var fs = require('fs');
var mustache = require('mustache');
var database = require('./database.js');
var language = require('./language.js');
var path = require('path');
var Template = {

    /**
     * Obtiene la plantilla
     * @param {String} templateName - Nombre de la plantilla
     * @param {Object} langCode - Código del idioma
     * @param {Object} params - Datos a reemplazar.
     * @param {Object} callback - Callback
     */
    getTemplate: function(templateName, langCode, params, callback) {
        database.pool.query('SELECT name, attachmentPath FROM vn.mailTemplates WHERE name = ?', [templateName], function(error, rs) {
            // Comprobamos que exista la plantilla
            if (rs.length == 0)
                throw new Error('La plantilla ' + templateName + ' no existe');

            var langParams = language.load(templateName, langCode);
            params = Object.assign({}, langParams, params);
            var templatePath = path.join(__dirname, 'Template', `${rs[0].name}.html`);

            if (!fs.existsSync(templatePath))
                throw new Error('No se ha podido cargar la plantilla ' + templateName + '.html');

            Template.render(templatePath, params, function(tplBody) {
                callback({subject: params.subject, body: tplBody});
            });
        });
    },

    /**
     * Renderiza las plantillas
     * @param {String} path - Ruta de la plantilla
     * @param {Object} params - Listado de parámetros a remplazar
     * @param {Object} callback - Callback
     */
    render: function(path, params, callback) {
        fs.readFile(path, 'utf8', function(error, body) {
            mustache.parse(body);
            callback(mustache.render(body, params));
        });
    }
};

module.exports = Template;