import platform
import sys
from pathlib import Path
from shutil import rmtree

if (system := platform.system()) != "Linux":
    raise SystemExit(f"{system} is not supported")


def find_hd2_shadercache():
    HD2_APPID = "553850"
    registry = Path.home().joinpath(".steam/steam/steamapps/libraryfolders.vdf")

    if not registry.exists():
        raise RuntimeError("Steam is not installed")

    with registry.open() as fd:
        for line in fd:
            if '"path"' in line:
                path = Path(line.split(maxsplit=1)[1].replace('"', "").rstrip())
            elif HD2_APPID in line:
                shader_cache = path.joinpath("steamapps/shadercache", HD2_APPID)
                if not shader_cache.exists():
                    raise RuntimeError("Shader cache of HELLDIVERS2 not found")
                return shader_cache

    raise RuntimeError("HELLDIVERS2 not found")


def human_size(size: int) -> str:
    for unit in ("", "KiB", "MiB", "GiB"):
        if size < 1024:
            break
        size /= 1024

    return f"{size:.2f} {unit}"


def get_size_ext(path: Path) -> (int, set[str]):
    files = [element for element in path.rglob("*") if element.is_file()]
    return sum(element.stat().st_size for element in files), {
        suffix for file in files if (suffix := file.suffix)
    }


def ask_delete(shader_cache: Path):
    print("Calculating size of shader cache")
    size, extensions_found = get_size_ext(shader_cache)

    print("Detected Path:", shader_cache)
    print("Size:", human_size(size))
    print("Found extensions:", " / ".join(sorted(extensions_found)))

    user_input = input("Do you want to delete the shader cache? [n/y]: ")
    if user_input.lower() == "y":
        print(f"Deleting path: {shader_cache}")
        rmtree(shader_cache)
    else:
        print("Keeping shader cache")


def main():
    RED = "\033[0;31m"
    NO_COLOR = "\033[0m"

    try:
        ask_delete(find_hd2_shadercache())

    except Exception as e:
        info = "no furter information"

        if e.args:
            info = e.args[0]

        print(f"{type(e).__name__}: {RED}{info}{NO_COLOR}")
        return 1
    except KeyboardInterrupt:
        print("\nKeyboardInterrupt")
        return 1

    return 0


if __name__ == "__main__":
    sys.exit(main())