const http = require('http');

const webpack = require('webpack');
const wdm = require('webpack-dev-middleware');
const whm = require('webpack-hot-middleware');

const debug = require('debug')('truss:persea');

const {webpackConfig} = require('./webpack.config');

const backendHostname = process.env.PERSEA_BACKHOST || 'persea';
const backendPort = process.env.PERSEA_BACKPORT || 8004;
const frontendHostname = process.env.PERSEA_FRONTHOST || 'localhost';

exports.Responder = class Responder {

  constructor() {
    const httpServer = this.server = http.createServer();

    httpServer.on('listening', () => {
      const address = this.address = httpServer.address();
      const config = webpackConfig();

      for (const i in config.entry) {
        config.entry[i].unshift(`webpack-hot-middleware/client?path=http://${
          frontendHostname}:${address.port
        }/__webpack_hmr`);
      }

      const compiler = webpack(config);
      this.dm = wdm(compiler, {
        headers: {
          "Access-Control-Allow-Origin": "*",
          "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE, PATCH, OPTIONS",
          "Access-Control-Allow-Headers": "X-Requested-With, content-type, Authorization"
        },
        stats: {
          chunkModules: true,
          colors: true,
          context: process.cwd(),
        },
      });
      this.hm = whm(compiler, {
        path: '/__webpack_hmr',
      });

      debug(`HTTP listening on ${JSON.stringify(address)}...`);
    });

    httpServer.on('request', (req, res) => {
      this.dm(req, res, (error) => {
        if (error) {
          return console.error(error);
        }
        this.hm(req, res, (error) => {
          if (error) {
            return console.error(error);
          }
        });
      });
    });

    httpServer.on('error', console.error);

    httpServer.on('close', () => httpServer.removeAllListeners());
  }

  start() {
    this.server.listen(backendPort);
  }

  respond({payload: {headers, url}}) {
    // forward to internal HTTP
    return new Promise((resolve, reject) => {

      const options = {
        headers,
        backendHostname,
        path: url,
        port: this.address.port,
      };

      const client = http.get(options);
      client.on('response', (res) => {
        let data = '';
        res.setEncoding('utf8');
        res.on('data', (chunk) => {
          data += chunk;
        });
        res.on('end', () => {
          resolve({
            html: data,
            headers: res.headers
          });
        });
      });
      client.on('error', reject);
    });
  }

  stop() {
    this.server.close();
  }
}