<?php
/**
 * Finds related workflows by shared node types.
 *
 * @package BreznFlow
 * @since   1.0.0
 */

namespace BreznFlow\Features;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Finds and displays workflows related by shared node types.
 *
 * @since 1.0.0
 */
class RelatedWorkflows {
	/**
	 * Registers related workflows hooks.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	public function register(): void {
		// Can be extended to add hooks for related workflow display.
	}

	/**
	 * Gets related workflows by shared node types.
	 * Results are cached in a transient for 1 hour.
	 *
	 * @param int $post_id Workflow post ID.
	 * @param int $limit   Max number of related workflows to return.
	 * @return array Array of WP_Post objects.
	 */
	public static function get( int $post_id, int $limit = 5 ): array {
		$settings = get_option( 'breznflow_settings', array() );
		if ( isset( $settings['related_workflows'] ) && ! $settings['related_workflows'] ) {
			return array();
		}

		$cache_key = 'breznflow_related_' . $post_id;
		$cached    = get_transient( $cache_key );
		if ( false !== $cached ) {
			return $cached;
		}

		$summary = get_post_meta( $post_id, '_breznflow_node_summary', true );
		if ( ! $summary ) {
			return array();
		}

		$node_types = array_keys( (array) json_decode( $summary, true ) );
		if ( empty( $node_types ) ) {
			return array();
		}

		// Search other workflows with overlapping node types.
		$related = get_posts(
			array(
				'post_type'      => 'breznflow_workflow',
				'post_status'    => 'publish',
				'posts_per_page' => $limit,
				'post__not_in'   => array( $post_id ), // phpcs:ignore WordPressVIPMinimum.Performance.WPQueryParams.PostNotIn_post__not_in
				'meta_query'     => array( // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
					array(
						'key'     => '_breznflow_node_summary',
						'compare' => 'EXISTS',
					),
				),
			)
		);

		// Filter by shared node types.
		$scored = array();
		foreach ( $related as $post ) {
			$other_summary = get_post_meta( $post->ID, '_breznflow_node_summary', true );
			if ( ! $other_summary ) {
				continue;
			}
			$other_types = array_keys( (array) json_decode( $other_summary, true ) );
			$shared      = count( array_intersect( $node_types, $other_types ) );
			if ( $shared > 0 ) {
				$scored[] = array(
					'post'   => $post,
					'shared' => $shared,
				);
			}
		}

		usort(
			$scored,
			static function ( $a, $b ) {
				return $b['shared'] - $a['shared'];
			}
		);

		$result = array_column( array_slice( $scored, 0, $limit ), 'post' );

		set_transient( $cache_key, $result, HOUR_IN_SECONDS );
		return $result;
	}
}