Merge branch 'main' of https://github.com/python-discord/sir-lancebot into feature/stackoverflow

1 files changed, 39 insertions, 2 deletions

diff --git a/bot/exts/evergreen/error_handler.py b/bot/exts/evergreen/error_handler.py
index de8e53d0..5873fb83 100644
--- a/bot/exts/evergreen/error_handler.py
+++ b/bot/exts/evergreen/error_handler.py
@@ -1,3 +1,4 @@
+import difflib
 import logging
 import math
 import random
@@ -8,16 +9,22 @@ from discord.ext import commands
 from sentry_sdk import push_scope
 
 from bot.bot import Bot
-from bot.constants import Channels, Colours, ERROR_REPLIES, NEGATIVE_REPLIES
+from bot.constants import Channels, Colours, ERROR_REPLIES, NEGATIVE_REPLIES, RedirectOutput
 from bot.utils.decorators import InChannelCheckFailure, InMonthCheckFailure
 from bot.utils.exceptions import UserNotPlayingError
 
 log = logging.getLogger(__name__)
 
 
+QUESTION_MARK_ICON = "https://cdn.discordapp.com/emojis/512367613339369475.png"
+
+
 class CommandErrorHandler(commands.Cog):
     """A error handler for the PythonDiscord server."""
 
+    def __init__(self, bot: Bot) -> None:
+        self.bot = bot
+
     @staticmethod
     def revert_cooldown_counter(command: commands.Command, message: Message) -> None:
         """Undoes the last cooldown counter for user-error cases."""
@@ -58,6 +65,7 @@ class CommandErrorHandler(commands.Cog):
         )
 
         if isinstance(error, commands.CommandNotFound):
+            await self.send_command_suggestion(ctx, ctx.invoked_with)
             return
 
         if isinstance(error, (InChannelCheckFailure, InMonthCheckFailure)):
@@ -129,7 +137,36 @@ class CommandErrorHandler(commands.Cog):
 
             log.exception(f"Unhandled command error: {str(error)}", exc_info=error)
 
+    async def send_command_suggestion(self, ctx: commands.Context, command_name: str) -> None:
+        """Sends user similar commands if any can be found."""
+        raw_commands = []
+        for cmd in self.bot.walk_commands():
+            if not cmd.hidden:
+                raw_commands += (cmd.name, *cmd.aliases)
+        if similar_command_data := difflib.get_close_matches(command_name, raw_commands, 1):
+            similar_command_name = similar_command_data[0]
+            similar_command = self.bot.get_command(similar_command_name)
+
+            if not similar_command:
+                return
+
+            log_msg = "Cancelling attempt to suggest a command due to failed checks."
+            try:
+                if not await similar_command.can_run(ctx):
+                    log.debug(log_msg)
+                    return
+            except commands.errors.CommandError as cmd_error:
+                log.debug(log_msg)
+                await self.on_command_error(ctx, cmd_error)
+                return
+
+            misspelled_content = ctx.message.content
+            e = Embed()
+            e.set_author(name="Did you mean:", icon_url=QUESTION_MARK_ICON)
+            e.description = misspelled_content.replace(command_name, similar_command_name, 1)
+            await ctx.send(embed=e, delete_after=RedirectOutput.delete_delay)
+
 
 def setup(bot: Bot) -> None:
     """Load the ErrorHandler cog."""
-    bot.add_cog(CommandErrorHandler())
+    bot.add_cog(CommandErrorHandler(bot))