/* eslint-env node */

const path = require('path');
const HttpProxy = require('http-proxy');

const config = require('../../config/environment')(process.env.EMBER_ENV).APP;

module.exports = function(app, options) {
  var httpServer = options.httpServer;


  const proxy = HttpProxy.createProxyServer({
    ws: true,
    xfwd: false,
    target: config.apiServer,
    secure: false,
    followRedirects: true,
  });

  proxy.on('error', onProxyError);

  // WebSocket for Rancher
  httpServer.on('upgrade', (req, socket, head) => {
    if ( req.url.startsWith('/_lr/') ) {
      return;
    }

    let targetHost = config.apiServer.replace(/^https?:\/\//, '');
    let host = req.headers['host'];
    let port;

    if ( socket.ssl ) {
      req.headers['x-forwarded-proto'] = 'https';
      port = 443;
    } else {
      req.headers['x-forwarded-proto'] = 'http';
      port = 80;
    }

    if ( host ) {
      idx = host.lastIndexOf(':');
      if ( ( host.startsWith('[') && host.includes(']:') || !host.startsWith('[') ) && idx > 0 ){
        port = host.substr(idx+1);
        host = host.substr(0, host.lastIndexOf(':'));
      }
    }

    req.headers['x-forwarded-host'] = host;
    req.headers['x-forwarded-port'] = port;
    req.headers['host'] = targetHost;
    req.headers['origin'] = config.apiServer;
    req.socket.servername = targetHost;

    proxyLog('WS', req);

    try {
      proxy.ws(req, socket, head);
    } catch (err) {
      proxyLog(err);
    }
  });

  let map = {
    'Project':   config.projectEndpoint.replace(config.projectToken, ''),
    'Cluster':   config.clusterEndpoint.replace(config.clusterToken, ''),
    'Global':    config.apiEndpoint,
    'Public':    config.publicApiEndpoint,
    'Magic':     config.magicEndpoint,
    'Telemetry': config.telemetryEndpoint,

    'K8s':       '/k8s',
    'Meta':      '/meta',
    'Swagger':   '/swaggerapi',
    'Version':   '/version',
    'Apiui':     '/api-ui',
    'Samlauth':  '/v1-saml',
  }

  app.use('/', function(req, res, next) {
    if ( (req.headers['user-agent']||'').toLowerCase().includes('mozilla') ) {
      next();
    } else {
      proxyLog('Root', req);
      req.headers['X-Forwarded-Proto'] = req.protocol;
      proxy.web(req, res);
    }
  }),

  console.log('Proxying APIs to', config.apiServer);
  Object.keys(map).forEach(function(label) {
    let base = map[label];
    app.use(base, function(req, res, next) {
      if ( req.url === '/' ) {
        req.url = '';
      }

      // include root path in proxied request
      req.url = path.join(base, req.url);
      req.headers['X-Forwarded-Proto'] = req.protocol;

      // don't include the original host header
      req.headers['X-Forwarded-Host'] = req.headers['host'];
      delete req.headers['host'];

      proxyLog(label, req);
      proxy.web(req, res);
    });
  });
}

function onProxyError(err, req, res) {
  console.log('Proxy Error on '+ req.method + ' to', req.url, err);
  var error = {
    type: 'error',
    status: 500,
    code: 'ProxyError',
    message: 'Error connecting to proxy',
    detail: err.toString()
  }

  if ( req.upgrade )
  {
    res.end();
  }
  else
  {
    res.writeHead(500, {'Content-Type': 'application/json'});
    res.end(JSON.stringify(error));
  }
}

function proxyLog(label, req) {
  console.log(`[${ label }]`, req.method, req.url);
}

function proxyError(label, req, err) {
  console.error(`[${ label }][${ req._source }]`, req.method, req.url, err);
}