/***********************************************************************************************************************************************************************
 * File Name: notificationTemplate.service.js
 * Type of Program: Service
 * Description: Renders system-triggered notification title/message from the
 *              notification_templates table (admin-editable, see
 *              controllers/admin/notification_templates.controller.js).
 *              Mirrors the template-loading half of services/email.service.js's
 *              sendEmail() — same "only live columns count as published" rule,
 *              same {{placeholder}} substitution via utils/renderTemplate.util.js.
 * Author: Kenneth Obsequio (@lash0000)
 * Date Created: Jul. 3, 2026
 ***********************************************************************************************************************************************************************
 * HOW TO USE:
 *   const { renderNotification } = require('../services/notificationTemplate.service');
 *   const notify = await renderNotification({ type: 'task_overdue', data: { count } });
 *   await AdminNotification.create(notify);
 *
 *   // Bulk/loop use — fetch once, render per-row without re-querying the DB:
 *   const { getNotificationTemplate, renderNotificationContent } = require('../services/notificationTemplate.service');
 *   const template = await getNotificationTemplate('tier_expired');
 *   const rows = expired.map((t) => ({ user_id: t.user_id, ...renderNotificationContent(template, { tier: t.tier, label: t.plan?.label ?? null }) }));
 ***********************************************************************************************************************************************************************/
const mdl_NotificationTemplate = require('../models/notifications/notification_template.mdl');
const { enrichNotificationData } = require('../data/notification_template_enrichers.data');
const { renderTemplate }         = require('../utils/renderTemplate.util');

const getNotificationTemplate = async (type) => {
  const template = await mdl_NotificationTemplate.findOne({ where: { type } });
  if (!template || !template.title || !template.message) {
    throw new Error(`Notification template "${type}" has no published version yet`);
  }
  return template;
};

// Pure — no DB access. Use when a template has already been fetched once
// (e.g. reused across a bulk-create loop) to avoid a query per row.
const renderNotificationContent = (template, data = {}) => {
  const enriched = enrichNotificationData(template.type, data);
  return {
    type:    template.notify_type,
    title:   renderTemplate(template.title, enriched),
    message: renderTemplate(template.message, enriched),
    data,
  };
};

const renderNotification = async ({ type, data = {} }) => {
  const template = await getNotificationTemplate(type);
  return renderNotificationContent(template, data);
};

module.exports = { getNotificationTemplate, renderNotificationContent, renderNotification };