import cv2

class CameraViewer:
    def __init__(self, device_index=0):
        self.device_index = device_index
        self.window_name = "Camera Viewer"
        
    def start_stream(self):
        cap = cv2.VideoCapture(self.device_index)
        if not cap.isOpened():
            print(f"无法打开摄像头设备 {self.device_index}")
            return
            
        cv2.namedWindow(self.window_name, cv2.WINDOW_NORMAL)
        
        while True:
            ret, frame = cap.read()
            if not ret:
                print("无法获取视频帧")
                break
                
            cv2.imshow(self.window_name, frame)
            
            if cv2.waitKey(1) & 0xFF == ord('q'):
                break
                
        cap.release()
        cv2.destroyAllWindows()

if __name__ == "__main__":
    # 修改这里的数字可以切换不同摄像头设备
    viewer = CameraViewer(device_index=3)
    viewer.start_stream()

# import ctypes
# from ctypes import c_int, c_uint16, c_uint8, c_char, c_char_p, Structure, POINTER, byref

# # 设备结构体，对应wrapper中FPMS_DEVICE_C
# class FPMS_DEVICE_C(Structure):
#     _pack_ = 1
#     _fields_ = [
#         ("mn", c_uint16),
#         ("sn", c_char * 64),
#         ("fwVersion", c_uint16),
#         ("protoVer", c_uint8),
#         ("pid", c_uint16),
#         ("vid", c_uint16),
#         ("rows", c_uint16),
#         ("cols", c_uint16),
#     ]

# # 加载DLL
# dll_path = r"D:\BodyBalanceEvaluation\backend\SMiTSenseUsbWrapper.dll"
# dll = ctypes.windll.LoadLibrary(dll_path)

# # 函数原型声明

# # int fpms_usb_init_c(int debugFlag);
# dll.fpms_usb_init_c.argtypes = [c_int]
# dll.fpms_usb_init_c.restype = c_int

# dll.fpms_usb_get_device_list_c.argtypes = [POINTER(FPMS_DEVICE_C), c_int]
# dll.fpms_usb_get_device_list_c.restype = c_int

# dll.fpms_usb_open_c.argtypes = [POINTER(FPMS_DEVICE_C), POINTER(ctypes.c_void_p)]
# dll.fpms_usb_open_c.restype = c_int

# # int fpms_usb_read_frame_c(void* handle, uint16_t* frame);
# dll.fpms_usb_read_frame_c.argtypes = [ctypes.c_void_p, POINTER(c_uint16)]
# dll.fpms_usb_read_frame_c.restype = c_int

# # int fpms_usb_close_c(void* handle);
# dll.fpms_usb_close_c.argtypes = [ctypes.c_void_p]
# dll.fpms_usb_close_c.restype = c_int

# # 其他函数如果需要可以类似声明

# def main():
#     # 初始化
#     ret = dll.fpms_usb_init_c(0)
#     print(f"fpms_usb_init_c 返回值: {ret}")
#     if ret != 0:
#         print("初始化失败")
#         return

#     MAX_DEVICES = 8
#     devices = (FPMS_DEVICE_C * MAX_DEVICES)()  # 创建数组
#     count = dll.fpms_usb_get_device_list_c(devices, MAX_DEVICES)
#     print(f"设备数量: {count}")
#     if count <= 0:
#         print("未找到设备或错误")
#         return

#     for i in range(count):
#         dev = devices[i]
#         print(f"设备{i}: mn={dev.mn}, sn={dev.sn.decode(errors='ignore').rstrip(chr(0))}, fwVersion={dev.fwVersion}")

#     # 打开第一个设备
#     handle = ctypes.c_void_p()
#     ret = dll.fpms_usb_open_c(byref(devices[0]), byref(handle))
#     print(f"fpms_usb_open_c 返回值: {ret}")
#     if ret != 0:
#         print("打开设备失败")
#         return

#     # 假设帧大小是 rows * cols
#     rows = devices[0].rows
#     cols = devices[0].cols
#     frame_size = rows * cols
#     frame_buffer = (c_uint16 * frame_size)()

#     ret = dll.fpms_usb_read_frame_c(handle, frame_buffer)
#     print(f"fpms_usb_read_frame_c 返回值: {ret}")
#     if ret == 0:
#         # 打印前10个数据看看
#         print("帧数据前10个点:", list(frame_buffer[:10]))
#     else:
#         print("读取帧失败")

#     # 关闭设备
#     ret = dll.fpms_usb_close_c(handle)
#     print(f"fpms_usb_close_c 返回值: {ret}")

# if __name__ == "__main__":
#     main()