Merge pull request jagrosh#218 from SlapGaming/pullreqs

Move track command

src/main/java/com/jagrosh/jmusicbot/JMusicBot.java

@@ -114,6 +114,7 @@ public static void main(String[] args)
                         new SkipCmd(bot),
 
                         new ForceskipCmd(bot),
+                        new MoveTrackCmd(bot),
                         new PauseCmd(bot),
                         new PlaynextCmd(bot, config.getLoading()),
                         new RepeatCmd(bot),

src/main/java/com/jagrosh/jmusicbot/commands/dj/MoveTrackCmd.java

@@ -0,0 +1,85 @@
+package com.jagrosh.jmusicbot.commands.dj;
+
+
+import com.jagrosh.jdautilities.command.CommandEvent;
+import com.jagrosh.jmusicbot.Bot;
+import com.jagrosh.jmusicbot.audio.AudioHandler;
+import com.jagrosh.jmusicbot.audio.QueuedTrack;
+import com.jagrosh.jmusicbot.commands.DJCommand;
+import com.jagrosh.jmusicbot.queue.FairQueue;
+
+/**
+ * Command that provides users the ability to move a track in the playlist.
+ */
+public class MoveTrackCmd extends DJCommand
+{
+
+    public MoveTrackCmd(Bot bot)
+    {
+        super(bot);
+        this.name = "movetrack";
+        this.help = "move a track in the current queue to a different position";
+        this.arguments = "<from> <to>";
+        this.aliases = new String[]{"move"};
+        this.bePlaying = true;
+    }
+
+    @Override
+    public void doCommand(CommandEvent event)
+    {
+        int from;
+        int to;
+
+        String[] parts = event.getArgs().split("\\s+", 2);
+        if(parts.length < 2)
+        {
+            event.replyError("Please include two valid indexes.");
+            return;
+        }
+
+        try
+        {
+            // Validate the args
+            from = Integer.parseInt(parts[0]);
+            to = Integer.parseInt(parts[1]);
+        }
+        catch (NumberFormatException e)
+        {
+            event.replyError("Please provide two valid indexes.");
+            return;
+        }
+
+        if (from == to)
+        {
+            event.replyError("Can't move a track to the same position.");
+            return;
+        }
+
+        // Validate that from and to are available
+        AudioHandler handler = (AudioHandler) event.getGuild().getAudioManager().getSendingHandler();
+        FairQueue<QueuedTrack> queue = handler.getQueue();
+        if (isUnavailablePosition(queue, from))
+        {
+            String reply = String.format("`%d` is not a valid position in the queue!", from);
+            event.replyError(reply);
+            return;
+        }
+        if (isUnavailablePosition(queue, to))
+        {
+            String reply = String.format("`%d` is not a valid position in the queue!", to);
+            event.replyError(reply);
+            return;
+        }
+
+        // Move the track
+        QueuedTrack track = queue.moveItem(from - 1, to - 1);
+        String trackTitle = track.getTrack().getInfo().title;
+        String reply = String.format("Moved **%s** from position `%d` to `%d`.", trackTitle, from, to);
+        event.replySuccess(reply);
+    }
+
+    private static boolean isUnavailablePosition(FairQueue<QueuedTrack> queue, int position)
+    {
+        return (position < 1 || position > queue.size());
+    }
+}

src/main/java/com/jagrosh/jmusicbot/queue/FairQueue.java

@@ -128,4 +128,17 @@ public void skip(int number)
         for(int i=0; i<number; i++)
             list.remove(0);
     }
+
+    /**
+     * Move an item to a different position in the list
+     * @param from The position of the item
+     * @param to The new position of the item
+     * @return the moved item
+     */
+    public T moveItem(int from, int to)
+    {
+        T item = list.remove(from);
+        list.add(to, item);
+        return item;
+    }
 }