<?php
// HashAlgorithmInfo.php
// Created: 2021-06-16
// Updated: 2022-02-27

namespace Index\Security;

use RuntimeException;

class HashAlgorithmInfo {
    private string $name;
    private bool $hmac;
    private ?string $key;

    public function __construct(string $algorithm, ?string $key = null) {
        $this->name = $algorithm;
        $this->hmac = $key === null;
        $this->key = $key;
    }

    private static bool $constructed = false;
    private static HashAlgorithmInfo $md5;
    private static HashAlgorithmInfo $sha1;
    private static HashAlgorithmInfo $sha2_256;
    private static HashAlgorithmInfo $sha2_512;
    private static HashAlgorithmInfo $sha3_256;
    private static HashAlgorithmInfo $sha3_512;
    private static HashAlgorithmInfo $crc32;
    private static HashAlgorithmInfo $crc32b;
    private static HashAlgorithmInfo $crc32c;

    public static function construct(): void {
        if(self::$constructed)
            throw new RuntimeException('Static constructor was already called.');
        self::$constructed = true;
        self::$md5 = new HashAlgorithmInfo('md5');
        self::$sha1 = new HashAlgorithmInfo('sha1');
        self::$sha2_256 = new HashAlgorithmInfo('sha256');
        self::$sha2_512 = new HashAlgorithmInfo('sha512');
        self::$sha3_256 = new HashAlgorithmInfo('sha3-256');
        self::$sha3_512 = new HashAlgorithmInfo('sha3-512');
        self::$crc32 = new HashAlgorithmInfo('crc32');
        self::$crc32b = new HashAlgorithmInfo('crc32b');
        self::$crc32c = new HashAlgorithmInfo('crc32c');
    }

    public function getName(): string {
        return $this->name;
    }

    public function isHMAC(): bool {
        return $this->hmac;
    }

    public function getKey(): string {
        return $this->key;
    }

    public function create(): HashAlgorithm {
        return new HashAlgorithm($this);
    }

    public static function hashAlgos(): array {
        return hash_algos();
    }

    public static function hmacAlgos(): array {
        return hash_hmac_algos();
    }

    public static function md5(?string $key = null): HashAlgorithmInfo {
        if($key === null)
            return new HashAlgorithmInfo('md5', $key);
        return self::$md5;
    }

    public static function sha1(?string $key = null): HashAlgorithmInfo {
        if($key === null)
            return new HashAlgorithmInfo('sha1', $key);
        return self::$sha1;
    }

    public static function sha2_256(?string $key = null): HashAlgorithmInfo {
        if($key === null)
            return new HashAlgorithmInfo('sha256', $key);
        return self::$sha2_256;
    }

    public static function sha2_512(?string $key = null): HashAlgorithmInfo {
        if($key === null)
            return new HashAlgorithmInfo('sha512', $key);
        return self::$sha2_512;
    }

    public static function sha3_256(?string $key = null): HashAlgorithmInfo {
        if($key === null)
            return new HashAlgorithmInfo('sha3-256', $key);
        return self::$sha3_256;
    }

    public static function sha3_512(?string $key = null): HashAlgorithmInfo {
        if($key === null)
            return new HashAlgorithmInfo('sha3-512', $key);
        return self::$sha3_512;
    }

    public static function crc32(): HashAlgorithmInfo {
        return self::$crc32;
    }

    public static function crc32b(): HashAlgorithmInfo {
        return self::$crc32b;
    }

    public static function crc32c(): HashAlgorithmInfo {
        return self::$crc32c;
    }
}

HashAlgorithmInfo::construct();