import cv2
from PyQt5.QtCore import qDebug

from .base_thread import BaseThread
from .structures import ImageFrame
from .utils import gstreamer_pipeline


class CaptureThread(BaseThread):

    def __init__(self,
                 device_id,
                 flip_method=2,
                 drop_if_full=True,
                 api_preference=cv2.CAP_GSTREAMER,
                 resolution=None,
                 use_gst=True,
                 parent=None):
        """
        device_id: device number of the camera.
        flip_method: 0 for identity, 2 for 180 degree rotation (if the camera is installed
            up-side-down).
        drop_if_full: drop the frame if buffer is full.
        api_preference: cv2.CAP_GSTREAMER for csi cameras, usually cv2.CAP_ANY would suffice.
        resolution: camera resolution (width, height).
        """
        super(CaptureThread, self).__init__(parent)
        self.device_id = device_id
        self.flip_method = flip_method
        self.use_gst = use_gst
        self.drop_if_full = drop_if_full
        self.api_preference = api_preference
        self.resolution = resolution
        self.cap = cv2.VideoCapture()
        # an instance of the MultiBufferManager object,
        # for synchronizing this thread with other cameras.
        self.buffer_manager = None

    def run(self):
        if self.buffer_manager is None:
            raise ValueError("This thread has not been binded to any buffer manager yet")

        while True:
            self.stop_mutex.lock()
            if self.stopped:
                self.stopped = False
                self.stop_mutex.unlock()
                break
            self.stop_mutex.unlock()

            # save capture time
            self.processing_time = self.clock.elapsed()
            # start timer (used to calculate capture rate)
            self.clock.start()

            # synchronize with other streams (if enabled for this stream)
            self.buffer_manager.sync(self.device_id)

            if not self.cap.grab():
                continue

            # retrieve frame and add it to buffer
            _, frame = self.cap.retrieve()
            img_frame = ImageFrame(self.clock.msecsSinceStartOfDay(), frame)
            self.buffer_manager.get_device(self.device_id).add(img_frame, self.drop_if_full)

            # update statistics
            self.update_fps(self.processing_time)
            self.stat_data.frames_processed_count += 1
            # inform GUI of updated statistics
            self.update_statistics_gui.emit(self.stat_data)

        qDebug("Stopping capture thread...")

# 在surround-view-system-introduction/surround_view/capture_thread.py中修改connect_camera方法
    def connect_camera(self):
        # 如果设备ID是字符串且以rtsp开头，则视为RTSP地址
        if isinstance(self.device_id, str) and self.device_id.startswith('rtsp://'):
            # 使用FFmpeg的H265解码方式打开RTSP流
            # 降低延迟参数：-fflags nobuffer -flags low_delay -rtsp_transport tcp
            ffmpeg_cmd = (
                f"rtspsrc location={self.device_id} latency=0 ! "
                "rtph265depay ! h265parse ! avdec_h265 ! "
                "videoconvert ! video/x-raw,format=BGR ! appsink"
            )
            self.cap.open(ffmpeg_cmd, cv2.CAP_GSTREAMER)
        elif self.use_gst:
            options = gstreamer_pipeline(cam_id=self.device_id, flip_method=self.flip_method)
            self.cap.open(options, self.api_preference)
        else:
            self.cap.open(self.device_id)
        
        if not self.cap.isOpened():
            qDebug(f"Cannot open camera {self.device_id}")
            return False
        
        # 设置分辨率（RTSP流通常固定分辨率，可根据实际情况调整）
        if self.resolution is not None:
            width, height = self.resolution
            self.cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)
            self.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)
        
        return True
    def disconnect_camera(self):
        # disconnect camera if it's already opened.
        if self.cap.isOpened():
            self.cap.release()
            return True
        # else do nothing and return
        else:
            return False

    def is_camera_connected(self):
        return self.cap.isOpened()