From 843453b72efb56d7da4bfbf4fce614e72633f917 Mon Sep 17 00:00:00 2001
From: A5rocks <40616000+A5rocks@users.noreply.github.com>
Date: Sun, 27 Oct 2019 02:27:00 +0900
Subject: [PATCH] Easily use multiple prefixes... Now onto programmatic
 fetching and conquering the world!

---
 disco/bot/bot.py | 37 +++++++++++++++++++++++++++++++------
 1 file changed, 31 insertions(+), 6 deletions(-)

diff --git a/disco/bot/bot.py b/disco/bot/bot.py
index cba656b..75995b3 100644
--- a/disco/bot/bot.py
+++ b/disco/bot/bot.py
@@ -46,6 +46,9 @@ class BotConfig(Config):
     commands_prefix : str
         A string prefix that is required for a message to be considered for
         command parsing.
+    commands_prefixes : list[string]
+        A list of string prefixes that are required for a message to be considered
+        for command parsing.
     commands_allow_edit : bool
         If true, the bot will re-parse an edited message if it was the last sent
         message in a channel, and did not previously trigger a command. This is
@@ -88,6 +91,7 @@ class BotConfig(Config):
         'user': True,
     }
     commands_prefix = ''
+    commands_prefixes = []
     commands_allow_edit = True
     commands_level_getter = None
     commands_group_abbrev = True
@@ -275,21 +279,33 @@ class Bot(LoggingClass):
         else:
             self.command_matches_re = None
 
-    def get_commands_for_message(self, require_mention, mention_rules, prefix, msg):
+    def get_commands_for_message(self, require_mention, mention_rules, msg_prefix, msg, prefixes=[]):
         """
         Generator of all commands that a given message object triggers, based on
         the bots plugins and configuration.
 
         Parameters
         ---------
+        require_mention : bool
+            Checks if the message starts with a mention (and then ignores the prefix(es))
+        mention_rules : dict(str, bool)
+            Whether `user`, `everyone`, and `role` mentions are allowed. Defaults to:
+            `{'user': True, 'everyone': False, 'role': False}
+        msg_prefix : str
+            The prefix to check the message starts with.
         msg : :class:`disco.types.message.Message`
-            The message object to parse and find matching commands for.
+            The newly created or updated message object to parse/handle.
+        prefixes : list[string]
+            A list of prefixes to check the message starts with (combines with `prefix`)
 
         Yields
         -------
         tuple(:class:`disco.bot.command.Command`, `re.MatchObject`)
             All commands the message triggers.
         """
+        # somebody better figure out what this yields...
+
+        prefixes = (prefixes or []) + [msg_prefix]  # don't break the tests and keep compatibility
         content = msg.content
 
         if require_mention:
@@ -326,11 +342,18 @@ class Bot(LoggingClass):
                     content = content.replace('<@{}>'.format(role), '', 1)
 
             content = content.lstrip()
-
-        if prefix and not content.startswith(prefix):
-            return []
         else:
-            content = content[len(prefix):]
+            # Scan through the prefixes to find the first one that matches.
+            # This may lead to unexpected results, but said unexpectedness
+            # should be easy to avoid. An example of the unexpected results
+            # that may occur would be if one prefix was `!` and one was `!a`.
+            if not any([content.startswith(prefix) for prefix in prefixes]):
+                return []
+            else:
+                for prefix in prefixes:
+                    if prefix and content.startswith(prefix):
+                        content = content[len(prefix):]
+                        break
 
         if not self.command_matches_re or not self.command_matches_re.match(content):
             return []
@@ -340,6 +363,7 @@ class Bot(LoggingClass):
             match = command.compiled_regex.match(content)
             if match:
                 options.append((command, match))
+
         return sorted(options, key=lambda obj: obj[0].group is None)
 
     def get_level(self, actor):
@@ -388,6 +412,7 @@ class Bot(LoggingClass):
             self.config.commands_mention_rules,
             self.config.commands_prefix,
             msg,
+            self.config.commands_prefixes,
         ))
 
         if not len(commands):