const webpack = require('webpack');
const path = require('path');
const MFS = require('memory-fs');
const webpackDevMiddleware = require('webpack-dev-middleware');
const webpackHotMiddleware = require('webpack-hot-middleware');
const pkg = require('../package.json');
let clientConfig = require('./webpack.client.conf.js');
let serverConfig = require('./webpack.server.conf.js');

let devMiddleware;
let hotMiddleware;

const _readFile = (fs, file) => {
  try {
    return fs.readFileSync(path.join(clientConfig.output.path, file), 'utf-8');
  } catch (e) {
    console.error('file load failure!', file);
  }
};

exports.readFile = (file) => {
  try {
    return devMiddleware.fileSystem.readFileSync(path.join(clientConfig.output.path, file), 'utf-8');
  } catch (e) {
    return false;
  }
};
exports.publish = (data) => {
  return hotMiddleware.publish(data);
};

exports.devServer = (app, cb) => {
  let resolve;
  let realyPromise = new Promise(r => {
    resolve = r;
  });
  let ready = (...args) => {
    resolve();
    cb(...args);
  };

  clientConfig.entry.app = ['./build/client-hot.js', clientConfig.entry.app];
  clientConfig.output.publicPath = 'http://localhost:6005/';
  clientConfig.output.filename = '[name].js';
  clientConfig.plugins.push(
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NoEmitOnErrorsPlugin()
  );
  const clientCompiler = webpack(clientConfig);

  devMiddleware = webpackDevMiddleware(clientCompiler, {
    publicPath: clientConfig.output.publicPath,
    quiet: true,
    headers: {
      'Access-Control-Allow-Origin': '*'
    }
  });

  app.use(devMiddleware);

  let bundle, clientManifest;

  clientCompiler.plugin('done', stats => {
    stats = stats.toJson();
    stats.errors.forEach(error => console.log(error));
    stats.warnings.forEach(warning => console.log(warning));
    if (stats.errors.length) {
      return;
    }
    clientManifest = JSON.parse(_readFile(devMiddleware.fileSystem, `yoho-ssr-client-${pkg.version}.json`));

    if (bundle) {
      ready({bundle, options: {clientManifest}});
    }
  });
  hotMiddleware = webpackHotMiddleware(clientCompiler, { heartbeat: 5000 });

  app.use(hotMiddleware);

  const serverCompiler = webpack(serverConfig);
  let mfs = new MFS();

  serverCompiler.outputFileSystem = mfs;
  serverCompiler.watch({}, (err, stats) => {
    if (err) {
      throw err;
    }
    stats = stats.toJson();
    if (stats.errors.length) {
      return;
    }
    bundle = JSON.parse(_readFile(mfs, `yoho-ssr-server-${pkg.version}.json`));

    if (clientManifest) {
      ready({bundle, options: {clientManifest}});
    }
  });

  return realyPromise;
};