import { describe, it, expect, vi, beforeEach } from 'vitest';
import { GET, POST } from '@/app/api/suppliers/route';

const mockToArray = vi.fn();
const mockSort = vi.fn(() => ({ toArray: mockToArray }));
const mockFind = vi.fn(() => ({ sort: mockSort }));
const mockInsertOne = vi.fn();
const mockCollection = vi.fn(() => ({
  find: mockFind,
  insertOne: mockInsertOne,
}));
const mockDb = { collection: mockCollection };

vi.mock('@/lib/mongodb', () => ({
  getDb: vi.fn(() => Promise.resolve(mockDb)),
}));

describe('GET /api/suppliers', () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it('returns sorted suppliers', async () => {
    const suppliers = [
      { _id: 'sup1', name: 'Acme Foods' },
      { _id: 'sup2', name: 'Best Produce' },
    ];
    mockToArray.mockResolvedValue(suppliers);

    const response = await GET();
    const data = await response.json();

    expect(mockCollection).toHaveBeenCalledWith('suppliers');
    expect(mockSort).toHaveBeenCalledWith({ name: 1 });
    expect(data).toEqual(suppliers);
  });
});

describe('POST /api/suppliers', () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it('creates supplier and returns 201', async () => {
    mockInsertOne.mockResolvedValue({ insertedId: 'new-sup' });

    const request = new Request('http://localhost/api/suppliers', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ name: 'Fresh Farms' }),
    });

    const response = await POST(request);
    const data = await response.json();

    expect(response.status).toBe(201);
    expect(data.name).toBe('Fresh Farms');
    expect(data._id).toBe('new-sup');
    expect(data.createdAt).toBeDefined();
  });

  it('returns 400 when name is missing', async () => {
    const request = new Request('http://localhost/api/suppliers', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({}),
    });

    const response = await POST(request);
    const data = await response.json();

    expect(response.status).toBe(400);
    expect(data.error).toBe('Name is required');
  });

  it('returns 400 when name is empty string', async () => {
    const request = new Request('http://localhost/api/suppliers', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ name: '' }),
    });

    const response = await POST(request);
    expect(response.status).toBe(400);
  });
});