From 2f56a05a226848ded95875ab45eac0b2af20bab8 Mon Sep 17 00:00:00 2001
From: rubenlagus <rberlopez@gmail.com>
Date: Wed, 4 Nov 2020 01:23:37 +0000
Subject: [PATCH] Fix #795

---
 .../timedbot/TimedSendLongPollingBot.java     | 86 ++++++++++++++++---
 1 file changed, 74 insertions(+), 12 deletions(-)

diff --git a/telegrambots-extensions/src/main/java/org/telegram/telegrambots/extensions/bots/timedbot/TimedSendLongPollingBot.java b/telegrambots-extensions/src/main/java/org/telegram/telegrambots/extensions/bots/timedbot/TimedSendLongPollingBot.java
index 00a240a3..97ee169c 100644
--- a/telegrambots-extensions/src/main/java/org/telegram/telegrambots/extensions/bots/timedbot/TimedSendLongPollingBot.java
+++ b/telegrambots-extensions/src/main/java/org/telegram/telegrambots/extensions/bots/timedbot/TimedSendLongPollingBot.java
@@ -11,9 +11,9 @@ import java.util.concurrent.atomic.AtomicBoolean;
  * Created by Daniil Nikanov aka JetCoder
  */
 
-@SuppressWarnings("unused")
 public abstract class TimedSendLongPollingBot extends TelegramLongPollingBot
 {
+	private static final long MANY_CHATS_SEND_INTERVAL = 33;
 	private static final long ONE_CHAT_SEND_INTERVAL = 1000;
 	private static final long CHAT_INACTIVE_INTERVAL = 1000 * 60 * 10;
 	private final Timer mSendTimer = new Timer(true);
@@ -21,29 +21,85 @@ public abstract class TimedSendLongPollingBot extends TelegramLongPollingBot
 	private final ArrayList<MessageQueue> mSendQueues = new ArrayList<>();
 	private final AtomicBoolean mSendRequested = new AtomicBoolean(false);
 
+	private final class MessageSenderTask extends TimerTask
+	{
+		@Override
+		public void run()
+		{
+			//mSendRequested used for optimisation to not traverse all mMessagesMap 30 times per second all the time
+			if (!mSendRequested.getAndSet(false))
+				return;
+
+			long currentTime = System.currentTimeMillis();
+			mSendQueues.clear();
+			boolean processNext = false;
+
+			//First step - find all chats in which already allowed to send message (passed more than 1000 ms from previuos send)
+			Iterator<Map.Entry<Long,MessageQueue>> it = mMessagesMap.entrySet().iterator();
+			while (it.hasNext())
+			{
+				MessageQueue queue = it.next().getValue();
+				int state = queue.getCurrentState(currentTime); //Actual check here
+				if (state == MessageQueue.GET_MESSAGE)
+				{
+					mSendQueues.add(queue);
+					processNext = true;
+				}
+				else if (state == MessageQueue.WAIT)
+				{
+					processNext = true;
+				}
+				else if (state == MessageQueue.DELETE)
+				{
+					it.remove();
+				}
+			}
+
+			//If any of chats are in state WAIT or GET_MESSAGE, request another iteration
+			if (processNext)
+				mSendRequested.set(true);
+
+			//Second step - find oldest waiting queue and peek it's message
+			MessageQueue sendQueue = null;
+			long oldestPutTime = Long.MAX_VALUE;
+			for (MessageQueue queue : mSendQueues) {
+				long putTime = queue.getPutTime();
+				if (putTime < oldestPutTime) {
+					oldestPutTime = putTime;
+					sendQueue = queue;
+				}
+			}
+			if (sendQueue == null) //Possible if on first step wasn't found any chats in state GET_MESSAGE
+				return;
+
+			//Invoke the send callback. ChatId is passed for possible additional processing
+			sendMessageCallback(sendQueue.getChatId(), sendQueue.getMessage(currentTime));
+		}
+	}
+
 	private static class MessageQueue
 	{
-		static final int EMPTY = 0; //Queue is empty
-		static final int WAIT = 1; //Queue has message(s) but not yet allowed to send
-		static final int DELETE = 2; //No one message of given queue was sent longer than CHAT_INACTIVE_INTERVAL, delete for optimisation
-		static final int GET_MESSAGE = 3; //Queue has message(s) and ready to send
+		public static final int EMPTY = 0; //Queue is empty
+		public static final int WAIT = 1; //Queue has message(s) but not yet allowed to send
+		public static final int DELETE = 2; //No one message of given queue was sent longer than CHAT_INACTIVE_INTERVAL, delete for optimisation
+		public static final int GET_MESSAGE = 3; //Queue has message(s) and ready to send
 		private final ConcurrentLinkedQueue<Object> mQueue = new ConcurrentLinkedQueue<>();
 		private final Long mChatId;
 		private long mLastSendTime; //Time of last peek from queue
 		private volatile long mLastPutTime; //Time of last put into queue
 
-		MessageQueue(Long chatId)
+		public MessageQueue(Long chatId)
 		{
 			mChatId = chatId;
 		}
 
-		synchronized void putMessage(Object msg)
+		public synchronized void putMessage(Object msg)
 		{
 			mQueue.add(msg);
 			mLastPutTime = System.currentTimeMillis();
 		}
 
-		synchronized int getCurrentState(long currentTime)
+		public synchronized int getCurrentState(long currentTime)
 		{
 			//currentTime is passed as parameter for optimisation to do not recall currentTimeMillis() many times
 			long interval = currentTime - mLastSendTime;
@@ -58,23 +114,29 @@ public abstract class TimedSendLongPollingBot extends TelegramLongPollingBot
 				return WAIT;
 		}
 
-		synchronized Object getMessage(long currentTime)
+		public synchronized Object getMessage(long currentTime)
 		{
 			mLastSendTime = currentTime;
 			return mQueue.poll();
 		}
 
-		long getPutTime()
+		public long getPutTime()
 		{
 			return mLastPutTime;
 		}
 
-		Long getChatId()
+		public Long getChatId()
 		{
 			return mChatId;
 		}
 	}
 
+	//Constructor
+	protected TimedSendLongPollingBot()
+	{
+		mSendTimer.schedule(new MessageSenderTask(), MANY_CHATS_SEND_INTERVAL, MANY_CHATS_SEND_INTERVAL);
+	}
+
 	//Something like destructor
 	public void finish()
 	{
@@ -149,5 +211,5 @@ public abstract class TimedSendLongPollingBot extends TelegramLongPollingBot
 		}
 	}
     */
-	abstract void sendMessageCallback(Long chatId, Object messageRequest);
+	public abstract void sendMessageCallback(Long chatId, Object messageRequest);
 }