"""Git 热更新：定期检查远端新版本，更新前先推送通知，再拉取并重启进程。

基于 GitPython。
"""
import asyncio
import logging
import os
import sys

import git

log = logging.getLogger("updater")


class Updater:
    def __init__(self, ob, cfg: dict):
        self.ob = ob
        self.interval = cfg.get("interval", 300)
        self.groups = cfg.get("groups", []) or []
        self.friends = cfg.get("friends", []) or []
        self._updating = False
        try:
            self.repo = git.Repo(".")
        except (git.InvalidGitRepositoryError, git.NoSuchPathError):
            self.repo = None

    def start(self):
        if self.repo is None:
            log.info("非 git 仓库，热更新已禁用")
            return
        self._task = asyncio.get_running_loop().create_task(self._loop())

    async def stop(self):
        if hasattr(self, "_task"):
            self._task.cancel()

    async def _loop(self):
        log.info("热更新已启动: 每 %ds 检查一次远端", self.interval)
        while True:
            try:
                await asyncio.sleep(self.interval)
                if self.ob.connected and not self._updating:
                    await self.check_once()
            except asyncio.CancelledError:
                break
            except Exception:
                log.exception("热更新检查出错")

    async def check_once(self):
        """检查远端；有更新则通知、拉取并重启进程。"""
        self._updating = True
        try:
            await asyncio.to_thread(self.repo.remotes.origin.fetch)
            refs = self.repo.remotes.origin.refs
            remote = getattr(refs, "HEAD", None) or (refs[0] if refs else None)
            if remote is None or remote.commit == self.repo.head.commit:
                return
            log.info("发现新版本: %s -> %s",
                     self.repo.head.commit.hexsha[:8], remote.commit.hexsha[:8])
            if self.ob.connected and (self.groups or self.friends):
                await self.ob.broadcast(
                    "[更新] 检测到新版本，正在更新并重启机器人...",
                    self.groups, self.friends)
            await asyncio.to_thread(self.repo.remotes.origin.pull, "--ff-only")
            log.warning("更新完成，重启进程...")
            await asyncio.sleep(1)
            os.execv(sys.executable, [sys.executable] + sys.argv)
        finally:
            self._updating = False