专项：剪贴板、系统分享与全屏——手势驱动的浏览器交互 API

// 写入（复制）：安全上下文（HTTPS/localhost）+ 用户手势内调用
await navigator.clipboard.writeText('要复制的内容');

// 读取（粘贴）：需要 clipboard-read 权限，浏览器会弹授权框
const text = await navigator.clipboard.readText();

async function copyButton(label, text) {
  try {
    await navigator.clipboard.writeText(text);
    showTip(label, '已复制');
  } catch {
    // 兜底：老浏览器或权限受限时走 execCommand 时代方案
    legacyCopy(text) ? showTip(label, '已复制') : showTip(label, '复制失败，请手动选择');
  }
}

function legacyCopy(text) {
  const ta = document.createElement('textarea');
  ta.value = text;
  ta.style.position = 'fixed';
  ta.style.opacity = '0';
  document.body.appendChild(ta);
  ta.select();
  const ok = document.execCommand('copy');   // 已废弃，仅作回退
  ta.remove();
  return ok;
}

// 接收粘贴（推荐）：在输入框上监听 paste
inputEl.addEventListener('paste', (e) => {
  const items = e.clipboardData.items;
  for (const item of items) {
    if (item.type.startsWith('image/')) {
      const file = item.getAsFile();
      handlePastedImage(file);          // 粘贴截图上传的常见实现路径
    }
  }
});

shareBtn.addEventListener('click', async () => {
  if (!navigator.share) return fallbackCopy();
  try {
    await navigator.share({
      title: document.title,
      text: '发现一篇好文章',
      url: location.href,
    });
  } catch (err) {
    if (err.name !== 'AbortError') fallbackCopy();  // 用户取消不算失败
  }
});

const stage = document.querySelector('.player');

enterBtn.addEventListener('click', () => {
  stage.requestFullscreen().catch(() => showTip('全屏被拒绝'));
});
exitBtn.addEventListener('click', () => document.exitFullscreen());

// 关键：用户按 Esc 退出时不会走你的 exitBtn 逻辑，只能靠事件感知
document.addEventListener('fullscreenchange', () => {
  const isFull = document.fullscreenElement === stage;
  enterBtn.hidden = isFull;      // 同步按钮状态
  stage.classList.toggle('is-full', isFull);
});

pipBtn.addEventListener('click', async () => {
  if (document.pictureInPictureElement) {
    await document.exitPictureInPicture();
  } else if (video.requestPictureInPicture) {
    await video.requestPictureInPicture();
  }
});

async function shareArticle({ title, text, url }) {
  if (navigator.share) {
    try {
      await navigator.share({ title, text, url });
      return 'shared';
    } catch (err) {
      if (err.name === 'AbortError') return 'cancelled';  // 用户主动取消
      // 分享失败（如参数不支持）继续走降级
    }
  }
  return copyButton(shareBtn, url) ? 'copied' : 'manual';
}

shareBtn.addEventListener('click', async () => {
  const result = await shareArticle({
    title: document.title,
    text: '发现一篇好文章',
    url: location.href,
  });
  if (result === 'manual') alert('请手动复制地址栏链接分享');
});

const player = document.querySelector('.player');
const video = player.querySelector('video');
const fsBtn = player.querySelector('.fs-btn');
const pipBtn = player.querySelector('.pip-btn');

function toggleFullscreen() {
  if (document.fullscreenElement) {
    document.exitFullscreen();
  } else {
    player.requestFullscreen().then(() => player.focus());
  }
}

document.addEventListener('fullscreenchange', () => {
  const isFull = document.fullscreenElement === player;
  fsBtn.textContent = isFull ? '退出全屏' : '全屏';
  if (!isFull) fsBtn.focus();   // 焦点归还触发按钮
});

pipBtn.addEventListener('click', async () => {
  if (!video.requestPictureInPicture) return showTip('当前浏览器不支持画中画');
  document.pictureInPictureElement
    ? await document.exitPictureInPicture()
    : await video.requestPictureInPicture();
});

fsBtn.addEventListener('click', toggleFullscreen);