import { afterEach, describe, expect, it, vi } from 'vitest';
import {
  ApiClientError,
  deleteNotification,
  deleteNotifications,
  getUnreadNotificationCount,
  listNotifications,
} from '../src/lib/api';

const originalFetch = globalThis.fetch;

function mockFetch(responder: (input: RequestInfo | URL, init?: RequestInit) => {
  status?: number;
  body?: unknown;
  statusText?: string;
}) {
  const calls: { path: string; init?: RequestInit }[] = [];
  const fetchMock = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
    const path = typeof input === 'string' ? input : new URL(input.toString()).pathname;
    calls.push({ path, init });
    const { status = 200, body = {}, statusText = 'OK' } = responder(input, init);
    return new Response(JSON.stringify(body), {
      status,
      statusText,
      headers: { 'content-type': 'application/json' },
    });
  });
  globalThis.fetch = fetchMock as unknown as typeof fetch;
  return { calls, fetchMock };
}

afterEach(() => {
  globalThis.fetch = originalFetch;
});

describe('notifications api client', () => {
  it('listNotifications GETs /api/notifications with credentials', async () => {
    const { calls } = mockFetch(() => ({
      body: { notifications: [{ id: 'n1', title: 'A', kind: 'promotion_approved', status: 'viewed' }] },
    }));

    const result = await listNotifications();

    expect(calls[0].path).toBe('/api/notifications');
    expect(calls[0].init?.method).toBeUndefined();
    expect(calls[0].init?.credentials).toBe('include');
    expect(result.notifications).toHaveLength(1);
  });

  it('getUnreadNotificationCount GETs the unread-count endpoint', async () => {
    const { calls } = mockFetch(() => ({ body: { count: 3 } }));

    const result = await getUnreadNotificationCount();

    expect(calls[0].path).toBe('/api/notifications/unread-count');
    expect(result.count).toBe(3);
  });

  it('deleteNotification issues DELETE to /api/notifications/:id', async () => {
    const { calls } = mockFetch(() => ({ body: { ok: true } }));

    const result = await deleteNotification('n1');

    expect(calls[0].path).toBe('/api/notifications/n1');
    expect(calls[0].init?.method).toBe('DELETE');
    expect(result.ok).toBe(true);
  });

  it('deleteNotifications POSTs the ids array to the batch endpoint', async () => {
    const { calls } = mockFetch(() => ({ body: { ok: true, deleted: 2 } }));

    const result = await deleteNotifications(['n1', 'n2']);

    expect(calls[0].path).toBe('/api/notifications/delete-batch');
    expect(calls[0].init?.method).toBe('POST');
    const body = JSON.parse(calls[0].init?.body as string);
    expect(body).toEqual({ ids: ['n1', 'n2'] });
    expect(result.deleted).toBe(2);
  });

  it('encodes notification ids with special characters', async () => {
    const { calls } = mockFetch(() => ({ body: { ok: true } }));

    await deleteNotification('a/b');

    expect(calls[0].path).toBe('/api/notifications/a%2Fb');
  });

  it('surfaces server errors as ApiClientError', async () => {
    mockFetch(() => ({ status: 401, body: { error: 'Authentication required' } }));

    await expect(listNotifications()).rejects.toMatchObject({
      name: 'ApiClientError',
      status: 401,
      message: 'Authentication required',
    });
  });
});