import { BadRequestException } from '@nestjs/common';
import { RoomsService } from './rooms.service';

function createService(room: { id: number; gender: '男' | '女' | null }, activeCount: number) {
  const repo = {
    findOne: jest.fn().mockResolvedValue(room),
    update: jest.fn(),
  };
  const occRepo = { count: jest.fn().mockResolvedValue(activeCount) };
  const service = new RoomsService(
    repo as never,
    occRepo as never,
    {} as never,
    {} as never,
    {} as never,
  );
  return { service, repo, occRepo };
}

describe('RoomsService — room gender maintenance', () => {
  it('allows an empty room gender to be changed or cleared', async () => {
    const { service, repo } = createService({ id: 1, gender: '男' }, 0);

    await service.update(1, { gender: null });

    expect(repo.update).toHaveBeenCalledWith(1, { gender: null });
  });

  it('rejects changing gender while students are living in the room', async () => {
    const { service, repo } = createService({ id: 1, gender: '男' }, 1);

    await expect(service.update(1, { gender: '女' })).rejects.toBeInstanceOf(BadRequestException);
    expect(repo.update).not.toHaveBeenCalled();
  });

  it('does not query occupants when gender is unchanged or omitted', async () => {
    const { service, occRepo } = createService({ id: 1, gender: '男' }, 1);

    await service.update(1, { roomType: '四人间' });

    expect(occRepo.count).not.toHaveBeenCalled();
  });
});