import os
from pathlib import Path
from shutil import copytree, rmtree

CURRENT_DIR = Path(__file__).parent
STATIC_OUTPUT_DIR = CURRENT_DIR / "anime/static"
FRONTEND_DIR = CURRENT_DIR / "frontend"
DIST_DIR = FRONTEND_DIR / "dist"


class DirChanger:
    """Class for changing current directory and returning back after exit."""

    def __init__(self, path: Path):
        self.path = path

    def __enter__(self):
        os.chdir(self.path)

    def __exit__(self, *args):
        os.chdir(CURRENT_DIR)


def build():
    """
    Build frontend and copy it to the static directory.

    This script is useful for packaging the application.
    """
    print("Starting building frontend ...")

    with DirChanger(CURRENT_DIR / "frontend"):
        ret_status = os.system("pnpm build")
        if ret_status != 0:
            raise Exception("Frontend build failed.")

    print("Frontend build finished.")
    rmtree(STATIC_OUTPUT_DIR, ignore_errors=True)
    copytree(symlinks=True, src=DIST_DIR, dst=STATIC_OUTPUT_DIR)


if __name__ == "__main__":
    build()