import time
import threading

import cv2 as cv


class VideoCapture:
	def __init__(self, video_source=0):
		self._ownMessages=None
		self._coreMessages=None
		self._shutdown=False
		
		self._vid = cv.VideoCapture(video_source)
		if not self._vid.isOpened():
			raise ValueError("Unable to open video source", video_source)

		self.width = self._vid.get(cv.CAP_PROP_FRAME_WIDTH)
		self.height = self._vid.get(cv.CAP_PROP_FRAME_HEIGHT)

	def getFrame(self):
		if self._vid.isOpened():
			(res,frame) = self._vid.read()
			if res:
				return (res, cv.cvtColor(frame, cv.COLOR_BGR2RGB))
			else:
				return (res,None)
		else:
			return (False,None)

	def shutDown(self):
		self._ownMessages.send("!kill",("video",))
		self._shutdown=True

	def __call__(self,ownMessages,coreMessages):
		self._ownMessages=ownMessages
		self._coreMessages=coreMessages

		self.listenerThread=threading.Thread(target=lambda: ownMessages.listen(self._handleEvent))
		self.listenerThread.start()

		t=0
		while not self._shutdown:
			self._vid.set(cv.CAP_PROP_POS_MSEC,t*1000)
			(res,frame)=self.getFrame()
			if res: self._coreMessages.send("putFrame",(frame,))
			time.sleep(1)
			t+=1

	def __del__(self):
		if self._vid.isOpened():
			self._vid.release()
			
	def _handleEvent(self,e):
		actions={
			"shutDown": self.shutDown
		}
		(actionName,args,kwargs)=e

		return actions[actionName](*args,**kwargs)


def capVideo(stream,ownMessages,coreMessages):
	v=VideoCapture(stream)
	v(ownMessages,coreMessages)