import { Injectable } from '@nestjs/common';
import { PrismaService } from '../../prisma/prisma.service';
import { Category } from '../../prisma/generated/client';
import { CategoryCreateInput } from '../../prisma/generated/models/Category';

/** Database access to categories. Rows are matched with Hiboutik by `hiboutikId`. */
@Injectable()
export class CategoryDatabaseRepository {
  constructor(private readonly prisma: PrismaService) {}

  async getAll(): Promise<Category[]> {
    return this.prisma.category.findMany({
      orderBy: { hiboutikId: 'asc' },
    });
  }

  /** Creates or updates the category with the same `hiboutikId`. */
  async upsert(category: CategoryCreateInput): Promise<Category> {
    return this.prisma.category.upsert({
      where: { hiboutikId: category.hiboutikId },
      create: category,
      update: category,
    });
  }

  /** Links a category to its parent (null for a root category). Both must already exist. */
  async setParent(hiboutikId: number, parentHiboutikId: number | null): Promise<Category> {
    return this.prisma.category.update({
      where: { hiboutikId },
      data: { parent: parentHiboutikId ? { connect: { hiboutikId: parentHiboutikId } } : { disconnect: true } },
    });
  }

  /**
   * Deletes the categories that no longer exist in Hiboutik.
   * Their products and sub-categories are kept: the relation is set to null (onDelete: SetNull).
   */
  async deleteMissing(keptHiboutikIds: number[]): Promise<number> {
    const result = await this.prisma.category.deleteMany({
      where: { hiboutikId: { notIn: keptHiboutikIds } },
    });
    return result.count;
  }
}