# SPDX-License-Identifier: MIT

from __future__ import annotations

import io
import os
from typing import TYPE_CHECKING, Any, Literal, Optional, Tuple, Union

import yarl

from . import utils
from .errors import DiscordException, InvalidArgument
from .file import File

__all__ = ("Asset",)

if TYPE_CHECKING:
    ValidStaticFormatTypes = Literal["webp", "jpeg", "jpg", "png"]
    ValidAssetFormatTypes = Literal["webp", "jpeg", "jpg", "png", "gif"]

VALID_STATIC_FORMATS = frozenset({"jpeg", "jpg", "webp", "png"})
VALID_ASSET_FORMATS = VALID_STATIC_FORMATS | {"gif"}


MISSING = utils.MISSING


class AssetMixin:
    url: str
    _state: Optional[Any]
    __slots__: tuple[str, ...] = ()

    async def read(self) -> bytes:
        """|coro|

        Retrieves the content of this asset as a :class:`bytes` object.

        Raises
        ------
        DiscordException
            There was no internal connection state.
        HTTPException
            Downloading the asset failed.
        NotFound
            The asset was deleted.

        Returns
        -------
        :class:`bytes`
            The content of the asset.
        """
        if self._state is None:
            raise DiscordException("Invalid state (no ConnectionState provided)")

        return await self._state.http.get_from_cdn(self.url)

    async def save(
        self, fp: Union[str, bytes, os.PathLike, io.BufferedIOBase], *, seek_begin: bool = True
    ) -> int:
        """|coro|

        Saves this asset into a file-like object.

        Parameters
        ----------
        fp: Union[:class:`io.BufferedIOBase`, :class:`os.PathLike`]
            The file-like object to save this asset to or the filename
            to use. If a filename is passed then a file is created with that
            filename and used instead.
        seek_begin: :class:`bool`
            Whether to seek to the beginning of the file after saving is
            successfully done.

        Raises
        ------
        DiscordException
            There was no internal connection state.
        HTTPException
            Downloading the asset failed.
        NotFound
            The asset was deleted.

        Returns
        -------
        :class:`int`
            The number of bytes written.
        """

        data = await self.read()
        if isinstance(fp, io.BufferedIOBase):
            written = fp.write(data)
            if seek_begin:
                fp.seek(0)
            return written
        else:
            with open(fp, "wb") as f:
                return f.write(data)

    async def to_file(
        self,
        *,
        filename: Optional[str] = MISSING,
        description: Optional[str] = None,
        spoiler: bool = False,
        force_close: bool = True,
    ) -> File:
        """|coro|

        Converts the asset into a :class:`File` suitable for sending via
        :meth:`abc.Messageable.send`.

        .. versionadded:: 2.0

        Parameters
        ----------
        filename: Optional[:class:`str`]
            The filename of the file. If not provided, then the filename from
            the asset's URL is used.
        description: Optional[:class:`str`]
            The description for the file.
        spoiler: :class:`bool`
            Whether the file is a spoiler.
        force_close: :class:`bool`
            Whether to forcibly close the bytes used to create the file
            when ``.close()`` is called.
            This will also make the file bytes unusable by flushing it from
            memory after it is sent or used once.
            Keep this enabled if you don't wish to reuse the same bytes.

            .. versionadded:: 2.2

        Raises
        ------
        DiscordException
            The asset does not have an associated state.
        InvalidArgument
            The asset is a unicode emoji.
        TypeError
            The asset is a sticker with lottie type.
        HTTPException
            Downloading the asset failed.
        NotFound
            The asset was deleted.

        Returns
        -------
        :class:`File`
            The asset as a file suitable for sending.
        """

        data = await self.read()
        file_filename = filename if filename is not MISSING else yarl.URL(self.url).name
        return File(
            io.BytesIO(data),
            filename=file_filename,
            description=description,
            spoiler=spoiler,
            force_close=force_close,
        )


class Asset(AssetMixin):
    """Represents a CDN asset on Discord.

    .. container:: operations

        .. describe:: str(x)

            Returns the URL of the CDN asset.

        .. describe:: len(x)

            Returns the length of the CDN asset's URL.

        .. describe:: x == y

            Checks if the asset is equal to another asset.

        .. describe:: x != y

            Checks if the asset is not equal to another asset.

        .. describe:: hash(x)

            Returns the hash of the asset.
    """

    __slots__: Tuple[str, ...] = (
        "_state",
        "_url",
        "_animated",
        "_key",
    )

    BASE = "https://cdn.discordapp.com"

    def __init__(self, state, *, url: str, key: str, animated: bool = False) -> None:
        self._state = state
        self._url = url
        self._animated = animated
        self._key = key

    @classmethod
    def _from_default_avatar(cls, state, index: int) -> Asset:
        return cls(
            state,
            url=f"{cls.BASE}/embed/avatars/{index}.png",
            key=str(index),
            animated=False,
        )

    @classmethod
    def _from_avatar(cls, state, user_id: int, avatar: str) -> Asset:
        animated = avatar.startswith("a_")
        format = "gif" if animated else "png"
        return cls(
            state,
            url=f"{cls.BASE}/avatars/{user_id}/{avatar}.{format}?size=1024",
            key=avatar,
            animated=animated,
        )

    @classmethod
    def _from_guild_avatar(cls, state, guild_id: int, member_id: int, avatar: str) -> Asset:
        animated = avatar.startswith("a_")
        format = "gif" if animated else "png"
        return cls(
            state,
            url=f"{cls.BASE}/guilds/{guild_id}/users/{member_id}/avatars/{avatar}.{format}?size=1024",
            key=avatar,
            animated=animated,
        )

    @classmethod
    def _from_icon(cls, state, object_id: int, icon_hash: str, path: str) -> Asset:
        return cls(
            state,
            url=f"{cls.BASE}/{path}-icons/{object_id}/{icon_hash}.png?size=1024",
            key=icon_hash,
            animated=False,
        )

    @classmethod
    def _from_cover_image(cls, state, object_id: int, cover_image_hash: str) -> Asset:
        return cls(
            state,
            url=f"{cls.BASE}/app-assets/{object_id}/store/{cover_image_hash}.png?size=1024",
            key=cover_image_hash,
            animated=False,
        )

    @classmethod
    def _from_guild_image(cls, state, guild_id: int, image: str, path: str) -> Asset:
        animated = False
        format = "png"
        if path == "banners":
            animated = image.startswith("a_")
            format = "gif" if animated else "png"

        return cls(
            state,
            url=f"{cls.BASE}/{path}/{guild_id}/{image}.{format}?size=1024",
            key=image,
            animated=animated,
        )

    @classmethod
    def _from_guild_icon(cls, state, guild_id: int, icon_hash: str) -> Asset:
        animated = icon_hash.startswith("a_")
        format = "gif" if animated else "png"
        return cls(
            state,
            url=f"{cls.BASE}/icons/{guild_id}/{icon_hash}.{format}?size=1024",
            key=icon_hash,
            animated=animated,
        )

    @classmethod
    def _from_sticker_banner(cls, state, banner: int) -> Asset:
        return cls(
            state,
            url=f"{cls.BASE}/app-assets/710982414301790216/store/{banner}.png",
            key=str(banner),
            animated=False,
        )

    @classmethod
    def _from_user_banner(cls, state, user_id: int, banner_hash: str) -> Asset:
        animated = banner_hash.startswith("a_")
        format = "gif" if animated else "png"
        return cls(
            state,
            url=f"{cls.BASE}/banners/{user_id}/{banner_hash}.{format}?size=512",
            key=banner_hash,
            animated=animated,
        )

    @classmethod
    def _from_scheduled_event_image(cls, state, event_id: int, image_hash: str) -> Asset:
        return cls(
            state,
            url=f"{cls.BASE}/guild-events/{event_id}/{image_hash}.png",
            key=image_hash,
            animated=False,
        )

    def __str__(self) -> str:
        return self._url

    def __len__(self) -> int:
        return len(self._url)

    def __repr__(self) -> str:
        shorten = self._url.replace(self.BASE, "")
        return f"<Asset url={shorten!r}>"

    def __eq__(self, other):
        return isinstance(other, Asset) and self._url == other._url

    def __hash__(self):
        return hash(self._url)

    @property
    def url(self) -> str:
        """:class:`str`: Returns the underlying URL of the asset."""
        return self._url

    @property
    def key(self) -> str:
        """:class:`str`: Returns the identifying key of the asset."""
        return self._key

    def is_animated(self) -> bool:
        """:class:`bool`: Returns whether the asset is animated."""
        return self._animated

    def replace(
        self,
        *,
        size: int = MISSING,
        format: ValidAssetFormatTypes = MISSING,
        static_format: ValidStaticFormatTypes = MISSING,
    ) -> Asset:
        """Returns a new asset with the passed components replaced.

        Parameters
        ----------
        size: :class:`int`
            The new size of the asset.
        format: :class:`str`
            The new format to change it to. Must be either
            'webp', 'jpeg', 'jpg', 'png', or 'gif' if it's animated.
        static_format: :class:`str`
            The new format to change it to if the asset isn't animated.
            Must be either 'webp', 'jpeg', 'jpg', or 'png'.

        Raises
        ------
        InvalidArgument
            An invalid size or format was passed.

        Returns
        -------
        :class:`Asset`
            The newly updated asset.
        """
        url = yarl.URL(self._url)
        path, _ = os.path.splitext(url.path)

        if format is not MISSING:
            if self._animated:
                if format not in VALID_ASSET_FORMATS:
                    raise InvalidArgument(f"format must be one of {VALID_ASSET_FORMATS}")
                url = url.with_path(f"{path}.{format}")
            elif static_format is MISSING:
                if format not in VALID_STATIC_FORMATS:
                    raise InvalidArgument(f"format must be one of {VALID_STATIC_FORMATS}")
                url = url.with_path(f"{path}.{format}")

        if static_format is not MISSING and not self._animated:
            if static_format not in VALID_STATIC_FORMATS:
                raise InvalidArgument(f"static_format must be one of {VALID_STATIC_FORMATS}")
            url = url.with_path(f"{path}.{static_format}")

        if size is not MISSING:
            if not utils.valid_icon_size(size):
                raise InvalidArgument("size must be a power of 2 between 16 and 4096")
            url = url.with_query(size=size)
        else:
            url = url.with_query(url.raw_query_string)

        url = str(url)
        return Asset(state=self._state, url=url, key=self._key, animated=self._animated)

    def with_size(self, size: int, /) -> Asset:
        """Returns a new asset with the specified size.

        Parameters
        ----------
        size: :class:`int`
            The new size of the asset.

        Raises
        ------
        InvalidArgument
            The asset had an invalid size.

        Returns
        -------
        :class:`Asset`
            The new updated asset.
        """
        if not utils.valid_icon_size(size):
            raise InvalidArgument("size must be a power of 2 between 16 and 4096")

        url = str(yarl.URL(self._url).with_query(size=size))
        return Asset(state=self._state, url=url, key=self._key, animated=self._animated)

    def with_format(self, format: ValidAssetFormatTypes, /) -> Asset:
        """Returns a new asset with the specified format.

        Parameters
        ----------
        format: :class:`str`
            The new format of the asset.

        Raises
        ------
        InvalidArgument
            The asset had an invalid format.

        Returns
        -------
        :class:`Asset`
            The new updated asset.
        """

        if self._animated:
            if format not in VALID_ASSET_FORMATS:
                raise InvalidArgument(f"format must be one of {VALID_ASSET_FORMATS}")
        else:
            if format not in VALID_STATIC_FORMATS:
                raise InvalidArgument(f"format must be one of {VALID_STATIC_FORMATS}")

        url = yarl.URL(self._url)
        path, _ = os.path.splitext(url.path)
        url = str(url.with_path(f"{path}.{format}").with_query(url.raw_query_string))
        return Asset(state=self._state, url=url, key=self._key, animated=self._animated)

    def with_static_format(self, format: ValidStaticFormatTypes, /) -> Asset:
        """Returns a new asset with the specified static format.

        This only changes the format if the underlying asset is
        not animated. Otherwise, the asset is not changed.

        Parameters
        ----------
        format: :class:`str`
            The new static format of the asset.

        Raises
        ------
        InvalidArgument
            The asset had an invalid format.

        Returns
        -------
        :class:`Asset`
            The new updated asset.
        """

        if self._animated:
            return self
        return self.with_format(format)
