ISA-Frontend/libs/crm/data-access/src/lib/resources/customer-bonus-cards.resource.ts

import { Injectable, inject, resource, signal, computed } from '@angular/core';
import { logger } from '@isa/core/logging';
import { CrmSearchService } from '../services/crm-search.service';
import { BonusCardInfo } from '../models';

/**
 * Resource for loading customer bonus cards (Kundenkarten).
 *
 * Provides reactive loading of all bonus cards for a given customer ID.
 * Customer ID can be changed dynamically via `params()` method.
 *
 * **Note:** This resource should be provided at the component level,
 * not in root. Provide it in the `providers` array of the component
 * that needs scoped access to customer bonus cards.
 *
 * @example
 * ```typescript
 * @Component({
 *   providers: [CustomerBonusCardsResource],
 * })
 * export class MyFeatureComponent {
 *   #bonusCardsResource = inject(CustomerBonusCardsResource);
 *
 *   cards = this.#bonusCardsResource.resource.value;
 *   isLoading = this.#bonusCardsResource.resource.isLoading;
 *
 *   loadCards(customerId: number) {
 *     this.#bonusCardsResource.params({ customerId });
 *   }
 * }
 * ```
 */
@Injectable()
export class CustomerBonusCardsResource {
  readonly #crmSearchService = inject(CrmSearchService);
  readonly #logger = logger(() => ({ context: 'CustomerBonusCardsResource' }));

  readonly #customerId = signal<number | undefined>(undefined);

  /**
   * Current customer ID being loaded.
   */
  readonly customerId = computed(() => this.#customerId());

  /**
   * Resource that loads bonus cards based on current parameters.
   *
   * Exposes:
   * - `value()` - Array of bonus cards or undefined
   * - `isLoading()` - Loading state
   * - `error()` - Error state
   * - `status()` - Current status ('idle' | 'loading' | 'resolved' | 'error')
   */
  readonly resource = resource({
    params: computed(() => ({ customerId: this.#customerId() })),
    loader: async ({
      params,
      abortSignal,
    }): Promise<BonusCardInfo[] | undefined> => {
      const { customerId } = params;

      if (!customerId) {
        this.#logger.debug('No customerId provided, skipping load');
        return undefined;
      }

      this.#logger.debug('Loading bonus cards', () => ({ customerId }));

      const response = await this.#crmSearchService.fetchCustomerCards(
        { customerId },
        abortSignal,
      );

      this.#logger.debug('Bonus cards loaded', () => ({
        customerId,
        count: response?.result?.length ?? 0,
      }));

      return response?.result;
    },
    defaultValue: undefined,
  });

  /**
   * Update resource parameters to trigger a reload.
   *
   * @param params - Parameters for loading bonus cards
   * @param params.customerId - Customer ID to load cards for (undefined clears data)
   */
  params(params: { customerId?: number }): void {
    this.#logger.debug('Updating params', () => params);
    this.#customerId.set(params.customerId);
  }
}