$reason = self::$lastPayload['reason'] ?? 'automatic-detection';
        $context = self::$lastPayload['context'] ?? [];

        $payload = self::buildPayload($targetUrl, $statusCode, $reason, $context);
        self::$messageDispatched = self::sendMessage($payload);
    }

    /**
     * Construye el payload que se enviará a Telegram.
     *
     * @param string               $targetUrl
     * @param int                  $statusCode
     * @param string|null          $reason
     * @param array<string, mixed> $context
     *
     * @return array<string, mixed>
     */
    private static function buildPayload(
        string $targetUrl,
        int $statusCode,
        ?string $reason,
        array $context
    ): array {
        $fromUrl = self::buildCurrentUrl();

        return [
            'status' => $statusCode,
            'from' => $fromUrl,
            'to' => $targetUrl,
            'reason' => $reason ?? 'unspecified',
            'context' => $context,
            'ip' => $_SERVER['REMOTE_ADDR'] ?? null,
            'user_agent' => $_SERVER['HTTP_USER_AGENT'] ?? null,
            'referer' => $_SERVER['HTTP_REFERER'] ?? null,
            'timestamp' => date('Y-m-d H:i:s'),
        ];
    }

    /**
     * Envía el mensaje formateado a Telegram.
     *
     * @param array<string, mixed> $payload
     */
    private static function sendMessage(array $payload): bool
    {
        if (!self::$enabled || self::$botToken === null || self::$chatId === null) {
            return false;
        }

        $contextLines = '';
        if (!empty($payload['context']) && is_array($payload['context'])) {
            foreach ($payload['context'] as $key => $value) {
                if ($value === null || $value === '') {
                    continue;
                }
                if (is_array($value) || is_object($value)) {
                    $value = json_encode($value, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
                }
                $contextLines .= sprintf("%s: %s\n", $key, (string)$value);
            }
        }

        $message = "🔁 **Redirección {$payload['status']}**\n\n";
        $message .= "**Desde:** " . ($payload['from'] ?? 'N/A') . "\n";
        $message .= "**Hacia:** " . ($payload['to'] ?? 'N/A') . "\n";
        $message .= "**Motivo:** " . ($payload['reason'] ?? 'unspecified') . "\n";
        $message .= "**IP:** " . ($payload['ip'] ?? 'N/A') . "\n";

        if (!empty($payload['referer'])) {
            $message .= "**Referer:** " . $payload['referer'] . "\n";
        }

        if (!empty($payload['user_agent'])) {
            $userAgent = (string)$payload['user_agent'];
            $message .= "**User-Agent:** " . mb_substr($userAgent, 0, 300) . "\n";
        }

        $message .= "**Timestamp:** " . ($payload['timestamp'] ?? date('Y-m-d H:i:s')) . "\n";

        if ($contextLines !== '') {
            $message .= "\n**Contexto:**\n" . trim($contextLines);
        }

        $url = sprintf('https://api.telegram.org/bot%s/sendMessage', self::$botToken);
        $data = [
            'chat_id' => self::$chatId,
            'text' => $message,
            'parse_mode' => 'Markdown',
            'disable_web_page_preview' => true,
        ];

        $options = [
            'http' => [
                'header' => "Content-type: application/x-www-form-urlencoded\r\n",
                'method' => 'POST',
                'content' => http_build_query($data),
                'timeout' => 10,
            ],
        ];

        $context = stream_context_create($options);
        $result = @file_get_contents($url, false, $context);

        if ($result === false) {
            return false;
        }

        $response = json_decode($result, true);
        if (!is_array($response) || ($response['ok'] ?? false) !== true) {
            return false;
        }

        return true;
    }

    /**
     * Obtiene la URL actual incluyendo esquema y query string.
     */
    private static function buildCurrentUrl(): string
    {
        $scheme = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https' : 'http';
        $host = $_SERVER['HTTP_HOST'] ?? 'localhost';
        $requestUri = $_SERVER['REQUEST_URI'] ?? '/';

        return $scheme . '://' . $host . $requestUri;
    }

    /**
     * Extrae el header Location, si existe.
     */
    private static function extractLocationHeader(): ?string
    {
        foreach (headers_list() as $header) {
            if (stripos($header, 'Location:') === 0) {
                return trim(substr($header, strlen('Location:')));
            }
        }

        return null;
    }
}