var express = require('express'); // Web Framework
var bodyParser = require('body-parser');
var sql = require('mssql'); // MS Sql Server client
var app = express();
var router = express.Router();

//Body Parser
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json({ type: 'application/json' }));

//Route
app.use("/api/images", router)

//CORS Middleware
router.use(function (req, res, next) {
    //Enabling CORS
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT");
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, contentType,Content-Type, Accept, Authorization");
    next();
});

//Starting the server on port 8080
var server = app.listen(process.env.PORT || 8080, function () {
    var port = server.address().port;
    console.log("App now running on port", port);
 });

// Connection string parameters.
var dbConfig = {
    user: 'sa',
    password: '********',
    server: 'localhost\\SQLEXPRESS01',
    database: 'ImageDB'
};


//Start connection pool
var dbConn = new sql.ConnectionPool(dbConfig);

//ExecuteQuery that is passed in.
var  executeQuery = function(res, query){
    sql.connect(dbConfig, function (err, dbConn) {
        if (err) {
            console.log("Error while connecting database :- " + err);
            res.send(err);
            sql.close();
        }
         else {
                // create Request object
                var request = new sql.Request(dbConn);
                // query to the database
                request.query(query, function (err, rs) {
                //handling errors
                if (err) {
                    console.log("Error while querying database :- " + err);
                    sql.close();
                    res.send(err);
                }
                else {
                    //close connection
                    sql.close();
                    // Prepare the response
                    res.writeHead(200, {'Content-Type': 'application/json'});
                    //Create an array and push query results to it
                    var images = [];
                    for (var i = 0; i < rs.recordset.length; i++) {
                        images.push({id: rs.recordset[i].ID.toString(), image : new Buffer(rs.recordset[i].Image).toString("base64")});
                    };
                    res.end(JSON.stringify({ images }));
                }
            });
        }
    });
}

//GET API
router.get("/:id", function(req , res){
                var id = req.params.id;
                var query = "select * from [Images] where ID=" + id;
                executeQuery (res, query);
});

module.export = router;