import { BadRequestException, Injectable } from "@nestjs/common";
import dayjs from "dayjs";
import Decimal from "decimal.js";
import { DataSource, In, Not, QueryRunner } from "typeorm";

import { ServiceMessage, SubscriptionMessage } from "../../../common/enums/message.enum";
import { DanakServicesService } from "../../danak-services/providers/danak-services.service";
import { INVOICE } from "../../invoices/constants";
import { InvoicesService } from "../../invoices/providers/invoices.service";
import { UsersService } from "../../users/providers/users.service";
import { PaginationUtils } from "../../utils/providers/pagination.utils";
import { AddSubscriptionsToServiceDto } from "../DTO/create-subscription.dto";
import { SearchUserSubsQueryDto } from "../DTO/search-user-subs-query.dto";
import { ServiceSubsQueryDto } from "../DTO/service-subs-query.dto";
import { SubscribeServiceDto } from "../DTO/subscribe-service.dto";
import { UpdateSubscriptionPlanDto } from "../DTO/update-subscription.dto";
import { SubscriptionPlan } from "../entities/subscription.entity";
import { UserSubscription } from "../entities/user-subscription.entity";
import { SubscriptionStatus } from "../enums/subscription-status.enum";
import { SubscriptionsPlanRepository } from "../repositories/subscriptions.repository";
import { UserSubscriptionsRepository } from "../repositories/user-subscriptions.repository";

@Injectable()
export class SubscriptionsService {
  constructor(
    private readonly subscriptionsPlanRepository: SubscriptionsPlanRepository,
    private readonly userSubscriptionsRepository: UserSubscriptionsRepository,
    private readonly invoicesService: InvoicesService,
    private readonly usersService: UsersService,
    private readonly danakServices: DanakServicesService,
    private readonly dataSource: DataSource,
  ) {}

  //************************************ */
  async createSubscriptionsPlan(createDto: AddSubscriptionsToServiceDto) {
    const danakService = await this.danakServices.findServiceById(createDto.serviceId);
    if (!danakService) throw new BadRequestException(ServiceMessage.SERVICE_NOT_FOUND_BY_ID);

    const subscriptions = createDto.subs.map((sub) => ({
      ...sub,
      service: { id: createDto.serviceId },
      originalPrice: new Decimal(sub.price),
    }));

    const subscriptionNames = createDto.subs.map((sub) => sub.name);
    const existingSubscriptions = await this.subscriptionsPlanRepository.find({
      where: {
        name: In(subscriptionNames),
        service: { id: createDto.serviceId },
      },
    });

    if (existingSubscriptions.length > 0)
      throw new BadRequestException({ message: [SubscriptionMessage.NAME_EXIST, existingSubscriptions] });

    const createdSubscriptions = this.subscriptionsPlanRepository.create(subscriptions);
    await this.subscriptionsPlanRepository.save(createdSubscriptions);

    return {
      message: SubscriptionMessage.CREATED,
      subscriptions: createdSubscriptions,
    };
  }

  //************************************ */
  async getUserSubscriptions(userId: string, queryDto: SearchUserSubsQueryDto) {
    const queryBuilder = this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .leftJoinAndSelect("userSubscription.plan", "plan")
      .leftJoinAndSelect("plan.service", "service")
      .where("userSubscription.user.id = :userId", { userId });

    if (queryDto.q) {
      queryBuilder.andWhere("(service.name ILIKE :query OR service.title ILIKE :query OR service.description ILIKE :query)", {
        query: `%${queryDto.q}%`,
      });
    }

    const subscriptions = await queryBuilder.getMany();

    return {
      subscriptions,
    };
  }
  //************************************ */

  async getUserSubscriptionById(userSubId: string, userId: string) {
    const userSubscription = await this.userSubscriptionsRepository.findOne({
      where: { id: userSubId, user: { id: userId } },
      relations: {
        plan: {
          service: {
            images: true,
            subscriptionPlans: true,
          },
        },
      },
    });
    if (!userSubscription) throw new BadRequestException(SubscriptionMessage.USER_SUBS_NOT_FOUND);

    return {
      userSubscription,
    };
  }
  //************************************ */
  async updateSubscriptionPlan(id: string, updateDto: UpdateSubscriptionPlanDto) {
    // Find the existing subscription plan
    const subscription = await this.subscriptionsPlanRepository.findOne({ where: { id }, relations: { service: true } });
    if (!subscription) throw new BadRequestException(SubscriptionMessage.NOT_FOUND);

    // Check if service exists when trying to update it
    if (updateDto.serviceId) {
      const danakService = await this.danakServices.findServiceById(updateDto.serviceId);
      if (!danakService) throw new BadRequestException(ServiceMessage.SERVICE_NOT_FOUND_BY_ID);
      subscription.service = danakService;
    }

    // Check for name uniqueness if updating name
    if (updateDto.name) {
      const existSubscription = await this.subscriptionsPlanRepository.findOneBy({
        name: updateDto.name,
        id: Not(id),
        service: { id: subscription.service.id },
      });
      if (existSubscription) throw new BadRequestException(SubscriptionMessage.NAME_EXIST);
      subscription.name = updateDto.name;
    }

    if (updateDto.duration) subscription.duration = updateDto.duration;
    if (updateDto.price) {
      subscription.price = new Decimal(updateDto.price);
      subscription.originalPrice = new Decimal(updateDto.price);
    }

    await this.subscriptionsPlanRepository.save(subscription);

    return {
      message: SubscriptionMessage.UPDATED,
      subscription,
    };
  }
  //************************************ */

  async getSubscriptionPlanById(subscriptionId: string) {
    const subscription = await this.subscriptionsPlanRepository.findOneBy({ id: subscriptionId });
    if (!subscription) throw new BadRequestException(SubscriptionMessage.NOT_FOUND);
    return {
      subscription,
    };
  }
  //************************************ */

  async All(serviceId: string, queryDto: ServiceSubsQueryDto) {
    const service = await this.danakServices.findServiceById(serviceId);

    const { limit, skip } = PaginationUtils(queryDto);

    const queryBuilder = this.subscriptionsPlanRepository
      .createQueryBuilder("subscription")
      .leftJoin("subscription.service", "service")
      .addSelect(["service.id"])
      // .leftJoin("subscription.discounts", "discount")
      // .addSelect(["discount.calculationType", "discount.amount", "discount.startDate", "discount.endDate", "discount.isActive"])
      .where("service.id = :serviceId", { serviceId });

    if (queryDto.q) {
      queryBuilder.andWhere("subscription.name ILIKE :query", { query: `%${queryDto.q}%` });
    }

    if (queryDto.isActive !== undefined) {
      queryBuilder.andWhere("subscription.isActive = :isActive", { isActive: queryDto.isActive === 1 });
    }

    const [subscriptions, count] = await queryBuilder.skip(skip).take(limit).getManyAndCount();

    return {
      service,
      subscriptions,
      count,
      pagination: true,
    };
  }

  //************************************ */

  async toggleSubStatus(subId: string) {
    const subscription = await this.subscriptionsPlanRepository.findOneBy({ id: subId });
    if (!subscription) throw new BadRequestException(SubscriptionMessage.NOT_FOUND);

    subscription.isActive = !subscription.isActive;

    await this.subscriptionsPlanRepository.save(subscription);
    return {
      message: SubscriptionMessage.STATUS_UPDATED,
      isActive: subscription.isActive,
    };
  }
  //************************************ */

  async subscribeToPlan(serviceId: string, subscribeDto: SubscribeServiceDto, userId: string) {
    const queryRunner = this.dataSource.createQueryRunner();
    await queryRunner.connect();
    await queryRunner.startTransaction();
    try {
      const user = await this.usersService.findOneByIdWithQueryRunner(userId, queryRunner);

      const plan = await queryRunner.manager.findOne(SubscriptionPlan, {
        where: { id: subscribeDto.planId, service: { id: serviceId } },
        relations: {
          service: true,
          directDiscount: true,
        },
      });

      if (!plan) throw new BadRequestException(SubscriptionMessage.NOT_FOUND);

      const startDate = dayjs().toDate();
      const endDate = dayjs().add(plan.duration, "day").toDate();

      //
      const userSubscription = queryRunner.manager.create(UserSubscription, { ...subscribeDto, user, plan, startDate, endDate });

      await queryRunner.manager.save(UserSubscription, userSubscription);
      //

      const invoiceDueDate = dayjs(userSubscription.startDate).add(INVOICE.DUEDATE, "day").toDate();

      const invoice = await this.invoicesService.createInvoiceForSubscription(user, plan, userSubscription, invoiceDueDate, queryRunner);
      userSubscription.status = SubscriptionStatus.INACTIVE;

      await queryRunner.manager.save(UserSubscription, userSubscription);

      await queryRunner.commitTransaction();
      return {
        message: SubscriptionMessage.SUBSCRIBED,
        userSubscription,
        invoice,
      };
    } catch (error) {
      await queryRunner.rollbackTransaction();
      throw error;
    } finally {
      await queryRunner.release();
    }
  }
  //************************************ */
  async getServiceSubscriptions(serviceId: string, queryDto: ServiceSubsQueryDto) {
    const service = await this.danakServices.findServiceById(serviceId);

    const { limit, skip } = PaginationUtils(queryDto);

    const queryBuilder = this.subscriptionsPlanRepository
      .createQueryBuilder("subscription")
      .leftJoin("subscription.service", "service")
      .addSelect(["service.id"])
      // .leftJoin("subscription.discounts", "discount")
      // .addSelect(["discount.calculationType", "discount.amount", "discount.startDate", "discount.endDate", "discount.isActive"])
      .where("service.id = :serviceId", { serviceId });

    if (queryDto.q) {
      queryBuilder.andWhere("subscription.name ILIKE :query", { query: `%${queryDto.q}%` });
    }

    if (queryDto.isActive !== undefined) {
      queryBuilder.andWhere("subscription.isActive = :isActive", { isActive: queryDto.isActive === 1 });
    }

    const [subscriptions, count] = await queryBuilder.skip(skip).take(limit).getManyAndCount();

    return {
      service,
      subscriptions,
      count,
      pagination: true,
    };
  }
  //************************************ */

  async getAllServiceSubscriptions(serviceIds: string[], queryRunner: QueryRunner) {
    const subscriptions = await queryRunner.manager.find(this.subscriptionsPlanRepository.target, {
      where: { service: { id: In(serviceIds) }, isActive: true },
      relations: { directDiscount: true, service: true },
    });
    return subscriptions;
  }
  //************************************ */

  async countUserSubscriptions(userId: string) {
    const subscriptionCount = await this.userSubscriptionsRepository.count({
      where: { user: { id: userId }, status: SubscriptionStatus.ACTIVE },
    });

    return subscriptionCount;
  }

  //************************************ */

  async getPlanRevenueAverage() {
    const currentYear = new Date().getFullYear();
    const startOfYear = new Date(currentYear, 0, 1);
    const endOfYear = new Date(currentYear, 11, 31);

    const result = await this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .leftJoin("userSubscription.plan", "plan")
      .select("AVG(plan.price)", "averageRevenue")
      .where("userSubscription.startDate >= :startDate", { startDate: startOfYear })
      .andWhere("userSubscription.startDate <= :endDate", { endDate: endOfYear })
      .andWhere("userSubscription.status = :status", { status: SubscriptionStatus.ACTIVE })
      .getRawOne();

    return Number(result.averageRevenue) || 0;
  }

  async getPlansSalesCount() {
    const currentYear = new Date().getFullYear();
    const startOfYear = new Date(currentYear, 0, 1);
    const endOfYear = new Date(currentYear, 11, 31);

    return await this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .where("userSubscription.startDate >= :startDate", { startDate: startOfYear })
      .andWhere("userSubscription.startDate <= :endDate", { endDate: endOfYear })
      .andWhere("userSubscription.status = :status", { status: SubscriptionStatus.ACTIVE })
      .getCount();
  }

  async getPlansSalesCountByMonthsInYear() {
    const now = new Date();
    const startOfYear = new Date(now.getFullYear(), 0, 1);
    const endOfYear = new Date(now.getFullYear(), 11, 31);

    const sales = await this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .select("EXTRACT(MONTH FROM userSubscription.startDate)", "month")
      .addSelect("COUNT(*)", "count")
      .where("userSubscription.startDate >= :startDate", { startDate: startOfYear })
      .andWhere("userSubscription.startDate <= :endDate", { endDate: endOfYear })
      .andWhere("userSubscription.status = :status", { status: SubscriptionStatus.ACTIVE })
      .groupBy("EXTRACT(MONTH FROM userSubscription.startDate)")
      .orderBy("month", "ASC")
      .getRawMany();

    const salesByMonth = Array(12).fill(0);

    sales.forEach((sale) => {
      const month = parseInt(sale.month) - 1;
      salesByMonth[month] = parseInt(sale.count);
    });

    return salesByMonth;
  }

  async getPlansSalesCountByDaysInMonth() {
    const now = new Date();
    const startOfMonth = new Date(now.getFullYear(), now.getMonth(), 1);
    const endOfMonth = new Date(now.getFullYear(), now.getMonth() + 1, 0);

    const sales = await this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .select("DATE(userSubscription.startDate)", "date")
      .addSelect("COUNT(*)", "count")
      .where("userSubscription.startDate >= :startDate", { startDate: startOfMonth })
      .andWhere("userSubscription.startDate <= :endDate", { endDate: endOfMonth })
      .andWhere("userSubscription.status = :status", { status: SubscriptionStatus.ACTIVE })
      .groupBy("DATE(userSubscription.startDate)")
      .orderBy("date", "ASC")
      .getRawMany();

    const daysInMonth = endOfMonth.getDate();
    const salesByDay = Array(daysInMonth).fill(0);

    sales.forEach((sale) => {
      const day = new Date(sale.date).getDate() - 1;
      salesByDay[day] = parseInt(sale.count);
    });

    return salesByDay;
  }

  async getPlansSalesCountByDaysInWeek() {
    const startOfWeek = dayjs().startOf("week").toDate();
    const endOfWeek = dayjs().endOf("week").toDate();

    const sales = await this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .select("DATE(userSubscription.startDate)", "date")
      .addSelect("COUNT(*)", "count")
      .where("userSubscription.startDate >= :startDate", { startDate: startOfWeek })
      .andWhere("userSubscription.startDate <= :endDate", { endDate: endOfWeek })
      .andWhere("userSubscription.status = :status", { status: SubscriptionStatus.ACTIVE })
      .groupBy("DATE(userSubscription.startDate)")
      .orderBy("date", "ASC")
      .getRawMany();

    const salesByDay = Array(7).fill(0);

    sales.forEach((sale) => {
      const day = (dayjs(sale.date).day() + 1) % 7;
      salesByDay[day] = parseInt(sale.count);
    });

    return salesByDay;
  }

  async getSubscriptionGrowthRate() {
    const currentYear = new Date().getFullYear();
    const lastYear = currentYear - 1;

    const currentYearCount = await this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .where("EXTRACT(YEAR FROM userSubscription.startDate) = :year", { year: currentYear })
      .andWhere("userSubscription.status = :status", { status: SubscriptionStatus.ACTIVE })
      .getCount();

    const lastYearCount = await this.userSubscriptionsRepository
      .createQueryBuilder("userSubscription")
      .where("EXTRACT(YEAR FROM userSubscription.startDate) = :year", { year: lastYear })
      .andWhere("userSubscription.status = :status", { status: SubscriptionStatus.ACTIVE })
      .getCount();

    if (lastYearCount === 0) return 100;

    const growthRate = ((currentYearCount - lastYearCount) / lastYearCount) * 100;
    return Math.round(growthRate * 100) / 100;
  }
}