###############################################################################
# 实时视频播放模块 - 监听 Image_Analysis 文件夹并播放新视频
###############################################################################

import os
import time
import cv2
import numpy as np
import threading
import queue
from pathlib import Path
from logger import logger


class RealtimeVideoPlayer:
    """实时监控文件夹并播放新到达的视频"""
    
    def __init__(self, watch_dir, fps=20):
        """
        初始化视频播放器
        
        Args:
            watch_dir: 监听的文件夹路径
            fps: 帧率（默认20fps）
        """
        self.watch_dir = watch_dir
        self.fps = fps
        self.frame_interval = 1.0 / fps
        
        # 确保监听目录存在
        os.makedirs(watch_dir, exist_ok=True)
        
        # 状态管理
        self.is_running = False
        self.is_playing = False
        self.current_video = None
        
        # 帧队列
        self.frame_queue = queue.Queue(maxsize=100)
        self.audio_queue = queue.Queue(maxsize=100)
        
        # 已处理的文件
        self.processed_files = set()
        
        # 线程控制
        self.watch_thread = None
        self.play_thread = None
        self.stop_event = threading.Event()
        
        # 回调函数
        self.on_frame_callback = None
        self.on_audio_callback = None
        
        logger.info(f"RealtimeVideoPlayer 初始化，监听目录: {watch_dir}")
    
    def set_callbacks(self, on_frame=None, on_audio=None):
        """设置回调函数"""
        self.on_frame_callback = on_frame
        self.on_audio_callback = on_audio
    
    def start(self):
        """启动监听和播放"""
        if self.is_running:
            logger.warning("RealtimeVideoPlayer 已经在运行中")
            return
        
        self.is_running = True
        self.stop_event.clear()
        
        # 启动监听线程
        self.watch_thread = threading.Thread(target=self._watch_loop, daemon=True)
        self.watch_thread.start()
        
        # 启动播放线程
        self.play_thread = threading.Thread(target=self._play_loop, daemon=True)
        self.play_thread.start()
        
        logger.info("RealtimeVideoPlayer 已启动")
    
    def stop(self):
        """停止监听和播放"""
        if not self.is_running:
            return
        
        self.is_running = False
        self.stop_event.set()
        
        # 清空队列
        while not self.frame_queue.empty():
            try:
                self.frame_queue.get_nowait()
            except:
                break
        
        while not self.audio_queue.empty():
            try:
                self.audio_queue.get_nowait()
            except:
                break
        
        if self.watch_thread:
            self.watch_thread.join(timeout=2)
        if self.play_thread:
            self.play_thread.join(timeout=2)
        
        logger.info("RealtimeVideoPlayer 已停止")
    
    def _watch_loop(self):
        """监听文件夹循环"""
        logger.info("开始监听文件夹...")
        
        while not self.stop_event.is_set():
            try:
                # 获取所有视频文件
                if not os.path.exists(self.watch_dir):
                    time.sleep(0.5)
                    continue
                
                video_files = []
                for ext in ['*.mp4', '*.avi', '*.mov', '*.mkv', '*.flv']:
                    video_files.extend(Path(self.watch_dir).glob(ext))
                
                # 过滤出未处理的文件
                new_videos = []
                for video_path in video_files:
                    if video_path.name not in self.processed_files:
                        # 确保文件已经完全写入
                        if self._is_file_ready(video_path):
                            new_videos.append(video_path)
                
                # 按修改时间排序，处理最新的
                if new_videos:
                    new_videos.sort(key=lambda p: p.stat().st_mtime)
                    
                    for video_path in new_videos:
                        if self.stop_event.is_set():
                            break
                        
                        logger.info(f"📹 发现新视频: {video_path.name}")
                        self._play_video(video_path)
                        self.processed_files.add(video_path.name)
                        
                        # 限制已处理文件数量，避免内存占用过大
                        if len(self.processed_files) > 1000:
                            self.processed_files = set(list(self.processed_files)[-500:])
                
                time.sleep(0.5)  # 每0.5秒检查一次
                
            except Exception as e:
                logger.error(f"监听文件夹时出错: {e}")
                time.sleep(1)
        
        logger.info("文件夹监听已停止")
    
    def _is_file_ready(self, file_path):
        """检查文件是否已经完全写入"""
        try:
            # 尝试打开文件，如果能打开说明写入完成
            with open(file_path, 'rb') as f:
                f.seek(0, 2)  # 移动到文件末尾
                size = f.tell()
                return size > 0
        except:
            return False
    
    def _play_video(self, video_path):
        """播放单个视频文件"""
        try:
            logger.info(f"🎬 开始播放视频: {video_path.name}")
            self.is_playing = True
            self.current_video = str(video_path)
            
            # 打开视频
            cap = cv2.VideoCapture(str(video_path))
            if not cap.isOpened():
                logger.error(f"无法打开视频: {video_path}")
                self.is_playing = False
                return
            
            # 获取视频信息
            fps = cap.get(cv2.CAP_PROP_FPS)
            total_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
            width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
            height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
            
            logger.info(f"视频信息: {width}x{height}, FPS={fps}, 总帧数={total_frames}")
            
            # 读取帧
            frame_count = 0
            while not self.stop_event.is_set():
                ret, frame = cap.read()
                if not ret:
                    break
                
                # 将帧放入队列
                if self.frame_queue.full():
                    # 如果队列满了，丢弃最旧的帧
                    try:
                        self.frame_queue.get_nowait()
                    except:
                        pass
                
                self.frame_queue.put(frame)
                frame_count += 1
                
                # 控制帧率
                time.sleep(self.frame_interval)
            
            cap.release()
            self.is_playing = False
            logger.info(f"✅ 视频播放完成: {video_path.name} ({frame_count} 帧)")
            
        except Exception as e:
            logger.error(f"播放视频时出错: {e}")
            self.is_playing = False
    
    def _play_loop(self):
        """播放帧循环"""
        logger.info("开始播放帧循环...")
        
        while not self.stop_event.is_set():
            try:
                # 从队列获取帧
                try:
                    frame = self.frame_queue.get(timeout=0.1)
                    
                    # 调用回调函数
                    if self.on_frame_callback:
                        self.on_frame_callback(frame)
                    
                except queue.Empty:
                    continue
                
            except Exception as e:
                logger.error(f"播放帧时出错: {e}")
                time.sleep(0.1)
        
        logger.info("播放帧循环已停止")
    
    def get_status(self):
        """获取播放器状态"""
        return {
            'is_running': self.is_running,
            'is_playing': self.is_playing,
            'current_video': self.current_video,
            'queue_size': self.frame_queue.qsize(),
            'processed_files': len(self.processed_files)
        }