var http = require('http');
var url = require('url');
var winston = require('winston');
var logger = new (winston.Logger)({
    transports: [
      new (winston.transports.Console)(),
      new (winston.transports.File)({ filename: 'proxy.log', json: false })
    ]
  });
var base_url;

http.createServer(function (clientRequest, clientResponse) {
  logger.info('ENTERING createServer');

  function makeProxyRequest(clientRequestUrl) {
    logger.info('ENTERING makeProxyRequest');

    // hack!
    clientRequestUrl.protocol = 'http:';

    if (typeof(clientRequestUrl.hostname) === "undefined") {
      clientRequestUrl.hostname = base_url.hostname;
    }

    logger.info('client url: ' + url.format(clientRequestUrl));

    proxy = http.request(clientRequestUrl, proxyResponseHandler);
    proxy.on('error', function(e) {
      logger.error('problem with proxy request to '
                    + clientRequestUrl.host + '/' + clientRequestUrl.path
                    + ': ' + JSON.stringify(e));
      clientResponse.end();
    });
    proxy.end();
    logger.info('EXITING makeProxyRequest');
  }

  function proxyResponseHandler(proxyResponse) {
    logger.info('ENTERING proxyResponseHandler');
    logger.info('status: ' + proxyResponse.statusCode);

    switch(proxyResponse.statusCode) {
      case 301:
      case 302:
        var new_url = url.parse(proxyResponse.headers['location']);
        if(typeof(new_url.host) !== 'undefined') {
          base_url = new_url;
        }
        logger.info('redirect received: ' + JSON.stringify(new_url));
        makeProxyRequest(new_url);
      break;

      case 200:
        for(header in proxyResponse.headers) {
          logger.info(' ' + header + ': ' + proxyResponse.headers[header]);
          clientResponse.setHeader(header, proxyResponse.headers[header]);
        }

        clientResponse.writeHead(proxyResponse.statusCode);

        proxyResponse.on('data', function(data) {
          clientResponse.write(data);
        });
        proxyResponse.on('end', function() {
          logger.info('end from origin');
          clientResponse.end();
        });
      break;
    }
    logger.info('EXITING proxyResponseHandler');
  }
  //////////////////////// Execution starts here //////////////////////////////
  var tmp_url = url.parse(clientRequest.url.substring(1));
  logger.info(JSON.stringify(tmp_url));
  logger.info(tmp_url.host);
  if (typeof(tmp_url.host) !== 'undefined' && typeof(base_url) === 'undefined' ) {
    base_url = tmp_url;
  }
  makeProxyRequest(tmp_url);

  logger.info('EXITING createServer');
}).listen(8124);

console.log('Server running at http://127.0.0.1:8124/');