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/');