require('./check-versions')();

const { readSettings } = require('../SettingsHelper');

const settings = readSettings();

const config = require('../config');

if (!process.env.NODE_ENV) {
  process.env.NODE_ENV = JSON.parse(config.dev.env.NODE_ENV);
}

const opn = require('opn');
const path = require('path');
const express = require('express');
const webpack = require('webpack');
const proxyMiddleware = require('http-proxy-middleware');
const webpackConfig = require('./webpack.dev.conf');
const history = require('connect-history-api-fallback');

// default port where dev server listens for incoming traffic
const port = process.env.PORT || config.dev.port;
// automatically open browser, if not set will be false
const autoOpenBrowser = !!config.dev.autoOpenBrowser;
// Define HTTP proxies to your custom API backend
// https://github.com/chimurai/http-proxy-middleware
const proxyTable = config.dev.proxyTable;

const app = express();
const compiler = webpack(webpackConfig);

const devMiddleware = require('webpack-dev-middleware')(compiler, {
  publicPath: webpackConfig.output.publicPath,
  quiet: true,
});

const hotMiddleware = require('webpack-hot-middleware')(compiler, {
  publicPath: webpackConfig.output.publicPath,
  log: () => {},
});

// force page reload when html-webpack-plugin template changes
compiler.plugin('compilation', (compilation) => {
  compilation.plugin('html-webpack-plugin-after-emit', (data, cb) => {
    hotMiddleware.publish({ action: 'reload' });
    cb();
  });
});

// proxy api requests
Object.keys(proxyTable).forEach((context) => {
  let options = proxyTable[context];
  if (typeof options === 'string') {
    options = { target: options };
  }
  app.use(proxyMiddleware(options.filter || context, options));
});

const staticPath = path.posix.join(config.dev.assetsPublicPath, config.dev.assetsSubDirectory);

// handle fallback for HTML5 history API
const indexPath = path.posix.join(staticPath, 'index.html');
app.use(
  history({
    index: indexPath,
  }),
);

// serve webpack bundle output
app.use(devMiddleware);

// enable hot-reload and state-preserving
// compilation error display
app.use(hotMiddleware);

// serve pure static assets
app.use(staticPath, express.static('./static'));

const uri = `http://localhost:${port}${staticPath}`;

let _resolve;
const readyPromise = new Promise((resolve) => {
  _resolve = resolve;
});

console.log('> Starting dev server...');
devMiddleware.waitUntilValid(() => {
  console.log(`> Listening at ${uri}\n`);
  // when env is testing, don't need open it
  if (autoOpenBrowser && process.env.NODE_ENV !== 'testing') {
    opn(uri);
  }
  _resolve();
});

const configPath = path.posix.join(staticPath, 'config');
app.get(configPath, (req, res) => {
  res.header('Cache-Control', 'private, no-cache, no-store, must-revalidate');
  res.header('Expires', '-1');
  res.header('Pragma', 'no-cache');
  res.send(settings);
});

const server = app.listen(port);

module.exports = {
  ready: readyPromise,
  close: () => {
    server.close();
  },
};