var express = require('express');
var Promise = require("bluebird");
var getSqlConnection = require('../common/database');
var redisModules = require("../common/redismodule");

function getSettings(request, response)
{
    if (redisModules.IsRedisConnectionOpened() == true)
    {
        return GetData();
    }
    else
    {
        response.status(500).send();
        return;
    }

    function GetData()
    {
        redisModules.GetRedisValue("key")
        .then(function (result)
        {
            if (!result)
                return new SetData();
            else
                return result;
        })
        .catch(function (e)
        {
            response.status(500).send();
        })
        .then(function (result)
        {
            response.status(200).send({ value : result });
        });
    }

    function SetData()
    {
        return Promise.using(getSqlConnection(), function(connection)
        {
            return connection.query('select url from blog')
            .then(function(results)
            {
                var data = "";
                // some code
                return data;
            })
            .then(function (result)
            {
                return new redisModules.SetRedisValue("key", result);
            });
        });
    }
}

var mysql = require('promise-mysql');

pool = mysql.createPool({
  host: '',
  user: '',
  password: '',
  database: '',
  connectionLimit: 4
});

function getSqlConnection() {
  return pool.getConnection().disposer(function(connection) {
    pool.releaseConnection(connection);
  });
}

module.exports = getSqlConnection;

var Promise = require('bluebird');
var constants = require('../common/contants');

var redisClient;        // Global (Avoids Duplicate Connections)

module.exports =
{
    OpenRedisConnection : function()
    {
        if (redisClient == null)
        {
            redisClient = require("redis").createClient(6379, 'localhost');
        }
    },
    IsRedisConnectionOpened : function()
    {
        if (redisClient && redisClient.connected == true)
        {
            return true;
        }
        else
        {
            if(redisClient)
                redisClient.end();  // End and open once more

            module.exports.OpenRedisConnection();
            return true;
        }
    },
    GetRedisValue: function (key)
    {
        return new Promise(function (resolve, reject)
        {
            redisClient.get(key, function (error, result)
            {
                if (error)
                {
                    reject(error);
                }
                else
                {
                    if (result == null)
                        resolve();    // Key not present so create
                    else
                        resolve(result);
                }
            });
        });
    },
    SetRedisValue: function (key, value)
    {
        return new Promise(function (resolve, reject)
        {
            redisClient.set(key, value, 'EX', 1000,
            function(err,reply)
            {
                if (reply == 'OK')
                    resolve(value);         // Send the value
                else
                    reject(err);
            });
        });
    }
};