import { Injectable, Logger } from '@nestjs/common';
import { Cron, CronExpression } from '@nestjs/schedule';
import { SalonNotificationsService } from '../notifications/salon-notifications.service';
import { SmsService } from '../sms/sms.service';
import { SalonSubscriptionsService } from './salon-subscriptions.service';

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

  constructor(
    private readonly salonSubscriptionsService: SalonSubscriptionsService,
    private readonly salonNotificationsService: SalonNotificationsService,
    private readonly smsService: SmsService,
  ) {}

  /**
   * Detects subscriptions (trial or paid) whose validity period just ended
   * and, once per subscription, notifies the salon owner in-app and by SMS
   * that they need to purchase a plan to keep using the product. Access is
   * already blocked automatically by `ActiveSubscriptionGuard` once the
   * subscription's `endDate` has passed, independent of this job.
   */
  @Cron(CronExpression.EVERY_DAY_AT_10AM, {
    name: 'subscription-expiry-notifications',
  })
  async notifyExpiredSubscriptions(): Promise<number> {
    const subscriptions =
      await this.salonSubscriptionsService.findSubscriptionsPendingExpiryNotification();

    let notifiedCount = 0;

    for (const subscription of subscriptions) {
      try {
        await this.salonSubscriptionsService.markExpiryNotified(
          subscription.id,
        );

        const planLabel = subscription.plan?.isTrial
          ? 'دوره آزمایشی رایگان'
          : `اشتراک ${subscription.plan?.name ?? ''}`.trim();

        await this.salonNotificationsService.notifySubscriptionExpired({
          salonId: subscription.salonId,
          salonOwnerId: subscription.salon.ownerId,
          salonName: subscription.salon.name,
          planLabel,
          endDate: subscription.endDate,
        });

        const ownerMobile = subscription.salon.owner?.mobile;
        if (ownerMobile) {
          await this.smsService.sendSms(
            ownerMobile,
            `${planLabel} سالن ${subscription.salon.name} به پایان رسید. برای ادامه استفاده از امکانات و ارسال پیامک، همین حالا اشتراک تهیه کنید.`,
          );
        }

        notifiedCount += 1;
      } catch (error) {
        this.logger.error(
          `Failed to send expiry notification for subscription ${subscription.id}`,
          error instanceof Error ? error.stack : undefined,
        );
      }
    }

    if (notifiedCount > 0) {
      this.logger.log(
        `Sent expiry notifications for ${notifiedCount} subscription(s)`,
      );
    }

    return notifiedCount;
  }
}