cartridges/cartridges/store/managers/cover_manager.py

# local_cover_manager.py
#
# Copyright 2023 Geoffrey Coulaud
# Copyright 2023 kramo
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# SPDX-License-Identifier: GPL-3.0-or-later

from pathlib import Path
from typing import NamedTuple

import requests
from gi.repository import GdkPixbuf, Gio
from requests.exceptions import HTTPError, SSLError

from cartridges import shared
from cartridges.game import Game
from cartridges.store.managers.manager import Manager
from cartridges.store.managers.steam_api_manager import SteamAPIManager
from cartridges.utils.save_cover import convert_cover, save_cover


class ImageSize(NamedTuple):
    width: float = 0
    height: float = 0

    @property
    def aspect_ratio(self) -> float:
        return self.width / self.height

    def __str__(self):
        return f"{self.width}x{self.height}"

    def __mul__(self, scale: float | int) -> "ImageSize":
        return ImageSize(
            self.width * scale,
            self.height * scale,
        )

    def __truediv__(self, divisor: float | int) -> "ImageSize":
        return self * (1 / divisor)

    def __add__(self, other_size: "ImageSize") -> "ImageSize":
        return ImageSize(
            self.width + other_size.width,
            self.height + other_size.height,
        )

    def __sub__(self, other_size: "ImageSize") -> "ImageSize":
        return self + (other_size * -1)

    def element_wise_div(self, other_size: "ImageSize") -> "ImageSize":
        """Divide every element of self by the equivalent in the other size"""
        return ImageSize(
            self.width / other_size.width,
            self.height / other_size.height,
        )

    def element_wise_mul(self, other_size: "ImageSize") -> "ImageSize":
        """Multiply every element of self by the equivalent in the other size"""
        return ImageSize(
            self.width * other_size.width,
            self.height * other_size.height,
        )

    def invert(self) -> "ImageSize":
        """Invert the element of self"""
        return ImageSize(1, 1).element_wise_div(self)


class CoverManager(Manager):
    """
    Manager in charge of adding the cover image of the game

    Order of priority is:
    1. local cover
    2. icon cover
    3. online cover
    """

    run_after = (SteamAPIManager,)
    retryable_on = (HTTPError, SSLError, ConnectionError)

    def download_image(self, url: str) -> Path:
        image_file = Gio.File.new_tmp()[0]
        path = Path(image_file.get_path())
        with requests.get(url, timeout=5) as cover:
            cover.raise_for_status()
            path.write_bytes(cover.content)
        return path

    def is_stretchable(self, source_size: ImageSize, cover_size: ImageSize) -> bool:
        is_taller = source_size.aspect_ratio < cover_size.aspect_ratio
        if is_taller:
            return True
        max_stretch = 0.12
        resized_height = (1 / source_size.aspect_ratio) * cover_size.width
        stretch = 1 - (resized_height / cover_size.height)
        return stretch <= max_stretch

    def composite_cover(
        self,
        image_path: Path,
        scale: float = 1,
        blur_size: ImageSize = ImageSize(2, 2),
    ) -> GdkPixbuf.Pixbuf:
        """
        Return the image composited with a background blur.
        If the image is stretchable, just stretch it.

        :param path: Path where the source image is located
        :param scale:
            Scale of the smalled image side
            compared to the corresponding side in the cover
        :param blur_size: Size of the downscaled image used for the blur
        """

        # Load source image
        source = GdkPixbuf.Pixbuf.new_from_file(
            str(convert_cover(image_path, resize=False))
        )
        source_size = ImageSize(source.get_width(), source.get_height())
        cover_size = ImageSize._make(shared.image_size)

        # Stretch if possible
        if scale == 1 and self.is_stretchable(source_size, cover_size):
            return source

        # Create the blurred cover background
        # fmt: off
        cover = (
            source
            .scale_simple(*blur_size, GdkPixbuf.InterpType.BILINEAR)
            .scale_simple(*cover_size, GdkPixbuf.InterpType.BILINEAR)
        )
        # fmt: on

        # Scale to fit, apply scaling, then center
        uniform_scale = scale * min(cover_size.element_wise_div(source_size))
        source_in_cover_size = source_size * uniform_scale
        source_in_cover_position = (cover_size - source_in_cover_size) / 2

        # Center the scaled source image in the cover
        source.composite(
            cover,
            *source_in_cover_position,
            *source_in_cover_size,
            *source_in_cover_position,
            uniform_scale,
            uniform_scale,
            GdkPixbuf.InterpType.BILINEAR,
            255,
        )
        return cover

    def main(self, game: Game, additional_data: dict) -> None:
        if game.blacklisted:
            return
        for key in (
            "local_image_path",
            "local_icon_path",
            "online_cover_url",
        ):
            # Get an image path
            if not (value := additional_data.get(key)):
                continue
            if key == "online_cover_url":
                image_path = self.download_image(value)
            else:
                image_path = Path(value)
            if not image_path.is_file():
                continue

            # Icon cover
            composite_kwargs = {}

            if key == "local_icon_path":
                composite_kwargs["scale"] = 0.7
                composite_kwargs["blur_size"] = ImageSize(1, 2)

            save_cover(
                game.game_id,
                convert_cover(
                    pixbuf=self.composite_cover(image_path, **composite_kwargs)
                ),
            )