[commands] Port special cased discord converters to commands.Converter

discord/ext/commands/converter.py

@@ -0,0 +1,155 @@
+# -*- coding: utf-8 -*-
+
+"""
+The MIT License (MIT)
+
+Copyright (c) 2015-2016 Rapptz
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+"""
+
+import discord
+import asyncio
+import re
+
+from .errors import BadArgument, NoPrivateMessage
+
+__all__ = [ 'Converter', 'MemberConverter', 'UserConverter',
+            'ChannelConverter', 'InviteConverter', 'RoleConverter',
+            'GameConverter', 'ColourConverter' ]
+
+class Converter:
+    """The base class of custom converters that require the :class:`Context`
+    to be passed to be useful.
+
+    This allows you to implement converters that function similar to the
+    special cased ``discord`` classes.
+
+    Classes that derive from this should override the :meth:`convert` method
+    to do its conversion logic. This method could be a coroutine or a regular
+    function.
+
+    Attributes
+    -----------
+    ctx: :class:`Context`
+        The invocation context that the argument is being used in.
+    argument: str
+        The argument that is being converted.
+    """
+    def __init__(self, ctx, argument):
+        self.ctx = ctx
+        self.argument = argument
+
+    def convert(self):
+        raise NotImplementedError('Derived classes need to implement this.')
+
+class MemberConverter(Converter):
+    def convert(self):
+        message = self.ctx.message
+        bot = self.ctx.bot
+
+        match = re.match(r'<@!?([0-9]+)>$', self.argument)
+        server = message.server
+        result = None
+        if match is None:
+            # not a mention...
+            if server:
+                result = server.get_member_named(self.argument)
+            else:
+                result = self._get_from_servers(bot, 'get_member_named', self.argument)
+        else:
+            user_id = match.group(1)
+            if server:
+                result = server.get_member(user_id)
+            else:
+                result = self._get_from_servers(bot, 'get_member', user_id)
+
+        if result is None:
+            raise BadArgument('Member "{}" not found'.format(self.argument))
+
+        return result
+
+UserConverter = MemberConverter
+
+class ChannelConverter(Converter):
+    def convert(self):
+        message = self.ctx.message
+        bot = self.ctx.bot
+
+        match = re.match(r'<#([0-9]+)>$', self.argument)
+        result = None
+        server = message.server
+        if match is None:
+            # not a mention
+            if server:
+                result = discord.utils.get(server.channels, name=self.argument)
+            else:
+                result = discord.utils.get(bot.get_all_channels(), name=self.argument)
+        else:
+            channel_id = match.group(1)
+            if server:
+                result = server.get_channel(channel_id)
+            else:
+                result = self._get_from_servers(bot, 'get_channel', channel_id)
+
+        if result is None:
+            raise BadArgument('Channel "{}" not found.'.format(self.argument))
+
+        return result
+
+class ColourConverter(Converter):
+    def convert(self):
+        arg = self.argument.replace('0x', '').lower()
+
+        if arg[0] == '#':
+            arg = arg[1:]
+        try:
+            value = int(arg, base=16)
+            return discord.Colour(value=value)
+        except ValueError:
+            method = getattr(discord.Colour, arg, None)
+            if method is None or not inspect.ismethod(method):
+                raise BadArgument('Colour "{}" is invalid.'.format(arg))
+            return method()
+
+class RoleConverter(Converter):
+    def convert(self):
+        server = self.ctx.message.server
+        if not server:
+            raise NoPrivateMessage()
+
+        match = re.match(r'<@&([0-9]+)>$', self.argument)
+        params = dict(id=match.group(1)) if match else dict(name=self.argument)
+        result = discord.utils.get(server.roles, **params)
+        if result is None:
+            raise BadArgument('Role "{}" not found.'.format(self.argument))
+        return result
+
+class GameConverter(Converter):
+    def convert(self):
+        return discord.Game(name=self.argument)
+
+class InviteConverter(Converter):
+    @asyncio.coroutine
+    def convert(self):
+        try:
+            invite = yield from self.ctx.bot.get_invite(self.argument)
+            return invite
+        except Exception as e:
+            raise BadArgument('Invite is invalid or expired') from e