Added a delete command

Author: Taaku18

cogs/modmail.py

@@ -566,21 +566,7 @@ async def note(self, ctx, *, msg=''):
         async with ctx.typing():
             await ctx.thread.note(ctx.message)
 
-    @commands.command()
-    @checks.has_permissions(PermissionLevel.SUPPORTER)
-    @checks.thread_only()
-    async def edit(self, ctx, message_id: Optional[int] = None,
-                   *, new_message):
-        """Edit a message that was sent using the reply command.
-
-        If no `message_id` is provided, the
-        last message sent by a mod will be edited.
-
-        `[message_id]` the id of the message that you want to edit.
-        `new_message` is the new message that will be edited in.
-        """
-        thread = ctx.thread
-
+    async def find_linked_message(self, ctx, message_id):
         linked_message_id = None
 
         async for msg in ctx.channel.history():
@@ -600,8 +586,31 @@ async def edit(self, ctx, message_id: Optional[int] = None,
                 linked_message_id = str(url).split('/')[-1]
                 break
 
-        if not linked_message_id:
-            raise commands.UserInputError
+        return linked_message_id
+
+    @commands.command()
+    @checks.has_permissions(PermissionLevel.SUPPORTER)
+    @checks.thread_only()
+    async def edit(self, ctx, message_id: Optional[int] = None,
+                   *, new_message):
+        """Edit a message that was sent using the reply command.
+
+        If no `message_id` is provided, the
+        last message sent by a mod will be edited.
+
+        `[message_id]` the id of the message that you want to edit.
+        `new_message` is the new message that will be edited in.
+        """
+        thread = ctx.thread
+
+        linked_message_id = await self.find_linked_message(ctx, message_id)
+
+        if linked_message_id is None:
+            return await ctx.send(embed=discord.Embed(
+                title='Failed',
+                description='Cannot find a message to edit.',
+                color=discord.Color.red()
+            ))
 
         await asyncio.gather(
             thread.edit_message(linked_message_id, new_message),
@@ -801,6 +810,27 @@ async def unblock(self, ctx, *, user: User = None):
 
         return await ctx.send(embed=embed)
 
+    @commands.command()
+    @checks.has_permissions(PermissionLevel.SUPPORTER)
+    async def delete(self, ctx, message_id: int = None):
+        """
+        Deletes the previous message, unless a message ID is provided, which in that case,
+        delete the message with that message ID.
+        """
+        thread = ctx.thread
+
+        linked_message_id = await self.find_linked_message(ctx, message_id)
+
+        if linked_message_id is None:
+            return await ctx.send(embed=discord.Embed(
+                title='Failed',
+                description='Cannot find a message to delete.',
+                color=discord.Color.red()
+            ))
+
+        await thread.delete_message(linked_message_id)
+        await ctx.message.add_reaction('✅')
+
 
 def setup(bot):
     bot.add_cog(Modmail(bot))

core/thread.py

@@ -313,21 +313,38 @@ async def cancel_closure(self):
             await self.bot.config.update()
 
     @staticmethod
-    async def _edit_thread_message(channel, message_id, message):
+    async def _find_thread_message(channel, message_id):
         async for msg in channel.history():
             if not msg.embeds:
                 continue
             embed = msg.embeds[0]
             if embed and embed.author and embed.author.url:
                 if str(message_id) == str(embed.author.url).split('/')[-1]:
-                    embed.description = message
-                    await msg.edit(embed=embed)
-                    break
+                    return msg
 
     async def edit_message(self, message_id, message):
+        msg_recipient, msg_channel = await asyncio.gather(
+            self._find_thread_message(self.recipient, message_id),
+            self._find_thread_message(self.channel, message_id)
+        )
+
+        embed_recipient = msg_recipient.embeds[0]
+        embed_channel = msg_recipient.embeds[0]
+        embed_recipient.description = message
+        embed_channel.description = message
+        await asyncio.gather(
+            msg_recipient.edit(embed=embed_recipient),
+            msg_channel.edit(embed=embed_channel)
+        )
+
+    async def delete_message(self, message_id):
+        msg_recipient, msg_channel = await asyncio.gather(
+            self._find_thread_message(self.recipient, message_id),
+            self._find_thread_message(self.channel, message_id)
+        )
         await asyncio.gather(
-            self._edit_thread_message(self.recipient, message_id, message),
-            self._edit_thread_message(self.channel, message_id, message)
+            msg_recipient.delete(),
+            msg_channel.delete()
         )
 
     async def note(self, message):