import zmq
import threading
import qi
import logging

from robot_interface.endpoints.socket_base import SocketBase
from robot_interface.state import state


class VideoSender(SocketBase):
    def __init__(self, zmq_context, port=5556):
        super(VideoSender, self).__init__("video")
        self.create_socket(zmq_context, zmq.PUB, port, [(zmq.CONFLATE,1)])
    
    def start_video_rcv(self):
        """
        Prepares arguments for retrieving video images from Pepper and starts video loop on a separate thread.
        """        
        app = qi.Application()
        app.start()
        session = app.session

        video = session.service("ALVideoDevice")

        camera_index = 0
        kQVGA = 2
        kRGB = 11
        FPS = 15
        vid_stream_name = video.subscribeCamera("Pepper Video", camera_index, kQVGA, kRGB, FPS)
        thread = threading.Thread(target=self.video_rcv_loop, args=(video, vid_stream_name))
        thread.start()

    def video_rcv_loop(self, vid_service, vid_stream_name):
        """
        The main loop of retrieving video images from the robot.

        :param vid_service: The video service object that the active Qi session is connected to. 
        :type vid_service: Object (Qi service object)

        :param vid_stream_name: The name of a camera subscription on the video service object vid_service
        :type vid_stream_name: String
        """
        while not state.exit_event.is_set():
            try:
                img = vid_service.getImageRemote(vid_stream_name)
                #Possibly limit images sent if queuing issues arise
                self.socket.send(img[6])
            except:
                logging.warn("Failed to retrieve video image from robot.")