"""中控本机快速更新:git pull + pm2 restart."""
from __future__ import annotations

import os
import shlex
import subprocess
import sys
import threading
import time
from pathlib import Path
from typing import Any

_ROOT = Path(__file__).resolve().parent.parent
_update_lock = threading.Lock()
_update_pending_until = 0.0


def _repo_root() -> Path:
    env_root = (os.getenv("REPO") or "").strip()
    if env_root:
        return Path(env_root)
    return _ROOT


def _run_git(args: list[str], *, cwd: Path) -> tuple[bool, str]:
    try:
        proc = subprocess.run(
            ["git", *args],
            cwd=str(cwd),
            capture_output=True,
            text=True,
            timeout=15,
        )
    except FileNotFoundError:
        return False, "未找到 git"
    except subprocess.TimeoutExpired:
        return False, "git 超时"
    except Exception as e:
        return False, str(e) or "git 失败"
    out = (proc.stdout or "").strip() or (proc.stderr or "").strip()
    return proc.returncode == 0, out


def read_git_version() -> dict[str, Any]:
    root = _repo_root()
    out: dict[str, Any] = {
        "ok": True,
        "repo": str(root),
        "sha": "",
        "short_sha": "",
        "branch": "",
        "dirty": False,
        "msg": "",
        "online": True,
    }
    if not (root / ".git").exists() and not (root / ".git").is_file():
        out["ok"] = False
        out["msg"] = "非 git 仓库"
        return out
    ok, sha = _run_git(["rev-parse", "HEAD"], cwd=root)
    if not ok or not sha:
        out["ok"] = False
        out["msg"] = sha or "无法读取 HEAD"
        return out
    out["sha"] = sha
    out["short_sha"] = sha[:7]
    ok_b, branch = _run_git(["rev-parse", "--abbrev-ref", "HEAD"], cwd=root)
    if ok_b and branch:
        out["branch"] = branch
    ok_d, dirty = _run_git(["status", "--porcelain"], cwd=root)
    if ok_d:
        out["dirty"] = bool(dirty.strip())
    return out


def schedule_pull_and_restart(*, delay_seconds: float = 1.5) -> dict[str, Any]:
    if not sys.platform.startswith("linux"):
        return {"ok": False, "msg": "仅 Linux 服务器支持更新", "deferred": False}
    root = _repo_root()
    script = root / "deploy" / "pull_and_restart.sh"
    if not script.is_file():
        return {"ok": False, "msg": f"缺少更新脚本: {script}", "deferred": False}

    global _update_pending_until
    now = time.time()
    with _update_lock:
        if now < _update_pending_until:
            return {"ok": False, "msg": "已有更新任务进行中,请稍后再试", "deferred": False}
        _update_pending_until = now + 120.0

    version = read_git_version()
    try:
        delay = max(0.5, float(delay_seconds))
        cmd = (
            f"sleep {delay} && "
            f"cd {shlex.quote(str(root))} && "
            f"exec bash {shlex.quote(str(script))}"
        )
        subprocess.Popen(
            ["bash", "-c", cmd],
            stdout=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL,
            start_new_session=True,
            cwd=str(root),
        )
        return {
            "ok": True,
            "msg": "更新已受理,即将 git pull 并重启",
            "deferred": True,
            "before_sha": version.get("sha") or "",
            "before_short_sha": version.get("short_sha") or "",
            "branch": version.get("branch") or "",
        }
    except FileNotFoundError:
        with _update_lock:
            _update_pending_until = 0.0
        return {"ok": False, "msg": "未找到 bash", "deferred": False}
    except Exception as e:
        with _update_lock:
            _update_pending_until = 0.0
        return {"ok": False, "msg": str(e) or "触发更新失败", "deferred": False}