import { Injectable, Logger } from '@nestjs/common'
import { Cron } from '@nestjs/schedule'
import { SlotGeneratorService } from '../time-slot/slot-generator.service'
import { FlashSaleService } from '../flash-sale/flash-sale.service'

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

  constructor(
    private readonly slotGenerator: SlotGeneratorService,
    private readonly flashSaleService: FlashSaleService,
  ) {}

  /** 02:00 daily — generate slots 14 days ahead from week templates */
  @Cron('0 2 * * *')
  async handleSlotGeneration(): Promise<void> {
    try {
      const count = await this.slotGenerator.generateSlots(14)
      this.logger.log(`[handleSlotGeneration] Created ${count} new time slots`)
    } catch (err) {
      this.logger.error('[handleSlotGeneration] Failed to generate slots', err)
    }
  }

  /** 02:30 daily — close past OPEN slots */
  @Cron('30 2 * * *')
  async handleCleanupSlots(): Promise<void> {
    try {
      const count = await this.slotGenerator.cleanupExpiredSlots()
      this.logger.log(`[handleCleanupSlots] Closed ${count} expired slots`)
    } catch (err) {
      this.logger.error('[handleCleanupSlots] Failed to clean up slots', err)
    }
  }

  /** 03:00 daily — expire memberships past their end date or with 0 sessions */
  @Cron('0 3 * * *')
  async handleCheckMemberships(): Promise<void> {
    try {
      const count = await this.slotGenerator.checkExpiredMemberships()
      this.logger.log(`[handleCheckMemberships] Updated ${count} memberships`)
    } catch (err) {
      this.logger.error('[handleCheckMemberships] Failed to check memberships', err)
    }
  }

  /** 22:00 daily — mark past CONFIRMED bookings as COMPLETED */
  @Cron('0 22 * * *')
  async handleCompleteBookings(): Promise<void> {
    try {
      const count = await this.slotGenerator.completeBookings()
      this.logger.log(`[handleCompleteBookings] Completed ${count} bookings`)
    } catch (err) {
      this.logger.error('[handleCompleteBookings] Failed to complete bookings', err)
    }
  }

  /** Every 5 min — expire unpaid flash sale reservations older than 15min */
  @Cron('*/5 * * * *')
  async handleExpireFlashSaleReservations(): Promise<void> {
    try {
      const count = await this.flashSaleService.expireUnpaidReservations(15)
      if (count > 0) {
        this.logger.log(`[handleExpireFlashSaleReservations] Expired ${count} unpaid reservations`)
      }
    } catch (err) {
      this.logger.error('[handleExpireFlashSaleReservations] Failed', err)
    }
  }
}