<?php
/**
 * JSON helpers.
 *
 * @package Recast\WCS
 */

namespace Recast\WCS\Support;

defined( 'ABSPATH' ) || exit;

/**
 * Canonical (sorted-key) JSON encoding so hashes are stable regardless of array order.
 */
final class Json {

	/**
	 * Encodes with recursively sorted keys.
	 *
	 * @param mixed $value Value.
	 * @return string
	 */
	public static function canonical( $value ) {
		return wp_json_encode( self::sort( $value ), JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
	}

	/**
	 * Encodes for storage (no key sorting needed, but same flags).
	 *
	 * @param mixed $value Value.
	 * @return string
	 */
	public static function encode( $value ) {
		return wp_json_encode( $value, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
	}

	/**
	 * Decodes to an associative array, returning the default on failure.
	 *
	 * @param string|null $json    JSON string.
	 * @param mixed       $fallback Value when decoding fails.
	 * @return mixed
	 */
	public static function decode( $json, $fallback = array() ) {
		if ( ! is_string( $json ) || '' === $json ) {
			return $fallback;
		}
		$decoded = json_decode( $json, true );
		return ( null === $decoded && JSON_ERROR_NONE !== json_last_error() ) ? $fallback : $decoded;
	}

	/**
	 * Recursively sorts associative arrays by key; lists keep their order.
	 *
	 * @param mixed $value Value.
	 * @return mixed
	 */
	private static function sort( $value ) {
		if ( ! is_array( $value ) ) {
			return $value;
		}
		$is_list = array_keys( $value ) === range( 0, count( $value ) - 1 );
		foreach ( $value as $k => $v ) {
			$value[ $k ] = self::sort( $v );
		}
		if ( ! $is_list ) {
			ksort( $value, SORT_STRING );
		}
		return $value;
	}
}