import { HfInference } from '@huggingface/inference';
import { HuggingFaceStream, StreamingTextResponse, StreamData } from '.';
import { huggingfaceChunks } from '../tests/snapshots/huggingface';
import { createClient } from '../tests/utils/mock-client';
import { DEFAULT_TEST_URL, createMockServer } from '../tests/utils/mock-server';

const server = createMockServer([
  {
    url: DEFAULT_TEST_URL,
    chunks: huggingfaceChunks,
    formatChunk: chunk => `data: ${JSON.stringify(chunk)}\n\n`,
  },
]);

describe('HuggingFace stream', () => {
  const Hf = new HfInference();

  beforeAll(() => {
    server.listen();
  });

  afterEach(() => {
    server.resetHandlers();
  });

  afterAll(() => {
    server.close();
  });

  function readAllChunks(response: Response) {
    return createClient(response).readAll();
  }

  it('should send text', async () => {
    const data = new StreamData();

    const stream = HuggingFaceStream(
      Hf.textGenerationStream(
        { model: 'model', inputs: '' },
        { fetch: () => fetch(DEFAULT_TEST_URL) },
      ),
      {
        onFinal() {
          data.close();
        },
      },
    );

    const response = new StreamingTextResponse(stream, {}, data);

    expect(await readAllChunks(response)).toEqual([
      '0:"Hello"\n',
      '0:","\n',
      '0:" world"\n',
      '0:"."\n',
    ]);
  });

  it('should send text and data', async () => {
    const data = new StreamData();

    data.append({ t1: 'v1' });

    const stream = HuggingFaceStream(
      Hf.textGenerationStream(
        { model: 'model', inputs: '' },
        { fetch: () => fetch(DEFAULT_TEST_URL) },
      ),
      {
        onFinal() {
          data.close();
        },
      },
    );

    const response = new StreamingTextResponse(stream, {}, data);

    expect(await readAllChunks(response)).toEqual([
      '2:[{"t1":"v1"}]\n',
      '0:"Hello"\n',
      '0:","\n',
      '0:" world"\n',
      '0:"."\n',
    ]);
  });
});