import { Injectable, Logger, NotFoundException } from '@nestjs/common';
import { EntityManager, FilterQuery } from '@mikro-orm/postgresql';
import { Notification } from '../entities/notification.entity';
import { NotificationPreferenceService } from './notification-preference.service';
import { NotificationQueueService } from './notification-queue.service';
import { NotificationsGateway } from '../notifications.gateway';
import { NotifChannelEnum, NotifRequest, NotifTitleEnum } from '../interfaces/notification.interface';
import { SmsLog } from '../entities/smsLogs.entity';
import { SmsLogRepository } from '../repositories/sms-log.repository';
import { PaginatedResult } from '../../../common/interfaces/pagination.interface';

@Injectable()
export class NotificationService {
  private readonly logger = new Logger(NotificationService.name);

  constructor(
    private readonly em: EntityManager,
    private readonly preferenceService: NotificationPreferenceService,
    private readonly queueService: NotificationQueueService,
    private readonly notificationGateway: NotificationsGateway,
    private readonly smsLogRepository: SmsLogRepository,
  ) { }

//   async sendNotification(params: NotifRequest): Promise<Notification[]> {
//     const { recipients, message, metadata, } = params;

//     // create Database notifications
//     const notifications = await this.createAdminBulkNotifications(
//       recipients.map(recipient => ({
//          title: message.title,
//         content: message.content,
//         adminId: 'adminId' in recipient ? recipient.adminId : null,
//         userId: 'userId' in recipient ? recipient.userId : null,
//       })),
//     );

//   // get admin prefrences
//   const preference = await this.preferenceService.findByRestaurantAndType(, message.title);

//   if(preference?.channels?.length === 0) {
//   this.logger.warn(`Notification type is NONE for restaurant ${}, title ${message.title}`);
//   return notifications;
// }

// // send in app notification
// if (preference?.channels?.includes(NotifChannelEnum.IN_APP)) {
//   await this.queueService.addBulkInAppNotifications(
//     notifications.map(notification => ({
//       recipient: { adminId: notification.admin?.id || '', },
//       subject: message.title,
//       body: message.content,
//       notificationId: notification.id,
//     })),
//   );
// }

// // add sms notifications to queue
// if (preference?.channels?.includes(NotifChannelEnum.SMS)) {
//   await this.queueService.addBulkSmsNotifications(
//     recipients.map(recipient => ({
//       recipient,
//       templateId: message.sms.templateId,
//       parameters: message.sms.parameters,
//     })),
//   );
// }

// this.logger.log(`Queued notification for restaurant ${}, title ${message.title}`);

// return notifications;
//   }

//   async createAdminBulkNotifications(
//   params: {
  
//     title: NotifTitleEnum;
//     content: string;
//     adminId: string | null;
//     userId: string | null;
//   }[],
// ): Promise < Notification[] > {
//   const notifications = params.map(param => {
//     return this.em.create(Notification, {
//             admin: param.adminId,
//       user: param.userId && param.userId.trim() !== '' ? param.userId : null,
//       title: param.title,
//       content: param.content,
//     });
//   });
//   await this.em.persistAndFlush(notifications);
//   return notifications;
// }

//   async findOne(id: string): Promise < Notification > {
//   const notification = await this.em.findOne(Notification, { id }, { populate: ['restaurant', 'user'] });
//   if(!notification) {
//     throw new NotFoundException('Notification not found');
//   }
//     return notification;
// }

//   async findByRestaurant(
//     : string,
//   adminId: string,
//   limit = 50,
//   cursor ?: string,
//   status ?: 'seen' | 'unseen',
// ): Promise < { data: Notification[]; nextCursor: string | null } > {
//   const where: FilterQuery<Notification> = {
//   restaurant: { id:  },
//   admin: { id: adminId },
// };

// // Filter by status (seen/unseen)
// if (status === 'seen') {
//   where.seenAt = { $ne: null };
// } else if (status === 'unseen') {
//   where.seenAt = null;
// }

// // Cursor-based pagination: if cursor is provided, get items with id < cursor
// if (cursor) {
//   where.id = { $lt: cursor };
// }

// const notifications = await this.em.find(Notification, where, {
//   orderBy: { createdAt: 'DESC', id: 'DESC' },
//   limit: limit + 1, // fetch one extra to determine next page
//   populate: ['user'],
// });

// const hasNextPage = notifications.length > limit;
// const data = hasNextPage ? notifications.slice(0, limit) : notifications;
// const nextCursor = hasNextPage && data.length > 0 ? data[data.length - 1].id : null;

// return {
//   data,
//   nextCursor: nextCursor ?? null,
// };
//   }

//   async findByUserAndRestaurant(
//   userId: string,
//     : string,
//   limit = 50,
//   cursor ?: string,
//   status ?: 'seen' | 'unseen',
// ): Promise < { data: Notification[]; nextCursor: string | null } > {
//   const where: FilterQuery<Notification> = {
//   user: { id: userId },
//   restaurant: { id:  },
// };

// // Filter by status (seen/unseen)
// if (status === 'seen') {
//   where.seenAt = { $ne: null };
// } else if (status === 'unseen') {
//   where.seenAt = null;
// }

// // Cursor-based pagination: if cursor is provided, get items with id < cursor (since ULIDs are time-ordered)
// if (cursor) {
//   where.id = { $lt: cursor };
// }

// const notifications = await this.em.find(Notification, where, {
//   orderBy: { createdAt: 'DESC', id: 'DESC' },
//   limit: limit + 1, // Fetch one extra to determine if there's a next page
// });

// // Check if there's a next page
// const hasNextPage = notifications.length > limit;
// const data = hasNextPage ? notifications.slice(0, limit) : notifications;
// const nextCursor = hasNextPage && data.length > 0 ? data[data.length - 1].id : null;

// return {
//   data,
//   nextCursor: nextCursor ?? null,
// };
//   }

//   async readNotificationAdmin(id: string, adminId: string, : string): Promise < void> {
//   const notification = await this.em.findOne(Notification, {
//     id,
//     admin: { id: adminId },
//     restaurant: { id:  },
//   });
//   if(!notification) {
//     throw new NotFoundException('Notification not found');
//   }
//     notification.seenAt = new Date();
//   await this.em.persistAndFlush(notification);
// }
//   async readNotificationAsUser(id: string, userId: string, : string): Promise < void> {
//   const notification = await this.em.findOne(Notification, {
//     id,
//     user: { id: userId },
//     restaurant: { id:  },
//   });
//   if(!notification) {
//     throw new NotFoundException('Notification not found');
//   }
//     notification.seenAt = new Date();
//   await this.em.persistAndFlush(notification);
// }

//   async findByRestaurantAndType(: string, title: NotifTitleEnum, limit = 50): Promise < Notification[] > {
//   return this.em.find(
//     Notification,
//     {
//       restaurant: { id:  },
//       title,
//     },
//     {
//       orderBy: { createdAt: 'DESC' },
//       limit,
//       populate: ['user'],
//     },
//   );
// }

//   async findByAdminAndRestaurant(adminId: string, : string, limit = 50): Promise < Notification[] > {
//   return this.em.find(
//     Notification,
//     { admin: { id: adminId }, restaurant: { id:  } },
//     {
//       orderBy: { createdAt: 'DESC' },
//       limit,
//     },
//   );
// }

//   async countUnseenByUserAndRestaurant(userId: string, : string): Promise < number > {
//   const where: FilterQuery<Notification> = {
//   user: { id: userId },
//   restaurant: { id:  },
//   seenAt: null,
//     };
// return this.em.count(Notification, where);
//   }

//   async countUnseenByRestaurant(adminId: string, : string): Promise < number > {
//   const where: FilterQuery<Notification> = {
//   admin: { id: adminId },
//   restaurant: { id:  },
//   seenAt: null,
//     };
// return this.em.count(Notification, where);
//   }

// readAllNotifsAsUser(userId: string, : string): Promise < number > {
//   const where: FilterQuery<Notification> = {
//   user: { id: userId },
//   restaurant: { id:  },
//   seenAt: null,
//     };
// return this.em.nativeUpdate(Notification, where, { seenAt: new Date() });
//   }

// readAllNotifsAsAdmin(adminId: string, : string): Promise < number > {
//   const where: FilterQuery<Notification> = {
//   admin: { id: adminId },
//   restaurant: { id:  },
//   seenAt: null,
//     };
// return this.em.nativeUpdate(Notification, where, { seenAt: new Date() });
//   }

//   async getSmsCountByRestaurant(
//   page: number = 1,
//   limit: number = 10,
// ): Promise < PaginatedResult < { : string; restaurantName: string; smsCount: number } >> {
//   return this.smsLogRepository.getSmsCountByRestaurant(page, limit);
// }

//   async getSmsCountBy(: string): Promise < number > {
//   return this.smsLogRepository.getSmsCountBy();
// }
}