import { BadRequestException } from '@nestjs/common';
import { DepositsService } from './deposits.service';
import { Deposit } from '../entities/deposit.entity';

function serviceWith(deposit?: Partial<Deposit>) {
  const record = deposit ? ({ id: 1, studentId: 2, ...deposit } as Deposit) : null;
  const repo = {
    findOne: jest.fn(async (options: any) => options?.where?.studentId ? record : record),
    create: jest.fn((value) => value),
    save: jest.fn(async (value) => value),
  };
  const installmentRepo = {
    create: jest.fn((value) => value),
    save: jest.fn(async (value) => value),
  };
  const studentRepo = { findOne: jest.fn().mockResolvedValue({ id: 2 }) };
  return { service: new DepositsService(repo as any, installmentRepo as any, studentRepo as any), repo, installmentRepo };
}

describe('DepositsService boundaries', () => {
  it('rejects an installment amount that rounds to zero', async () => {
    const { service, installmentRepo } = serviceWith({ amount: 500, status: 'paid' });

    await expect(service.addInstallment(1, 0.004, '2026-08-01')).rejects.toBeInstanceOf(BadRequestException);
    expect(installmentRepo.save).not.toHaveBeenCalled();
  });

  it('rejects a repeated full refund', async () => {
    const { service, repo } = serviceWith({ amount: 0, status: 'refunded' });

    await expect(service.refund(1, { refundDate: '2026-07-14' })).rejects.toBeInstanceOf(BadRequestException);
    expect(repo.save).not.toHaveBeenCalled();
  });

  it('rounds cumulative collections and clears stale refund audit fields', async () => {
    const { service } = serviceWith({
      amount: 10.01,
      status: 'refunded',
      refundDate: '2026-07-01',
      refundAmount: 5,
      refundedBy: 9,
      refundedAt: new Date(),
    });

    const result = await service.create({ studentId: 2, amount: 0.02, paidDate: '2026-07-14' }, 7);

    expect(result).toMatchObject({ amount: 10.03, status: 'paid', recordedBy: 7 });
    expect(result.refundDate).toBeNull();
    expect(result.refundAmount).toBeNull();
    expect(result.refundedBy).toBeNull();
    expect(result.refundedAt).toBeNull();
  });
});
