class Tribe__Events__Pro__Editor__Recurrence__Provider {
	public function hook() {
		add_filter( 'rest_pre_echo_response', array( $this, 'trigger_recurrence_rules' ), 10, 3 );
		add_filter( 'tribe_is_recurring_event', array( $this, 'is_recurring_event' ), 10, 2 );
	}

	/**
	 * Hook before the response of a endpoint is executed to maybe trigger the recurrence rules, in
	 * order to execute a recurrence rule it must follow the following:
	 *
	 * - if $request is valid
	 * - and has an ID that is of type Events
	 * - and is part of the valid methods that are used to update / create a new item (PUT/POST)
	 * - and is not part of an /autosaves request as shouldn't be trigger on auto saves
	 *
	 * The hook does not modify the original response so the response is returned without any
	 * modifications on it
	 *
	 * @since 4.5
	 *
	 * @param $result
	 * @param $server
	 * @param $request
	 *
	 * @return mixed
	 */
	public function trigger_recurrence_rules( $result, $server, $request ) {
		$valid_methods = array( 'POST', 'PUT', 'PATCH' );

		if (
			$request instanceof WP_REST_Request
			&& get_post_type( $request->get_param( 'id' ) ) === Tribe__Events__Main::POSTTYPE
			&& in_array( $request->get_method(), $valid_methods )
			&& false === strpos(   $request->get_route(), '/autosaves' )
		) {
			$this->to_classic_format( $request->get_param( 'id' ) );
		}
		return $result;
	}

	/**
	 * Format events from block into classic shape for recurrence structure
	 *
	 * @since 4.5
	 *
	 * @param $event_id
	 *
	 * @return bool
	 */
	public function to_classic_format( $event_id ) {
		/** @var Tribe__Events__Pro__Editor__Meta $meta */
		$meta       = tribe( 'events-pro.editor.meta' );
		/** @var Tribe__Events__Pro__Editor__Recurrence__Blocks_Meta $blocks_meta */
		$blocks_meta = tribe( 'events-pro.editor.recurrence.blocks-meta' );
		$rules      = json_decode( $meta->get_value( $event_id, $blocks_meta->get_rules_key() ), true );
		$exclusions = json_decode( $meta->get_value( $event_id, $blocks_meta->get_exclusions_key() ), true );

		// Don't do anything if the block does not have any data.
		if ( is_null( $rules ) ) {
			return false;
		}

		/** @var Tribe__Events__Pro__Editor__Recurrence__Blocks_Meta $blocks_meta */
		$blocks_meta = tribe( 'events-pro.editor.recurrence.blocks-meta' );
		$data = array(
			'EventStartDate' => get_post_meta( $event_id, '_EventStartDate', true ),
			'EventEndDate'   => get_post_meta( $event_id, '_EventEndDate', true ),
			'recurrence'     => array(
				'rules'      => $this->parse_rules( $rules ),
				'exclusions' => $this->parse_rules( $exclusions ),
				'description'    => get_post_meta( $event_id, $blocks_meta->get_description_key(), true ),
			),
		);
		/**
		 * Use same mechanism as PRO to update the parsed data into the event
		 */
		$meta_builder    = new Tribe__Events__Pro__Recurrence__Meta_Builder( $event_id, $data );
		$recurrence_meta = $meta_builder->build_meta();

		/**
		 * Filters the recurring event save operation.
		 *
		 * Returning a non `null` value in this filter will prevent the normal save operation from going forward.
		 *
		 * @since 4.7
		 *
		 * @param mixed $saved           A boolean to indicate the recurring event save operation was handled, a non `null` value
		 *                               here will make the method bail and stop.
		 * @param array $recurrence_meta The recurrence information.
		 * @param int   $event_id        The post ID of the event recurring information that is being saved.
		 * @param array $data            The complete data, not just the recurrence meta, sent as part of the request.
		 */
		$saved = apply_filters(
			'tribe_events_pro_editor_save_recurrence_meta',
			null,
			$recurrence_meta,
			$event_id,
			$data
		);
		if ( null !== $saved ) {
			return $saved;
		}

		$updated = update_post_meta( $event_id, '_EventRecurrence', $recurrence_meta );

		$events_saver = new Tribe__Events__Pro__Recurrence__Events_Saver( $event_id, $updated );

		return $events_saver->save_events();
	}

	/**
	 * Convert all the rules from the Block into classic rules using the
	 *
	 * @since 4.5
	 *
	 * @param array $rules
	 *
	 * @return array
	 */
	protected function parse_rules( $rules ) {
		if ( null === $rules ) {
			return array();
		}
		$parsed = array();
		foreach ( $rules as $rule ) {
			$converter = new Tribe__Events__Pro__Editor__Recurrence__Classic( $rule );
			$converter->parse();
			$parsed[]  = $converter->get_parsed();
		}

		return $parsed;
	}

	/**
	 * Test if an event has only the rules being set by the block editor so it can be consider a
	 * recurring event
	 *
	 * @since 4.5
	 *
	 * @param $is_recurring
	 * @param $post_id
	 *
	 * @return bool
	 */
	public function is_recurring_event( $is_recurring, $post_id ) {
		if ( $is_recurring ) {
			return $is_recurring;
		}

		/** @var Tribe__Events__Pro__Editor__Recurrence__Blocks_Meta $blocks_meta */
		$blocks_meta = tribe( 'events-pro.editor.recurrence.blocks-meta' );
		$rules = get_post_meta( $post_id, $blocks_meta->get_rules_key(), true );

		return ! empty( $rules );
	}
}