"use strict";

const CONFIG         = require('./config');
const EXPRESS        = require( 'express' );
const JADE           = require( 'jade' );
const FS             = require( 'fs' );
const BODYPARSER     = require( 'body-parser' );
const METHODOVERRIDE = require( 'method-override' );
const ERRORHANDLER   = require( 'error-handler' );
const HTTP           = require( 'http' );
const PATH           = require( 'path' );
const APP            = module.exports = EXPRESS();
const SEQUELIZE = require( 'sequelize' );

APP.set( 'models', require('./models') );
APP.set( 'port', CONFIG.app.port );

APP.use( METHODOVERRIDE() );
APP.use( EXPRESS.static( PATH.join( __dirname, 'public' ) ) );

//APP.use( BODYPARSER() );

// Load the Server Side Processing model
var SSP = APP.get('models').SSP;

// Page loading the HTML DataTable
APP.get( '/', ( req, res ) => {
    var pageContent = JADE.renderFile('templates/container.jade', {
        sources: CONFIG.sources,
        pageContent: JADE.renderFile('templates/datatable.jade')
    });

    res.send( pageContent );
});

// Start a new SSP result by creating an object with the draw integer
function newSspResult( sspParams ) {
    return new Promise(( resolve, reject ) => {
        resolve(sspParams, {
            draw: parseInt( sspParams.draw ),
            data: []
        });
    })
}

// Get the total rows in the table, append it to the SSP result object
function totalRows( sspParams, sspResult ) {
    console.log('sspResult',typeof sspResult);

    return new Promise( ( resolve, reject ) => {
        SSP.findOne({
            attributes: [[SEQUELIZE.fn('COUNT', SEQUELIZE.col('*')), 'total_rows']]
        }).then(( result ) => {
            sspResult.recordsTotal = result.dataValues.total_rows;

            resolve( sspParams, sspResult );
        });
    })
}

function execSspQuery( sspParams, sspResult ){
    var query = {};

    if(typeof sspParams.length !== 'undefined' && parseInt(sspParams.length) !== 0)
        query.limit = parseInt(sspParams.length);

    if(typeof sspParams.start !== 'undefined')
        query.offset = parseInt(sspParams.start);

    query.order = [];

    // Check if were supposed to be ordering anything..
    if( typeof sspParams.order !== 'undefined' )
        sspParams.order.forEach(( elem, key, arr ) => {
            query.order.push([ SEQUELIZE.col(`dtCol_${elem.column}` ), elem.dir]);
        });

    SSP.findAll( query ).then( ( result ) => {

        result.forEach( (element, index, arr) => {
            var thisRow = [];
            sspParams.columns.forEach( (cElement, cIndex, cArr) => {
                thisRow.push( element.dataValues[`dtCol_${cElement.data}`] )
            });
            sspResult.data.push( thisRow );
        });

        resolve( sspResult );
    });
}

SSP.utils.APP = APP;

APP.get( '/ssp', ( req, res ) => {
    // Inbound SSP Query
    var sspParams = req.query;
    var dbQuery = {};

    newSspResult( sspParams )
        .then(totalRows)
        .then(execSspQuery)
        .then(( sspResult ) => {
            console.log( 'sspResult',sspResult );
            res.send( JSON.stringify( sspResult ) );
        })
        .catch((err) => {console.log(`ERROR: ${err}`)});
});

HTTP.createServer( APP ).listen( APP.get( 'port' ), ( ) => {
    console.log( `Express server listening on port ${APP.get( 'port' )}` );
});