import { describe, it, expect, vi, beforeEach } from 'vitest';
import { NextRequest } from 'next/server';

vi.mock('@/lib/verification/socratic', () => ({
  runSocraticProbe: vi.fn(),
}));

import { POST } from '../route';
import { runSocraticProbe } from '@/lib/verification/socratic';

const mockProbe = vi.mocked(runSocraticProbe);

const VALID_BODY = {
  gradeId: '123e4567-e89b-12d3-a456-426614174000',
  userId: 'user-abc',
  followUpText: 'I meant that closures hold a reference to the outer scope, not a copy.',
};

function makeRequest(body: unknown) {
  return new NextRequest('http://localhost:3000/api/socratic', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
  });
}

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

  it('returns 400 when gradeId is missing', async () => {
    const res = await POST(makeRequest({ userId: 'u', followUpText: 'text' }));
    expect(res.status).toBe(400);
  });

  it('returns 400 when gradeId is not a UUID', async () => {
    const res = await POST(makeRequest({ ...VALID_BODY, gradeId: 'not-a-uuid' }));
    expect(res.status).toBe(400);
  });

  it('returns 400 when followUpText is empty', async () => {
    const res = await POST(makeRequest({ ...VALID_BODY, followUpText: '' }));
    expect(res.status).toBe(400);
  });

  it('returns 200 with reply and upgradedVerdict on success', async () => {
    mockProbe.mockResolvedValue({ reply: 'Yes, that is correct.', upgradedVerdict: 'mastered' });
    const res = await POST(makeRequest(VALID_BODY));
    expect(res.status).toBe(200);
    const body = await res.json();
    expect(body.reply).toBe('Yes, that is correct.');
    expect(body.upgradedVerdict).toBe('mastered');
  });

  it('returns 404 when grade not found', async () => {
    mockProbe.mockRejectedValue(
      new Error(`Grade not found: ${VALID_BODY.gradeId}`),
    );
    const res = await POST(makeRequest(VALID_BODY));
    expect(res.status).toBe(404);
  });

  it('returns 500 on unexpected error', async () => {
    mockProbe.mockRejectedValue(new Error('DB down'));
    const res = await POST(makeRequest(VALID_BODY));
    expect(res.status).toBe(500);
  });
});