/** @jsxImportSource solid-js */
import { cleanup, findByText, render, screen } from '@solidjs/testing-library';
import '@testing-library/jest-dom';
import userEvent from '@testing-library/user-event';
import { For } from 'solid-js';
import {
  mockFetchDataStream,
  mockFetchDataStreamWithGenerator,
  mockFetchError,
} from '../tests/utils/mock-fetch';
import { useChat } from './use-chat';

const TestComponent = () => {
  const { messages, append, error, data, isLoading } = useChat();

  return (
    <div>
      <div data-testid="loading">{isLoading().toString()}</div>
      <div data-testid="error">{error()?.toString()}</div>
      <div data-testid="data">{JSON.stringify(data())}</div>

      <For each={messages()}>
        {(m, idx) => (
          <div data-testid={`message-${idx()}`} class="whitespace-pre-wrap">
            {m.role === 'user' ? 'User: ' : 'AI: '}
            {m.content}
          </div>
        )}
      </For>

      <button
        data-testid="button"
        onClick={() => {
          append({ role: 'user', content: 'hi' });
        }}
      />
    </div>
  );
};

beforeEach(() => {
  render(() => <TestComponent />);
});

afterEach(() => {
  vi.restoreAllMocks();
  cleanup();
});

it('should return messages', async () => {
  mockFetchDataStream({
    url: 'https://example.com/api/chat',
    chunks: ['0:"Hello"\n', '0:","\n', '0:" world"\n', '0:"."\n'],
  });

  await userEvent.click(screen.getByTestId('button'));

  await screen.findByTestId('message-0');
  expect(screen.getByTestId('message-0')).toHaveTextContent('User: hi');

  await screen.findByTestId('message-1');
  expect(screen.getByTestId('message-1')).toHaveTextContent(
    'AI: Hello, world.',
  );
});

it('should return messages and data', async () => {
  mockFetchDataStream({
    url: 'https://example.com/api/chat',
    chunks: ['2:[{"t1":"v1"}]\n', '0:"Hello"\n'],
  });

  await userEvent.click(screen.getByTestId('button'));

  await screen.findByTestId('data');
  expect(screen.getByTestId('data')).toHaveTextContent('[{"t1":"v1"}]');

  await screen.findByTestId('message-1');
  expect(screen.getByTestId('message-1')).toHaveTextContent('AI: Hello');
});

it('should return error', async () => {
  mockFetchError({ statusCode: 404, errorMessage: 'Not found' });

  await userEvent.click(screen.getByTestId('button'));

  await screen.findByTestId('error');
  expect(screen.getByTestId('error')).toHaveTextContent('Error: Not found');
});

describe('loading state', () => {
  it('should show loading state', async () => {
    let finishGeneration: ((value?: unknown) => void) | undefined;
    const finishGenerationPromise = new Promise(resolve => {
      finishGeneration = resolve;
    });

    mockFetchDataStreamWithGenerator({
      url: 'https://example.com/api/chat',
      chunkGenerator: (async function* generate() {
        const encoder = new TextEncoder();
        yield encoder.encode('0:"Hello"\n');
        await finishGenerationPromise;
      })(),
    });

    await userEvent.click(screen.getByTestId('button'));

    await screen.findByTestId('loading');
    expect(screen.getByTestId('loading')).toHaveTextContent('true');

    finishGeneration?.();

    await findByText(await screen.findByTestId('loading'), 'false');
    expect(screen.getByTestId('loading')).toHaveTextContent('false');
  });

  it('should reset loading state on error', async () => {
    mockFetchError({ statusCode: 404, errorMessage: 'Not found' });

    await userEvent.click(screen.getByTestId('button'));

    await screen.findByTestId('loading');
    expect(screen.getByTestId('loading')).toHaveTextContent('false');
  });
});