const PORT = process.env.PORT || 7000;

const Koa = require('koa');
const router = require('koa-router')();
const MemoryFS = require('memory-fs');
const Promise = require('bluebird');
const webpack = require('webpack');


const app = new Koa();
const fs = new MemoryFS();

// webpack compiler. once compiled, client.js
// will be available at fs.readFileSync('/client-bundle.js')
const compiler = webpack({
    context: __dirname,
    entry: {
        client: './client'
    },
    output: {
        filename: '[name]-bundle.js',
        path: '/'
    }
});
compiler.outputFileSystem = fs;

// start compiler.watch()
// p will resolve when the first compile finishes
// we should wait to start the server until p resolves,
// but it's more readable not to
const p = Promise.fromCallback(cb => compiler.watch({}, cb));
p.tap(() => console.log('Client assets compiled'));

router.get('/client.js', ctx => {
    ctx.type = 'application/javascript; charset=utf-8';
    ctx.body = fs.readFileSync('/client-bundle.js');
});

app.use(router.routes());
app.listen(PORT);
console.log('Prototype server listening on', PORT);