var express = require('express');
var bodyParser = require('body-parser');
var app = express();
const json2xls = require('json2xls');
var fs = require('fs');
var AWS = require('aws-sdk');
AWS.config.update({
    region: "us-east-1",
});

var events = new AWS.DynamoDB.DocumentClient();

app.use(bodyParser.json({
    limit: '50mb'
})); // parse application/vnd.api+json as json
app.use(bodyParser.urlencoded({
    limit: '50mb',
    extended: true,
    parameterLimit: 50000
})); // parse application/x-www-form-urlencoded

app.use(function (req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    next();
});

app.set('port', process.env.PORT || 4000);

var server = app.listen(app.get('port'), function () {
    console.log('Express server listening on port ' + server.address().port);

    var params = {
        TableName: 'ses-events'
    };
    events.scan(params, function (err, data) {
        if (err) {
            console.log("Error", err);
        } else {
            var xls = json2xls(data.Items);
            var path = './' + Date.now() + '.xlsx';
            fs.writeFile(path, xls, 'binary', function (err, data) {
                if (err) {
                    throw err;
                } else {
                    console.log('File created');
                }
            });
        }
    });
});