using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace StardustCore.Math
{
    /// <summary>
    /// Base class for hex representation.
    /// </summary>
    public class Hex
    {
        /// <summary>
        /// The hex value represented as a string.
        /// </summary>
        public string hexValue;

        /// <summary>
        /// Default constructor.
        /// </summary>
        public Hex()
        {

        }
        /// <summary>
        /// Empty Constructor;
        /// </summary>
        /// <param name="HexValue"></param>
        public Hex(string HexValue)
        {

        }

        /// <summary>
        /// Verifies that the hex is of the specified length.
        /// </summary>
        /// <returns></returns>
        public virtual bool verifyHexLength()
        {
            return true;
        }

        /// <summary>
        /// Trims the hex value by removing the leading 0x;
        /// </summary>
        /// <returns></returns>
        public virtual string trimHex()
        {
            return this.hexValue.Split('x')[1];
        }

        /// <summary>
        /// A virtual function to be overriden.
        /// </summary>
        /// <returns></returns>
        public virtual List<string> getBytes()
        {
            return new List<string>();
        }

        /// <summary>
        /// Converts a Hex byte (represented as a length two string) to an int equal or less than 255. Ex ff=255;
        /// </summary>
        /// <param name="value">The length two value to be converted.</param>
        /// <returns></returns>
        public virtual int convertHexByteTo255Int(string value)
        {
            int val1 = convertHexValueToInt(value[0]);
            int val2 = convertHexValueToInt(value[1]);
            val1 *= 16;
            val2 *= 16;
            return val1 + val2;
        }

        /// <summary>
        /// Converts a hex char to an int.
        /// </summary>
        /// <param name="c"></param>
        /// <returns></returns>
        public virtual int convertHexValueToInt(char c)
        {
            if (c == 'a') return 10;
            else if (c == 'b') return 11;
            else if (c == 'c') return 12;
            else if (c == 'd') return 13;
            else if (c == 'e') return 14;
            else if (c == 'f') return 15;
            else return Convert.ToInt32(c);
        }

        /// <summary>
        /// Gets the associated byte from the hex positioning.
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        public virtual string getByte(int index)
        {
            string hex = this.trimHex();
            int val = index * 2 + 1;
            char str1 = hex[index * 2];
            char str2 = hex[val];
            return (str1.ToString() + str2.ToString());
        }
    }
}