(function (Drupal, CKEditor5) {
  const pluginNamespace = 'blockquoteAttribution';
  const toolbarItem = 'blockquote_attribution';

  const icon = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20"><path d="M4.6 5.1h4.8v4.8H6.9c.1 1.8.9 3.1 2.5 4.1l-.9 1.3c-2.7-1.5-4-3.7-3.9-6.7V5.1zm7 0h4.8v4.8h-2.5c.1 1.8.9 3.1 2.5 4.1l-.9 1.3c-2.7-1.5-4-3.7-3.9-6.7V5.1z"/></svg>';

  function escapeHtml(value) {
    return String(value || '')
      .replace(/&/g, '&amp;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&#039;');
  }

  function getSelectedHtml(editor) {
    const selection = editor.model.document.selection;

    if (selection.isCollapsed) {
      return '<p>' + Drupal.t('Quote text') + '</p>';
    }

    try {
      const selectedContent = editor.model.getSelectedContent(selection);
      const html = editor.data.stringify(selectedContent);
      return html && html.trim() ? html : '<p>' + Drupal.t('Quote text') + '</p>';
    }
    catch (e) {
      return '<p>' + Drupal.t('Quote text') + '</p>';
    }
  }

  function insertHtml(editor, html) {
    const viewFragment = editor.data.processor.toView(html);
    const modelFragment = editor.data.toModel(viewFragment);

    editor.model.change(() => {
      editor.model.insertContent(modelFragment);
    });

    editor.editing.view.focus();
  }

  class BlockquoteAttribution extends CKEditor5.core.Plugin {
    static get pluginName() {
      return 'BlockquoteAttribution';
    }

    init() {
      const editor = this.editor;

      editor.ui.componentFactory.add(toolbarItem, (locale) => {
        const button = new CKEditor5.ui.ButtonView(locale);

        button.set({
          label: Drupal.t('Blockquote with Attribution'),
          icon,
          tooltip: true,
        });

        button.on('execute', () => {
          const source = window.prompt(Drupal.t('Source attribution:'), '');

          if (source === null) {
            return;
          }

          const selectedHtml = getSelectedHtml(editor);
          const attribution = escapeHtml(source.trim());
          const figcaption = attribution ? '<figcaption>' + attribution + '</figcaption>' : '';
          const citeAttribute = attribution ? ' cite="' + attribution + '"' : '';
          const html = '<figure class="quote"><blockquote' + citeAttribute + '>' + selectedHtml + '</blockquote>' + figcaption + '</figure>';

          insertHtml(editor, html);
        });

        return button;
      });
    }
  }

  CKEditor5[pluginNamespace] = CKEditor5[pluginNamespace] || {};
  CKEditor5[pluginNamespace].BlockquoteAttribution = BlockquoteAttribution;
})(Drupal, CKEditor5);