/**
 * 背景选择器的**界面可达性**判据。
 *
 * 为什么需要这一层：`stores/background.test.ts` 只钉了 store 的状态机，
 * 而线上真实缺陷恰好落在"状态 → 控件"这一跳上 ——
 * 点「图片」时 kind 被折叠回 `none`，于是上传控件（只在 `kind === 'image'`
 * 下渲染）**从不出现**：store 的单测全绿，用户却完全无法自定义背景。
 *
 * 所以这里测的是"用户走得到走不到"：点「图片」→ 选文件按钮必须出现 →
 * 选完图背景必须真的亮起来。
 */

import { describe, expect, it, vi, beforeEach } from 'vitest';
import { render, screen, waitFor } from '@testing-library/react';
import userEvent from '@testing-library/user-event';

import BackgroundPicker from '../../src/components/BackgroundPicker';
import { LEGACY_STORAGE_KEY, storageKey, useBackgroundStore } from '../../src/stores/backgroundStore';
import * as store from '../../src/stores/backgroundStore';

describe('BackgroundPicker', () => {
  beforeEach(() => {
    localStorage.clear();
    document.documentElement.removeAttribute('data-bg');
    document.documentElement.className = '';
    document.documentElement.removeAttribute('style');
    useBackgroundStore.setState({ ...store.DEFAULT_BACKGROUND });
    vi.restoreAllMocks();
  });

  it('★ 点「图片」后必须出现选文件控件（否则自定义背景根本走不到）', async () => {
    render(<BackgroundPicker />);
    // 初始是「无」：没有文件输入
    expect(document.querySelector('input[type=file]')).toBeNull();

    await userEvent.click(screen.getByRole('button', { name: '图片' }));

    expect(useBackgroundStore.getState().kind).toBe('image');
    expect(document.querySelector('input[type=file]')).not.toBeNull();
    expect(screen.getByRole('button', { name: /选择图片|更换图片/ })).toBeInTheDocument();
  });

  it('★ 选完图片后背景真的亮起来，并落盘', async () => {
    vi.spyOn(store, 'prepareImage').mockResolvedValue({
      ok: true,
      dataUrl: 'data:image/jpeg;base64,ZZZZ'
    });
    render(<BackgroundPicker />);
    await userEvent.click(screen.getByRole('button', { name: '图片' }));

    const input = document.querySelector('input[type=file]') as HTMLInputElement;
    const file = new File(['x'], 'bg.jpg', { type: 'image/jpeg' });
    await userEvent.upload(input, file);

    await waitFor(() => expect(document.documentElement.dataset.bg).toBe('on'));
    expect(document.documentElement.style.getPropertyValue('--bg-image')).toContain('ZZZZ');
    expect(JSON.parse(localStorage.getItem(storageKey(''))!).kind).toBe('image');
  });

  it('图片准备失败时说出原因，并且不假装成功', async () => {
    vi.spyOn(store, 'prepareImage').mockResolvedValue({ ok: false, reason: '图片过大（超过 20MB），请先裁剪' });
    render(<BackgroundPicker />);
    await userEvent.click(screen.getByRole('button', { name: '图片' }));
    const input = document.querySelector('input[type=file]') as HTMLInputElement;
    await userEvent.upload(input, new File(['x'], 'bg.jpg', { type: 'image/jpeg' }));

    expect(await screen.findByRole('alert')).toHaveTextContent('图片过大');
    // 没换成就不该亮背景
    expect(document.documentElement.dataset.bg).toBe('off');
  });

  it('「无」把背景关掉（对照：图片档不是永久卡住）', async () => {
    useBackgroundStore.getState().setImage('data:image/png;base64,YYYY');
    render(<BackgroundPicker />);
    await userEvent.click(screen.getByRole('button', { name: '无' }));
    expect(useBackgroundStore.getState().kind).toBe('none');
    expect(document.documentElement.dataset.bg).toBe('off');
  });
});