/***********************************************************************************************************************************************************************
 * File Name    : notification.controller.js
 * Type         : Controller (Client)
 * Description  : Per-user notification management.
 *                GET  /client/notifications        — paginated list for the auth user
 *                GET  /client/notifications/unseen — unseen count
 *                PATCH /client/notifications/:id/seen — mark one as seen
 *                PATCH /client/notifications/seen-all  — mark all as seen
 *                DELETE /client/notifications/clear-all — delete all notifications
 *
 * Author: Kenneth Obsequio (@lash0000)
 * Date Created: Jun. 19, 2026
 ***********************************************************************************************************************************************************************/
const UserNotification = require('../../models/notifications/user_notification.mdl');
const R = require('../../utils/response.util');

// ─── GET /client/notifications ────────────────────────────────────────────────
async function list(req, res) {
    try {
        const userId = req.user.user_id;
        const page   = Math.max(1, parseInt(req.query.page)  || 1);
        const limit  = Math.min(50, parseInt(req.query.limit) || 20);
        const offset = (page - 1) * limit;

        const { count, rows } = await UserNotification.findAndCountAll({
            where: { user_id: userId },
            order: [['createdAt', 'DESC']],
            limit,
            offset,
        });

        return R.success(res, 'Notifications fetched.', {
            notifications: rows,
            pagination: { page, limit, total: count, pages: Math.ceil(count / limit) },
        });
    } catch (err) {
        console.error('[CLIENT NOTIFICATION] list error:', err);
        return R.error(res, 'Failed to fetch notifications.');
    }
}

// ─── GET /client/notifications/unseen ────────────────────────────────────────
async function unseenCount(req, res) {
    if (!req.user) return R.success(res, 'Unseen count fetched.', { count: null });
    try {
        const count = await UserNotification.count({
            where: { user_id: req.user.user_id, seen: false },
        });
        return R.success(res, 'Unseen count fetched.', { count });
    } catch (err) {
        console.error('[CLIENT NOTIFICATION] unseenCount error:', err);
        return R.error(res, 'Failed to fetch unseen count.');
    }
}

// ─── PATCH /client/notifications/:id/seen ────────────────────────────────────
async function markSeen(req, res) {
    try {
        const notification = await UserNotification.findOne({
            where: { notification_id: req.params.id, user_id: req.user.user_id },
        });
        if (!notification) return R.error(res, 'Notification not found.', 404);

        await notification.update({ seen: true, seen_at: new Date() });
        return R.success(res, 'Notification marked as seen.', notification);
    } catch (err) {
        console.error('[CLIENT NOTIFICATION] markSeen error:', err);
        return R.error(res, 'Failed to mark notification as seen.');
    }
}

// ─── PATCH /client/notifications/seen-all ────────────────────────────────────
async function markAllSeen(req, res) {
    try {
        const now = new Date();
        const [count] = await UserNotification.update(
            { seen: true, seen_at: now },
            { where: { user_id: req.user.user_id, seen: false } }
        );
        return R.success(res, `${count} notification(s) marked as seen.`, { count });
    } catch (err) {
        console.error('[CLIENT NOTIFICATION] markAllSeen error:', err);
        return R.error(res, 'Failed to mark all notifications as seen.');
    }
}

// ─── DELETE /client/notifications/clear-all ──────────────────────────────────
async function clearAll(req, res) {
    try {
        const count = await UserNotification.destroy({
            where: { user_id: req.user.user_id },
        });
        return R.success(res, `${count} notification(s) cleared.`, { count });
    } catch (err) {
        console.error('[CLIENT NOTIFICATION] clearAll error:', err);
        return R.error(res, 'Failed to clear notifications.');
    }
}

module.exports = { list, unseenCount, markSeen, markAllSeen, clearAll };