static string FormatIPAddress()

in src/PSRule.Rules.Azure/Data/Template/CidrParsing.cs [281:353]
65 lines of code
14 McCabe index (conditional complexity)

    static string FormatIPAddress(byte[] ip)
    {
        if (ip.Length == 4)
        {
            // IPv4
            return $"{ip[0]}.{ip[1]}.{ip[2]}.{ip[3]}";
        }

        // IPv6

        // Find the longest sequence of consecutive zero bytes
        var longestZeroStart = -1;
        var longestZeroLength = 0;
        var currentZeroStart = -1;
        var currentZeroLength = 0;
        for (var i = 0; i < ip.Length; i += 2)
        {
            if (ip[i] == 0 && ip[i + 1] == 0)
            {
                if (currentZeroStart == -1)
                {
                    currentZeroStart = i;
                }
                currentZeroLength += 2;
            }
            else
            {
                if (currentZeroLength > longestZeroLength)
                {
                    longestZeroStart = currentZeroStart;
                    longestZeroLength = currentZeroLength;
                }
                currentZeroStart = -1;
                currentZeroLength = 0;
            }
        }
        if (currentZeroLength > longestZeroLength)
        {
            longestZeroStart = currentZeroStart;
            longestZeroLength = currentZeroLength;
        }

        // Build the compressed IPv6 address string
        var sb = new StringBuilder(ip.Length);
        for (var i = 0; i < ip.Length; i += 2)
        {
            if (i == longestZeroStart)
            {
                sb.Append(COLON);
                i += longestZeroLength - 2;
            }
            else
            {
                if (ip[i] == 0 && ip[i + 1] == 0)
                {
                    sb.Append(ZERO);
                }
                else if (ip[i] == 0)
                {
                    sb.Append(ip[i + 1].ToString(FORMAT_HEX));
                }
                else
                {
                    sb.Append(ip[i].ToString(FORMAT_HEX));
                    sb.Append(ip[i + 1].ToString(FORMAT_2HEX));
                }

                if (i < ip.Length - 2)
                    sb.Append(COLON);
            }
        }
        return sb.ToString();
    }