"""
摄像头拍照模块 - Windows 兼容
"""
import cv2
import datetime
import time
from pathlib import Path
from config import config_mgr


class CameraCapture:
    """摄像头拍照管理"""
    
    def __init__(self):
        self.camera_index = config_mgr.get('camera_index', 0)
        self.cap = None
        self._closed = True
        self._release_time = 0
        
    def open(self):
        """打开摄像头"""
        if self.cap is not None and self.cap.isOpened():
            return True
        
        # 确保之前的摄像头已完全关闭
        if not self._closed:
            self.close()
            import time
            time.sleep(0.5)  # 等待摄像头完全释放
        
        self.camera_index = config_mgr.get('camera_index', 0)
        self.cap = cv2.VideoCapture(self.camera_index, cv2.CAP_DSHOW)  # Windows DirectShow
        if not self.cap.isOpened():
            raise Exception(f"无法打开摄像头 {self.camera_index}")
        
        # 设置分辨率
        self.cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1280)
        self.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 720)
        
        self._closed = False
        return self.cap.isOpened()
    
    def close(self):
        """关闭摄像头"""
        if self.cap is not None:
            self.cap.release()
            self.cap = None
            self._closed = True
            self._release_time = time.time()
    
    def capture(self, save_path=None, retry_count=3):
        """拍照并保存（每次拍照后自动关闭摄像头）
        
        Args:
            save_path: 保存路径
            retry_count: 重试次数
            
        Returns:
            dict: {'success': bool, 'path': str, 'timestamp': str, 'date_folder': str, 'error': str}
        """
        for attempt in range(retry_count):
            try:
                # 每次拍照都重新打开摄像头
                self.open()
                
                # 等待摄像头稳定（Windows 上需要预热）
                time.sleep(0.5)
                
                # 读取帧（丢弃前几帧确保稳定）
                for _ in range(5):
                    ret, _ = self.cap.read()
                    if not ret:
                        self.close()
                        if attempt < retry_count - 1:
                            print(f"[Camera] 预热失败，重试 {attempt + 2}/{retry_count}")
                            time.sleep(1)
                            continue
                        return {'success': False, 'error': '摄像头预热失败'}
                
                # 拍照
                ret, frame = self.cap.read()
                
                # 立即关闭摄像头释放资源
                self.close()
                
                if not ret or frame is None:
                    if attempt < retry_count - 1:
                        print(f"[Camera] 捕获失败，重试 {attempt + 2}/{retry_count}")
                        time.sleep(1)
                        continue
                    return {'success': False, 'error': '无法捕获图像'}
                
                # 检查图像是否全黑
                if self._is_black_frame(frame):
                    if attempt < retry_count - 1:
                        print(f"[Camera] 全黑图像，重试 {attempt + 2}/{retry_count}")
                        time.sleep(2)
                        continue
                    return {'success': False, 'error': '捕获到全黑图像'}
                
                # 成功，保存图片
                now = datetime.datetime.now()
                timestamp = now.strftime('%Y%m%d_%H%M%S')
                date_str = now.strftime('%Y-%m-%d')
                
                if save_path is None:
                    date_folder = config_mgr.get_images_dir(date_str)
                    filename = f"capture_{timestamp}.jpg"
                    save_path = date_folder / filename
                
                cv2.imwrite(str(save_path), frame, [cv2.IMWRITE_JPEG_QUALITY, 90])
                
                print(f"[Camera] 拍照成功: {save_path.name}")
                
                return {
                    'success': True,
                    'path': str(save_path),
                    'timestamp': timestamp,
                    'date_folder': save_path.parent.name,
                    'filename': save_path.name
                }
                
            except Exception as e:
                self.close()
                if attempt < retry_count - 1:
                    print(f"[Camera] 异常: {e}, 重试 {attempt + 2}/{retry_count}")
                    time.sleep(2)
                    continue
                return {'success': False, 'error': str(e)}
        
        return {'success': False, 'error': '重试后仍失败'}
    
    def _is_black_frame(self, frame):
        """检测图像是否全黑"""
        if frame is None:
            return True
        
        # 计算平均亮度
        gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
        mean_brightness = cv2.mean(gray)[0]
        
        # 如果平均亮度小于 5，视为全黑
        return mean_brightness < 5
    
    def get_camera_info(self):
        """获取摄像头信息"""
        try:
            self.open()
            width = int(self.cap.get(cv2.CAP_PROP_FRAME_WIDTH))
            height = int(self.cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
            fps = int(self.cap.get(cv2.CAP_PROP_FPS))
            self.close()
            return {
                'index': self.camera_index,
                'width': width,
                'height': height,
                'fps': fps,
                'status': 'ok'
            }
        except Exception as e:
            self.close()
            return {
                'index': self.camera_index,
                'status': 'error',
                'error': str(e)
            }
    
    def __del__(self):
        self.close()


def list_available_cameras(max_test=5):
    """列出可用的摄像头"""
    available = []
    for i in range(max_test):
        cap = cv2.VideoCapture(i, cv2.CAP_DSHOW)
        if cap.isOpened():
            available.append(i)
            cap.release()
    return available


if __name__ == "__main__":
    # 测试摄像头
    print("检测可用摄像头...")
    cams = list_available_cameras()
    print(f"可用摄像头: {cams}")
    
    if cams:
        print("\n测试拍照...")
        camera = CameraCapture()
        result = camera.capture()
        print(f"结果: {result}")
        camera.close()