using System;
using System.Globalization;
using System.Text;
using System.Text.RegularExpressions;

namespace gist.yifeitao.com
{
    [Serializable]
    public class Mac
    {
        private readonly byte[] _address = new byte[6];
        /// <summary>
        /// use byte array to construct
        /// </summary>
        /// <param name="address">a byte array(length==6)</param>
        public Mac(byte[] address)
        {
            if (address.Length != 6)
            {
                throw new ArgumentException("address.Length != 6");
            }
            Array.Copy(address, _address, 6);
        }
        /// <summary>
        /// get a copy of address in bytes
        /// </summary>
        /// <returns></returns>
        public byte[] GetAddressBytesCopy()
        {
            byte[] copy = new byte[6];
            Array.Copy(_address,copy,6);
            return copy;

        }
        /// <summary>
        /// Parse a string to mac
        /// </summary>
        /// <param name="s">a string looks like "XX-XX-XX-XX-XX-XX"</param>
        /// <returns>Mac address</returns>
        public static Mac Parse(string s)
        {
            Regex regex = new Regex("[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]");
            if (!regex.IsMatch(s)) throw new ArgumentException("the string can't mactch XX-XX-XX-XX-XX-XX");
            var address = ParesAddressBytes(s);
            return new Mac(address);
        }

        private static byte[] ParesAddressBytes(string s)
        {
            byte[] address = new byte[6];
            string[] addrStrings = s.Split('-');
            for (int i = 0; i < 6; i++)
            {
                address[i] = byte.Parse(addrStrings[i], NumberStyles.HexNumber);
            }
            return address;
        }

        public bool TryParse(string s, out Mac mac)
        {
            Regex regex = new Regex("[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]-[0-9A-F][0-9A-F]");
            mac = null;
            if (!regex.IsMatch(s)) return false;
            var address = ParesAddressBytes(s);
            mac = new Mac(address);
            return true;
        }

        public override string ToString()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append(_address[0].ToString("X2"));
            sb.Append("-");
            sb.Append(_address[1].ToString("X2"));
            sb.Append("-");
            sb.Append(_address[2].ToString("X2"));
            sb.Append("-");
            sb.Append(_address[3].ToString("X2"));
            sb.Append("-");
            sb.Append(_address[4].ToString("X2"));
            sb.Append("-");
            sb.Append(_address[5].ToString("X2"));
            return sb.ToString();
        }

        public override bool Equals(object obj)
        {
            if (!(obj is Mac))
            {
                return false;
            }
            byte[] bytes1 = GetAddressBytesCopy();
            byte[] bytes2 = ((Mac) obj).GetAddressBytesCopy();
            for (int i = 0; i < 6; i++)
            {
                if (bytes1[i] != bytes2[i])
                    return false;
            }
            return true;
        }

        public override int GetHashCode()
        {
            return ((_address[0] << 40) & (_address[1] << 32) & (_address[2] << 24)
                    & (_address[3] << 16) & (_address[4] << 8) & _address[5])
                .GetHashCode();
        }
    }
}