<?php

namespace ComCen\Security;

class TokenHandler
{
    private static ?self $instance = null;
    private static $tokens = [];
    private static int $iterations = 0;

    private static function random32Characters(): string {
        $data = random_bytes(16);
        $data[6] = chr(ord($data[6]) & 0x0f | 0x40);
        $data[8] = chr(ord($data[8]) & 0x3f | 0x80);
        return bin2hex($data);
    }
    public static function doesUserHaveToken(string $username): bool
    {
        return array_any(self::$tokens, fn($token) => $token[0] === $username);
    }
    public static function getNewTokenForUser(string $username): string
    {
        $tokenBody = self::random32Characters() . str_pad(self::$iterations++, 5, '0');
        if (self::$iterations >= 99999) {
            self::$iterations = 0;
        }
        $timestamp = microtime(true) * 10000;
        self::$tokens[] = [$username, $timestamp, $tokenBody];
        return $timestamp . $tokenBody;
    }
    public static function getTokenOwnership(string $controlledToken): string | null
    {
        for ($i = 0; $i < count(self::$tokens); ++$i) {
            $token = self::$tokens[$i];
            if ($token[1] . $token[2] === $controlledToken) {
                return $token[0];
            }
        }
        return null;
    }
    public static function deleteOldTokens(): void
    {
        for ($i = 0; $i < count(self::$tokens); ++$i) {
            $token = self::$tokens[$i];
            //                                1 hour
            if (time() - ($token[1] / 10000) > 3600) {
                array_splice(self::$tokens, $i, 1);
            }
        }
    }
    public static function deleteTokensForUser(string $user): void
    {
        for ($i = 0; $i < count(self::$tokens); ++$i) {
            if (self::$tokens[$i][0] === $user) {
                array_splice(self::$tokens, $i, 1);
            }
        }
    }
}