import React, { useState, useLayoutEffect, useEffect, useRef, useCallback } from 'react';
import { BrowserRouter as Router, Route, Link, Switch } from 'react-router-dom';
import localForage from 'localforage';
import './Style-light.css';
import './Style-dark.css';
import './Style-black.css';
import './Style-red.css';
import './fonts/Fonts.css';
import { BackwardDot, ForwardDot } from './utils.js';
import Feed from './Feed.js';
import Article from './Article.js';
import Comments from './Comments.js';
import Search from './Search.js';
import Submit from './Submit.js';
import Results from './Results.js';
import ScrollToTop from './ScrollToTop.js';
import Settings from './Settings.js';

function App() {
	const [theme, setTheme] = useState(localStorage.getItem('theme') || '');
	const cache = useRef({});
	const [isFullScreen, setIsFullScreen] = useState(!!document.fullscreenElement);
	const [waitingWorker, setWaitingWorker] = useState(null);
	const [settingsOpen, setSettingsOpen] = useState(false);
	const defaultBodyFontSize = 1.0;
	const [bodyFontSize, setBodyFontSize] = useState(Number(localStorage.getItem('bodyFontSize')) || defaultBodyFontSize);
	const [bodyFont, setBodyFont] = useState(localStorage.getItem('bodyFont') || 'Sans Serif');
	const [articleFont, setArticleFont] = useState(localStorage.getItem('articleFont') || 'Apparatus SIL');
	const [filterSmallweb, setFilterSmallweb] = useState(() => localStorage.getItem('filterSmallweb') === 'true');
	const [feedSources, setFeedSources] = useState(() => {
		const saved = localStorage.getItem('feedSources');
		return saved ? JSON.parse(saved) : {
			hackernews: true,
			reddit: true,
			lobsters: true,
			tildes: true,
		};
	});

	const updateCache = useCallback((key, value) => {
		cache.current[key] = value;
	}, []);

	useEffect(() => {
		const onSWUpdate = e => {
			setWaitingWorker(e.detail.waiting);
		};
		window.addEventListener('swUpdate', onSWUpdate);
		return () => window.removeEventListener('swUpdate', onSWUpdate);
	}, []);

	useEffect(() => {
		if (Object.keys(cache.current).length === 0) {
			localForage.iterate((value, key) => {
				updateCache(key, value);
			}).then(() => {
				console.log('loaded cache from localforage');
			});
		}
	}, [updateCache]);

	useEffect(() => {
		const onFullScreenChange = () => setIsFullScreen(!!document.fullscreenElement);
		document.addEventListener('fullscreenchange', onFullScreenChange);
		return () => document.removeEventListener('fullscreenchange', onFullScreenChange);
	}, []);

	useLayoutEffect(() => {
		if (theme === 'dark') {
			document.body.style.backgroundColor = '#1a1a1a';
		} else if (theme === 'black') {
			document.body.style.backgroundColor = '#000';
		} else if (theme === 'red') {
			document.body.style.backgroundColor = '#000';
		} else {
			document.body.style.backgroundColor = '#eeeeee';
		}
	}, [theme]);

	useEffect(() => {
		document.documentElement.style.fontSize = `${bodyFontSize}rem`;
	}, [bodyFontSize]);

	const fontMap = {
		'Sans Serif': 'sans-serif',
		'Serif': 'serif',
		'Apparatus SIL': "'Apparatus SIL', sans-serif"
	};

	useEffect(() => {
		document.body.style.fontFamily = fontMap[bodyFont];
	}, [bodyFont]);

	useEffect(() => {
		const styleId = 'article-font-family-style';
		let style = document.getElementById(styleId);
		if (!style) {
			style = document.createElement('style');
			style.id = styleId;
			document.head.appendChild(style);
		}
		style.innerHTML = `.story-text { font-family: ${fontMap[articleFont]} !important; }`;
	}, [articleFont]);


	return (
		<div className={theme}>
			<Settings
				settingsOpen={settingsOpen}
				setSettingsOpen={setSettingsOpen}
				theme={theme}
				setTheme={setTheme}
				isFullScreen={isFullScreen}
				filterSmallweb={filterSmallweb}
				setFilterSmallweb={setFilterSmallweb}
				feedSources={feedSources}
				setFeedSources={setFeedSources}
				bodyFontSize={bodyFontSize}
				setBodyFontSize={setBodyFontSize}
				defaultBodyFontSize={defaultBodyFontSize}
				bodyFont={bodyFont}
				setBodyFont={setBodyFont}
				articleFont={articleFont}
				setArticleFont={setArticleFont}
			/>

			{waitingWorker &&
				<div className='update-banner'>
					Client version mismatch, please refresh:{' '}
					<button onClick={() => {
						waitingWorker.postMessage({ type: 'SKIP_WAITING' });
						const reload = () => window.location.reload();
						navigator.serviceWorker.addEventListener('controllerchange', reload, { once: true });

						// Fallback for when the controller has already changed (ie. in another tab)
						navigator.serviceWorker.getRegistration().then(reg => {
							if (!reg || !reg.waiting) {
								reload();
							}
						});
					}}>
						Refresh
					</button>
				</div>
			}
			<Router>
				<div className='container menu'>
					<p>
						<Link to='/'>QotNews</Link>

						<button className="settings-button" onClick={() => setSettingsOpen(true)}>Settings</button>
						<br />
						<span className='slogan'>Hacker News, Reddit, Lobsters, and Tildes articles rendered in reader mode.</span>
					</p>
					<Route path='/(|search)' component={Search} />
					<Route path='/(|search)' component={Submit} />
				</div>

				<Route path='/' exact render={(props) => <Feed {...props} updateCache={updateCache} filterSmallweb={filterSmallweb} feedSources={feedSources} />} />
				<Switch>
					<Route path='/search' component={Results} />
					<Route path='/:id' exact render={(props) => <Article {...props} cache={cache.current} />} />
				</Switch>
				<Route path='/:id/c' exact render={(props) => <Comments {...props} cache={cache.current} />} />

				<BackwardDot />
				<ForwardDot />

				<ScrollToTop />
			</Router>
		</div>
	);
}

export default App;