var https = require('https'),
    zlib = require('zlib'),
    path = require('path'),
    fs = require('fs');

var stable = '1.7.1',
    done;

function getVersion(path, cb) {
    var data = '',
        req = https.request({
        host: 'raw.github.com',
        port: 443,
        path: '/timrwood/moment/' + path
    }, function (res) {
        res.setEncoding('utf8');
        res.on('data', function (chunk) {
            data += chunk;
        });
        res.on('end', function (e) {
            zlib.gzip(data, function (error, result) {
                cb(data.length, result.length);
            });
        });
    });
    req.on('error', function (e) {
        console.log('problem with request: ' + e.message);
    });
    req.end();
}

function printDiffs(stableLen, stableGzip, currentLen, currentGzip) {
    var diff = currentLen - stableLen,
        gzipDiff = currentGzip - stableGzip;

    console.log('Filesize difference from current branch to ' + stable);
    console.log(stable + '   ' + stableLen + ' / ' + stableGzip);
    console.log('curr    ' + currentLen + ' / ' + currentGzip);
    console.log('diff    ' + (diff > 0 ? '+' : '') + diff);
    console.log('gzip    ' + (gzipDiff > 0 ? '+' : '') + gzipDiff);
}


module.exports = function (grunt) {
    grunt.registerTask('size', 'Check the codebase filesize against the latest stable version.', function () {
        done = this.async();
        fs.readFile(path.normalize(__dirname + '/../min/moment.min.js'), 'utf8', function (err, data) {
            if (err) {
                throw err;
            }
            zlib.gzip(data, function (error, result) {
                getVersion(stable + '/min/moment.min.js', function (stableLength, stableGzipLength) {
                    printDiffs(stableLength, stableGzipLength, data.length, result.length);
                    done();
                });
            });
        });
    });
};
