import React from "react";

import BackgroundTasksContext from "./context";
import { handleTask, queueCustom } from "./tasks";
import { QueuedTask, Task, TaskData } from "./types";

export const backgroundTasksRefreshTime = 15 * 1000;

export function useBackgroundTasks() {
  const idCounter = React.useRef(0);
  const tasks = React.useRef<QueuedTask[]>([]);

  React.useEffect(() => {
    const intervalId = setInterval(() => {
      tasks.current = tasks.current.filter(task => !handleTask(task));
    }, backgroundTasksRefreshTime);

    return () => clearInterval(intervalId);
  });

  function cancel(id: number) {
    tasks.current = tasks.current.filter(task => task.id !== id);
  }

  function queue(type: Task, data?: TaskData) {
    idCounter.current += 1;

    switch (type) {
      case Task.CUSTOM:
        queueCustom(idCounter.current, tasks, data);
    }

    return idCounter.current;
  }

  return {
    cancel,
    queue
  };
}

const BackgroundTasksProvider: React.FC = ({ children }) => {
  const { cancel, queue } = useBackgroundTasks();

  return (
    <BackgroundTasksContext.Provider
      value={{
        cancel,
        queue
      }}
    >
      {children}
    </BackgroundTasksContext.Provider>
  );
};

BackgroundTasksProvider.displayName = "BackgroundTasksProvider";
export default BackgroundTasksProvider;