// Defining the required NodeJS dependencies
var graph = require('fbgraph');
var fs = require('fs');
var config = require('config-ini');

// Defining variables needed globally
var oldMessage = "";
var fileLocation = "";

// Extanding static access token
function extendAccessToken(){
    graph.extendAccessToken ({
        "client_id":        config.app.client_id,
        "client_secret":    config.app.client_secret
    }, function(err, facebookRes) {
        if (err) {
            console.log(err);
        }
    });
}

// Main function that outputs the update to the terminal and writes it to a file
function getFeed(){
    graph.get("me/home?limit=1", function(err, res) {
        if(err) {
            console.log(err);
        }
        if ( typeof JSON.stringify(res).split('"')[5] !== 'undefined') {
            if ( JSON.stringify(res).split('"')[5] != oldMessage ) {
                console.log(res);
                fs.appendFile(fileLocation, "\r\n"+JSON.stringify(res), function (err) {
                    if (err) {
                        console.log(err);
                    }
                });
                console.log("******************************************");
                oldMessage = JSON.stringify(res).split('"')[5];;
            }
        }
    });
}

// What should be executed when this node is run
config.load(['config.ini'], function(err) {
    if (err) {
        throw new Error(err); //File not found
    }
    graph.setAccessToken(config.app.accessToken);
    fileLocation = config.file.location;
    setInterval(extendAccessToken, 10000);
    setInterval(getFeed, 3000);
});