import { TestBed } from '@angular/core/testing';
import { ChatFontService, CHAT_FONT_SIZES, DEFAULT_CHAT_FONT } from './chat-font.service';
import { SessionService } from './session.service';

describe('ChatFontService（会话字号偏好）', () => {
  let svc: ChatFontService;
  let session: SessionService;

  /*
   * effect() 由 Angular 的变更检测调度，测试里必须手动 flush 才会跑。
   * 不 flush 的话读到的永远是初始值（实测：默认 15 时读到的还是 CSS 兜底的 14）。
   */
  const flush = () => TestBed.flushEffects();

  beforeEach(() => {
    localStorage.clear();
    document.documentElement.style.removeProperty('--chat-read-size');
    TestBed.configureTestingModule({});
    svc = TestBed.inject(ChatFontService);
    session = TestBed.inject(SessionService);
    session.setSession('tok', { id: 'u1', name: '测试', companyId: 'c1' } as never);
    svc.load();
  });

  afterEach(() => {
    localStorage.clear();
    document.documentElement.style.removeProperty('--chat-read-size');
  });

  it('未保存过时为默认值', () => {
    expect(svc.size()).toBe(DEFAULT_CHAT_FONT);
  });

  it('设置后写进 DOM 变量（正文即时生效）', () => {
    svc.set(17);
    flush();
    expect(document.documentElement.style.getPropertyValue('--chat-read-size')).toBe('17px');
  });

  it('默认值也会写进 DOM 变量（不依赖 CSS 兜底）', () => {
    flush();
    expect(document.documentElement.style.getPropertyValue('--chat-read-size')).toBe(
      `${DEFAULT_CHAT_FONT}px`,
    );
  });

  it('非法值吸附到最近的合法档位', () => {
    svc.set(16.4);
    expect(svc.size()).toBe(16);
    svc.set(100);
    expect(svc.size()).toBe(CHAT_FONT_SIZES[CHAT_FONT_SIZES.length - 1]);
    svc.set(-5);
    expect(svc.size()).toBe(CHAT_FONT_SIZES[0]);
  });

  it('持久化：重载后保持', () => {
    svc.set(18);
    // 模拟刷新
    (svc as unknown as { loadedFor: string | null }).loadedFor = null;
    svc.load();
    expect(svc.size()).toBe(18);
  });

  it('按用户隔离', () => {
    svc.set(18);
    session.setSession('tok2', { id: 'u2', name: '乙', companyId: 'c1' } as never);
    (svc as unknown as { loadedFor: string | null }).loadedFor = null;
    svc.load();
    expect(svc.size()).toBe(DEFAULT_CHAT_FONT);
  });
});