// @vitest-environment node
import { beforeEach, describe, expect, it, vi } from 'vitest';
import { createLearningAgentClient } from '@electron/services/learning-agent-client';

describe('Learning Agent client', () => {
  const fetchImpl = vi.fn<typeof fetch>();
  const getAccessToken = vi.fn();

  beforeEach(() => {
    fetchImpl.mockReset();
    getAccessToken.mockReset();
    getAccessToken.mockResolvedValue('works-token');
  });

  it('binds the exact course hash and collects the Learning Runtime answer', async () => {
    const event = (type: string, payload: Record<string, unknown>) => `event: agent.event\ndata: ${JSON.stringify({ run_id: 'run-1', type, payload })}\n\n`;
    fetchImpl
      .mockResolvedValueOnce(new Response(JSON.stringify({ session_id: 'session-1' }), { status: 201 }))
      .mockResolvedValueOnce(new Response(JSON.stringify({ run_id: 'run-1' }), { status: 202 }))
      .mockResolvedValueOnce(new Response(JSON.stringify({ stream_url: '/api/agents/sessions/session-1/events?ticket=ticket-1' }), { status: 200 }))
      .mockResolvedValueOnce(new Response(
        event('learning.assistant.delta', { delta: 'Python ' })
        + event('learning.assistant.delta', { delta: '很适合入门。' })
        + event('learning.assistant.completed', { sources: [] }),
        { status: 200, headers: { 'Content-Type': 'text/event-stream' } },
      ));
    const client = createLearningAgentClient({ fetchImpl, getAccessToken, apiBaseUrl: 'https://square.example' });

    await expect(client.ask({
      courseId: 'course-1',
      contentHash: 'a'.repeat(64),
      message: '为什么要学 Python？',
      anchor: { sceneId: 'scene-1', sceneOrder: 1 },
    })).resolves.toEqual({ text: 'Python 很适合入门。' });

    expect(JSON.parse(String(fetchImpl.mock.calls[0][1]?.body))).toMatchObject({
      runtime: 'learning',
      runtime_version: 'v1',
      binding: { kind: 'learning-course', key: `course-1:${'a'.repeat(64)}` },
    });
    expect(fetchImpl.mock.calls[3][1]?.headers).toEqual({ Accept: 'text/event-stream' });
    expect(fetchImpl.mock.calls.some((call) => call[1]?.method === 'DELETE')).toBe(false);
  });

  it('reuses one course-bound Works Agent session across multiple turns', async () => {
    const stream = (runId: string, answer: string) => new Response(
      `data: ${JSON.stringify({ run_id: runId, type: 'learning.assistant.delta', payload: { delta: answer } })}\n\n`
      + `data: ${JSON.stringify({ run_id: runId, type: 'learning.assistant.completed', payload: {} })}\n\n`,
      { status: 200, headers: { 'Content-Type': 'text/event-stream' } },
    );
    fetchImpl
      .mockResolvedValueOnce(new Response(JSON.stringify({ session_id: 'session-shared' }), { status: 201 }))
      .mockResolvedValueOnce(new Response(JSON.stringify({ run_id: 'run-1' }), { status: 202 }))
      .mockResolvedValueOnce(new Response(JSON.stringify({ stream_url: '/api/agents/sessions/session-shared/events?ticket=1' }), { status: 200 }))
      .mockResolvedValueOnce(stream('run-1', '第一轮'))
      .mockResolvedValueOnce(new Response(JSON.stringify({ run_id: 'run-2' }), { status: 202 }))
      .mockResolvedValueOnce(new Response(JSON.stringify({ stream_url: '/api/agents/sessions/session-shared/events?ticket=2' }), { status: 200 }))
      .mockResolvedValueOnce(stream('run-2', '第二轮'));
    const client = createLearningAgentClient({ fetchImpl, getAccessToken, apiBaseUrl: 'https://square.example' });
    const binding = { courseId: 'course-1', contentHash: 'a'.repeat(64) };

    await expect(client.ask({ ...binding, message: '第一问' })).resolves.toEqual({ text: '第一轮' });
    await expect(client.ask({ ...binding, message: '追问' })).resolves.toEqual({ text: '第二轮' });

    const urls = fetchImpl.mock.calls.map(([url]) => String(url));
    expect(urls.filter((url) => url === 'https://square.example/api/agents/sessions')).toHaveLength(1);
    expect(urls.filter((url) => url.endsWith('/sessions/session-shared/commands'))).toHaveLength(2);
    expect(fetchImpl.mock.calls.some((call) => call[1]?.method === 'DELETE')).toBe(false);
  });

  it('stops before the network for an invalid package hash', async () => {
    const client = createLearningAgentClient({ fetchImpl, getAccessToken });
    await expect(client.ask({ courseId: 'course-1', contentHash: 'bad', message: '你好' })).rejects.toThrow('助教请求无效');
    expect(fetchImpl).not.toHaveBeenCalled();
  });

  it('bounds compatibility history and anchor before network access', async () => {
    const client = createLearningAgentClient({ fetchImpl, getAccessToken });
    await expect(client.ask({
      courseId: 'course-1',
      contentHash: 'a'.repeat(64),
      message: '你好',
      history: [{ role: 'user', content: 'x'.repeat(4_001) }],
    })).rejects.toThrow('助教请求无效');
    await expect(client.ask({
      courseId: 'course-1',
      contentHash: 'a'.repeat(64),
      message: '你好',
      anchor: { sceneId: 'x'.repeat(257) },
    })).rejects.toThrow('助教请求无效');
    expect(fetchImpl).not.toHaveBeenCalled();
  });

  it('serializes concurrent turns for the same durable session', async () => {
    let firstStreamResolve!: (response: Response) => void;
    const firstStream = new Promise<Response>((resolve) => { firstStreamResolve = resolve; });
    let commandCount = 0;
    fetchImpl.mockImplementation(async (input, init) => {
      const url = String(input);
      if (url.endsWith('/api/agents/sessions')) {
        return new Response(JSON.stringify({ session_id: 'session-1' }), { status: 201 });
      }
      if (url.endsWith('/commands')) {
        commandCount += 1;
        return new Response(JSON.stringify({ run_id: `run-${commandCount}` }), { status: 202 });
      }
      if (url.endsWith('/stream-tickets')) {
        return new Response(JSON.stringify({ stream_url: '/api/agents/sessions/session-1/events' }), { status: 200 });
      }
      if (url.includes('/events')) {
        if (commandCount === 1) return firstStream;
        return new Response(
          `data: ${JSON.stringify({ run_id: 'run-2', type: 'learning.assistant.delta', payload: { delta: '第二轮' } })}\n\n`
          + `data: ${JSON.stringify({ run_id: 'run-2', type: 'learning.assistant.completed', payload: {} })}\n\n`,
          { status: 200 },
        );
      }
      throw new Error(`unexpected ${url} ${init?.method}`);
    });
    const client = createLearningAgentClient({ fetchImpl, getAccessToken, apiBaseUrl: 'https://square.example' });
    const binding = { courseId: 'course-1', contentHash: 'a'.repeat(64) };
    const one = client.ask({ ...binding, message: '第一问' });
    await vi.waitFor(() => expect(commandCount).toBe(1));
    const two = client.ask({ ...binding, message: '第二问' });
    await Promise.resolve();
    expect(commandCount).toBe(1);
    firstStreamResolve(new Response(
      `data: ${JSON.stringify({ run_id: 'run-1', type: 'learning.assistant.delta', payload: { delta: '第一轮' } })}\n\n`
      + `data: ${JSON.stringify({ run_id: 'run-1', type: 'learning.assistant.completed', payload: {} })}\n\n`,
      { status: 200 },
    ));
    await expect(Promise.all([one, two])).resolves.toEqual([{ text: '第一轮' }, { text: '第二轮' }]);
    expect(commandCount).toBe(2);
  });

  it('redacts SSE failure payloads and malformed event data', async () => {
    const responses = (stream: string) => [
      new Response(JSON.stringify({ session_id: 'session-1' }), { status: 201 }),
      new Response(JSON.stringify({ run_id: 'run-1' }), { status: 202 }),
      new Response(JSON.stringify({ stream_url: '/api/agents/sessions/session-1/events' }), { status: 200 }),
      new Response(stream, { status: 200 }),
    ];
    fetchImpl.mockImplementationOnce(async () => responses('')[0]);
    fetchImpl.mockResolvedValueOnce(responses('')[1]).mockResolvedValueOnce(responses('')[2]).mockResolvedValueOnce(
      responses(`data: ${JSON.stringify({ run_id: 'run-1', type: 'learning.assistant.failed', payload: { message: 'provider secret traceback' } })}\n\n`)[3],
    );
    const client = createLearningAgentClient({ fetchImpl, getAccessToken, apiBaseUrl: 'https://square.example' });
    await expect(client.ask({ courseId: 'course-1', contentHash: 'a'.repeat(64), message: '你好' }))
      .rejects.toThrow('助教回答失败');
  });

  it('does not create a session after its captured account changes during token lookup', async () => {
    let resolveToken!: (token: string) => void;
    getAccessToken.mockReturnValueOnce(new Promise((resolve) => { resolveToken = resolve; }));
    let current = true;
    const client = createLearningAgentClient({ fetchImpl, getAccessToken, apiBaseUrl: 'https://square.example' });
    const result = client.ask(
      { courseId: 'course-1', contentHash: 'a'.repeat(64), message: '你好' },
      () => { if (!current) throw Object.assign(new Error('account changed'), { code: 'LEARNING_ACCOUNT_CHANGED' }); },
    );
    current = false;
    resolveToken('new-account-token');
    await expect(result).rejects.toThrow('account changed');
    expect(fetchImpl).not.toHaveBeenCalled();
  });

  it('does not retry a 401 after its captured account changes during refresh', async () => {
    let resolveRefresh!: (token: string) => void;
    getAccessToken.mockResolvedValueOnce('old-token').mockReturnValueOnce(new Promise((resolve) => { resolveRefresh = resolve; }));
    fetchImpl.mockResolvedValueOnce(new Response(null, { status: 401 }));
    let current = true;
    const client = createLearningAgentClient({ fetchImpl, getAccessToken, apiBaseUrl: 'https://square.example' });
    const result = client.ask(
      { courseId: 'course-1', contentHash: 'a'.repeat(64), message: '你好' },
      () => { if (!current) throw Object.assign(new Error('account changed'), { code: 'LEARNING_ACCOUNT_CHANGED' }); },
    );
    await vi.waitFor(() => expect(getAccessToken).toHaveBeenCalledTimes(2));
    current = false;
    resolveRefresh('new-account-token');
    await expect(result).rejects.toMatchObject({ code: 'LEARNING_ACCOUNT_CHANGED' });
    expect(fetchImpl).toHaveBeenCalledOnce();
  });
});