(function () {
    "use strict";

    var fs = require('fs'),
        /**
         * Create new Polyglot object
         * @type {Polyglot}
         */
        I18n;

    I18n = function (ghost) {

        // TODO: validate
        var lang = ghost.config().defaultLang,
            path = ghost.paths().lang,
            langFilePath = path + lang + '.json';

        return function (req, res, next) {

            if (lang === 'en') {
                // TODO: do stuff here to optimise for en

                // Make jslint empty block error go away
                lang = 'en';
            }

            /** TODO potentially use req.acceptedLanguages rather than the default
            *   TODO handle loading language file for frontend on frontend request etc
            *   TODO switch this mess to be promise driven */
            fs.stat(langFilePath, function (error, stat) {
                if (error) {
                    console.log('No language file found for language ' + lang + '. Defaulting to en');
                    lang = 'en';
                }

                fs.readFile(langFilePath, function (error, data) {
                    if (error) {
                        throw error;
                    }

                    try {
                        data = JSON.parse(data);
                    } catch (e) {
                        throw e; // TODO - do something better with the error here
                    }

                    ghost.polyglot().extend(data);

                    next();
                });
            });
        };
    };


    module.exports.load = I18n;
}());