var express = require('express');
var router = express.Router();
var debug = require('debug')('Icarus:server');

var mongoClient = require('mongodb').MongoClient;
var ObjectID = require('mongodb').ObjectID;

var assert = assert = require('assert');

// Connection URL
var mongoUrl = 'mongodb://icarus:icarus@webdev.ewlab.di.unimi.it:27017/icarus';

//Connect to the server and intialise the pool
var icarusDb;
mongoClient.connect(mongoUrl, function(err, db) {

    assert.equal(null, err, err);
    debug("Connected to MongoDB database: "+db.databaseName);

    icarusDb = db;

});

router.get('/:resource_id', function(req, res, next) {

    var collection = icarusDb.collection('resources');

    var _id = new ObjectID(req.params.resource_id);
    collection.find({"_id":_id}).limit(1).next(function(err, doc){

        if(err!=null){

            debug(err);
            next(err);

        }else{

            if(doc==undefined){

                res.sendStatus(404);

            }else{

                res.send(doc);

            }

        }

    });

});

router.post('/', function(req, res, next){

    var collection = icarusDb.collection('resources');
    var resource = req.body;

    if(Object.keys(resource).length>0) {

        var timestampContainer = getTimestampContainer(resource);

        if(timestampContainer!=undefined){

            preprocessTimestampContainer(timestampContainer);

        }

        collection.insertOne(resource, function (err, r) {

            if (err != null) {

                debug(err);
                next(err);

            } else {

                res.statusCode = 201;
                res.send({"_id":r.insertedId});

            }

        });

    }else{

        var error = new Error("You can't store an empty resource!");
        error.status = 400;

        debug(error);
        next(error);

    }

});

function getTimestampContainer(arg){

    if(arg['timestamp']!=undefined&&(arg['timestamp']['utc']!=undefined)||arg['timestamp']['user']!=undefined)
            return arg['timestamp'];

    return undefined;

}

function preprocessTimestampContainer(container){

    var utcSeconds = container['utc'];
    var userSeconds = container['user'];

    if(utcSeconds!=undefined){

        var utcMsec = utcSeconds * 1000;
        container['utc'] = new Date(utcMsec);

    }

    if(userSeconds!=undefined){

        var userMsec = userSeconds * 1000;
        container['user'] = new Date(userMsec);

    }

    container['server'] = new Date();

}

module.exports = router;