import React from 'react';
import '@testing-library/jest-dom';
import { render, screen, fireEvent, waitFor } from '@testing-library/react';
import { BrowserRouter } from 'react-router-dom';
import { describe, it, expect, vi, beforeEach } from 'vitest';
import Login from './Login';

// Mock fetch
global.fetch = vi.fn();

const renderLogin = () => {
  render(
    <BrowserRouter>
      <Login />
    </BrowserRouter>
  );
};

describe('Login Component', () => {
  beforeEach(() => {
    vi.resetAllMocks();
  });

  it('renders login form', () => {
    renderLogin();
    expect(screen.getByLabelText(/password/i)).toBeInTheDocument();
    expect(screen.getByRole('button', { name: /login/i })).toBeInTheDocument();
  });

  it('handles successful login', async () => {
    vi.mocked(global.fetch).mockResolvedValueOnce({
      ok: true,
    } as Response);

    renderLogin();

    fireEvent.change(screen.getByLabelText(/password/i), { target: { value: 'secret' } });
    fireEvent.click(screen.getByRole('button', { name: /login/i }));

    await waitFor(() => {
      expect(global.fetch).toHaveBeenCalledWith(
        '/api/login',
        expect.objectContaining({
          method: 'POST',
        })
      );
    });
    // Navigation assertion is tricky without mocking useNavigate,
    // but if no error is shown, we assume success path was taken
    expect(screen.queryByText(/login failed/i)).not.toBeInTheDocument();
  });

  it('handles failed login', async () => {
    vi.mocked(global.fetch).mockResolvedValueOnce({
      ok: false,
      json: async () => ({ message: 'Bad credentials' }),
    } as Response);

    renderLogin();

    fireEvent.change(screen.getByLabelText(/password/i), { target: { value: 'wrong' } });
    fireEvent.click(screen.getByRole('button', { name: /login/i }));

    await waitFor(() => {
      expect(screen.getByText(/bad credentials/i)).toBeInTheDocument();
    });
  });

  it('handles network error', async () => {
    vi.mocked(global.fetch).mockRejectedValueOnce(new Error('Network error'));

    renderLogin();

    fireEvent.change(screen.getByLabelText(/password/i), { target: { value: 'secret' } });
    fireEvent.click(screen.getByRole('button', { name: /login/i }));

    await waitFor(() => {
      expect(screen.getByText(/network error/i)).toBeInTheDocument();
    });
  });
});