<?php
/**
 * Rule evaluator.
 *
 * @package Extrova
 */

declare( strict_types=1 );

namespace Extrova\Rules;

use Extrova\Core\Context;
use Extrova\Registry\ConditionRegistry;

defined( 'ABSPATH' ) || exit;

/**
 * Evaluates a condition list with implicit AND, delegating each item to its registered
 * condition. Unknown conditions fail closed. Composite conditions (registered by add-ons)
 * call `passes()` recursively, so the evaluator never changes.
 *
 * @since 1.0.0
 */
final class RuleEvaluator {

	/**
	 * Constructor.
	 *
	 * @param ConditionRegistry $conditions Conditions.
	 */
	public function __construct( private ConditionRegistry $conditions ) {}

	/**
	 * Whether every condition passes.
	 *
	 * @param array   $conditions Condition list.
	 * @param Context $context    Context.
	 */
	public function passes( array $conditions, Context $context ): bool {
		foreach ( $conditions as $condition ) {
			if ( ! is_array( $condition ) ) {
				return false;
			}
			$object = $this->conditions->get( (string) ( $condition['type'] ?? '' ) );
			if ( ! $object || ! $object->matches( $condition, $context, $this ) ) {
				return false;
			}
		}
		return true;
	}

	/**
	 * Whether the list contains conditions that are not registered (top level).
	 *
	 * @param array $conditions Condition list.
	 */
	public function has_unknown( array $conditions ): bool {
		foreach ( $conditions as $condition ) {
			if ( ! is_array( $condition ) || ! $this->conditions->has( (string) ( $condition['type'] ?? '' ) ) ) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Context dependencies of a list (for frontend resync).
	 *
	 * @param array $conditions Condition list.
	 * @return string[]
	 */
	public function dependencies( array $conditions ): array {
		$deps = array();
		foreach ( $conditions as $condition ) {
			$object = is_array( $condition ) ? $this->conditions->get( (string) ( $condition['type'] ?? '' ) ) : null;
			if ( $object ) {
				$deps = array_merge( $deps, $object->context_dependencies() );
			}
		}
		return array_values( array_unique( $deps ) );
	}
}