import { Injectable, Logger } from '@nestjs/common';
import { CategoryHiboutikRepository } from '../../hiboutik/category.hiboutik.repository';
import { CategoryDatabaseRepository } from '../../database/category.database.repository';
import { CategoryConverter } from '../../models/converter/category.converter';
import { forEachSafely } from '../../utils/sync';

@Injectable()
export class CategoryHiboutikService {
  private readonly logger = new Logger('CategoryHiboutikService');

  constructor(
    private readonly categoryHiboutikRepository: CategoryHiboutikRepository,
    private readonly categoryDatabaseRepository: CategoryDatabaseRepository,
    private readonly categoryConverter: CategoryConverter,
  ) {}

  /**
   * Mirrors Hiboutik categories and their tree: upserts each of them, links them to their parent,
   * then deletes the categories missing from Hiboutik.
   */
  async syncCategories() {
    const hiboutikCategories = await this.categoryHiboutikRepository.getCategories();

    // Pass 1: categories themselves. One upsert per category: an invalid category must not prevent the others from being saved
    const nbFailed = await forEachSafely(
      this.categoryConverter.fromHiboutikList(hiboutikCategories),
      (category) => this.categoryDatabaseRepository.upsert(category),
      this.logger,
      (category) => `Hiboutik category ${category.hiboutikId}`,
    );

    // Pass 2: parent links, once every category exists (a child can come before its parent in Hiboutik's list)
    const nbParentsFailed = await forEachSafely(
      hiboutikCategories,
      (dto) => this.categoryDatabaseRepository.setParent(dto.category_id, dto.category_id_parent || null),
      this.logger,
      (dto) => `parent of Hiboutik category ${dto.category_id}`,
    );

    // Hiboutik is trusted: a successful (2xx) answer, even an empty list, is the truth. An HTTP error throws before this point.
    const nbDeleted = await this.categoryDatabaseRepository.deleteMissing(hiboutikCategories.map((dto) => dto.category_id));
    this.logger.log(
      `Categories sync ended: ${hiboutikCategories.length - nbFailed}/${hiboutikCategories.length} synced, ${nbFailed} failed, ` +
        `${nbParentsFailed} parent links failed, ${nbDeleted} deleted.`,
    );
  }
}