Adds command documentation and improves tab-completion

Adds documentation for all commands to the README
Adds option to force an update if changing the pitch or volume of a minstrel
Adds tab-completions for removeSong, listSongs, volume and pitch commands
Adds filtering for tab-completions based on current input

README.MD

@@ -26,3 +26,45 @@ There are limitations connected to directly playing media using playSound:
   the song if played by any other minstrels at the same time. As songs are only stopped if a song has been played for a
   player outside the global cycle, it shouldn't be too much of a problem, but if several minstrels play the same song,
   there may be silent minstrels until the next song plays.
+
+## Commands
+
+| Command | Arguments | Description |
+| --- | --- | --- |
+| /minstrel addsong | <sound category> <sound identifier> <duration> | Adds the specified song to the selected minstrel's playlist |
+| /minstrel removesong | <index (0-10000)> | Removes the song at the given index from the selected minstrel's playlist |
+| /minstrel listsongs | none | Lists all songs in the selected NPC's playlist in the format CATEGORY:identifier:duration |
+| /minstrel volume | <new volume (0.01 to 10000)> \[force update (true/false)] | Displays or sets the volume of the selected minstrel  |
+| /minstrel pitch | <new pitch (0.01 to 10000)> \[force update (true/false)] | Displays or sets the pitch of the selected minstrel |
+
+### /minstrel addsong
+
+- sound category - The category to use when playing the song. This is used when playing the sound to decide which volume
+  slider can be used to alter the volume. RECORDS is recommended for minstrels. You may also specify "null" as the sound
+  category. It will then be played without a specific category being specified.
+- sound identifier - The string used to identify the sound to play. Example: "minecraft:music_disc.cat" identifies the
+  cat music disc. You can also specify music in a resource pack, though nothing can be heard for players without the
+  resource pack.
+- duration - The duration of the track, in seconds. It's important that this is exact, and not too short, as it's used
+  to decide when to start playing the next track in the playlist. If it's too short, several songs will end up playing
+  at once! Setting it higher than the actual duration can be used to add a pause before the next song is played.
+
+Example: `/minstrel addsong RECORDS minecraft:music_disc.cat 185` would be used to add the CAT music disc to a playlist.
+
+### /minstrel removesong
+
+- index - The 0-based index of the song's position in the playlist. Use `/minstrel listsongs` to see the current
+  playlist.
+
+Example: `/minstrel removesong 0` removes the first song in the playlist.
+
+### /minstrel volume
+
+- new volume - The new volume of the minstrel. Set to 1 for full volume, 0.5 for half volume, etc. If set above 1, the
+  minstrel can be heard from farther away, while the actual volume will be the same as for 1.0 when close to the NPC.
+- force update - Whether to forcefully stop and start the minstrel's playlist to make the change happen instantly.
+
+### /minstrel pitch
+
+- new pitch - The new pitch used by the minstrel. Set to 1 for normal.
+- force update - Whether to forcefully stop and start the minstrel's playlist to make the change happen instantly.

src/main/java/net/knarcraft/minstrel/command/MinstrelCommand.java

@@ -32,11 +32,12 @@ public class MinstrelCommand implements CommandExecutor {
             case "listsongs":
                 return new ListSongsCommand(minstrelTrait).onCommand(sender, command, label, args);
             case "pitch":
-                return updatePitch(minstrelTrait, args.length > 1 ? args[1] : null, sender);
+                return updatePitch(minstrelTrait, args.length > 1 ? args[1] : null, args.length > 2 &&
+                        Boolean.parseBoolean(args[2]), sender);
             case "volume":
-                return updateVolume(minstrelTrait, args.length > 1 ? args[1] : null, sender);
+                return updateVolume(minstrelTrait, args.length > 1 ? args[1] : null, args.length > 2 &&
+                        Boolean.parseBoolean(args[2]), sender);
         }
-        //TODO: Add another argument for volume and pitch for whether to immediately change the volume by restarting the playlist
         
         /* Sub-commands:
             AddSong category identifier duration (remember to run play again)
@@ -63,7 +64,7 @@ public class MinstrelCommand implements CommandExecutor {
      * @param sender        <p>The sender to send error/success messages to</p>
      * @return <p>True if the pitch was successfully updated</p>
      */
-    private boolean updatePitch(MinstrelTrait minstrelTrait, String newPitch, CommandSender sender) {
+    private boolean updatePitch(MinstrelTrait minstrelTrait, String newPitch, boolean forceRefresh, CommandSender sender) {
         if (newPitch == null) {
             sender.sendMessage("Current pitch: " + minstrelTrait.getPitch());
             return true;
@@ -75,6 +76,10 @@ public class MinstrelCommand implements CommandExecutor {
                 sender.sendMessage("The pitch cannot be negative");
             } else {
                 minstrelTrait.setPitch(pitch);
+                if (forceRefresh) {
+                    minstrelTrait.getPlaylist().stop();
+                    minstrelTrait.getPlaylist().play(minstrelTrait);
+                }
             }
         } catch (NumberFormatException exception) {
             sender.sendMessage("The given pitch is not a number!");
@@ -92,7 +97,7 @@ public class MinstrelCommand implements CommandExecutor {
      * @param sender        <p>The sender to send error/success messages to</p>
      * @return <p>True if the volume was successfully updated</p>
      */
-    private boolean updateVolume(MinstrelTrait minstrelTrait, String newVolume, CommandSender sender) {
+    private boolean updateVolume(MinstrelTrait minstrelTrait, String newVolume, boolean forceRefresh, CommandSender sender) {
         if (newVolume == null) {
             sender.sendMessage("Current volume: " + minstrelTrait.getVolume());
             return true;
@@ -104,6 +109,10 @@ public class MinstrelCommand implements CommandExecutor {
                 sender.sendMessage("The volume must be greater than 0");
             } else {
                 minstrelTrait.setVolume(volume);
+                if (forceRefresh) {
+                    minstrelTrait.getPlaylist().stop();
+                    minstrelTrait.getPlaylist().play(minstrelTrait);
+                }
             }
         } catch (NumberFormatException exception) {
             sender.sendMessage("The given volume is not a number!");

src/main/java/net/knarcraft/minstrel/command/MinstrelTabCompleter.java

@@ -1,5 +1,8 @@
 package net.knarcraft.minstrel.command;
 
+import net.citizensnpcs.api.CitizensAPI;
+import net.citizensnpcs.api.npc.NPC;
+import net.knarcraft.minstrel.trait.MinstrelTrait;
 import org.bukkit.SoundCategory;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
@@ -10,10 +13,16 @@ import org.jetbrains.annotations.Nullable;
 import java.util.ArrayList;
 import java.util.List;
 
+import static net.knarcraft.minstrel.util.TabCompletionHelper.filterMatchingContains;
+
 public class MinstrelTabCompleter implements TabCompleter {
 
     private final List<String> baseCommands;
     private final List<String> soundCategories;
+    private final List<String> exampleLengths;
+    private final List<String> empty = new ArrayList<>();
+    private final List<String> exampleFloats;
+    private final List<String> booleans;
 
     public MinstrelTabCompleter() {
         baseCommands = new ArrayList<>();
@@ -26,27 +35,91 @@ public class MinstrelTabCompleter implements TabCompleter {
         for (SoundCategory category : SoundCategory.values()) {
             soundCategories.add(category.name());
         }
+        exampleLengths = new ArrayList<>();
+        exampleLengths.add("60");
+        exampleLengths.add("90");
+        exampleLengths.add("120");
+        exampleFloats = new ArrayList<>();
+        exampleFloats.add("0.5");
+        exampleFloats.add("1");
+        exampleFloats.add("1.5");
+        booleans = new ArrayList<>();
+        booleans.add("true");
+        booleans.add("false");
     }
 
     @Nullable
     @Override
     public List<String> onTabComplete(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label,
                                       @NotNull String[] args) {
-        if (args.length < 2) {
-            return baseCommands;
+        NPC npc = CitizensAPI.getDefaultNPCSelector().getSelected(sender);
+        if (npc == null || !npc.hasTrait(MinstrelTrait.class)) {
+            return empty;
         }
+        MinstrelTrait minstrelTrait = npc.getTraitNullable(MinstrelTrait.class);
+
+        if (args.length < 2) {
+            return filterMatchingContains(baseCommands, args[0]);
+        }
+
         switch (args[0].toLowerCase()) {
             case "addsong":
+                return tabCompleteAddSong(args);
+            case "removesong":
+                return tabCompleteRemoveSong(minstrelTrait, args);
+            case "listsongs":
+                return empty;
+            case "volume":
+            case "pitch":
                 if (args.length == 2) {
-                    return soundCategories;
+                    return exampleFloats;
                 } else if (args.length == 3) {
-                    List<String> exampleSongNames = new ArrayList<>();
-                    exampleSongNames.add("minecraft:records.custom.medieval_3_g_mixolydian");
-                    exampleSongNames.add("minecraft:block.amethyst_block.step");
-                    return exampleSongNames;
+                    return booleans;
+                } else {
+                    return empty;
                 }
         }
         return null;
     }
 
+    /**
+     * Gets the tab-completions for removing a song
+     *
+     * @param minstrelTrait <p>The currently selected minstrel</p>
+     * @param args          <p>THe arguments given by the user</p>
+     * @return <p>The tab-completion options to display to the user</p>
+     */
+    private List<String> tabCompleteRemoveSong(MinstrelTrait minstrelTrait, String[] args) {
+        if (args.length == 2) {
+            List<String> indices = new ArrayList<>();
+            for (int i = 0; i < minstrelTrait.getPlaylist().getSongs().size(); i++) {
+                indices.add(String.valueOf(i));
+            }
+            return filterMatchingContains(indices, args[1]);
+        } else {
+            return empty;
+        }
+    }
+
+    /**
+     * Gets the tab-completions for adding a song
+     *
+     * @param args <p>The arguments given by the user</p>
+     * @return <p>The tab-completion options to display to the user</p>
+     */
+    private List<String> tabCompleteAddSong(String[] args) {
+        if (args.length == 2) {
+            return filterMatchingContains(soundCategories, args[1]);
+        } else if (args.length == 3) {
+            List<String> exampleSongNames = new ArrayList<>();
+            exampleSongNames.add("minecraft:records.custom.medieval_3_g_mixolydian");
+            exampleSongNames.add("minecraft:block.amethyst_block.step");
+            return filterMatchingContains(exampleSongNames, args[2]);
+        } else if (args.length == 4) {
+            return filterMatchingContains(exampleLengths, args[3]);
+        } else {
+            return empty;
+        }
+    }
+
 }

src/main/java/net/knarcraft/minstrel/util/TabCompletionHelper.java

@@ -0,0 +1,32 @@
+package net.knarcraft.minstrel.util;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A helper class for tab-completion
+ */
+public final class TabCompletionHelper {
+
+    private TabCompletionHelper() {
+
+    }
+
+    /**
+     * Finds tab complete values that contain the typed text
+     *
+     * @param values    <p>The values to filter</p>
+     * @param typedText <p>The text the player has started typing</p>
+     * @return <p>The given string values that contain the player's typed text</p>
+     */
+    public static List<String> filterMatchingContains(List<String> values, String typedText) {
+        List<String> configValues = new ArrayList<>();
+        for (String value : values) {
+            if (value.toLowerCase().contains(typedText.toLowerCase())) {
+                configValues.add(value);
+            }
+        }
+        return configValues;
+    }
+
+}