import React, { useEffect, useRef, useState } from 'react';
import { CSSTransition } from 'react-transition-group';
import styles from './App.module.css';
import GamePanel from './components/screens/GamePanel';
import GameSummary from './components/screens/GameSummary';
import HomePage from './components/screens/HomePage';
import Lobby from './components/screens/Lobby';
import RoundSummary from './components/screens/RoundSummary';
import ApiInfo from './components/util/ApiInfo';
import { ERROR, IN_ROUND, POST_GAME, POST_ROUND, PRE_GAME, PRE_ROUND } from './domain/GameState';
import { dispatch, useGameState } from './domain/gameStore';

const needsHeaderFooter = {
  [PRE_GAME]: true,
  [PRE_ROUND]: true,
  [IN_ROUND]: false,
  [POST_ROUND]: false,
  [POST_GAME]: false,
  [ERROR]: true
};

const Header = ({ show }) => {
  const transitionRef = useRef(null);

  return (
    <CSSTransition
      nodeRef={transitionRef}
      in={show}
      timeout={500}
      mountOnEnter
      unmountOnExit
      classNames="fade"
    >
      <div className={styles.header} ref={transitionRef}>
        <p>TerrAssumptions!</p>
      </div>
    </CSSTransition>
  );
}

const Footer = ({ show }) => {
  const transitionRef = useRef(null);

  return (
    <CSSTransition
      nodeRef={transitionRef}
      in={show}
      timeout={500}
      mountOnEnter
      unmountOnExit
      classNames="fade"
    >
      <div className={styles.footer} ref={transitionRef}>
        <ApiInfo />
      </div>
    </CSSTransition>
  );
}

const paramRouter = {
  join: dispatch.goToLobby,
  summary: gameId => dispatch.goToSummary(gameId, false),
}

const State = ({ show, children, setTransitioning }) => {
  const transitionRef = useRef(null);

  return (
    <CSSTransition
      nodeRef={transitionRef}
      in={show}
      timeout={500}
      mountOnEnter
      unmountOnExit
      classNames="fade"
      onEnter={() => setTransitioning(true)} 
      onExited={() => setTransitioning(false)}
    >
      <div className={styles.state} ref={transitionRef}>
        {children}
      </div>
    </CSSTransition>
  );
}

export default () => {
  const [transitioning, setTransitioning] = useState(true);
  const gameState = useGameState();
  useEffect(() => {
    const url = new URL(window.location.href);
    for (let [param, value] of url.searchParams.entries()) {
      const route = paramRouter[param];
      if (route) {
        url.searchParams.delete(param);
        window.history.replaceState({}, document.title, url.href);
        route(value);
        break;
      }
    }
  }, []);
  const needsHF = needsHeaderFooter[gameState];

  return (
    <React.StrictMode>
      <div className={styles.page}>
        <Header show={needsHF} />
        <State show={gameState === PRE_GAME} setTransitioning={setTransitioning}>
          <HomePage />
        </State>
        <State show={gameState === PRE_ROUND} setTransitioning={setTransitioning}>
          <Lobby />
        </State>
        {!transitioning && gameState === IN_ROUND && <GamePanel />}
        <State show={gameState === POST_ROUND} setTransitioning={setTransitioning}>
          <RoundSummary />
        </State>
        <State show={gameState === POST_GAME} setTransitioning={setTransitioning}>
          <GameSummary />
        </State>
        <State show={gameState === ERROR}>
          <p>Application encountered unrecoverable error, please refresh the page.</p>
        </State>
        <Footer show={needsHF} />
      </div>
    </React.StrictMode>
  );
};