<?php
/**
 * Thin plugin orchestrator.
 *
 * @package AkavaBackToTop
 */

namespace Akava\BackToTop;

use Akava\BackToTop\Admin\Admin;
use Akava\BackToTop\Frontend\ButtonRenderer;

defined( 'ABSPATH' ) || exit;

final class Plugin {

	/** @var Plugin|null */
	private static $instance = null;

	/** @var bool */
	private $booted = false;

	/**
	 * Singleton accessor.
	 *
	 * @return Plugin
	 */
	public static function instance() {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	/**
	 * Wire modules once.
	 *
	 * @return void
	 */
	public function boot() {
		if ( $this->booted ) {
			return;
		}
		$this->booted = true;

		add_action( 'admin_init', array( $this, 'maybe_upgrade' ), 5 );
		( new ButtonRenderer() )->boot();

		if ( is_admin() ) {
			( new Admin() )->boot();
		}
	}

	/**
	 * Normalize copied or upgraded installations even if activation was skipped.
	 *
	 * @return void
	 */
	public function maybe_upgrade() {
		if ( AKAVA_BTT_VERSION === get_option( Config::VERSION_OPTION ) ) {
			return;
		}
		Activator::activate();
	}
}