window.__ModuleLoader__.load({ id: 'dsh-preview-download', factory: require => {
  const React = require('react');
  const { createElement: h, useState, useRef, useEffect } = React;
  const namespace = 'previewDownload';

  function filename(path) {
    const name = path.replaceAll('\\', '/').split('/').pop() || 'download';
    return Array.from(name, char => char.charCodeAt(0) < 32 || char.charCodeAt(0) === 127 || '<>:"|?*'.includes(char) ? '_' : char).join('');
  }

  async function readOriginal(remote, sessionId, path, signal) {
    signal.throwIfAborted();
    const result = await remote.workspaceFiles.readBytes(sessionId, path, {}, signal);
    signal.throwIfAborted();
    if (!result.ok) throw Object.assign(new Error('Download refused'), { code: result.error.code });
    const file = result.value;
    if (!file.eof || file.offset !== 0 || !(file.data instanceof Uint8Array) || (file.bytes !== undefined && file.bytes !== file.data.byteLength)) {
      throw new Error('Incomplete file response');
    }
    return file.data;
  }

  function Download({ absolutePath, download, t }) {
    const [busy, setBusy] = useState(false);
    const [error, setError] = useState('');
    const pending = useRef(null);
    useEffect(() => {
      setBusy(false);
      setError('');
      return () => { pending.current?.abort(); pending.current = null; };
    }, [absolutePath, download]);
    async function start() {
      if (pending.current) return;
      const controller = new AbortController();
      pending.current = controller;
      setBusy(true);
      setError('');
      try {
        const bytes = await download(absolutePath, controller.signal);
        controller.signal.throwIfAborted();
        const url = URL.createObjectURL(new Blob([bytes], { type: 'application/octet-stream' }));
        const link = document.createElement('a');
        link.href = url;
        link.download = filename(absolutePath);
        link.hidden = true;
        document.body.appendChild(link);
        try { link.click(); }
        finally { link.remove(); setTimeout(() => URL.revokeObjectURL(url), 60000); }
      } catch (cause) {
        if (!controller.signal.aborted) setError(t(cause?.code === 'workspace-file/too-large' ? 'tooLarge' : 'failed'));
      } finally {
        if (pending.current === controller) { pending.current = null; setBusy(false); }
      }
    }
    return h('span', { style: { display: 'inline-flex', alignItems: 'center', gap: '6px', flexShrink: 0 } },
      h('button', { type: 'button', disabled: busy, onClick: start, title: t('download'), 'aria-label': t('download'), 'aria-busy': busy, 'data-preview-download': '',
        style: { color: 'inherit', background: 'transparent', border: '1px solid currentColor', borderRadius: '6px', padding: '4px 8px', font: 'inherit', cursor: busy ? 'wait' : 'pointer' }
      }, busy ? t('loading') : t('download')),
      error && h('span', { role: 'alert', style: { fontSize: '12px', maxWidth: '180px' } }, error));
  }

  return {
    inject: ['slots', 'locale', 'remote.workspaceFiles'],
    apply(ctx) {
      ctx.effect(() => ctx.locale.register(namespace, {
        zh: { download: '下载原文件', loading: '下载中…', failed: '下载失败，请检查文件权限或重试。', tooLarge: '文件超过下载大小限制。' },
        en: { download: 'Download original', loading: 'Downloading…', failed: 'Download failed. Check access or retry.', tooLarge: 'File exceeds the download size limit.' }
      }));
      ctx.effect(() => ctx.slots.inject('sidebar.right.tab.document.actions', () => ctx.slots.register({
        name: 'sidebar.right.tab.document.actions', id: 'dsh-preview-download', locale: namespace,
        inject: sessionId => ({ download: (path, signal) => readOriginal(ctx.remote, sessionId, path, signal) })
      }, Download)));
    },
    // Pure helpers are also exercised by the offline regression suite.
    filename, readOriginal
  };
} });