<?php

namespace Kirby\Cms;

use Kirby\Toolkit\Properties;

/**
 * Foundation for Page, Site, File and User models.
 *
 * @package   Kirby Cms
 * @author    Bastian Allgeier <bastian@getkirby.com>
 * @link      https://getkirby.com
 * @copyright Bastian Allgeier
 * @license   https://getkirby.com/license
 */
abstract class Model
{
	use Properties;

	/**
	 * Each model must define a CLASS_ALIAS
	 * which will be used in template queries.
	 * The CLASS_ALIAS is a short human-readable
	 * version of the class name. I.e. page.
	 */
	public const CLASS_ALIAS = null;

	/**
	 * The parent Kirby instance
	 *
	 * @var \Kirby\Cms\App
	 */
	public static $kirby;

	/**
	 * The parent site instance
	 *
	 * @var \Kirby\Cms\Site
	 */
	protected $site;

	/**
	 * Makes it possible to convert the entire model
	 * to a string. Mostly useful for debugging
	 *
	 * @return string
	 */
	public function __toString(): string
	{
		return $this->id();
	}

	/**
	 * Each model must return a unique id
	 *
	 * @return string|null
	 */
	public function id()
	{
		return null;
	}

	/**
	 * Returns the parent Kirby instance
	 *
	 * @return \Kirby\Cms\App
	 */
	public function kirby()
	{
		return static::$kirby ??= App::instance();
	}

	/**
	 * Returns the parent Site instance
	 *
	 * @return \Kirby\Cms\Site
	 */
	public function site()
	{
		return $this->site ??= $this->kirby()->site();
	}

	/**
	 * Setter for the parent Kirby object
	 *
	 * @param \Kirby\Cms\App|null $kirby
	 * @return $this
	 */
	protected function setKirby(App $kirby = null)
	{
		static::$kirby = $kirby;
		return $this;
	}

	/**
	 * Setter for the parent site object
	 *
	 * @internal
	 * @param \Kirby\Cms\Site|null $site
	 * @return $this
	 */
	public function setSite(Site $site = null)
	{
		$this->site = $site;
		return $this;
	}

	/**
	 * Convert the model to a simple array
	 *
	 * @return array
	 */
	public function toArray(): array
	{
		return $this->propertiesToArray();
	}
}