<?php

namespace Glovario\Domain;

use Glovario\Repository\VariableRepository;

defined( 'ABSPATH' ) || exit;

/**
 * Keys generated from labels, shared by the variable form and Make variable.
 */
final class VariableKey {
	/**
	 * Whether a key is already used by a variable, a built-in, or an extension.
	 *
	 * @param string             $key        Key to check.
	 * @param VariableRepository $repository Variable storage.
	 * @return bool
	 */
	public static function taken( $key, VariableRepository $repository ) {
		return BuiltinVariables::is_reserved_key( $key )
			|| null !== $repository->find_by_key( $key )
			|| null !== apply_filters( 'glovario_missing_variable', null, $key, array() );
	}

	/**
	 * A free key built from a label: "Opening hours" becomes opening_hours,
	 * then opening_hours_2 and so on when it is taken.
	 *
	 * @param string             $label      Variable label.
	 * @param VariableRepository $repository Variable storage.
	 * @return string
	 */
	public static function from_label( $label, VariableRepository $repository ) {
		$base = str_replace( '-', '_', sanitize_title( remove_accents( (string) $label ) ) );
		$base = trim( preg_replace( '/[^a-z0-9_]+/', '', $base ), '_' );
		$base = '' === $base ? 'variable' : substr( $base, 0, 60 );
		$key  = $base;
		for ( $suffix = 2; self::taken( $key, $repository ); $suffix++ ) {
			$key = $base . '_' . $suffix;
		}
		return $key;
	}
}