var http        = require('http');
var url         = require('url');
var _ = require('underscore');

var SQLAPIEmulator = function(port, cb) {

  this.queries = [];
  var that = this;
  this.requests = [];

  this.sqlapi_server = http.createServer(function(req,res) {
      //console.log("server got request with method " + req.method);
      var query;

      that.requests.push(req);

      if ( req.method == 'GET' ) {
        query = url.parse(req.url, true).query;
        that.handleQuery(query, res);
      }
      else if ( req.method == 'POST') {
        var data = '';
        req.on('data', function(chunk) {
          //console.log("GOT Chunk  " + chunk);
          data += chunk;
        });
        req.on('end', function() {
          //console.log("Data is: "); console.dir(data);
          query = JSON.parse(data);
          //console.log("handleQuery is " + that.handleQuery);
          that.handleQuery(query, res);
        });
      }
      else {
        that.handleQuery('SQLAPIEmu does not support method' + req.method, res);
      }
   }).listen(port, cb);
};

SQLAPIEmulator.prototype.handleQuery = function(query, res) {
    this.queries.push(query);
    if ( query.q.match('SQLAPIERROR') ) {
      res.statusCode = 400;
      res.write(JSON.stringify({'error':'Some error occurred'}));
    } else if ( query.q.match('SQLAPINOANSWER') ) {
        console.log("SQLAPIEmulator will never respond, on request");
        return;
    } else if (query.q.match('tablenames')) {
        var tableNames = JSON.stringify(query);
        res.write(queryResult({tablenames: '{' + tableNames + '}', max: 1234567890.123}));
    } else if ( query.q.match('EPOCH.* as max') ) {
      // This is the structure of the known query sent by tiler
        res.write(queryResult({max: 1234567890.123}));
    } else {
      if ( query.q.match('_private_') && query.api_key === undefined) {
        res.statusCode = 403;
        res.write(JSON.stringify({'error':'forbidden: ' + JSON.stringify(query)}));
      } else {
        var qs = JSON.stringify(query);
        res.write(queryResult({cdb_querytables: '{' + qs + '}', max: 1234567890.123}));
      }
    }
    res.end();
  };

SQLAPIEmulator.prototype.close = function(cb) {
  this.sqlapi_server.close(cb);
};

SQLAPIEmulator.prototype.getLastRequest = function() {
  return this.requests.pop();
};

function queryResult(row) {
    return JSON.stringify({
        rows: [row]
    });
}

module.exports = SQLAPIEmulator;