async function get_selected_blocks(editor) {
  const blocks = editor.model.document.selection.getSelectedBlocks();
  return Array.from(blocks);
}
async function text_move_lines_up() {
  const editor = await api.getActiveContextTextEditor();
  if (editor == null) return;
  const selected_blocks = await get_selected_blocks(editor);
    
  editor.model.change( writer => {
    // Store selection offsets
    const offsets = [
      editor.model.document.selection.getFirstPosition().offset,
      editor.model.document.selection.getLastPosition().offset
    ];
    // Move items (blocks are items are nodes apperently)
    for ( const block of selected_blocks ) {
      // Get the previous position (null if none)
      let target = block.previousSibling;
      if (target != null) {
        target = writer.createPositionBefore(target);
        writer.insert(block, target);
      } else {
        console.log('Cannot move items further up, first position reached');
        break;
      }
    }
    // Restore selection to all items if many have been moved
    const range = writer.createRange(
      writer.createPositionAt(selected_blocks[0], offsets[0]),
      writer.createPositionAt(
        selected_blocks[selected_blocks.length - 1], offsets[1]));
    writer.setSelection(range);
  });
}
// Move lines down
async function text_move_lines_down() {
  const editor = await api.getActiveContextTextEditor();
  if (editor == null) return;
  const selected_blocks = await get_selected_blocks(editor);
    
  editor.model.change( writer => {
    // Remember selection offsets to restore them later
    const offsets = [
      editor.model.document.selection.getFirstPosition().offset,
      editor.model.document.selection.getLastPosition().offset
    ];
    // Move items (blocks are items are nodes apperently)
    for ( const block of selected_blocks.slice().reverse() ) {
      // Get the next position (null if none)
      const target = writer.createPositionAfter(block.nextSibling);
      if (target != null) {
        writer.insert(block, target);
      } else {
        console.log('Cannot move items further down, last position reached');
        break;
      }
    }
    // Restore selection to all items if many have been moved
    const range = writer.createRange(
      writer.createPositionAt(selected_blocks[0], offsets[0]),
      writer.createPositionAt(
        selected_blocks[selected_blocks.length - 1], offsets[1]));
    writer.setSelection(range);
  });
}
api.bindGlobalShortcut('ctrl+alt+up', text_move_lines_up);
api.bindGlobalShortcut('ctrl+alt+down', text_move_lines_down);