import { Injectable, NotFoundException } from '@nestjs/common';

export interface Item {
  id: number;
  name: string;
  description: string;
}

@Injectable()
export class ItemsService {
  private readonly store = new Map<number, Item>();
  private counter = 1;

  findAll(): Item[] {
    return [...this.store.values()];
  }

  create(name: string, description = ''): Item {
    const item: Item = { id: this.counter++, name, description };
    this.store.set(item.id, item);
    return item;
  }

  findOne(id: number): Item {
    const item = this.store.get(id);
    if (!item) throw new NotFoundException(`Item ${id} not found`);
    return item;
  }

  update(id: number, name?: string, description?: string): Item {
    const item = this.findOne(id);
    const updated: Item = {
      id,
      name: name ?? item.name,
      description: description ?? item.description,
    };
    this.store.set(id, updated);
    return updated;
  }

  remove(id: number): { deleted: number } {
    this.store.delete(id);
    return { deleted: id };
  }
}