import os
import time
import tarfile
import hashlib
import shutil
from pathlib import Path
from typing import Optional
from dataclasses import dataclass
from contextlib import contextmanager
import logging
from dotenv import load_dotenv
from huggingface_hub import CommitScheduler, HfApi

@dataclass
class Config:
    repo_id: str
    sync_interval: int
    data_path: Path
    sync_path: Path
    tmp_path: Path
    archive_name: str

    @classmethod
    def from_env(cls):
        load_dotenv()
        repo_id = os.getenv('HF_REPO_ID')
        if not repo_id:
            raise ValueError("HF_REPO_ID must be set")
            
        return cls(
            repo_id=repo_id,
            sync_interval=int(os.getenv('SYNC_INTERVAL', '5')),
            data_path=Path("/data"),
            sync_path=Path("/sync"),
            tmp_path=Path("/tmp/sync"),
            archive_name="data.tar.gz"
        )

class Logger:
    def __init__(self):
        logging.basicConfig(
            level=logging.INFO,
            format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
        )
        self.logger = logging.getLogger(__name__)

class DirectoryMonitor:
    def __init__(self, path: Path):
        self.path = path
        self.last_hash: Optional[str] = None
    
    def get_directory_hash(self) -> str:
        sha256_hash = hashlib.sha256()
        
        all_files = sorted(
            str(p) for p in self.path.rglob('*') if p.is_file()
        )
        
        for file_path in all_files:
            rel_path = os.path.relpath(file_path, self.path)
            sha256_hash.update(rel_path.encode())
            
            with open(file_path, 'rb') as f:
                for chunk in iter(lambda: f.read(4096), b''):
                    sha256_hash.update(chunk)
        
        return sha256_hash.hexdigest()

    def has_changes(self) -> bool:
        current_hash = self.get_directory_hash()
        if current_hash != self.last_hash:
            self.last_hash = current_hash
            return True
        return False

class ArchiveManager:
    def __init__(self, config: Config, logger: Logger):
        self.config = config
        self.logger = logger.logger
        
    @contextmanager
    def safe_archive(self):
        """安全地创建归档文件的上下文管理器"""
        self.config.tmp_path.mkdir(parents=True, exist_ok=True)
        tmp_archive = self.config.tmp_path / self.config.archive_name
        
        try:
            with tarfile.open(tmp_archive, "w:gz") as tar:
                yield tar
            
            # 成功创建后移动到最终位置
            self.config.sync_path.mkdir(parents=True, exist_ok=True)
            shutil.move(tmp_archive, self.config.sync_path / self.config.archive_name)
            
        finally:
            # 清理临时文件
            if tmp_archive.exists():
                tmp_archive.unlink()

    def create_archive(self):
        """创建压缩包"""
        self.logger.info("Creating new archive...")
        with self.safe_archive() as tar:
            tar.add(self.config.data_path, arcname="data")
        self.logger.info("Archive created")

    def extract_archive(self):
        """解压现有数据"""
        api = HfApi()
        try:
            self.logger.info("Downloading data archive...")
            api.hf_hub_download(
                repo_id=self.config.repo_id,
                filename=self.config.archive_name,
                repo_type="dataset",
                local_dir=self.config.sync_path
            )
            
            self.logger.info("Extracting archive...")
            archive_path = self.config.sync_path / self.config.archive_name
            with tarfile.open(archive_path, "r:gz") as tar:
                tar.extractall(
                    path=self.config.data_path,
                    filter=self._tar_filter
                )
        except Exception as e:
            self.logger.info(f"No existing archive found or download failed: {e}")
            self.config.data_path.mkdir(parents=True, exist_ok=True)

    @staticmethod
    def _tar_filter(tarinfo, path):
        """tar 文件过滤器"""
        if tarinfo.name.startswith('data/'):
            tarinfo.name = tarinfo.name[5:]
            return tarinfo
        else:
            return None

class SyncService:
    def __init__(self, config: Config, logger: Logger):
        self.config = config
        self.logger = logger.logger
        self.monitor = DirectoryMonitor(config.data_path)
        self.archive_manager = ArchiveManager(config, logger)
        
    def run(self):
        self.logger.info(f"Starting sync process for repo: {self.config.repo_id}")
        self.logger.info(f"Sync interval: {self.config.sync_interval} minutes")
        
        # 初始化目录和下载数据
        self.config.sync_path.mkdir(parents=True, exist_ok=True)
        self.archive_manager.extract_archive()

        scheduler = CommitScheduler(
            repo_id=self.config.repo_id,
            repo_type="dataset",
            folder_path=str(self.config.sync_path),
            path_in_repo="",
            every=self.config.sync_interval,
            squash_history=True,
            private=True
        )

        try:
            while True:
                if self.monitor.has_changes():
                    self.logger.info("Directory changes detected, creating new archive...")
                    self.archive_manager.create_archive()
                else:
                    self.logger.info("No changes detected")
                
                self.logger.info(f"Waiting {self.config.sync_interval} minutes until next check...")
                time.sleep(self.config.sync_interval * 60)
        except KeyboardInterrupt:
            self.logger.info("Stopping sync process...")
            scheduler.stop()

def main():
    config = Config.from_env()
    logger = Logger()
    service = SyncService(config, logger)
    service.run()

if __name__ == "__main__":
    main()