import {
  Args,
  ID,
  Mutation,
  Parent,
  Query,
  ResolveField,
  Resolver,
} from '@nestjs/graphql';
import { NewItemInput } from './dto/new-item.input';
import { EANService } from './ean/ean.service';
import { ItemModel, PaginatedItems } from './items.model';
import { ItemsService } from './items.service';

@Resolver((of) => ItemModel)
export class ItemsResolver {
  constructor(private itemsService: ItemsService, private eans: EANService) {}

  @Query((returns) => ItemModel, { nullable: true })
  async item(@Args('id', { type: () => ID }) id: string) {
    return this.itemsService.getItem(id);
  }

  @Query((returns) => PaginatedItems)
  async itemList(
    @Args('cursor', { type: () => ID, nullable: true }) cursor?: string,
  ) {
    return this.itemsService.getItemList(cursor ? parseInt(cursor, 10) : 0);
  }

  @ResolveField()
  ean13(@Parent() item: ItemModel) {
    return this.eans.fromID(item.id);
  }

  @ResolveField()
  async parent(@Parent() item: ItemModel) {
    return this.itemsService.getItemParent(item);
  }

  @ResolveField()
  async ancestors(@Parent() item: ItemModel) {
    return this.itemsService.getItemAncestors(item);
  }

  @ResolveField()
  async children(@Parent() item: ItemModel) {
    return this.itemsService.getItemChildren(item);
  }

  @ResolveField()
  async descendants(@Parent() item: ItemModel) {
    return this.itemsService.getItemDescendants(item);
  }

  @Mutation((returns) => ItemModel)
  async createItem(@Args('itemData') itemData: NewItemInput) {
    return this.itemsService.createItem(itemData);
  }
}