Auto assign navigation after theme swith

NavigationAutoAssign.php

<?php

/**
 * Class NavigationAutoAssign
 * Automatically assigns a navigation menu to a specified theme location in WordPress.
 */
class NavigationAutoAssign {

    /**
     * @var string The location identifier for the navigation menu within the theme.
     */
    private $navLocationID;

    /**
     * @var string The name of the navigation menu to be assigned.
     */
    private $navigationName;

    /**
     * Constructor for the NavigationAutoAssign class.
     *
     * @param string $navigationName The name of the navigation menu to assign.
     * @param string $navLocationID The theme location ID where the menu should be assigned.
     *                              Default is set to 'header'.
     */
    public function __construct($navigationName, $navLocationID = 'header') {

        $this->navigationName = $navigationName;
        $this->navLocationID = $navLocationID;

        // Adds a callback function to the 'after_setup_theme' hook.
        add_action('after_setup_theme', [$this, 'assignMenuToLocation']);
    }

    /**
     * Assigns the navigation menu to the specified location.
     * This method is intended to be hooked into 'after_setup_theme' action.
     */
	public function assignMenuToLocation() {
		// Retrieve the menu object by menu name.
		$menu = get_term_by('name', $this->navigationName, 'nav_menu');
	
		if (!$menu) {
			// If the menu does not exist, log an error and return early.
			error_log('Menu not found: ' . $this->navigationName);
			return;
		}
	
		$menu_id = $menu->term_id;
		
		// Retrieve the current menu locations.
		$locations = get_theme_mod('nav_menu_locations');
	
		// Check if the menu is already assigned to the specified location to avoid unnecessary operations.
		if (isset($locations[$this->navLocationID]) && $locations[$this->navLocationID] === $menu_id) {
			// The menu is already assigned to the location, so no further action is needed.
			return;
		}
	
		// Assign the retrieved menu to the specified location.
		$locations[$this->navLocationID] = $menu_id;
	
		// Save the modified locations back to the theme.
		set_theme_mod('nav_menu_locations', $locations);
	}
}