugin.library;
 
-import java.io.IOException;
-import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;
 
 public class Library {
-    private List<Track> tracks = new ArrayList<>();
+    private final int id;
-    private int playingTrack;
+
+    private final List<Track> tracks = new ArrayList<>();
+    private int playingTrack = 0;
+
+    public Library(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return this.id;
+    }
 
     public void addTrack(Track track) {
         tracks.add(track);
@@ -21,14 +29,27 @@ public class Library {
         return tracks.get(playingTrack);
     }
 
-    public static Library load(InputStream inputStream) throws IOException {
+    /**
-        var tracks = new ArrayList<Track>();
+     * Previous Track
-
+     * @return the previous Track or null if this was the first
-        byte[] bytes = new byte[32];
+     */
-        while (inputStream.read(bytes) == 32) {
+    public Track previous() {
-            tracks.add(new Track(bytes));
+        if (playingTrack > 0) {
+            return tracks.get(--playingTrack);
+        } else {
+            return null;
         }
+    }
 
-        return new Library()
+    /**
+     * Next Track
+     * @return the next Track or null if this was the last
+     */
+    public Track next() {
+        if (playingTrack + 1 < tracks.size()) {
+            return tracks.get(++playingTrack);
+        } else {
+            return null;
+        }
     }
 }

src/main/java/eu/m724/music_plugin/library/LibraryStorage.java

@@ -0,0 +1,21 @@
+package eu.m724.music_plugin.library;
+
+import com.google.common.primitives.Ints;
+import eu.m724.music_plugin.DebugLogger;
+
+import java.nio.file.Path;
+import java.util.HexFormat;
+
+public class LibraryStorage {
+    private final Path libraryStoragePath;
+
+    public LibraryStorage(Path libraryStoragePath) {
+        this.libraryStoragePath = libraryStoragePath;
+    }
+
+    public Library load(int id) {
+        DebugLogger.fine("Now \"loading\" library %s", HexFormat.of().formatHex(Ints.toByteArray(id)));
+        // TODO
+        return new Library(id);
+    }
+}

src/main/java/eu/m724/music_plugin/library/Track.java

@@ -1,20 +1,52 @@
 package eu.m724.music_plugin.library;
 
+import eu.m724.music_plugin.DebugLogger;
+import eu.m724.music_plugin.MusicPlugin;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.HexFormat;
+import java.util.concurrent.CompletableFuture;
 
 public class Track {
+    /** SHA-256 hash as 32 bytes */
     private final byte[] hash;
 
+    /**
+     * Creates a new Track from an SHA-256 hash bytes
+     * @param hash the 32 bytes of the hash
+     */
     public Track(byte[] hash) {
         assert hash.length == 32;
         this.hash = hash;
     }
 
+    /**
+     * Creates a new Track from an SHA-256 hex encoded hash
+     * @param hash the hex encoded hash
+     */
     public Track(String hash) {
         this(HexFormat.of().parseHex(hash));
     }
 
+    /**
+     * @return the SHA-256 hash as 32 bytes
+     */
     public byte[] getHash() {
         return hash;
     }
+
+    public String getHashHex() {
+        return HexFormat.of().formatHex(hash);
+    }
+
+    public CompletableFuture<Path> getPath(int bitrate) {
+        var path = MusicPlugin.getStorage().get(getHashHex(), bitrate);
+        if (Files.isRegularFile(path))
+            return CompletableFuture.completedFuture(path);
+
+        DebugLogger.fine("Need to convert to %d", bitrate);
+
+        return MusicPlugin.getStorage().convert(MusicPlugin.getConverter(), getHashHex(), bitrate);
+    }
 }