import { BadRequestException, Injectable, Logger } from '@nestjs/common';
import { EventEmitter2 } from '@nestjs/event-emitter';
import { Transactional } from 'typeorm-transactional';
import { Roles } from '~/auth/enums';
import { NOTIFICATION_EVENTS } from '~/common/modules/notification/constants/event-names.constant';
import {
  IMoneyRequestApprovedEvent,
  IMoneyRequestCreatedEvent,
  IMoneyRequestDeclinedEvent,
} from '~/common/modules/notification/interfaces/notification-events.interface';
import { OciService } from '~/document/services';
import { Junior } from '~/junior/entities/junior.entity';
import { JuniorService } from '~/junior/services';
import { CreateMoneyRequestDto, MoneyRequestsFiltersRequestDto, RejectionMoneyRequestDto } from '../dtos/request';
import { MoneyRequest } from '../entities/money-request.entity';
import { MoneyRequestStatus } from '../enums';
import { MoneyRequestsRepository } from '../repositories';

@Injectable()
export class MoneyRequestsService {
  private readonly logger = new Logger(MoneyRequestsService.name);
  constructor(
    private readonly moneyRequestsRepository: MoneyRequestsRepository,
    private readonly juniorService: JuniorService,
    private readonly ociService: OciService,
    private readonly eventEmitter: EventEmitter2,
  ) {}
  async createMoneyRequest(juniorId: string, body: CreateMoneyRequestDto) {
    const junior = await this.juniorService.findJuniorById(juniorId);
    const moneyRequest = await this.moneyRequestsRepository.createMoneyRequest(junior.id, junior.guardianId, body);
    const moneyRequestWithRelations = await this.moneyRequestsRepository.findByIdWithAllRelations(moneyRequest.id);

    const event: IMoneyRequestCreatedEvent = {
      moneyRequest: moneyRequestWithRelations!,
      timestamp: new Date(),
    };
    this.eventEmitter.emit(NOTIFICATION_EVENTS.MONEY_REQUEST_CREATED, event);

    return this.findById(moneyRequest.id);
  }

  async findById(id: string, userId?: string, role?: Roles): Promise<MoneyRequest> {
    const moneyRequest = await this.moneyRequestsRepository.findById(id, userId, role);
    if (!moneyRequest) {
      throw new BadRequestException('MONEY_REQUEST.NOT_FOUND');
    }
    await this.prepareJuniorImages([moneyRequest.junior]);
    return moneyRequest;
  }

  async findMoneyRequests(
    userId: string,
    role: Roles,
    filters: MoneyRequestsFiltersRequestDto,
  ): Promise<[MoneyRequest[], number]> {
    const [moneyRequests, count] = await this.moneyRequestsRepository.findAll(userId, role, filters);
    const juniors = moneyRequests.map((moneyRequest) => moneyRequest.junior);
    await this.prepareJuniorImages(juniors);
    return [moneyRequests, count];
  }

  @Transactional()
  async approveMoneyRequest(id: string, guardianId: string): Promise<void> {
    const moneyRequest = await this.moneyRequestsRepository.findById(id, guardianId, Roles.GUARDIAN);

    if (!moneyRequest) {
      throw new BadRequestException('MONEY_REQUEST.NOT_FOUND');
    }

    if (moneyRequest.status == MoneyRequestStatus.APPROVED) {
      throw new BadRequestException('MONEY_REQUEST.ALREADY_APPROVED');
    }

    await Promise.all([
      this.moneyRequestsRepository.approveMoneyRequest(id),
      this.juniorService.transferToJunior(
        moneyRequest.juniorId,
        { amount: moneyRequest.amount },
        moneyRequest.guardianId,
      ),
    ]);

    const updatedMoneyRequest = await this.moneyRequestsRepository.findByIdWithAllRelations(id, guardianId, Roles.GUARDIAN);
    const event: IMoneyRequestApprovedEvent = {
      moneyRequest: updatedMoneyRequest!,
      timestamp: new Date(),
    };
    this.eventEmitter.emit(NOTIFICATION_EVENTS.MONEY_REQUEST_APPROVED, event);
  }

  async rejectMoneyRequest(
    id: string,
    guardianId: string,
    rejectionReasondto: RejectionMoneyRequestDto,
  ): Promise<void> {
    const moneyRequest = await this.moneyRequestsRepository.findById(id, guardianId, Roles.GUARDIAN);

    if (!moneyRequest) {
      throw new BadRequestException('MONEY_REQUEST.NOT_FOUND');
    }

    if (moneyRequest.status == MoneyRequestStatus.APPROVED) {
      throw new BadRequestException('MONEY_REQUEST.ALREADY_APPROVED');
    }

    if (moneyRequest.status == MoneyRequestStatus.REJECTED) {
      throw new BadRequestException('MONEY_REQUEST.ALREADY_REJECTED');
    }

    await this.moneyRequestsRepository.rejectMoneyRequest(id, rejectionReasondto?.rejectionReason);

    const updatedMoneyRequest = await this.moneyRequestsRepository.findByIdWithAllRelations(id, guardianId, Roles.GUARDIAN);
    const event: IMoneyRequestDeclinedEvent = {
      moneyRequest: updatedMoneyRequest!,
      rejectionReason: rejectionReasondto?.rejectionReason,
      timestamp: new Date(),
    };
    this.eventEmitter.emit(NOTIFICATION_EVENTS.MONEY_REQUEST_DECLINED, event);
  }

  private async prepareJuniorImages(juniors: Junior[]) {
    this.logger.log(`Preparing junior images`);
    await Promise.all(
      juniors.map(async (junior) => {
        const profilePicture = junior.customer.user.profilePicture;

        if (profilePicture) {
          profilePicture.url = await this.ociService.generatePreSignedUrl(profilePicture);
        }
      }),
    );
  }
}