<?php
defined( 'ABSPATH' ) || exit;
/**
 * Collects every hook the plugin registers and attaches them in one place.
 *
 * Components describe the hooks they want in their register() method and the
 * loader wires them on run(), so nothing is attached as a side effect of a
 * file being included.
 *
 * @package AdvisorPPC
 */

/**
 * Class AdvisorPPC_Loader.
 */
class AdvisorPPC_Loader {

	/**
	 * Queued actions.
	 *
	 * @var array[]
	 */
	protected $actions = array();

	/**
	 * Queued filters.
	 *
	 * @var array[]
	 */
	protected $filters = array();

	/**
	 * Queued shortcodes.
	 *
	 * @var array[]
	 */
	protected $shortcodes = array();

	/**
	 * Whether run() has already fired.
	 *
	 * @var bool
	 */
	protected $ran = false;

	/**
	 * Queue an action.
	 *
	 * @param string $hook          Hook name.
	 * @param object $component     Object holding the callback.
	 * @param string $callback      Method name.
	 * @param int    $priority      Priority.
	 * @param int    $accepted_args Number of arguments.
	 * @return AdvisorPPC_Loader
	 */
	public function add_action( $hook, $component, $callback, $priority = 10, $accepted_args = 1 ) {
		if ( $this->ran ) {
			add_action( $hook, array( $component, $callback ), (int) $priority, (int) $accepted_args );

			return $this;
		}

		$this->actions = $this->add( $this->actions, $hook, $component, $callback, $priority, $accepted_args );

		return $this;
	}

	/**
	 * Queue a filter.
	 *
	 * @param string $hook          Hook name.
	 * @param object $component     Object holding the callback.
	 * @param string $callback      Method name.
	 * @param int    $priority      Priority.
	 * @param int    $accepted_args Number of arguments.
	 * @return AdvisorPPC_Loader
	 */
	public function add_filter( $hook, $component, $callback, $priority = 10, $accepted_args = 1 ) {
		if ( $this->ran ) {
			add_filter( $hook, array( $component, $callback ), (int) $priority, (int) $accepted_args );

			return $this;
		}

		$this->filters = $this->add( $this->filters, $hook, $component, $callback, $priority, $accepted_args );

		return $this;
	}

	/**
	 * Queue a shortcode.
	 *
	 * @param string $tag       Shortcode tag.
	 * @param object $component Object holding the callback.
	 * @param string $callback  Method name.
	 * @return AdvisorPPC_Loader
	 */
	public function add_shortcode( $tag, $component, $callback ) {
		if ( $this->ran ) {
			add_shortcode( $tag, array( $component, $callback ) );

			return $this;
		}

		$this->shortcodes[] = array(
			'tag'       => $tag,
			'component' => $component,
			'callback'  => $callback,
		);

		return $this;
	}

	/**
	 * Attach everything queued.
	 *
	 * Safe to call more than once: anything queued after the first run is
	 * attached immediately instead of being silently dropped.
	 *
	 * @return void
	 */
	public function run() {
		foreach ( $this->filters as $hook ) {
			add_filter( $hook['hook'], array( $hook['component'], $hook['callback'] ), $hook['priority'], $hook['accepted_args'] );
		}

		foreach ( $this->actions as $hook ) {
			add_action( $hook['hook'], array( $hook['component'], $hook['callback'] ), $hook['priority'], $hook['accepted_args'] );
		}

		foreach ( $this->shortcodes as $shortcode ) {
			add_shortcode( $shortcode['tag'], array( $shortcode['component'], $shortcode['callback'] ) );
		}

		$this->actions    = array();
		$this->filters    = array();
		$this->shortcodes = array();
		$this->ran        = true;
	}

	/**
	 * Whether the loader has already attached its queue.
	 *
	 * @return bool
	 */
	public function has_run() {
		return $this->ran;
	}

	/**
	 * Append to a queue, or attach straight away when the loader already ran.
	 *
	 * @param array  $hooks         Existing queue.
	 * @param string $hook          Hook name.
	 * @param object $component     Object holding the callback.
	 * @param string $callback      Method name.
	 * @param int    $priority      Priority.
	 * @param int    $accepted_args Number of arguments.
	 * @return array
	 */
	protected function add( $hooks, $hook, $component, $callback, $priority, $accepted_args ) {
		$hooks[] = array(
			'hook'          => $hook,
			'component'     => $component,
			'callback'      => $callback,
			'priority'      => (int) $priority,
			'accepted_args' => (int) $accepted_args,
		);

		return $hooks;
	}
}