From 17cb062c9642313f17c3c5e070de2032031857d3 Mon Sep 17 00:00:00 2001
From: Yago <yago.ftw@gmail.com>
Date: Sat, 30 Jan 2016 18:02:09 +0100
Subject: [PATCH] onReplyToMessage

---
 src/telegram.js | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/telegram.js b/src/telegram.js
index 3aea15a..cde44af 100644
--- a/src/telegram.js
+++ b/src/telegram.js
@@ -43,6 +43,7 @@ var TelegramBot = function (token, options) {
     'new_chat_photo', 'delete_chat_photo', 'group_chat_created'
   ]; // Telegram message events
   this.textRegexpCallbacks = [];
+  this.onReplyToMessages = [];
 
   this.processUpdate = this._processUpdate.bind(this);
 
@@ -92,6 +93,19 @@ TelegramBot.prototype._processUpdate = function (update) {
         }
       });
     }
+    if (message.reply_to_message) {
+      // Only callbacks waiting for this message
+      this.onReplyToMessages.forEach(function (reply) {
+        // Message from the same chat
+        if (reply.chatId === message.chat.id) {
+          // Responding to that message
+          if (reply.messageId === message.reply_to_message.message_id) {
+            // Resolve the promise
+            reply.callback(message);
+          }
+        }
+      });
+    }
   } else if (inline_query) {
     debug('Process Update inline_query %j', inline_query);
     this.emit('inline_query', inline_query);
@@ -549,4 +563,18 @@ TelegramBot.prototype.onText = function (regexp, callback) {
   this.textRegexpCallbacks.push({regexp: regexp, callback: callback});
 };
 
+/**
+ * Register a reply to wait for a message response.
+ * @param  {Number|String}   messageId       The ID of the message to be replied
+ * @param  {Function} callback     Callback will be called with the reply 
+ * message.
+ */
+TelegramBot.prototype.onReplyToMessage = function (chatId, messageId, callback) {
+  this.onReplyToMessages.push({
+    chatId: chatId,
+    messageId: messageId,
+    callback: callback
+  });
+};
+
 module.exports = TelegramBot;