Start of commands. argument parsing.

twitchio/__init__.py

@@ -35,4 +35,5 @@
 from .exceptions import *
 from .models import *
 from .payloads import *
+from .user import *
 from .utils import Color as Color, Colour as Colour

twitchio/ext/commands/bot.py

@@ -30,6 +30,7 @@
 from twitchio.client import Client
 
 from .context import Context
+from .converters import _BaseConverter
 from .core import Command, CommandErrorPayload, Group, Mixin
 from .exceptions import *
 
@@ -65,6 +66,7 @@ def __init__(
 
         self._get_prefix: Prefix_T = prefix
         self._components: dict[str, Component] = {}
+        self._base_converter: _BaseConverter = _BaseConverter(self)
 
     @property
     def bot_id(self) -> str:
@@ -135,3 +137,5 @@ async def event_command_error(self, payload: CommandErrorPayload) -> None:
     async def before_invoke(self, ctx: Context) -> None: ...
 
     async def after_invoke(self, ctx: Context) -> None: ...
+
+    async def check(self, ctx: Context) -> None: ...

twitchio/ext/commands/context.py

@@ -59,6 +59,9 @@ def __init__(self, message: ChatMessage, bot: Bot) -> None:
 
         self._view: StringView = StringView(self._raw_content)
 
+        self._args: list[Any] = []
+        self._kwargs: dict[str, Any] = {}
+
     @property
     def message(self) -> ChatMessage:
         return self._message
@@ -111,6 +114,14 @@ def error_dispatched(self) -> bool:
     def error_dispatched(self, value: bool, /) -> None:
         self._error_dispatched = value
 
+    @property
+    def args(self) -> list[Any]:
+        return self._args
+
+    @property
+    def kwargs(self) -> dict[str, Any]:
+        return self._kwargs
+
     def is_valid(self) -> bool:
         return self._prefix is not None
 

twitchio/ext/commands/converters.py

@@ -0,0 +1,78 @@
+"""
+MIT License
+
+Copyright (c) 2017 - Present PythonistaGuild
+
+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.
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any
+
+from twitchio.user import User
+
+from .exceptions import *
+
+
+if TYPE_CHECKING:
+    from .bot import Bot
+    from .context import Context
+
+__all__ = ("_BaseConverter",)
+
+
+class _BaseConverter:
+    def __init__(self, client: Bot) -> None:
+        self.__client: Bot = client
+
+        self._MAPPING: dict[Any, Any] = {User: self._user}
+        self._DEFAULTS: dict[type, type] = {str: str, int: int, float: float}
+
+    async def _user(self, context: Context, arg: str) -> User:
+        arg = arg.lower()
+        users: list[User]
+        msg: str = 'Failed to convert "{}" to User. A User with the ID or login could not be found.'
+
+        if arg.startswith("@"):
+            arg = arg.removeprefix("@")
+            users = await self.__client.fetch_users(logins=[arg])
+
+            if not users:
+                raise BadArgument(msg.format(arg), value=arg)
+
+        if arg.isdigit():
+            users = await self.__client.fetch_users(logins=[arg], ids=[arg])
+        else:
+            users = await self.__client.fetch_users(logins=[arg])
+
+        potential: list[User] = []
+
+        for user in users:
+            # ID's should be taken into consideration first...
+            if user.id == arg:
+                return user
+
+            elif user.name == arg:
+                potential.append(user)
+
+        if potential:
+            return potential[0]
+
+        raise BadArgument(msg.format(arg), value=arg)

twitchio/ext/commands/core.py

@@ -25,8 +25,12 @@
 from __future__ import annotations
 
 import asyncio
+import inspect
 from collections.abc import Callable, Coroutine
-from typing import TYPE_CHECKING, Any, Concatenate, Generic, ParamSpec, TypeAlias, TypeVar, Unpack
+from types import UnionType
+from typing import TYPE_CHECKING, Any, Concatenate, Generic, ParamSpec, TypeAlias, TypeVar, Union, Unpack
+
+from twitchio.utils import MISSING
 
 from .exceptions import *
 from .types_ import CommandOptions, Component_T
@@ -112,10 +116,134 @@ def extras(self) -> dict[Any, Any]:
     def has_error(self) -> bool:
         return self._error is not None
 
+    async def _do_conversion(self, context: Context, param: inspect.Parameter, *, annotation: Any, raw: str | None) -> Any:
+        name: str = param.name
+
+        if isinstance(annotation, UnionType) or getattr(annotation, "__origin__", None) is Union:
+            converters = list(annotation.__args__)
+            converters.remove(type(None))
+
+            result: Any = MISSING
+
+            for c in converters:
+                try:
+                    result = await self._do_conversion(context, param=param, annotation=c, raw=raw)
+                except Exception:
+                    continue
+
+            if result is MISSING:
+                raise BadArgument(
+                    f'Failed to convert argument "{name}" with any converter from Union: {converters}. No default value was provided.',
+                    name=name,
+                    value=raw,
+                )
+
+            return result
+
+        base = context.bot._base_converter._DEFAULTS.get(annotation, None if annotation != param.empty else str)
+        if base:
+            try:
+                result = base(raw)
+            except Exception as e:
+                raise BadArgument(f'Failed to convert "{name}" to {base}', name=name, value=raw) from e
+
+            return result
+
+        converter = context.bot._base_converter._MAPPING.get(annotation, annotation)
+
+        try:
+            result = converter(context, raw)
+        except Exception as e:
+            raise BadArgument(f'Failed to convert "{name}" to {type(converter)}', name=name, value=raw) from e
+
+        if not asyncio.iscoroutine(result):
+            return result
+
+        try:
+            result = await result
+        except Exception as e:
+            raise BadArgument(f'Failed to convert "{name}" to {type(converter)}', name=name, value=raw) from e
+
+        return result
+
+    async def _parse_arguments(self, context: Context) -> ...:
+        context._view.skip_ws()
+        signature: inspect.Signature = inspect.signature(self._callback)
+
+        # We expect context always and self with commands in components...
+        skip: int = 1 if not self._injected else 2
+        params: list[inspect.Parameter] = list(signature.parameters.values())[skip:]
+
+        args: list[Any] = []
+        kwargs = {}
+
+        for param in params:
+            if param.kind == param.KEYWORD_ONLY:
+                raw = context._view.read_rest()
+
+                if not raw:
+                    if param.default == param.empty:
+                        raise MissingRequiredArgument(param=param)
+
+                    kwargs[param.name] = param.default
+                    continue
+
+                result = await self._do_conversion(context, param=param, raw=raw, annotation=param.annotation)
+                kwargs[param.name] = result
+                break
+
+            elif param.kind == param.VAR_POSITIONAL:
+                packed: list[Any] = []
+
+                while True:
+                    context._view.skip_ws()
+                    raw = context._view.get_quoted_word()
+                    if not raw:
+                        break
+
+                    result = await self._do_conversion(context, param=param, raw=raw, annotation=param.annotation)
+                    packed.append(result)
+
+                args.extend(packed)
+                break
+
+            elif param.kind == param.POSITIONAL_OR_KEYWORD:
+                raw = context._view.get_quoted_word()
+                context._view.skip_ws()
+
+                if not raw:
+                    if param.default == param.empty:
+                        raise MissingRequiredArgument(param=param)
+
+                    args.append(param.default)
+                    continue
+
+                result = await self._do_conversion(context, param=param, raw=raw, annotation=param.annotation)
+                args.append(result)
+
+        return args, kwargs
+
+    async def _do_checks(self, context: Context) -> ...:
+        # Bot
+        # Component
+        # Command
+        ...
+
     async def _invoke(self, context: Context) -> None:
-        # TODO: Argument parsing...
-        # TODO: Checks... Including cooldowns...
-        callback = self._callback(self._injected, context) if self._injected else self._callback(context)  # type: ignore
+        try:
+            args, kwargs = await self._parse_arguments(context)
+        except (ConversionError, MissingRequiredArgument):
+            raise
+        except Exception as e:
+            raise ConversionError("An unknown error occurred converting arguments.") from e
+
+        context._args = args
+        context._kwargs = kwargs
+
+        args: list[Any] = [context, *args]
+        args.insert(0, self._injected) if self._injected else None
+
+        callback = self._callback(*args, **kwargs)  # type: ignore
 
         try:
             await callback
@@ -127,6 +255,9 @@ async def invoke(self, context: Context) -> None:
             await self._invoke(context)
         except CommandError as e:
             await self._dispatch_error(context, e)
+        except Exception as e:
+            error = CommandInvokeError(str(e), original=e)
+            await self._dispatch_error(context, error)
 
     async def _dispatch_error(self, context: Context, exception: CommandError) -> None:
         payload = CommandErrorPayload(context=context, exception=exception)

twitchio/ext/commands/exceptions.py

@@ -22,6 +22,8 @@
 SOFTWARE.
 """
 
+import inspect
+
 from twitchio.exceptions import TwitchioException
 
 
@@ -35,6 +37,10 @@
     "PrefixError",
     "InputError",
     "ArgumentError",
+    "CheckFailure",
+    "ConversionError",
+    "BadArgument",
+    "MissingRequiredArgument",
 )
 
 
@@ -84,3 +90,22 @@ class ExpectedClosingQuoteError(ArgumentError):
     def __init__(self, close_quote: str) -> None:
         self.close_quote: str = close_quote
         super().__init__(f"Expected closing {close_quote}.")
+
+
+class CheckFailure(CommandError): ...
+
+
+class ConversionError(ArgumentError): ...
+
+
+class BadArgument(ConversionError):
+    def __init__(self, msg: str, *, name: str | None = None, value: str | None) -> None:
+        self.name: str | None = name
+        self.value: str | None = value
+        super().__init__(msg)
+
+
+class MissingRequiredArgument(ArgumentError):
+    def __init__(self, param: inspect.Parameter) -> None:
+        self.param: inspect.Parameter = param
+        super().__init__(f'"{param.name}" is a required argument which is missing.')