class DropDown_Nav_Menu extends Walker_Nav_Menu {

	// Easy way to check it's this walker we're using to mod the output.
	public function is_dropdown() {
		return true;
	}

	/**
	 * Start submenu level.
	 *
	 * Compatible with modern WordPress / PHP 8.x.
	 */
	public function start_lvl( &$output, $depth = 0, $args = null ) {
		$output .= "</option>";
	}

	/**
	 * End submenu level.
	 *
	 * Compatible with modern WordPress / PHP 8.x.
	 */
	public function end_lvl( &$output, $depth = 0, $args = null ) {
		$output .= "<option>";
	}

	/**
	 * Start menu element.
	 *
	 * Compatible with modern Walker_Nav_Menu signature.
	 */
	public function start_el(
		&$output,
		$data_object,
		$depth = 0,
		$args = null,
		$current_object_id = 0
	) {

		global $wp_query;

		// Keep compatibility with the original Pindol code.
		$item = $data_object;

		$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

		$class_names = '';
		$value = '';

		$classes = empty( $item->classes ) ? array() : (array) $item->classes;

		$classes[] = 'menu-item-' . $item->ID;
		$classes[] = 'menu-item-depth-' . $depth;

		$class_names = join(
			' ',
			apply_filters(
				'nav_menu_css_class',
				array_unique( array_filter( $classes ) ),
				$item,
				$args
			)
		);

		$class_names = ' class="' . esc_attr( $class_names ) . '"';

		// Select current item.
		$selected = in_array( 'current-menu-item', $classes, true )
			? ' selected="selected"'
			: '';

		$item_url = isset( $item->url ) ? $item->url : '';

		$output .= $indent
			. '<option'
			. $class_names
			. ' value="'
			. esc_url( $item_url )
			. '"'
			. $selected
			. '>';

		/*
		 * Push sub-menu items in because select elements
		 * cannot contain nested option groups the same way
		 * normal menus contain nested lists.
		 */

		$indent_string_setting = '';

		if ( is_object( $args ) && isset( $args->indent_string ) ) {
			$indent_string_setting = $args->indent_string;
		} elseif ( is_array( $args ) && isset( $args['indent_string'] ) ) {
			$indent_string_setting = $args['indent_string'];
		}

		if ( empty( $indent_string_setting ) ) {
			$indent_string_setting = '&ndash;&nbsp;';
		}

		$indent_after_setting = '';

		if ( is_object( $args ) && isset( $args->indent_after ) ) {
			$indent_after_setting = $args->indent_after;
		} elseif ( is_array( $args ) && isset( $args['indent_after'] ) ) {
			$indent_after_setting = $args['indent_after'];
		}

		$indent_string = str_repeat(
			apply_filters(
				'dropdown_menus_indent_string',
				$indent_string_setting,
				$item,
				$depth,
				$args
			),
			( $depth ) ? $depth : 0
		);

		if ( ! empty( $indent_string ) ) {
			$indent_string .= apply_filters(
				'dropdown_menus_indent_after',
				$indent_after_setting,
				$item,
				$depth,
				$args
			);
		}

		$before = '';
		$after = '';
		$link_before = '';
		$link_after = '';

		if ( is_object( $args ) ) {

			$before = isset( $args->before ) ? $args->before : '';
			$after = isset( $args->after ) ? $args->after : '';

			$link_before = isset( $args->link_before )
				? $args->link_before
				: '';

			$link_after = isset( $args->link_after )
				? $args->link_after
				: '';

		} elseif ( is_array( $args ) ) {

			$before = isset( $args['before'] ) ? $args['before'] : '';
			$after = isset( $args['after'] ) ? $args['after'] : '';

			$link_before = isset( $args['link_before'] )
				? $args['link_before']
				: '';

			$link_after = isset( $args['link_after'] )
				? $args['link_after']
				: '';
		}

		$item_output = $before . $indent_string;

		$item_output .= $link_before
			. apply_filters(
				'the_title',
				$item->title,
				$item->ID
			)
			. $link_after;

		$item_output .= $after;

		$output .= apply_filters(
			'walker_nav_menu_dropdown_start_el',
			$item_output,
			$item,
			$depth,
			$args
		);
	}

	/**
	 * End menu element.
	 *
	 * Compatible with modern Walker_Nav_Menu signature.
	 */
	public function end_el(
		&$output,
		$data_object,
		$depth = 0,
		$args = null
	) {

		$item = $data_object;

		$output .= apply_filters(
			'walker_nav_menu_dropdown_end_el',
			"</option>\n",
			$item,
			$depth
		);
	}
}