import { beforeEach, describe, expect, it, vi } from 'vitest';

const invokeIpcMock = vi.fn();

vi.mock('@/lib/api-client', () => ({
  invokeIpc: (...args: unknown[]) => invokeIpcMock(...args),
}));

describe('host-api', () => {
  beforeEach(() => {
    vi.resetModules();
    vi.resetAllMocks();
    vi.unstubAllGlobals();
    window.localStorage.removeItem('niancode:allow-localhost-fallback');
  });

  it('uses IPC proxy and returns unified envelope json', async () => {
    invokeIpcMock.mockResolvedValueOnce({
      ok: true,
      data: {
        status: 200,
        ok: true,
        json: { success: true },
      },
    });

    const { hostApiFetch } = await import('@/lib/host-api');
    const result = await hostApiFetch<{ success: boolean }>('/api/settings');

    expect(result.success).toBe(true);
    expect(invokeIpcMock).toHaveBeenCalledWith(
      'hostapi:fetch',
      expect.objectContaining({ path: '/api/settings', method: 'GET' }),
    );
  });

  it('throws the Host API error from a unified non-ok HTTP response', async () => {
    invokeIpcMock.mockResolvedValueOnce({
      ok: true,
      data: {
        status: 403,
        ok: false,
        json: { success: false, error: 'Game asset review is unavailable for an uninitialized project' },
      },
    });

    const { hostApiFetch } = await import('@/lib/host-api');

    const promise = hostApiFetch('/api/files/game-asset-review?invocationId=legacy-review');

    await expect(promise).rejects.toMatchObject({
          message: 'Game asset review is unavailable for an uninitialized project',
      details: expect.objectContaining({ status: 403 }),
    });
  });

  it('returns undefined for a unified 204 response', async () => {
    invokeIpcMock.mockResolvedValueOnce({
      ok: true,
      data: { status: 204, ok: true },
    });

    const { hostApiFetch } = await import('@/lib/host-api');

    await expect(hostApiFetch('/api/test')).resolves.toBeUndefined();
  });

  it('supports legacy proxy envelope response', async () => {
    invokeIpcMock.mockResolvedValueOnce({
      success: true,
      status: 200,
      ok: true,
      json: { ok: 1 },
    });

    const { hostApiFetch } = await import('@/lib/host-api');
    const result = await hostApiFetch<{ ok: number }>('/api/settings');
    expect(result.ok).toBe(1);
  });

  it('returns undefined for a legacy 204 response', async () => {
    invokeIpcMock.mockResolvedValueOnce({
      success: true,
      status: 204,
      ok: true,
    });

    const { hostApiFetch } = await import('@/lib/host-api');

    await expect(hostApiFetch('/api/test')).resolves.toBeUndefined();
  });

  it('falls back to browser fetch when hostapi handler is not registered', async () => {
    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      status: 200,
      json: async () => ({ fallback: true }),
    });
    vi.stubGlobal('fetch', fetchMock);
    window.localStorage.setItem('niancode:allow-localhost-fallback', '1');

    invokeIpcMock.mockResolvedValueOnce({
      ok: false,
      error: { message: 'No handler registered for hostapi:fetch' },
    });

    const { hostApiFetch } = await import('@/lib/host-api');
    const result = await hostApiFetch<{ fallback: boolean }>('/api/test');

    expect(result.fallback).toBe(true);
    expect(fetchMock).toHaveBeenCalledWith(
      'http://127.0.0.1:13210/api/test',
      expect.objectContaining({ headers: expect.any(Object) }),
    );
  });

  it('throws message from legacy non-ok envelope', async () => {
    invokeIpcMock.mockResolvedValueOnce({
      success: true,
      ok: false,
      status: 401,
      json: { error: 'Invalid Authentication' },
    });

    const { hostApiFetch } = await import('@/lib/host-api');
    await expect(hostApiFetch('/api/test')).rejects.toThrow('Invalid Authentication');
  });

  it('preserves HTTP status from a legacy non-ok envelope', async () => {
    invokeIpcMock.mockResolvedValueOnce({
      success: true,
      ok: false,
      status: 503,
      json: { error: 'Service unavailable' },
    });

    const { hostApiFetch } = await import('@/lib/host-api');

    await expect(hostApiFetch('/api/test')).rejects.toMatchObject({
      message: 'Service unavailable',
      details: expect.objectContaining({ status: 503 }),
    });
  });

  it('falls back to browser fetch only when IPC channel is unavailable', async () => {
    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      status: 200,
      json: async () => ({ fallback: true }),
    });
    vi.stubGlobal('fetch', fetchMock);
    window.localStorage.setItem('niancode:allow-localhost-fallback', '1');

    invokeIpcMock.mockRejectedValueOnce(new Error('Invalid IPC channel: hostapi:fetch'));

    const { hostApiFetch } = await import('@/lib/host-api');
    const result = await hostApiFetch<{ fallback: boolean }>('/api/test');

    expect(result.fallback).toBe(true);
    expect(fetchMock).toHaveBeenCalledWith(
      'http://127.0.0.1:13210/api/test',
      expect.objectContaining({ headers: expect.any(Object) }),
    );
  });

  it('does not use localhost fallback when policy flag is disabled', async () => {
    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      status: 200,
      json: async () => ({ fallback: true }),
    });
    vi.stubGlobal('fetch', fetchMock);

    invokeIpcMock.mockRejectedValueOnce(new Error('Invalid IPC channel: hostapi:fetch'));

    const { hostApiFetch } = await import('@/lib/host-api');
    await expect(hostApiFetch('/api/test')).rejects.toThrow('Invalid IPC channel: hostapi:fetch');
    expect(fetchMock).not.toHaveBeenCalled();
  });

  it('primes the host api token and base url before creating an event stream url', async () => {
    const eventSourceMock = vi.fn();
    vi.stubGlobal('EventSource', eventSourceMock);
    invokeIpcMock.mockImplementation(async (channel: string) => {
      if (channel === 'hostapi:token') return 'secret-token';
      if (channel === 'hostapi:base-url') return 'http://127.0.0.1:4567';
      return null;
    });

    const { createHostEventSource, ensureHostApiToken, getHostApiBase } = await import('@/lib/host-api');
    await ensureHostApiToken();
    createHostEventSource('/api/opencode/events?sessionId=ses_1');

    expect(invokeIpcMock).toHaveBeenCalledWith('hostapi:token');
    expect(invokeIpcMock).toHaveBeenCalledWith('hostapi:base-url');
    expect(getHostApiBase()).toBe('http://127.0.0.1:4567');
    expect(eventSourceMock).toHaveBeenCalledWith(
      'http://127.0.0.1:4567/api/opencode/events?sessionId=ses_1&token=secret-token',
    );
  });
});