var fs = require('fs');
var mustache = require('mustache');
var locale = require('./locale.js');
var path = require('path');
var inlineCss = require('inline-css');

module.exports = {
    /**
     * Obtiene la plantilla.
     * @param {String} template - Nombre de la plantilla
     * @param {Object} countryCode - Código del idioma
     * @param {Object} params - Datos a reemplazar.
     * @param {Object} cb - Callback
     */
    getTemplate: function(template, countryCode, params, cb) {
        var templatePath = path.join(__dirname, 'template', `${template}`, `${template}.html`);
        var classPath = path.join(__dirname, 'template', `${template}`, `${template}.js`);
        var stylePath = path.join(__dirname, 'template', `${template}`, `${template}.css`);

        fs.stat(templatePath, (error, stat) => {
            if (error)
                return cb(null, 'Template ' + template + ' not found');

            let TemplateClass = require(classPath);
            let instance = new TemplateClass();

            let getRenderedStyles = body => {
                this.renderStyles(stylePath, body, body => {
                    var titleSubject = body.match(new RegExp('<title>(.*?)</title>', 'i'))[1];
                    this.getAttachments(template, body, attachments => {
                        cb({body: body, subject: titleSubject, attachments: attachments});
                    });
                });
            };

            let getDataCb = () => {
                this.render(templatePath, instance, body => getRenderedStyles(body));
            };

            locale.load(template, countryCode, (translations, error) => {
                instance._ = translations;
                instance.getData(params, () => getDataCb());
            });
        });
    },

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

    /**
     * Renderiza los estilos de las plantillas.
     * @param {String} path - Ruta de la hoja de estilos
     * @param {String} body - Html renderizado
     * @param {Object} cb - Callback
     */
    renderStyles: function(path, html, cb) {
        fs.stat(path, error => {
            if (error) return cb(null, 'Template stylesheet not found');
            fs.readFile(path, 'utf8', (error, css) => {
                let style = '<style>' + css + '</style>';
                let body = style + html;
                let options = {url: ' '};

                inlineCss(body, options)
                    .then(function(body) {
                        cb(body);
                    });
            });
        });
    },

    /**
     * Obtiene todos los ficheros adjuntos de la plantilla
     * @param {String} template - Nombre de la plantilla
     * @param {String} body - html de la plantilla
     * @param {Object} cb - Callback
     */
    getAttachments: function(template, body, cb) {
        var attachments = [];
        var tplAttachments = body.match(new RegExp('src="cid:(.*?)"', 'ig'));

        for (var i = 0; i < tplAttachments.length; i++) {
            var name = tplAttachments[i].replace('src="cid:', '').replace('"', '');
            var attachmentPath = path.join(__dirname, 'template/image', name);

            attachments.push({filename: name, path: attachmentPath, cid: name});
        }

        var attachmentsPath = path.join(__dirname, 'template', `${template}`, 'attachment.json');

        fs.stat(attachmentsPath, (error, stats) => {
            if (error) return cb(null, 'Could not load attachments from template ' + template);

            var attachObj = require(attachmentsPath);

            for (var i = 0; i < attachObj.length; i++) {
                var attachmentPath = path.join(__dirname, 'template', `${template}`, 'attachment', attachObj[i]);
                attachments.push({filename: attachObj[i], path: attachmentPath, cid: attachObj[i]});
            }

            cb(attachments);
        });
    }
};