Added ability to delete playlists

src/main/java/net/locusworks/discord/eighttrack/handlers/ReactionHandler.java

@@ -0,0 +1,133 @@
+/**
+ *
+ * Project: Pseudo-Bot, File: ReactionHandler.java
+ *
+ * Copyright 2019 Locusworks LLC.
+ * All rights reserved. Federal copyright law prohibits unauthorized reproduction by
+ * any means and imposes fines up to $25,000 for violation.  No part of this material
+ * may be reproduced, transmitted, transcribed, stored in a retrieval system, copied,
+ * modified, duplicated, adapted or translated into another program language in any
+ * form or by any means, electronic, mechanical, photocopying, recording, or
+ * otherwise, without the prior written permission from Locusworks. Locusworks
+ * affirms that PSEUDO-BOT(R) software and data is subject to United States
+ * Government Purpose Rights.  Contact Locusworks, 1313 Lawnview Drive
+ * Forney TX 75126, (802) 488-0438, for commercial licensing opportunities.
+ *
+ * IN NO EVENT SHALL LOCUSWORKS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL,
+ * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT
+ * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF LOCUSWORKS HAS BEEN
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  NO RESPONSIBILITY IS ASSUMED BY
+ * LOCUSWORKS FOR ITS USE, OR FOR ANY INFRINGEMENTS OF PATENTS OR OTHER RIGHTS OF
+ * THIRD PARTIES RESULTING FROM ITS USE.  LOCUSWORKS SPECIFICALLY DISCLAIMS ANY
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE AND
+ * ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED HEREUNDER IS PROVIDED "AS
+ * IS". LOCUSWORKS HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
+ * ENHANCEMENTS, OR MODIFICATIONS.
+ */
+package net.locusworks.discord.eighttrack.handlers;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.springframework.stereotype.Component;
+
+import net.dv8tion.jda.api.Permission;
+import net.dv8tion.jda.api.entities.ChannelType;
+import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.MessageReaction;
+import net.dv8tion.jda.api.entities.TextChannel;
+import net.dv8tion.jda.api.requests.RestAction;
+import net.dv8tion.jda.internal.utils.PermissionUtil;
+import net.locusworks.discord.eighttrack.listeners.ReactionListener;
+
+@Component
+public class ReactionHandler {
+
+  private final ConcurrentHashMap<Long, ConcurrentHashMap<Long, ReactionListener<?>>> reactions;
+
+  private ReactionHandler() {
+    reactions = new ConcurrentHashMap<>();
+  }
+  
+  public synchronized void addReactionListener(long guildId, Message message, ReactionListener<?> handler) {
+    addReactionListener(guildId, message, handler, true);
+  }
+
+  public synchronized void addReactionListener(long guildId, Message message, ReactionListener<?> handler, boolean queue) {
+    if (handler == null) {
+      return;
+    }
+    if (message.getChannelType().equals(ChannelType.TEXT)) {
+      if (!PermissionUtil.checkPermission(message.getTextChannel(), message.getGuild().getSelfMember(), Permission.MESSAGE_ADD_REACTION)) {
+        return;
+      }
+    }
+    if (!reactions.containsKey(guildId)) {
+      reactions.put(guildId, new ConcurrentHashMap<>());
+    }
+    if (!reactions.get(guildId).containsKey(message.getIdLong())) {
+      for (String emote : handler.getEmotes()) {
+        RestAction<Void> action = message.addReaction(emote);
+        if (queue) action.queue(); else action.complete();
+      }
+    }
+    reactions.get(guildId).put(message.getIdLong(), handler);
+  }
+  
+  public synchronized void removeReactionListener(long guildId, long messageId) {
+    if (!reactions.containsKey(guildId)) return;
+    reactions.get(guildId).remove(messageId);
+  }
+
+  /**
+   * Handles the reaction
+   *
+   * @param channel   TextChannel of the message
+   * @param messageId id of the message
+   * @param userId    id of the user reacting
+   * @param reaction  the reaction
+   */
+  public void handle(TextChannel channel, long messageId, long userId, MessageReaction reaction) {
+    ReactionListener<?> listener = reactions.get(channel.getGuild().getIdLong()).get(messageId);
+    if (!listener.isActive() || listener.getExpiresInTimestamp() < System.currentTimeMillis()) {
+      reactions.get(channel.getGuild().getIdLong()).remove(messageId);
+    } else if ((listener.hasReaction(reaction.getReactionEmote().getName())) && listener.getUserId() == userId) {
+      reactions.get(channel.getGuild().getIdLong()).get(messageId).updateLastAction();
+      Message message = channel.retrieveMessageById(messageId).complete();
+      listener.react(reaction.getReactionEmote().getName(), message);
+    }
+  }
+
+  /**
+   * Do we have an event for a message?
+   *
+   * @param guildId   discord guild-id of the message
+   * @param messageId id of the message
+   * @return do we have an handler?
+   */
+  public boolean canHandle(long guildId, long messageId) {
+    return reactions.containsKey(guildId) && reactions.get(guildId).containsKey(messageId);
+  }
+
+  public synchronized void removeGuild(long guildId) {
+    reactions.remove(guildId);
+  }
+
+  /**
+   * Delete expired handlers
+   */
+  public synchronized void cleanCache() {
+    long now = System.currentTimeMillis();
+    for (Iterator<Map.Entry<Long, ConcurrentHashMap<Long, ReactionListener<?>>>> iterator = reactions.entrySet().iterator(); iterator.hasNext(); ) {
+      Map.Entry<Long, ConcurrentHashMap<Long, ReactionListener<?>>> mapEntry = iterator.next();
+      mapEntry.getValue().values().removeIf(listener -> !listener.isActive() || listener.getExpiresInTimestamp() < now);
+      if (mapEntry.getValue().values().isEmpty()) {
+        reactions.remove(mapEntry.getKey());
+      }
+    }
+  }
+
+
+}