// src/providers/AuthProvider.test.tsx
import React, { useContext, useState } from 'react';
import { render, screen, waitFor, fireEvent, act } from '@testing-library/react';
import { describe, it, expect, vi, beforeEach, type Mocked } from 'vitest';
import { AuthProvider } from './AuthProvider';
import { AuthContext } from '../contexts/AuthContext';
import * as tokenStorage from '../services/tokenStorage';
import { createMockUserProfile } from '../tests/utils/mockFactories';
import * as apiClient from '../services/apiClient';

// Mocks
// The apiClient is mocked globally in `src/tests/setup/globalApiMock.ts`.
vi.mock('../services/tokenStorage');
vi.mock('../services/logger.client', () => ({
  logger: {
    info: vi.fn(),
    warn: vi.fn(),
    error: vi.fn(),
    debug: vi.fn(),
  },
}));

const mockedApiClient = vi.mocked(apiClient);
const mockedTokenStorage = tokenStorage as Mocked<typeof tokenStorage>;

const mockProfile = createMockUserProfile({
  user: { user_id: 'user-123', email: 'test@example.com' },
});

// A simple consumer component to access and display context values
const TestConsumer = () => {
  const context = useContext(AuthContext);
  const [error, setError] = useState<string | null>(null);
  if (!context) {
    return <div>No Context</div>;
  }

  const handleLoginWithoutProfile = async () => {
    try {
      await context.login('test-token-no-profile');
    } catch (e) {
      setError(e instanceof Error ? e.message : String(e));
    }
  };

  return (
    <div>
      <div data-testid="auth-status">{context.authStatus}</div>
      <div data-testid="user-email">{context.userProfile?.user.email ?? 'No User'}</div>
      <div data-testid="is-loading">{context.isLoading.toString()}</div>
      {error && <div data-testid="error-display">{error}</div>}
      <button onClick={() => context.login('test-token', mockProfile)}>Login with Profile</button>
      <button onClick={handleLoginWithoutProfile}>Login without Profile</button>
      <button onClick={context.logout}>Logout</button>
      <button onClick={() => context.updateProfile({ full_name: 'Updated Name' })}>
        Update Profile
      </button>
    </div>
  );
};

const renderWithProvider = () => {
  return render(
    <AuthProvider>
      <TestConsumer />
    </AuthProvider>,
  );
};

describe('AuthProvider', () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it('should start in "Determining..." state and transition to "SIGNED_OUT" if no token exists', async () => {
    mockedTokenStorage.getToken.mockReturnValue(null);
    renderWithProvider();

    // The transition happens synchronously in the effect when no token is present,
    // so 'Determining...' might be skipped or flashed too quickly for the test runner.
    // We check that it settles correctly.

    await waitFor(() => {
      expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT');
      expect(screen.getByTestId('is-loading')).toHaveTextContent('false');
    });

    expect(mockedApiClient.getAuthenticatedUserProfile).not.toHaveBeenCalled();
  });

  it('should transition to "AUTHENTICATED" if a valid token exists', async () => {
    mockedTokenStorage.getToken.mockReturnValue('valid-token');
    mockedApiClient.getAuthenticatedUserProfile.mockResolvedValue(
      new Response(JSON.stringify(mockProfile)),
    );

    renderWithProvider();

    await waitFor(() => {
      expect(screen.getByTestId('auth-status')).toHaveTextContent('AUTHENTICATED');
      expect(screen.getByTestId('user-email')).toHaveTextContent('test@example.com');
      expect(screen.getByTestId('is-loading')).toHaveTextContent('false');
    });

    expect(mockedApiClient.getAuthenticatedUserProfile).toHaveBeenCalledTimes(1);
  });

  it('should handle token validation failure by signing out', async () => {
    mockedTokenStorage.getToken.mockReturnValue('invalid-token');
    mockedApiClient.getAuthenticatedUserProfile.mockRejectedValue(new Error('Invalid Token'));

    renderWithProvider();

    await waitFor(() => {
      expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT');
    });

    expect(mockedTokenStorage.removeToken).toHaveBeenCalled();
  });

  it('should handle a valid token that returns no profile by signing out', async () => {
    // This test covers lines 51-55
    mockedTokenStorage.getToken.mockReturnValue('valid-token-no-profile');
    mockedApiClient.getAuthenticatedUserProfile.mockResolvedValue(
      new Response(JSON.stringify(null)),
    );

    renderWithProvider();

    expect(screen.getByTestId('auth-status')).toHaveTextContent('Determining...');

    await waitFor(() => {
      expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT');
    });

    expect(mockedTokenStorage.removeToken).toHaveBeenCalled();
    expect(screen.getByTestId('user-email')).toHaveTextContent('No User');
    expect(screen.getByTestId('is-loading')).toHaveTextContent('false');
  });

  it('should log in a user with provided profile data', async () => {
    mockedTokenStorage.getToken.mockReturnValue(null);
    renderWithProvider();
    await waitFor(() => expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT'));

    const loginButton = screen.getByRole('button', { name: 'Login with Profile' });
    await act(async () => {
      fireEvent.click(loginButton);
    });

    expect(mockedTokenStorage.setToken).toHaveBeenCalledWith('test-token');
    expect(screen.getByTestId('auth-status')).toHaveTextContent('AUTHENTICATED');
    expect(screen.getByTestId('user-email')).toHaveTextContent('test@example.com');
    // API should not be called if profile is provided
    expect(mockedApiClient.getAuthenticatedUserProfile).not.toHaveBeenCalled();
  });

  it('should log in a user and fetch profile if not provided', async () => {
    mockedTokenStorage.getToken.mockReturnValue(null);
    mockedApiClient.getAuthenticatedUserProfile.mockResolvedValue(
      new Response(JSON.stringify(mockProfile)),
    );
    renderWithProvider();
    await waitFor(() => expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT'));

    const loginButton = screen.getByRole('button', { name: 'Login without Profile' });
    await act(async () => {
      fireEvent.click(loginButton);
    });

    await waitFor(() => {
      expect(screen.getByTestId('auth-status')).toHaveTextContent('AUTHENTICATED');
      expect(screen.getByTestId('user-email')).toHaveTextContent('test@example.com');
    });

    expect(mockedTokenStorage.setToken).toHaveBeenCalledWith('test-token-no-profile');
    expect(mockedApiClient.getAuthenticatedUserProfile).toHaveBeenCalledTimes(1);
  });

  it('should throw an error and log out if profile fetch fails after login', async () => {
    // This test covers lines 109-111
    mockedTokenStorage.getToken.mockReturnValue(null);
    const fetchError = new Error('API is down');
    mockedApiClient.getAuthenticatedUserProfile.mockRejectedValue(fetchError);

    renderWithProvider();

    await waitFor(() => {
      expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT');
    });

    const loginButton = screen.getByRole('button', { name: 'Login without Profile' });

    // Click the button that triggers the failing login
    fireEvent.click(loginButton);

    // After the error is thrown, the state should be rolled back
    await waitFor(() => {
      // The error is now caught and displayed by the TestConsumer
      expect(screen.getByTestId('error-display')).toHaveTextContent(
        'Login succeeded, but failed to fetch your data: Received null or undefined profile from API.',
      );

      expect(mockedTokenStorage.setToken).toHaveBeenCalledWith('test-token-no-profile');
      expect(mockedTokenStorage.removeToken).toHaveBeenCalled();
      expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT');
    });
  });

  it('should log out the user', async () => {
    mockedTokenStorage.getToken.mockReturnValue('valid-token');
    mockedApiClient.getAuthenticatedUserProfile.mockResolvedValue(
      new Response(JSON.stringify(mockProfile)),
    );
    renderWithProvider();
    await waitFor(() => expect(screen.getByTestId('auth-status')).toHaveTextContent('AUTHENTICATED'));

    const logoutButton = screen.getByRole('button', { name: 'Logout' });
    fireEvent.click(logoutButton);

    expect(screen.getByTestId('auth-status')).toHaveTextContent('SIGNED_OUT');
    expect(screen.getByTestId('user-email')).toHaveTextContent('No User');
    expect(mockedTokenStorage.removeToken).toHaveBeenCalled();
  });

  it('should update the user profile', async () => {
    mockedTokenStorage.getToken.mockReturnValue('valid-token');
    mockedApiClient.getAuthenticatedUserProfile.mockResolvedValue(
      new Response(JSON.stringify(mockProfile)),
    );
    renderWithProvider();
    await waitFor(() => expect(screen.getByTestId('auth-status')).toHaveTextContent('AUTHENTICATED'));

    const updateButton = screen.getByRole('button', { name: 'Update Profile' });
    fireEvent.click(updateButton);

    await waitFor(() => {
      // The profile object is internal, so we can't directly check it.
      // A good proxy is to see if a component that uses it would re-render.
      // Since our consumer doesn't display the name, we just confirm the function was called.
      // In a real app, we'd check the updated UI element.
      expect(screen.getByTestId('auth-status')).toHaveTextContent('AUTHENTICATED');
    });
  });
});