'use strict';

var express = require('express');
var morgan = require('morgan');
var bodyParser = require('body-parser');
var _ = require('lodash');
var app = express();

var request = require('request');

var timeout = process.env.TIMEOUT;

app.use(morgan('combined'));
app.use(bodyParser.json());

function setCORSHeaders(res) {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader("Access-Control-Allow-Methods", "POST");
  res.setHeader("Access-Control-Allow-Headers", "accept, content-type");  
}

app.all('/', function(req, res) {
  setCORSHeaders(res);
  res.send('https://grafana.com/plugins/grafana-simple-json-datasource\n');
  res.end();
});

function search(url, body, res)
{
    request.post({
            url: url,
            body: JSON.stringify(body),
            timeout: timeout
        },
        function (error, response, body) {
            if (!error && response.statusCode == 200) {
                if (search_result.length == 0) {
                    search_result = JSON.parse(body);
                } else {
                    var values = JSON.parse(body);
                    for (var i = 0; i < values.length; i++) {
                        if (search_result.indexOf(values[i]) === -1) {
                            search_result.push(values[i]);
                        }
                    }
                    search_result.sort();
                }
                
                if (res !== undefined) {
                    setCORSHeaders(res);
                    res.json(search_result);
                    res.end();
                }
            } else {
                console.log(error);
            }
        }
    );
}

function query(url, query_result, req, res)
{       
    request.post({
            url: url,
            headers: req.headers,
            body: JSON.stringify(req.body),
            timeout: timeout
        },
        function (error, response, body) {
            if (!error && response.statusCode == 200) {
                if (query_result.length == 0) {
                    query_result = JSON.parse(body);
                } else {
                    query_result = query_result.concat(JSON.parse(body));
                }
                
                if (res !== undefined) {
                    setCORSHeaders(res);
                    res.json(query_result);
                    res.end();
                }
            } else {
                console.log(error);
            }
        }
    );
}

var search_result = [];
app.all('/search', function (req, res) {
    search_result = [];
    search('http://mysql_jsonendpoint:8000/search', req.body);
    search('http://mongodb_jsonendpoint:8000/search', req.body, res);
});

app.all('/query', function (req, res) {
    var query_result = [];
    query('http://mysql_jsonendpoint:8000/query', query_result, req);
    query('http://mongodb_jsonendpoint:8000/query', query_result, req, res);
});

app.listen(8000);

console.log("Server is listening to port 8000");