Add react to close thread functionality

Author: kyb3r

bot.py

@@ -433,7 +433,23 @@ async def on_ready(self):
             )
         logger.info(LINE)
 
+    async def convert_emoji(self, name):
+        ctx = SimpleNamespace(bot=self, guild=self.modmail_guild)
+        converter = commands.EmojiConverter()
+
+        if name not in UNICODE_EMOJI:
+            try:
+                return await converter.convert(
+                    ctx, sent_emoji.strip(':')
+                )
+            except commands.BadArgument:
+                pass
+        return name
+
     async def retrieve_emoji(self):
+
+        # TODO: use a function to convert emojis
+
         ctx = SimpleNamespace(bot=self, guild=self.modmail_guild)
         converter = commands.EmojiConverter()
 
@@ -634,6 +650,45 @@ async def on_typing(self, channel, user, _):
             thread = await self.threads.find(channel=channel)
             if thread and thread.recipient:
                 await thread.recipient.trigger_typing()
+    
+    async def on_raw_reaction_add(self, payload):
+
+        user = self.get_user(payload.user_id)
+
+        if user.bot:
+            return
+
+        channel = self.get_channel(payload.channel_id)
+
+        if not channel: # dm channel not in internal cache
+            _thread = await self.threads.find(recipient=user)
+            if not _thread:
+                return
+            channel = await _thread.recipient.create_dm()
+
+        message = await channel.get_message(payload.message_id) # TODO: change to fetch_message (breaking change in d.py)
+        reaction = payload.emoji
+
+        close_emoji = await self.convert_emoji(self.config.get('close_emoji', '🔒'))
+
+        if isinstance(channel, discord.DMChannel) and str(reaction) == str(close_emoji): # closing thread
+            thread = await self.threads.find(recipient=user)
+            ts = message.embeds[0].timestamp if message.embeds else None
+            if thread and ts == thread.channel.created_at: 
+                # the reacted message is the corresponding thread creation embed
+                if not self.config.get('disable_recipient_thread_close'):
+                    await thread.close(closer=user)
+        elif not isinstance(channel, discord.DMChannel):
+            message_id = str(message.embeds[0].author.url).split('/')[-1]
+            if message_id.isdigit():
+                thread = await self.threads.find(channel=message.channel)
+                channel = thread.recipient.dm_channel
+                if not channel:
+                    channel = await thread.recipient.create_dm()
+                async for msg in channel.history():
+                    if msg.id == int(message_id):
+                        await msg.add_reaction(reaction)
+
 
     async def on_guild_channel_delete(self, channel):
         if channel.guild != self.modmail_guild: