"""
仓库管理器 - 自动下载 Git 仓库

功能：
- 从环境变量读取仓库列表
- 自动下载并解压 ZIP 文件
- 支持多个仓库并行处理
"""

import os
import shutil
import threading
import zipfile
import urllib.request
import urllib.error
from pathlib import Path
from typing import List
from dataclasses import dataclass
import logging

logger = logging.getLogger(__name__)


@dataclass
class RepoConfig:
    """仓库配置"""
    name: str  # 仓库名称（目录名）
    url: str  # Git URL (支持 GitHub HTTPS)
    branch: str = "main"  # 分支名
    auto_update: bool = True  # 是否自动更新


class RepoManager:
    """仓库管理器"""

    def __init__(self, base_dir: str = "./repos"):
        self.base_dir = Path(base_dir)
        self.base_dir.mkdir(parents=True, exist_ok=True)
        self.repos: List[RepoConfig] = []
        self._lock = threading.Lock()

    def load_from_env(self):
        """从环境变量加载仓库配置

        环境变量格式：
        REPO_URLS=repo1,repo2,repo3
        REPO_1_URL=https://github.com/user/repo1.git
        REPO_2_URL=https://github.com/user/repo2.git
        """
        self.repos = []

        # 方式1：逗号分隔的 URL 列表
        repo_urls = os.getenv("REPO_URLS", "")
        if repo_urls:
            for url in repo_urls.split(","):
                url = url.strip()
                if url:
                    name = self._extract_repo_name(url)
                    self.repos.append(RepoConfig(name=name, url=url))

        # 方式2：带编号的配置
        idx = 1
        while True:
            url_key = f"REPO_{idx}_URL"
            url = os.getenv(url_key, "")
            if not url:
                break

            name = os.getenv(f"REPO_{idx}_NAME", "")
            if not name:
                name = self._extract_repo_name(url)

            branch = os.getenv(f"REPO_{idx}_BRANCH", "main")
            auto_update = os.getenv(f"REPO_{idx}_AUTO_UPDATE", "true").lower() == "true"

            self.repos.append(RepoConfig(
                name=name,
                url=url,
                branch=branch,
                auto_update=auto_update
            ))

            idx += 1

        logger.info(f"加载了 {len(self.repos)} 个仓库配置")
        return self.repos

    def _extract_repo_name(self, url: str) -> str:
        """从 URL 提取仓库名称"""
        # 统一处理 URL
        url = url.replace("git@github.com:", "https://github.com/")
        url = url.rstrip("/")

        # 提取最后一部分
        if "/" in url:
            name = url.split("/")[-1]
            # 去除 .git 后缀
            if name.endswith(".git"):
                name = name[:-4]
            return name
        return url

    def _get_repo_dir(self, name: str) -> Path:
        """获取仓库目录路径"""
        return self.base_dir / name

    def _get_zip_url(self, url: str, branch: str) -> str:
        """将 Git URL 转换为 ZIP 下载 URL"""
        # git@github.com:user/repo.git -> https://github.com/user/repo/archive/refs/heads/branch.zip
        # https://github.com/user/repo.git -> https://github.com/user/repo/archive/refs/heads/branch.zip

        url = url.replace("git@github.com:", "https://github.com/")
        url = url.removesuffix(".git")

        # 提取 owner/repo
        parts = url.rstrip("/").split("/")
        if len(parts) >= 2:
            owner = parts[-2]
            repo = parts[-1]
            return f"https://github.com/{owner}/{repo}/archive/refs/heads/{branch}.zip"

        raise ValueError(f"无法解析仓库 URL: {url}")

    def download_repo(self, repo: RepoConfig, force: bool = False) -> bool:
        """下载并解压仓库
        
        Args:
            repo: 仓库配置
            force: 是否强制重新下载
        
        Returns:
            bool: 是否成功
        """
        repo_dir = self._get_repo_dir(repo.name)
        
        # 检查仓库是否已存在且有效（无需重新下载）
        if not force and repo_dir.exists() and any(repo_dir.iterdir()):
            logger.info(f"仓库已存在，跳过下载: {repo.name}")
            return True

        try:
            # 删除已存在的目录
            if repo_dir.exists():
                logger.info(f"删除旧版本: {repo.name}")
                shutil.rmtree(repo_dir)

            repo_dir.mkdir(parents=True, exist_ok=True)

            # 下载 ZIP
            zip_url = self._get_zip_url(repo.url, repo.branch)
            zip_path = repo_dir / "repo.zip"

            logger.info(f"下载仓库: {repo.name} ({zip_url})")

            headers = {"User-Agent": "Mozilla/5.0"}
            req = urllib.request.Request(zip_url, headers=headers)

            with urllib.request.urlopen(req, timeout=120) as response:
                with open(zip_path, 'wb') as f:
                    f.write(response.read())

            # 解压
            logger.info(f"解压仓库: {repo.name}")
            with zipfile.ZipFile(zip_path, 'r') as zip_ref:
                zip_ref.extractall(repo_dir)

            # ZIP 包会多一层目录，需要移动内容
            extracted_dir = repo_dir / f"{repo.name}-{repo.branch}"
            if extracted_dir.exists():
                for item in extracted_dir.iterdir():
                    item.rename(repo_dir / item.name)
                extracted_dir.rmdir()

            # 删除 ZIP 文件
            zip_path.unlink()

            logger.info(f"仓库 {repo.name} 下载成功")
            return True

        except Exception as e:
            logger.error(f"下载仓库 {repo.name} 失败: {e}")
            # 清理失败的目录
            if repo_dir.exists():
                shutil.rmtree(repo_dir)
            return False

    def sync_all(self, parallel: bool = True, force: bool = False) -> dict:
        """同步所有仓库
        
        Args:
            parallel: 是否并行下载
            force: 是否强制重新下载所有仓库
        
        Returns:
            dict: { "success": [成功列表], "skipped": [跳过列表], "failed": [失败列表] }
        """
        if not self.repos:
            self.load_from_env()

        if not self.repos:
            logger.warning("没有配置任何仓库")
            return {"success": [], "skipped": [], "failed": []}

        results = {"success": [], "skipped": [], "failed": []}

        if parallel:
            # 并行下载
            threads = []
            for repo in self.repos:
                t = threading.Thread(target=self._sync_single, args=(repo, results, force))
                t.start()
                threads.append(t)

            for t in threads:
                t.join()
        else:
            # 顺序下载
            for repo in self.repos:
                self._sync_single(repo, results, force)

        logger.info(f"仓库同步完成: 成功 {len(results['success'])}, 跳过 {len(results['skipped'])}, 失败 {len(results['failed'])}")
        return results

    def _sync_single(self, repo: RepoConfig, results: dict, force: bool = False):
        """同步单个仓库（线程安全）"""
        # 先检查是否已存在且有效（非强制模式）
        if not force:
            repo_dir = self._get_repo_dir(repo.name)
            if repo_dir.exists() and any(repo_dir.iterdir()):
                with self._lock:
                    results["skipped"].append(repo.name)
                return
        
        if self.download_repo(repo, force):
            with self._lock:
                results["success"].append(repo.name)
        else:
            with self._lock:
                results["failed"].append(repo.name)

    def get_repo_list(self) -> List[dict]:
        """获取已下载的仓库列表"""
        repos = []
        for item in self.base_dir.iterdir():
            if item.is_dir():
                repos.append({
                    "name": item.name,
                    "path": str(item)
                })
        return repos

    def remove_repo(self, name: str) -> bool:
        """删除仓库"""
        repo_dir = self._get_repo_dir(name)
        if repo_dir.exists():
            try:
                shutil.rmtree(repo_dir)
                logger.info(f"删除仓库: {name}")
                return True
            except Exception as e:
                logger.error(f"删除仓库 {name} 失败: {e}")
                return False
        return False

    def clear_all(self) -> int:
        """清空所有仓库"""
        count = 0
        for item in self.base_dir.iterdir():
            if item.is_dir():
                try:
                    shutil.rmtree(item)
                    count += 1
                except Exception as e:
                    logger.warning(f"删除 {item.name} 失败: {e}")
        logger.info(f"清空仓库: 删除 {count} 个")
        return count


def sync_repos_on_startup():
    """启动时同步仓库"""
    manager = RepoManager()
    repos = manager.load_from_env()

    if repos:
        logger.info(f"启动同步 {len(repos)} 个仓库...")
        results = manager.sync_all(parallel=True)
        return results
    else:
        logger.info("未配置仓库，跳过同步")
        return {"success": [], "failed": []}


if __name__ == "__main__":
    # 测试
    logging.basicConfig(level=logging.INFO)

    # 示例：设置环境变量后测试
    os.environ["REPO_1_URL"] = "https://github.com/psyche/astronomy.git"
    os.environ["REPO_1_NAME"] = "astronomy"
    os.environ["REPO_1_BRANCH"] = "main"

    manager = RepoManager("./test-code")
    manager.load_from_env()

    print(f"配置了 {len(manager.repos)} 个仓库:")
    for repo in manager.repos:
        print(f"  - {repo.name}: {repo.url}")

    results = manager.sync_all()
    print(f"\n同步结果: 成功 {len(results['success'])}, 失败 {len(results['failed'])}")