<?php
/**
 * A conditional group marker: [if field is "value"] … [/if].
 *
 * @package TFlexForms
 */

declare( strict_types = 1 );

namespace TFlexForms;

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

/**
 * Opening marker (field + operator + value) or closing marker (op "close").
 */
final readonly class Condition {

	public const OPERATORS = array( 'is', 'not', 'filled', 'empty' );

	/**
	 * Constructor.
	 *
	 * @param string $field Controlling field name.
	 * @param string $op    is | not | filled | empty | close.
	 * @param string $value Compared value (is/not).
	 */
	public function __construct(
		public string $field,
		public string $op,
		public string $value = '',
	) {}

	/**
	 * The closing [/if] marker.
	 */
	public static function close(): self {
		return new self( '', 'close' );
	}

	/**
	 * Whether this is the closing marker.
	 */
	public function is_close(): bool {
		return 'close' === $this->op;
	}

	/**
	 * Evaluates the condition against the controlling field's current values.
	 *
	 * @param string[] $values Selected/entered values (empty array = nothing).
	 */
	public function matches( array $values ): bool {
		$values = array_values( array_filter( array_map( 'strval', $values ), static fn( string $v ): bool => '' !== $v ) );
		return match ( $this->op ) {
			'is'     => in_array( $this->value, $values, true ),
			'not'    => ! in_array( $this->value, $values, true ),
			'filled' => array() !== $values,
			'empty'  => array() === $values,
			default  => true,
		};
	}

	/**
	 * Data for the browser (data-tflexforms-if attribute).
	 *
	 * @return array{field:string,op:string,value:string}
	 */
	public function to_array(): array {
		return array(
			'field' => $this->field,
			'op'    => $this->op,
			'value' => $this->value,
		);
	}
}