import React from 'react';
import ReactDOM from 'react-dom/server';
import Helmet from 'react-helmet';
import { flushChunkNames } from 'react-universal-component/server';
import flushChunks from 'webpack-flush-chunks';
import { Provider } from 'react-redux';
import { StaticRouter } from 'react-router';

import createDocument from './document';
import configureStore from '../shared/redux/store/configureStore';
import App from '../shared/App';

export default ({ clientStats }) => async (req, res) => {
    const preloadedState = {};
    const store = configureStore(preloadedState);
    const context = {};
    const app = (
        <Provider store={store}>
            <StaticRouter location={req.url} context={context}>
                <App/>
            </StaticRouter>
        </Provider>
    );

    const appString = ReactDOM.renderToString(app);
    const helmet = Helmet.renderStatic();
    const chunkNames = flushChunkNames();
    const { js, styles } = flushChunks(clientStats, { chunkNames });
    const document = createDocument({
        appString,
        js,
        styles,
        helmet,
        preloadedState: JSON.stringify(preloadedState)
    });

    if (context.url) {
        res.writeHead(301, {
            Location: context.url
        });
        res.end();
    } else {

        res.set('Content-Type', 'text/html').end(document);
    }
};