from PySide6.QtCore import QObject, QThread, QTimer, Signal, Slot, QMutex, QMutexLocker
from PySide6.QtGui import QImage, QPixmap
import cv2

from .base_camera import BaseCamera


class CameraController(QThread):
    frame_ready = Signal(QPixmap)
    photo_ready = Signal(QPixmap)
    error_occurred = Signal(str)
    _enable_timer = Signal(bool)


    def __init__(self, parent: QObject | None = None) -> None:
        super().__init__(parent)
        self.camera = None
        self.timer = None
        self.fps = 15
        self.is_streaming = False
        self.is_connected = False

        self._camera_mutex = QMutex()
        self.start()


    def run(self) -> None:
        self.timer = QTimer()
        self.timer.timeout.connect(self._update_frame)
        self._enable_timer.connect(self._set_timer)
        self.exec()
 
    def stop(self):
        self.stop_camera()
        self.quit()
        self.wait()

    def set_camera(self, camera: BaseCamera, fps: int = 15) -> None:
        with QMutexLocker(self._camera_mutex):
            self.stop_stream()
            self.stop_camera()

            self.camera = camera
            self.fps = fps

    def start_camera(self) -> None:
        if self.camera is None or self.is_connected:
            return

        if self.camera.connect():
            self.is_connected = True
        else:
            self.is_connected = False
            self.error_occurred.emit(self.camera.get_error_msg())

    def stop_camera(self) -> None:
        if self.is_streaming:
            self.stop_stream()

        if self.camera is not None:
            self.camera.disconnect()

        self.is_connected = False

    def start_stream(self):
        if not self.is_connected:
            return

        if self.is_streaming:
            return

        if self.timer:
            self.is_streaming = True
            # self.timer.start()
            self._enable_timer.emit(True)

    def stop_stream(self) -> None:
        if self.is_streaming:
            self.is_streaming = False
            if self.timer:
                # self.timer.stop()
                self._enable_timer.emit(False)

    def _update_frame(self) -> None:
        with QMutexLocker(self._camera_mutex):
            if self.camera is None or not self.is_connected:
                return
        
            if not self.is_streaming:
                return

            ret, frame = self.camera.get_frame()

            if not ret:
                self.error_occurred.emit(self.camera.get_error_msg())
                return

        if frame is not None:
            rgb_image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
            h, w, ch = rgb_image.shape
            qimg = QImage(rgb_image.data, w, h, ch * w, QImage.Format.Format_RGB888)
            pixmap = QPixmap.fromImage(qimg)

            self.frame_ready.emit(pixmap)

    def _set_timer(self, enable: bool):
        if not self.timer:
            return
        
        if enable:
            self.timer.setInterval(int(1000 / self.fps))
            self.timer.start()
        else:
            self.timer.stop()