Add initial support for buttons and components

4 files changed, 712 insertions, 0 deletions

diff --git a/discord/ui/__init__.py b/discord/ui/__init__.py
new file mode 100644
index 00000000..9aa9bea5
--- /dev/null
+++ b/discord/ui/__init__.py
@@ -0,0 +1,14 @@
+"""
+discord.ui
+~~~~~~~~~~~
+
+Bot UI Kit helper for the Discord API
+
+:copyright: (c) 2015-present Rapptz
+:license: MIT, see LICENSE for more details.
+
+"""
+
+from .view import *
+from .item import *
+from .button import *
diff --git a/discord/ui/button.py b/discord/ui/button.py
new file mode 100644
index 00000000..afc69f7a
--- /dev/null
+++ b/discord/ui/button.py
@@ -0,0 +1,288 @@
+"""
+The MIT License (MIT)
+
+Copyright (c) 2015-present 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.
+"""
+
+from __future__ import annotations
+
+from typing import Callable, Optional, TYPE_CHECKING, Tuple, Type, TypeVar, Union
+import inspect
+import re
+import os
+
+
+from .item import Item, ItemCallbackType
+from ..enums import ButtonStyle, ComponentType
+from ..partial_emoji import PartialEmoji
+from ..components import Button as ButtonComponent
+
+__all__ = (
+    'Button',
+    'button',
+)
+
+if TYPE_CHECKING:
+    from ..components import Component
+
+_custom_emoji = re.compile(r'<?(?P<animated>a)?:?(?P<name>[A-Za-z0-9\_]+):(?P<id>[0-9]{13,20})>?')
+
+
+def _to_partial_emoji(obj: Union[str, PartialEmoji], *, _custom_emoji=_custom_emoji) -> PartialEmoji:
+    if isinstance(obj, PartialEmoji):
+        return obj
+
+    obj = str(obj)
+    match = _custom_emoji.match(obj)
+    if match is not None:
+        groups = match.groupdict()
+        animated = bool(groups['animated'])
+        emoji_id = int(groups['id'])
+        name = groups['name']
+        return PartialEmoji(name=name, animated=animated, id=emoji_id)
+
+    return PartialEmoji(name=obj, id=None, animated=False)
+
+
+B = TypeVar('B', bound='Button')
+
+
+class Button(Item):
+    """Represents a UI button.
+
+    .. versionadded:: 2.0
+
+    Parameters
+    ------------
+    style: :class:`discord.ButtonStyle`
+        The style of the button.
+    custom_id: Optional[:class:`str`]
+        The ID of the button that gets received during an interaction.
+        If this button is for a URL, it does not have a custom ID.
+    url: Optional[:class:`str`]
+        The URL this button sends you to.
+    disabled: :class:`bool`
+        Whether the button is disabled or not.
+    label: :class:`str`
+        The label of the button.
+    emoji: Optional[:class:`PartialEmoji`]
+        The emoji of the button, if available.
+    """
+
+    __slots__: Tuple[str, ...] = Item.__slots__ + ('_underlying',)
+
+    __item_repr_attributes__: Tuple[str, ...] = (
+        'style',
+        'url',
+        'disabled',
+        'label',
+        'emoji',
+        'group_id',
+    )
+
+    def __init__(
+        self,
+        *,
+        style: ButtonStyle,
+        label: str,
+        disabled: bool = False,
+        custom_id: Optional[str] = None,
+        url: Optional[str] = None,
+        emoji: Optional[Union[str, PartialEmoji]] = None,
+        group: Optional[int] = None,
+    ):
+        super().__init__()
+        if custom_id is not None and url is not None:
+            raise TypeError('cannot mix both url and custom_id with Button')
+
+        if url is None and custom_id is None:
+            custom_id = os.urandom(16).hex()
+
+        self._underlying = ButtonComponent._raw_construct(
+            type=ComponentType.button,
+            custom_id=custom_id,
+            url=url,
+            disabled=disabled,
+            label=label,
+            style=style,
+            emoji=None if emoji is None else _to_partial_emoji(emoji),
+        )
+        self.group_id = group
+
+    @property
+    def style(self) -> ButtonStyle:
+        """:class:`discord.ButtonStyle`: The style of the button."""
+        return self._underlying.style
+
+    @style.setter
+    def style(self, value: ButtonStyle):
+        self._underlying.style = value
+
+    @property
+    def custom_id(self) -> Optional[str]:
+        """Optional[:class:`str`]: The ID of the button that gets received during an interaction.
+
+        If this button is for a URL, it does not have a custom ID.
+        """
+        return self._underlying.custom_id
+
+    @custom_id.setter
+    def custom_id(self, value: Optional[str]):
+        if value is not None and not isinstance(value, str):
+            raise TypeError('custom_id must be None or str')
+
+        self._underlying.custom_id = value
+
+    @property
+    def url(self) -> Optional[str]:
+        """Optional[:class:`str`]: The URL this button sends you to."""
+        return self._underlying.url
+
+    @url.setter
+    def url(self, value: Optional[str]):
+        if value is not None and not isinstance(value, str):
+            raise TypeError('url must be None or str')
+        self._underlying.url = value
+
+    @property
+    def disabled(self) -> bool:
+        """:class:`bool`: Whether the button is disabled or not."""
+        return self._underlying.disabled
+
+    @disabled.setter
+    def disabled(self, value: bool):
+        self._underlying.disabled = bool(value)
+
+    @property
+    def label(self) -> str:
+        """:class:`str`: The label of the button."""
+        return self._underlying.label
+
+    @label.setter
+    def label(self, value: str):
+        self._underlying.label = str(value)
+
+    @property
+    def emoji(self) -> Optional[PartialEmoji]:
+        """Optional[:class:`PartialEmoji`]: The emoji of the button, if available."""
+        return self._underlying.emoji
+
+    @emoji.setter
+    def emoji(self, value: Optional[Union[str, PartialEmoji]]):  # type: ignore
+        if value is not None:
+            self._underlying.emoji = _to_partial_emoji(value)
+        else:
+            self._underlying.emoji = None
+
+    def copy(self: B) -> B:
+        button = self.__class__(
+            style=self.style,
+            label=self.label,
+            disabled=self.disabled,
+            custom_id=self.custom_id,
+            url=self.url,
+            emoji=self.emoji,
+            group=self.group_id,
+        )
+        button.callback = self.callback
+        return button
+
+    @classmethod
+    def from_component(cls: Type[B], button: ButtonComponent) -> B:
+        return cls(
+            style=button.style,
+            label=button.label,
+            disabled=button.disabled,
+            custom_id=button.custom_id,
+            url=button.url,
+            emoji=button.emoji,
+            group=None,
+        )
+
+    @property
+    def type(self) -> ComponentType:
+        return self._underlying.type
+
+    def to_component_dict(self):
+        return self._underlying.to_dict()
+
+    def is_dispatchable(self) -> bool:
+        return True
+
+    def refresh_state(self, button: ButtonComponent) -> None:
+        self._underlying = button
+
+
+def button(
+    label: str,
+    *,
+    custom_id: Optional[str] = None,
+    disabled: bool = False,
+    style: ButtonStyle = ButtonStyle.grey,
+    emoji: Optional[Union[str, PartialEmoji]] = None,
+    group: Optional[int] = None,
+) -> Callable[[ItemCallbackType], Button]:
+    """A decorator that attaches a button to a component.
+
+    The function being decorated should have three parameters, ``self`` representing
+    the :class:`discord.ui.View`, the :class:`discord.ui.Button` being pressed and
+    the :class:`discord.Interaction` you receive.
+
+    .. note::
+
+        Buttons with a URL cannot be created with this function.
+        Consider creating a :class:`Button` manually instead.
+        This is because buttons with a URL do not have a callback
+        associated with them since Discord does not do any processing
+        with it.
+
+    Parameters
+    ------------
+    label: :class:`str`
+        The label of the button.
+    custom_id: Optional[:class:`str`]
+        The ID of the button that gets received during an interaction.
+        It is recommended not to set this parameter to prevent conflicts.
+    style: :class:`ButtonStyle`
+        The style of the button. Defaults to :attr:`ButtonStyle.grey`.
+    disabled: :class:`bool`
+        Whether the button is disabled or not. Defaults to ``False``.
+    emoji: Optional[Union[:class:`str`, :class:`PartialEmoji`]]
+        The emoji of the button. This can be in string form or a :class:`PartialEmoji`.
+    group: Optional[:class:`int`]
+        The relative group this button belongs to. A Discord component can only have 5
+        groups. By default, items are arranged automatically into those 5 groups. If you'd
+        like to control the relative positioning of the group then passing an index is advised.
+        For example, group=1 will show up before group=2. Defaults to ``None``, which is automatic
+        ordering.
+    """
+
+    def decorator(func: ItemCallbackType) -> Button:
+        nonlocal custom_id
+        if not inspect.iscoroutinefunction(func):
+            raise TypeError('button function must be a coroutine function')
+
+        custom_id = custom_id or os.urandom(32).hex()
+        button = Button(style=style, custom_id=custom_id, url=None, disabled=disabled, label=label, emoji=emoji, group=group)
+        button.callback = func
+        return button
+
+    return decorator
diff --git a/discord/ui/item.py b/discord/ui/item.py
new file mode 100644
index 00000000..7726407e
--- /dev/null
+++ b/discord/ui/item.py
@@ -0,0 +1,140 @@
+"""
+The MIT License (MIT)
+
+Copyright (c) 2015-present 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.
+"""
+
+from __future__ import annotations
+
+from typing import Any, Callable, Coroutine, Dict, Optional, TYPE_CHECKING, Tuple, Type, TypeVar, Union
+import inspect
+
+from ..interactions import Interaction
+
+__all__ = (
+    'Item',
+)
+
+if TYPE_CHECKING:
+    from ..enums import ComponentType
+    from .view import View
+    from ..components import Component
+
+I = TypeVar('I', bound='Item')
+ItemCallbackType = Callable[[Any, I, Interaction], Coroutine[Any, Any, Any]]
+
+
+class Item:
+    """Represents the base UI item that all UI components inherit from.
+
+    The current UI items supported are:
+
+    - :class:`discord.ui.Button`
+    """
+
+    __slots__: Tuple[str, ...] = (
+        '_callback',
+        '_pass_view_arg',
+        'group_id',
+    )
+
+    __item_repr_attributes__: Tuple[str, ...] = ('group_id',)
+
+    def __init__(self):
+        self._callback: Optional[ItemCallbackType] = None
+        self._pass_view_arg = True
+        self.group_id: Optional[int] = None
+
+    def to_component_dict(self) -> Dict[str, Any]:
+        raise NotImplementedError
+
+    def copy(self: I) -> I:
+        raise NotImplementedError
+
+    def refresh_state(self, component: Component) -> None:
+        return None
+
+    @classmethod
+    def from_component(cls: Type[I], component: Component) -> I:
+        return cls()
+
+    @property
+    def type(self) -> ComponentType:
+        raise NotImplementedError
+
+    def is_dispatchable(self) -> bool:
+        return False
+
+    def __repr__(self) -> str:
+        attrs = ' '.join(f'{key}={getattr(self, key)!r}' for key in self.__item_repr_attributes__)
+        return f'<{self.__class__.__name__} {attrs}>'
+
+    @property
+    def callback(self) -> Optional[ItemCallbackType]:
+        """Returns the underlying callback associated with this interaction."""
+        return self._callback
+
+    @callback.setter
+    def callback(self, value: Optional[ItemCallbackType]):
+        if value is None:
+            self._callback = None
+            return
+
+        # Check if it's a partial function
+        try:
+            partial = value.func
+        except AttributeError:
+            pass
+        else:
+            if not inspect.iscoroutinefunction(value.func):
+                raise TypeError(f'inner partial function must be a coroutine')
+
+            # Check if the partial is bound
+            try:
+                bound_partial = partial.__self__
+            except AttributeError:
+                pass
+            else:
+                self._pass_view_arg = not hasattr(bound_partial, '__discord_ui_view__')
+
+            self._callback = value
+            return
+
+        try:
+            func_self = value.__self__
+        except AttributeError:
+            pass
+        else:
+            if not isinstance(func_self, Item):
+                raise TypeError(f'callback bound method must be from Item not {func_self!r}')
+            else:
+                value = value.__func__
+
+        if not inspect.iscoroutinefunction(value):
+            raise TypeError(f'callback must be a coroutine not {value!r}')
+
+        self._callback = value
+
+    async def _do_call(self, view: View, interaction: Interaction):
+        if self._pass_view_arg:
+            await self._callback(view, self, interaction)
+        else:
+            await self._callback(self, interaction)  # type: ignore
diff --git a/discord/ui/view.py b/discord/ui/view.py
new file mode 100644
index 00000000..273a45d0
--- /dev/null
+++ b/discord/ui/view.py
@@ -0,0 +1,270 @@
+"""
+The MIT License (MIT)
+
+Copyright (c) 2015-present 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.
+"""
+
+from __future__ import annotations
+from typing import Any, Callable, ClassVar, Dict, Iterator, List, Optional, TYPE_CHECKING, Tuple
+from functools import partial
+from itertools import groupby
+
+import asyncio
+import sys
+import time
+import os
+from .item import Item
+from ..enums import ComponentType
+from ..components import (
+    Component,
+    _component_factory,
+    Button as ButtonComponent,
+)
+
+__all__ = (
+    'View',
+)
+
+
+if TYPE_CHECKING:
+    from ..interactions import Interaction
+    from ..types.components import Component as ComponentPayload
+
+
+def _walk_all_components(components: List[Component]) -> Iterator[Component]:
+    for item in components:
+        if item.type is ComponentType.group:
+            yield from item.children
+        else:
+            yield item
+
+
+def _component_to_item(component: Component) -> Item:
+    if isinstance(component, ButtonComponent):
+        from .button import Button
+
+        return Button.from_component(component)
+    return Item.from_component(component)
+
+
+class View:
+    """Represents a UI view.
+
+    This object must be inherited to create a UI within Discord.
+
+    Parameters
+    -----------
+    timeout: Optional[:class:`float`]
+        Timeout from last interaction with the UI before no longer accepting input.
+        If ``None`` then there is no timeout.
+
+    Attributes
+    ------------
+    timeout: Optional[:class:`float`]
+        Timeout from last interaction with the UI before no longer accepting input.
+        If ``None`` then there is no timeout.
+    children: List[:class:`Item`]
+        The list of children attached to this view.
+    """
+
+    __slots__ = (
+        'timeout',
+        'children',
+        'id',
+        '_cancel_callback',
+    )
+
+    __discord_ui_view__: ClassVar[bool] = True
+
+    if TYPE_CHECKING:
+        __view_children_items__: ClassVar[List[Item]]
+
+    def __init_subclass__(cls) -> None:
+        children: List[Item] = []
+        for base in reversed(cls.__mro__):
+            for member in base.__dict__.values():
+                if isinstance(member, Item):
+                    children.append(member)
+
+        if len(children) > 25:
+            raise TypeError('View cannot have more than 25 children')
+
+        cls.__view_children_items__ = children
+
+    def __init__(self, timeout: Optional[float] = 180.0):
+        self.timeout = timeout
+        self.children: List[Item] = [i.copy() for i in self.__view_children_items__]
+        self.id = os.urandom(16).hex()
+        self._cancel_callback: Optional[Callable[[View], None]] = None
+
+    def to_components(self) -> List[Dict[str, Any]]:
+        def key(item: Item) -> int:
+            if item.group_id is None:
+                return sys.maxsize
+            return item.group_id
+
+        children = sorted(self.children, key=key)
+        components: List[Dict[str, Any]] = []
+        for _, group in groupby(children, key=key):
+            group = list(group)
+            if len(group) <= 5:
+                components.append(
+                    {
+                        'type': 1,
+                        'components': [item.to_component_dict() for item in group],
+                    }
+                )
+            else:
+                components.extend(
+                    {
+                        'type': 1,
+                        'components': [item.to_component_dict() for item in group[index : index + 5]],
+                    }
+                    for index in range(0, len(group), 5)
+                )
+
+        return components
+
+    @property
+    def _expires_at(self) -> Optional[float]:
+        if self.timeout:
+            return time.monotonic() + self.timeout
+        return None
+
+    def add_item(self, item: Item) -> None:
+        """Adds an item to the view.
+
+        Parameters
+        -----------
+        item: :class:`Item`
+            The item to add to the view.
+
+        Raises
+        --------
+        TypeError
+            A :class:`Item` was not passed.
+        ValueError
+            Maximum number of children has been exceeded (25).
+        """
+
+        if len(self.children) > 25:
+            raise ValueError('maximum number of children exceeded')
+
+        if not isinstance(item, Item):
+            raise TypeError(f'expected Item not {item.__class__!r}')
+
+        self.children.append(item)
+
+    async def _scheduled_task(self, state: Any, item: Item, interaction: Interaction):
+        await state.http.create_interaction_response(interaction.id, interaction.token, type=6)
+        await item._do_call(self, interaction)
+
+    def dispatch(self, state: Any, item: Item, interaction: Interaction):
+        asyncio.create_task(self._scheduled_task(state, item, interaction), name=f'discord-ui-view-dispatch-{self.id}')
+
+    def refresh(self, components: List[Component]):
+        # This is pretty hacky at the moment
+        # fmt: off
+        old_state: Dict[Tuple[int, str], Item] = {
+            (item.type.value, item.custom_id): item  # type: ignore
+            for item in self.children
+            if item.is_dispatchable()
+        }
+        # fmt: on
+        children: List[Item] = []
+        for component in _walk_all_components(components):
+            try:
+                older = old_state[(component.type.value, component.custom_id)]  # type: ignore
+            except (KeyError, AttributeError):
+                children.append(_component_to_item(component))
+            else:
+                older.refresh_state(component)
+                children.append(older)
+
+        self.children = children
+
+    def stop(self) -> None:
+        """Stops listening to interaction events from this view.
+
+        This operation cannot be undone.
+        """
+        if self._cancel_callback:
+            self._cancel_callback(self)
+
+
+class ViewStore:
+    def __init__(self, state):
+        # (component_type, custom_id): (View, Item, Expiry)
+        self._views: Dict[Tuple[int, str], Tuple[View, Item, Optional[float]]] = {}
+        # message_id: View
+        self._synced_message_views: Dict[int, View] = {}
+        self._state = state
+
+    def __verify_integrity(self):
+        to_remove: List[Tuple[int, str]] = []
+        now = time.monotonic()
+        for (k, (_, _, expiry)) in self._views.items():
+            if expiry is not None and now >= expiry:
+                to_remove.append(k)
+
+        for k in to_remove:
+            del self._views[k]
+
+    def add_view(self, view: View, message_id: Optional[int] = None):
+        self.__verify_integrity()
+
+        expiry = view._expires_at
+        view._cancel_callback = partial(self.remove_view)
+        for item in view.children:
+            if item.is_dispatchable():
+                self._views[(item.type.value, item.custom_id)] = (view, item, expiry)  # type: ignore
+
+        if message_id is not None:
+            self._synced_message_views[message_id] = view
+
+    def remove_view(self, view: View):
+        for item in view.children:
+            if item.is_dispatchable():
+                self._views.pop((item.type.value, item.custom_id))  # type: ignore
+
+        for key, value in self._synced_message_views.items():
+            if value.id == view.id:
+                del self._synced_message_views[key]
+                break
+
+    def dispatch(self, component_type: int, custom_id: str, interaction: Interaction):
+        self.__verify_integrity()
+        key = (component_type, custom_id)
+        value = self._views.get(key)
+        if value is None:
+            return
+
+        view, item, _ = value
+        self._views[key] = (view, item, view._expires_at)
+        view.dispatch(self._state, item, interaction)
+
+    def is_message_tracked(self, message_id: int):
+        return message_id in self._synced_message_views
+
+    def update_view(self, message_id: int, components: List[ComponentPayload]):
+        # pre-req: is_message_tracked == true
+        view = self._synced_message_views[message_id]
+        view.refresh([_component_factory(d) for d in components])