# hls_cleanup.py
# HLS文件夹清理进程
# 功能：定时清理过期的HLS会话文件夹，支持浮点数天数，不依赖摄像头配置

import os
import sys
import argparse
import signal
import shutil
import time
from datetime import datetime, timedelta
from typing import List

from utils.logger import get_logger
logger = get_logger(__name__)

running = True


def parse_args():
    """解析命令行参数"""
    parser = argparse.ArgumentParser(description="HLS Folder Cleanup Service")
    parser.add_argument("--hls-root-path", required=True, help="HLS root path")
    parser.add_argument("--retention-days", required=True, type=float, 
                        help="Retention days (supports float, e.g. 0.5 for 12 hours)")
    parser.add_argument("--interval", required=True, type=int, 
                        help="Cleanup interval in hours")
    return parser.parse_args()


def parse_folder_time(folder_name: str) -> datetime:
    """
    从文件夹名称解析时间
    格式: yyyyMMdd_HHmmss
    """
    try:
        date_str, time_str = folder_name.split("_")
        return datetime.strptime(f"{date_str}{time_str}", "%Y%m%d%H%M%S")
    except (ValueError, IndexError) as e:
        raise ValueError(f"Invalid folder name format: {folder_name}") from e


def cleanup_hls_folders(hls_root_path: str, retention_days: float) -> tuple:
    """
    清理过期的HLS会话文件夹
    
    Args:
        hls_root_path: HLS根目录
        retention_days: 保留天数（支持浮点数）
    
    Returns:
        (deleted_count, error_count) 删除数量和错误数量
    """
    if not os.path.exists(hls_root_path):
        logger.info(f"HLS root path does not exist: {hls_root_path}")
        return 0, 0
    
    cutoff_time = datetime.now() - timedelta(days=retention_days)
    deleted_count = 0
    error_count = 0
    
    # 遍历所有摄像头目录
    for camera_folder in os.listdir(hls_root_path):
        camera_path = os.path.join(hls_root_path, camera_folder)
        
        if not os.path.isdir(camera_path):
            continue
        
        # 遍历该摄像头下的所有会话文件夹
        for session_folder in os.listdir(camera_path):
            session_path = os.path.join(camera_path, session_folder)
            
            if not os.path.isdir(session_path):
                continue
            
            try:
                # 解析文件夹名称获取时间
                folder_time = parse_folder_time(session_folder)
                
                if folder_time < cutoff_time:
                    shutil.rmtree(session_path)
                    logger.info(f"Deleted: {session_path} (created: {folder_time})")
                    deleted_count += 1
            except ValueError as e:
                # 文件夹名称格式不匹配，跳过
                logger.debug(f"Skipped: {session_path} ({e})")
            except Exception as e:
                logger.warning(f"Failed to delete {session_path}: {e}")
                error_count += 1
    
    return deleted_count, error_count


def signal_handler(signum, frame):
    """信号处理器"""
    global running
    logger.info(f"Received signal {signum}, shutting down...")
    running = False


def main():
    global running
    
    args = parse_args()
    
    # 注册信号处理器
    signal.signal(signal.SIGTERM, signal_handler)
    signal.signal(signal.SIGINT, signal_handler)
    
    logger.info(f"HLS Cleanup Service starting")
    logger.info(f"Config: hls_root={args.hls_root_path}, "
                f"retention_days={args.retention_days}, interval={args.interval}h")
    
    # 主循环
    while running:
        try:
            logger.info(f"Starting cleanup scan...")
            deleted, errors = cleanup_hls_folders(args.hls_root_path, args.retention_days)
            
            if deleted > 0 or errors > 0:
                logger.info(f"Cleanup completed: {deleted} deleted, {errors} errors "
                            f"(retention: {args.retention_days} days)")
            else:
                logger.info(f"Cleanup scan completed, no folders to delete "
                            f"(retention: {args.retention_days} days)")
        except Exception as e:
            logger.error(f"Error during cleanup: {e}")
        
        # 等待下一次轮询（每小时检查一次）
        for _ in range(args.interval * 3600):
            if not running:
                break
            time.sleep(1)
    
    logger.info("HLS Cleanup Service stopped")


if __name__ == "__main__":
    main()