// user-notification.js
// Copyright (C) 2022 DTP Technologies, LLC
// License: Apache-2.0

'use strict';

const path = require('path');

const mongoose = require('mongoose');
const UserNotification = mongoose.model('UserNotification');

const pug = require('pug');

const { SiteService } = require('../../lib/site-lib');

class UserNotificationService extends SiteService {

  constructor (dtp) {
    super(dtp, module.exports);
    this.populateUserNotification = [
      {
        path: 'user',
        select: '_id username username_lc displayName picture',
      },
      {
        path: 'attachment',
      },
    ];
  }

  async start ( ) {
    this.templates = { };
    this.templates.notification = pug.compileFile(path.join(this.dtp.config.root, 'app', 'views', 'notification', 'components', 'notification-standalone.pug'));
  }

  async create (user, event) {
    const notification = new UserNotification();
    notification.created = event.created;
    notification.user = user._id;
    notification.status = 'new';
    notification.event = event._id;
    await notification.save();

    return notification.toObject();
  }

  async getNewCountForUser (user) {
    const result = await UserNotification.aggregate([
      {
        $match: {
          user: user._id,
          status: 'new',
        },
      },
      {
        $group: {
          _id: { user: 1 },
          count: { $sum: 1 },
        },
      },
      {
        $project: {
          _id: -1,
          count: '$count',
        },
      },
    ]);
    this.log('getNewCountForUser', { result });
    return result[0].count;
  }

  async getForUser (user, pagination) {
    const notifications = await UserNotification
      .find({ user: user._id })
      .sort({ created: -1 })
      .skip(pagination.skip)
      .limit(pagination.cpp)
      .populate(this.populateUserNotification)
      .lean();
    const newNotifications = notifications.map((notif) => notif.status === 'new');
    if (newNotifications.length > 0) {
      await UserNotification.updateMany(
        { _id: { $in: newNotifications.map((notif) => notif._id) } },
        { $set: { stats: 'seen' } },
      );
    }
    return notifications;
  }
}

module.exports = {
  slug: 'user-notification',
  name: 'userNotification',
  create: (dtp) => { return new UserNotificationService(dtp); },
};