import { useEffect, useState, useCallback } from "react";
import { useDispatch, useSelector } from "react-redux";
import { setFetchedTorrents } from "../actions/torrents";
import { newMovieEvent, getMovieDetails } from "../actions/movies";
import { newEpisodeEvent, getEpisodeDetails } from "../actions/shows";

export const WsHandler = () => {
  const dispatch = useDispatch();

  const isLogged = useSelector((state) => state.user.isLogged);

  const [ws, setWs] = useState(null);

  const stop = useCallback(() => {
    if (!ws) {
      return;
    }
    ws.close();
    setWs(null);
  }, [ws]);

  const connect = useCallback(() => {
    if (ws) {
      return;
    }

    if (!isLogged) {
      stop();
    }

    const type = location.protocol === "https:" ? "wss" : "ws";
    const socket = new WebSocket(type + ":" + location.host + "/events");
    socket.onopen = () => {
      socket.send(
        JSON.stringify({
          type: "subscribe",
          message: "torrents",
        })
      );
      socket.send(
        JSON.stringify({
          type: "subscribe",
          message: "newVideo",
        })
      );
    };

    socket.onmessage = (event) => {
      if (!event.data) {
        return;
      }

      const data = JSON.parse(event.data);
      if (!data.type) {
        return;
      }

      if (data.status !== "ok") {
        // TODO: handle this somehow
        return;
      }

      switch (data.type) {
        case "torrents":
          dispatch(setFetchedTorrents(data.message));
          break;
        case "newVideo":
          if (data.message.type === "movie") {
            dispatch(newMovieEvent(data.message.data));
            dispatch(getMovieDetails(data.message.data.imdb_id));
          } else if (data.message.type === "episode") {
            dispatch(newEpisodeEvent(data.message.data));
            dispatch(
              getEpisodeDetails(
                data.message.data.show_imdb_id,
                data.message.data.season,
                data.message.data.episode
              )
            );
          }
          break;
      }
    };

    socket.onerror = () => {
      stop();
    };

    setWs(socket);
  }, [ws, isLogged, dispatch, stop]);

  useEffect(() => {
    const intervalID = setInterval(() => {
      if (!ws) {
        connect();
        return;
      }

      if (ws.readyState === WebSocket.CLOSED) {
        stop();
      }
    }, 10000);

    if (!ws) {
      connect();
    }

    return () => {
      if (ws) {
        stop();
      }
      clearInterval(intervalID);
    };
  }, [ws, connect, stop]);

  return null;
};