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

@Injectable()
export class CrudService<T> {
  constructor(protected readonly repository: Repository<T>) {}

  public async getById(id: number): Promise<T> {
    try {
      return await this.repository.findOne(id);
    } catch (error) {
      throw new NotFoundException();
    }
  }

  public async create(entity: T): Promise<T> {
    try {
      const instance = await this.repository.create(entity);
      return await this.repository.save(instance);
    } catch (error) {
      throw new BadRequestException(error.message);
    }
  }

  public async update(id: number, entity: T): Promise<T> {
    try {
      const entityToUpdate = await this.repository.findOne(id);

      Object.entries(entity).map(([key, value]) => {
        entityToUpdate[key] = value;
      });

      return await this.repository.save(entityToUpdate);
    } catch (error) {
      throw new BadRequestException(error.message);
    }
  }

  public async delete(id: number): Promise<void> {
    try {
      await this.repository.delete(id);
    } catch (error) {
      throw new NotFoundException();
    }
  }
}