import { TestBed } from '@angular/core/testing';

import { PiThemeService } from './theme.service';

describe('PiThemeService', () => {
  afterEach(() => {
    localStorage.clear();
    document.body.className = '';
    document.documentElement.classList.remove('dark-mode');
  });

  it('applies `pi-shell pi-shell__default` to <body> by default', () => {
    TestBed.inject(PiThemeService);
    TestBed.flushEffects();

    expect(document.body.className).toBe('pi-shell pi-shell__default');
  });

  it('updates <body> when the theme changes', () => {
    const service = TestBed.inject(PiThemeService);

    service.setTheme('alternative');
    TestBed.flushEffects();

    expect(document.body.className).toBe('pi-shell pi-shell__alternative');
  });

  it('toggles `dark-mode` on <html>', () => {
    const service = TestBed.inject(PiThemeService);

    service.setDarkMode(true);
    TestBed.flushEffects();
    expect(document.documentElement.classList.contains('dark-mode')).toBe(true);

    service.toggleDarkMode();
    TestBed.flushEffects();
    expect(document.documentElement.classList.contains('dark-mode')).toBe(false);
  });

  it('persists the theme and dark mode across a fresh instance (reload)', () => {
    const service = TestBed.inject(PiThemeService);
    service.setTheme('minimal');
    service.setDarkMode(true);
    TestBed.flushEffects();

    TestBed.resetTestingModule();
    const reloaded = TestBed.inject(PiThemeService);

    expect(reloaded.theme()).toBe('minimal');
    expect(reloaded.darkMode()).toBe(true);
  });

  it('falls back to the default theme when nothing valid is stored', () => {
    localStorage.setItem('pi-theme', JSON.stringify('not-a-real-theme'));

    const service = TestBed.inject(PiThemeService);

    expect(service.theme()).toBe('default');
  });
});