import * as express from 'express';

import * as http from 'http';

import {writeFile} from '../../utils/fs';

import {request} from '../../utils/http';

import {killAllProcesses, ng} from '../../utils/process';

import {ngServe} from '../../utils/project';

import {expectToFail} from '../../utils/utils';

export default function() {

// Create an express app that serves as a proxy.

const app = express();

const server = http.createServer(app);

server.listen(0);

app.set('port', server.address().port);

app.get('/api/test', function (req, res) {

res.send('TEST_API_RETURN');

});

const backendHost = 'localhost';

const backendPort = server.address().port;

const proxyServerUrl = `http://${backendHost}:${backendPort}`;

const proxyConfigFile = 'proxy.config.json';

const proxyConfig = {

'/api/*': {

target: proxyServerUrl

}

};

return Promise.resolve()

.then(() => writeFile(proxyConfigFile, JSON.stringify(proxyConfig, null, 2)))

.then(() => ngServe('--proxy', proxyConfigFile))

.then(() => request('http://localhost:4200/api/test'))

.then(body => {

if (!body.match(/TEST_API_RETURN/)) {

throw new Error('Response does not match expected value.');

}

})

.then(() => server.close(), (err) => { server.close(); throw err; })

.then(() => killAllProcesses(), (err) => { killAllProcesses(); throw err; })

// A non-existing proxy file should error.

.then(() => expectToFail(() => ng('serve', '--proxy', 'proxy.non-existent.json')));

}