namespace Common.Utils.Extensions
{
    using System;
    using System.Collections.Generic;

    public static class BytesExtensions
    {
        public static Int16 ToInt16BE(this Byte[] bytes, Int32 start)
        {
            var result = default(Int16);

            result ^= (Int16)(bytes[start++] << 8);
            result ^= bytes[start++];

            return result;
        }

        public static Int32 ToInt32BE(this Byte[] bytes, Int32 start)
        {
            var result = default(Int32);

            result ^= bytes[start++] << 24;
            result ^= bytes[start++] << 16;
            result ^= bytes[start++] << 8;
            result ^= bytes[start++];

            return result;
        }

        public static Int64 ToInt64BE(this Byte[] bytes, Int32 start)
        {
            var result = default(Int64);

            result ^= bytes[start++] << 56;
            result ^= bytes[start++] << 48;
            result ^= bytes[start++] << 40;
            result ^= bytes[start++] << 32;
            result ^= bytes[start++] << 24;
            result ^= bytes[start++] << 16;
            result ^= bytes[start++] << 8;
            result ^= bytes[start++];

            return result;
        }
        public static UInt16 ToUInt16BE(this Byte[] bytes, Int32 start)
        {
            var result = default(UInt16);

            result ^= (UInt16)(bytes[start++] << 8);
            result ^= bytes[start++];

            return result;
        }

        public static UInt32 ToUInt32BE(this Byte[] bytes, Int32 start)
        {
            var result = default(UInt32);

            result ^= (UInt32)(bytes[start++] << 24);
            result ^= (UInt32)(bytes[start++] << 16);
            result ^= (UInt32)(bytes[start++] << 8);
            result ^= bytes[start++];

            return result;
        }

        public static UInt64 ToUInt64BE(this Byte[] bytes, Int32 start)
        {
            var result = default(UInt64);

            result ^= (UInt64)(bytes[start++] << 56);
            result ^= (UInt64)(bytes[start++] << 48);
            result ^= (UInt64)(bytes[start++] << 40);
            result ^= (UInt64)(bytes[start++] << 32);
            result ^= (UInt64)(bytes[start++] << 24);
            result ^= (UInt64)(bytes[start++] << 16);
            result ^= (UInt64)(bytes[start++] << 8);
            result ^= bytes[start++];

            return result;
        }

        public static Int16 ToInt16LE(this Byte[] bytes, Int32 start)
        {
            var result = default(Int16);

            start += 2;

            result ^= (Int16)(bytes[start--] << 8);
            result ^= bytes[start--];

            return result;
        }

        public static Int32 ToInt32LE(this Byte[] bytes, Int32 start)
        {
            var result = default(Int32);

            start += 4;

            result ^= bytes[start--] << 24;
            result ^= bytes[start--] << 16;
            result ^= bytes[start--] << 8;
            result ^= bytes[start--];

            return result;
        }

        public static Int64 ToInt64LE(this Byte[] bytes, Int32 start)
        {
            var result = default(Int64);

            start += 8;

            result ^= bytes[start--] << 56;
            result ^= bytes[start--] << 48;
            result ^= bytes[start--] << 40;
            result ^= bytes[start--] << 32;
            result ^= bytes[start--] << 24;
            result ^= bytes[start--] << 16;
            result ^= bytes[start--] << 8;
            result ^= bytes[start--];

            return result;
        }
        public static UInt16 ToUInt16LE(this Byte[] bytes, Int32 start)
        {
            var result = default(UInt16);

            start += 2;

            result ^= (UInt16)(bytes[start--] << 8);
            result ^= bytes[start--];

            return result;
        }

        public static UInt32 ToUInt32LE(this Byte[] bytes, Int32 start)
        {
            var result = default(UInt32);

            start += 4;

            result ^= (UInt32)(bytes[start--] << 24);
            result ^= (UInt32)(bytes[start--] << 16);
            result ^= (UInt32)(bytes[start--] << 8);
            result ^= bytes[start--];

            return result;
        }

        public static UInt64 ToUInt64LE(this Byte[] bytes, Int32 start)
        {
            var result = default(UInt64);

            start += 8;

            result ^= (UInt64)(bytes[start--] << 56);
            result ^= (UInt64)(bytes[start--] << 48);
            result ^= (UInt64)(bytes[start--] << 40);
            result ^= (UInt64)(bytes[start--] << 32);
            result ^= (UInt64)(bytes[start--] << 24);
            result ^= (UInt64)(bytes[start--] << 16);
            result ^= (UInt64)(bytes[start--] << 8);
            result ^= bytes[start--];

            return result;
        }

        public static Byte[] GetBytesBE(this UInt16 value)
        {
            var bytes = new Byte[2];

            bytes[0] = (Byte)(value >> 8);
            bytes[1] = (Byte)value;

            return bytes;
        }

        public static Byte[] GetBytesBE(this UInt32 value)
        {
            var bytes = new Byte[2];

            bytes[0] = (Byte)(value >> 24);
            bytes[1] = (Byte)(value >> 16);
            bytes[2] = (Byte)(value >> 8);
            bytes[3] = (Byte)value;

            return bytes;
        }

        public static Byte[] GetBits(this Byte @byte)
        {
            var bits = new Byte[8];

            for (var i = 0; i < 8; i++)
            {
                bits[i] = (Byte)((@byte >> i) & 1);
            }

            return bits;
        }

        public static void SetBits(this Byte value, Byte[] bits, Int32 start, Int32 count)
        {
            for (var i = 0; i < count; i++)
            {
                bits[start + i] = (Byte)((value >> i) & 1);
            }
        }

        public static Byte ToByte(this Byte[] bits)
        {
            var _byte = default(Int32);

            for (var i = 0; i < 8; i++)
            {
                _byte |= bits[i] << i;
            }

            return (Byte)_byte;
        }

        public static Byte ToByte(this Byte[] bits, Int32 start, Int32 count)
        {
            var sum = 0;

            for (var i = 0; i < count; i++)
            {
                sum |= bits[start + i] << i;
            }

            return (Byte)sum;
        }

        public static Byte[] ToByteArray(this String hexString)
        {
            var bytes = new List<Byte>();

            if (!String.IsNullOrWhiteSpace(hexString))
            {
                var first = true;
                var x = 0;

                foreach (var hex in hexString)
                {
                    if ('0' <= hex && hex <= '9')
                    {
                        x += hex - '0';
                    }
                    else if ('A' <= hex && hex <= 'F')
                    {
                        x += hex - 'A' + 10;
                    }
                    else if ('a' <= hex && hex <= 'f')
                    {
                        x = hex - 'a' + 10;
                    }
                    else
                    {
                        continue;
                    }

                    if (first)
                    {
                        x *= 16;
                    }
                    else
                    {
                        bytes.Add((Byte)x);

                        x = 0;
                    }

                    first = !first;
                }
            }

            return bytes.ToArray();
        }

        public static Byte[] GetReversed(this Byte[] bytes, Int32 start, Int32 size)
        {
            var _bytes = new Byte[size];

            Array.Copy(bytes, start, _bytes, 0, size);
            Array.Reverse(_bytes);

            return _bytes;
        }

        public static Int32 ToInt32BigEndian(this Byte[] bytes, Int32 start)
        {
            var _bytes = bytes.GetReversed(start, sizeof(Int32));

            return BitConverter.ToInt32(_bytes, 0);
        }

        public static UInt16 ToUInt16BigEndian(this Byte[] bytes, Int32 start)
        {
            var _bytes = bytes.GetReversed(start, sizeof(UInt16));

            return BitConverter.ToUInt16(_bytes, 0);
        }

        public static UInt32 ToUInt32BigEndian(this Byte[] bytes, Int32 start)
        {
            var _bytes = bytes.GetReversed(start, sizeof(UInt32));

            return BitConverter.ToUInt32(_bytes, 0);
        }

        public static Byte[] Reverse(this Byte[] bytes)
        {
            Array.Reverse(bytes);

            return bytes;
        }

        public static Byte[] ToBigEndianBytes(this Int32 value)
            => BitConverter.GetBytes(value).Reverse();

        public static Byte[] ToBigEndianBytes(this UInt32 value)
            => BitConverter.GetBytes(value).Reverse();
    }
}