#!/usr/bin/env python3
from __future__ import annotations

import argparse
from pathlib import Path
import stat
import subprocess
import sys


PROJECT_DIR = Path(__file__).resolve().parents[1]


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="安装提交后自动推送到 Gitea 的 Git hook")
    parser.add_argument("--remote", default="origin", help="Gitea remote 名称，默认 origin")
    parser.add_argument("--force", action="store_true", help="覆盖已有 post-commit hook")
    parser.add_argument("--dry-run", action="store_true", help="只打印将要写入的 hook 内容")
    return parser.parse_args()


def run_git(args: list[str]) -> str:
    result = subprocess.run(
        ["git", *args],
        cwd=PROJECT_DIR,
        text=True,
        capture_output=True,
        check=False,
    )
    if result.returncode != 0:
        raise RuntimeError(result.stderr.strip() or result.stdout.strip())
    return result.stdout.strip()


def hook_text(remote: str) -> str:
    return f"""#!/bin/sh
set -eu

remote={remote!r}
branch=$(git symbolic-ref --quiet --short HEAD || true)

if [ -z "$branch" ]; then
  echo "[gitea-backup] detached HEAD，跳过自动推送" >&2
  exit 0
fi

if ! git remote get-url "$remote" >/dev/null 2>&1; then
  echo "[gitea-backup] remote '$remote' 不存在，跳过自动推送" >&2
  exit 0
fi

echo "[gitea-backup] pushing $branch to $remote"
if ! git push "$remote" "HEAD:$branch"; then
  echo "[gitea-backup] push 失败；本地提交已保留，请检查 SSH key 或远端权限" >&2
  exit 0
fi
"""


def main() -> int:
    args = parse_args()
    git_dir = Path(run_git(["rev-parse", "--git-dir"]))
    if not git_dir.is_absolute():
        git_dir = PROJECT_DIR / git_dir
    hook_path = git_dir / "hooks" / "post-commit"

    try:
        remote_url = run_git(["remote", "get-url", args.remote])
    except RuntimeError:
        remote_url = ""

    content = hook_text(args.remote)
    if args.dry_run:
        print(content)
        if remote_url:
            print(f"# remote {args.remote}: {remote_url}")
        else:
            print(f"# remote {args.remote}: 未配置")
        return 0

    if hook_path.exists() and not args.force:
        raise RuntimeError(f"{hook_path} 已存在；如需覆盖，请加 --force")

    hook_path.parent.mkdir(parents=True, exist_ok=True)
    hook_path.write_text(content, encoding="utf-8")
    mode = hook_path.stat().st_mode
    hook_path.chmod(mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
    print(f"已安装 {hook_path}")
    if remote_url:
        print(f"提交后将自动推送到 {args.remote}: {remote_url}")
    else:
        print(f"注意：当前尚未配置 remote '{args.remote}'，请先设置 Gitea SSH 地址")
    return 0


if __name__ == "__main__":
    try:
        raise SystemExit(main())
    except Exception as exc:
        print(f"安装失败: {exc}", file=sys.stderr)
        raise SystemExit(1)