#!/usr/bin/env python

# pkg
# Copyright (C) 2021-present  Michael Serajnik  https://sr.ht/~mser/
# Copyright (C) 2021-present  Chris Braun  https://github.com/cryzed

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import argparse
import enum
import os
import pathlib
import shutil
import subprocess
import sys
import typing as T

BASE_PATH = pathlib.Path(sys.argv[0]).parent.resolve()
PACKAGES_PATH = BASE_PATH / "packages"
REPOSITORY_PATH = BASE_PATH / "repository"

PathType = T.Union[str, os.PathLike]


class ExitCode(enum.IntEnum):
    SUCCESS = 0
    FAILURE = 1


def get_argument_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        formatter_class=argparse.ArgumentDefaultsHelpFormatter
    )
    return parser


def get_path(path: PathType) -> pathlib.Path:
    return path if isinstance(path, pathlib.Path) else pathlib.Path(path)


def get_all_packages() -> set[str]:
    return {path.name for path in PACKAGES_PATH.glob("*")}


def get_updated_packages(
    git_repo_path: PathType = pathlib.Path().resolve(),
) -> set[str]:
    process = subprocess.run(
        ["git", "log", "-1", "--name-only", "--oneline"],
        cwd=git_repo_path,
        stdout=subprocess.PIPE,
        text=True,
    )
    packages = set()
    for line in process.stdout.splitlines():
        if not (line := line.strip()):
            continue

        path = pathlib.Path(line)
        if len(path.parts) >= 2 and path.parts[0] == "packages":
            package_name = path.parts[1]
            packages.add(package_name)

    return packages


def get_vcs_packages() -> set[str]:
    return {path.name for path in PACKAGES_PATH.glob("*-git")}


def build_package(package_name: str) -> None:
    package_dir = PACKAGES_PATH / package_name
    subprocess.run(
        ["makepkg", "-fsc", "--needed", "--noconfirm"],
        cwd=package_dir,
        stdout=sys.stdout,
        stderr=sys.stderr,
        check=True,
    )


def move_package(package_name: str) -> None:
    package_dir = PACKAGES_PATH / package_name
    for package in package_dir.glob("*.pkg.tar.zst"):
        # Don't use pathlib.Path.rename() here, because we might be moving across filesystem boundaries
        shutil.move(str(package), REPOSITORY_PATH)


def run(arguments: argparse.Namespace) -> ExitCode:
    PACKAGES_PATH.mkdir(parents=True, exist_ok=True)
    REPOSITORY_PATH.mkdir(parents=True, exist_ok=True)

    force_rebuild_packages = os.getenv("FORCE_REBUILD_PACKAGES")

    packages = (
        get_all_packages()
        if force_rebuild_packages is not None
        else get_updated_packages()
    )

    rebuild_only_vcs_packages = os.getenv("REBUILD_ONLY_VCS_PACKAGES")

    if rebuild_only_vcs_packages:
        packages = get_vcs_packages()

    for package in packages:
        print(f"Building {package}…")
        build_package(package)
        move_package(package)

    return ExitCode.SUCCESS


def main() -> None:
    parser = get_argument_parser()
    arguments = parser.parse_args()
    parser.exit(run(arguments))


if __name__ == "__main__":
    main()