/**
 * Tab key support for TipTap docs editor.
 *
 * - In lists: Tab indents (sinks), Shift+Tab outdents (lifts)
 * - In code blocks: Tab inserts a tab character
 * - In normal paragraphs: Tab inserts 4 spaces
 */

import { Extension } from '@tiptap/core';

export const TabSupport = Extension.create({
  name: 'tabSupport',

  addKeyboardShortcuts() {
    return {
      Tab: () => {
        const { editor } = this;

        // In a list? Sink the list item (increase indent)
        if (editor.isActive('listItem') || editor.isActive('taskItem')) {
          return editor.chain().focus().sinkListItem('listItem').run()
            || editor.chain().focus().sinkListItem('taskItem').run();
        }

        // In a code block? Insert a tab character
        if (editor.isActive('codeBlock')) {
          return editor.chain().focus().command(({ tr, state }) => {
            tr.insertText('\t', state.selection.from, state.selection.to);
            return true;
          }).run();
        }

        // Normal paragraph: insert 4 spaces
        return editor.chain().focus().command(({ tr, state }) => {
          tr.insertText('    ', state.selection.from, state.selection.to);
          return true;
        }).run();
      },
      'Shift-Tab': () => {
        const { editor } = this;

        // In a list? Lift the list item (decrease indent)
        if (editor.isActive('listItem') || editor.isActive('taskItem')) {
          return editor.chain().focus().liftListItem('listItem').run()
            || editor.chain().focus().liftListItem('taskItem').run();
        }

        // In code block or normal text: do nothing special
        return false;
      },
    };
  },
});