import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import { getCsrfToken, setCsrfToken } from '@/api/client';
import { streamChat } from '@/api/ai';

describe('streamChat CSRF header', () => {
  const originalFetch = globalThis.fetch;

  beforeEach(() => {
    setCsrfToken('test-csrf-token');
    globalThis.fetch = vi.fn().mockResolvedValue(
      new Response(
        'data: {"type":"done"}\n\ndata: [DONE]\n\n',
        {
          status: 200,
          headers: { 'Content-Type': 'text/event-stream' },
        },
      ),
    ) as unknown as typeof fetch;
  });

  afterEach(() => {
    setCsrfToken(null);
    globalThis.fetch = originalFetch;
    vi.restoreAllMocks();
  });

  it('sends the shared client CSRF token as X-CSRF-Token header', async () => {
    expect(getCsrfToken()).toBe('test-csrf-token');

    const gen = streamChat('conv-1', 'Hallo');
    for await (const _ of gen) {
      // consume stream until [DONE]
    }

    const fetchMock = globalThis.fetch as ReturnType<typeof vi.fn>;
    expect(fetchMock).toHaveBeenCalledTimes(1);
    const [, init] = fetchMock.mock.calls[0] as [string, RequestInit];
    const headers = init.headers as Record<string, string>;
    // Regression: token previously came from a never-written sessionStorage key → 403
    expect(headers['X-CSRF-Token']).toBe('test-csrf-token');
  });

  it('targets the conversation stream endpoint with JSON body', async () => {
    const gen = streamChat('conv-42', 'Frage', 'agent-9');
    for await (const _ of gen) {
      // consume stream until [DONE]
    }

    const fetchMock = globalThis.fetch as ReturnType<typeof vi.fn>;
    const [url, init] = fetchMock.mock.calls[0] as [string, RequestInit];
    expect(url).toBe('/api/v1/ai/conversations/conv-42/stream');
    expect(init.method).toBe('POST');
    expect(init.credentials).toBe('include');
    expect(JSON.parse(init.body as string)).toEqual({ content: 'Frage', agent_id: 'agent-9' });
  });
});