namespace CPUSimulation
{
    public class Utils
    {
        static Random _random = new Random();

        /// <summary>
        /// Generates a random word 
        /// </summary>
        /// <param name="byteCount"></param>
        /// input must be between 0 and 2 (inclusive)
        /// <returns></returns>
        /// <exception cref="ArgumentException"></exception>
        public static Word GenerateRandomWord(int byteCount)
        {
            if (byteCount < 0)
            {
                byteCount = 0;
            }
            Byte[] bytes = new Byte[byteCount];
            for (int i = 0; i < byteCount; i++)
            {
                bytes[i] = GenerateRandomByte();
            }
            if (byteCount == 1)
            {
                bytes = new Byte[2] { new Byte("00000000"), bytes[0] };
            }
            else if (byteCount == 0)
            {
                bytes = new Byte[2] { new Byte("00000000"), new Byte("00000000") };
            }
            return new Word(bytes);
        
            
        }
        public static Byte GenerateRandomByte()
        {
            Bit[] bits = new Bit[8];
            for (int i = 0; i < 8; i++)
            {
                bits[i] = new Bit(_random.Next(2) == 1);
            }
            return new Byte(bits);
        }

        public static string Int16ToBinaryString(short value)
        {
            return Convert.ToString(value & 0xFFFF, 2).PadLeft(16, '0');
        }


        public static string BinaryStringToHexString(string binaryString)
        {
            if (binaryString.Length % 4 != 0)
            {
                throw new ArgumentException("Binary string length must be a multiple of 4.");
            }
            string hexString = "";
            for (int i = 0; i < binaryString.Length; i += 4)
            {
                string fourBits = binaryString.Substring(i, 4);
                switch (fourBits)
                {
                    case "0000":
                        hexString += "0";
                        break;
                    case "0001":
                        hexString += "1";
                        break;
                    case "0010":
                        hexString += "2";
                        break;
                    case "0011":
                        hexString += "3";
                        break;
                    case "0100":
                        hexString += "4";
                        break;
                    case "0101":
                        hexString += "5";
                        break;
                    case "0110":
                        hexString += "6";
                        break;
                    case "0111":
                        hexString += "7";
                        break;
                    case "1000":
                        hexString += "8";
                        break;
                    case "1001":
                        hexString += "9";
                        break;
                    case "1010":
                        hexString += "A";
                        break;
                    case "1011":
                        hexString += "B";
                        break;
                    case "1100":
                        hexString += "C";
                        break;
                    case "1101":
                        hexString += "D";
                        break;
                    case "1110":
                        hexString += "E";
                        break;
                    case "1111":
                        hexString += "F";
                        break;
                }
            }
            return hexString;
        }

        public static string HexStringToBinaryString(string hexString)
        {
            string binaryString = "";
            foreach (char hexChar in hexString)
            {
                switch (hexChar)
                {
                    case '0':
                        binaryString += "0000";
                        break;
                    case '1':
                        binaryString += "0001";
                        break;
                    case '2':
                        binaryString += "0010";
                        break;
                    case '3':
                        binaryString += "0011";
                        break;
                    case '4':
                        binaryString += "0100";
                        break;
                    case '5':
                        binaryString += "0101";
                        break;
                    case '6':
                        binaryString += "0110";
                        break;
                    case '7':
                        binaryString += "0111";
                        break;
                    case '8':
                        binaryString += "1000";
                        break;
                    case '9':
                        binaryString += "1001";
                        break;
                    case 'A':
                    case 'a':
                        binaryString += "1010";
                        break;
                    case 'B':
                    case 'b':
                        binaryString += "1011";
                        break;
                    case 'C':
                    case 'c':
                        binaryString += "1100";
                        break;
                    case 'D':
                    case 'd':
                        binaryString += "1101";
                        break;
                    case 'E':
                    case 'e':
                        binaryString += "1110";
                        break;
                    case 'F':
                    case 'f':
                        binaryString += "1111";
                        break;
                }
            }
            return binaryString;
        }

        public static Int16 HexStringToInt16(string hexString)
        {
            if (hexString.Length > 4)
            {
                throw new ArgumentException("Hex string length must be 4 or less.");
            }
            return Convert.ToInt16(hexString, 16);
        }
    }
}