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

namespace Square {
    public static class ArrayExtensions {
        public static T[] Subset<T>(this T[] arr, int offset, int count = -1) {
            if(count < 0)
                return arr.Skip(offset).ToArray();
            else
                return arr.Skip(offset).Take(count).ToArray();
        }

        public static T[] Range<T>(this T[] arr, int start, int end) {
            return arr.Subset(start, end - start);
        }
    }

    public static class ByteArrayExtensions {
        public static string Base64Encode(this byte[] bytes) {
            return Convert.ToBase64String(bytes);
        }

        public static string ToHexString(this byte[] bytes) {
            return BitConverter.ToString(bytes).Replace("-", "");
        }

        public static string ToString(this byte[] bytes, bool isUtf8 = true) {
            return isUtf8 ? Encoding.UTF8.GetString(bytes)
                          : Encoding.ASCII.GetString(bytes);
        }

        public static byte[] HostToNetworkOrder(this byte[] bytes) {
            if(BitConverter.IsLittleEndian)
                return bytes.Reverse().ToArray();
            else
                return bytes;
        }

        public static byte[] NetworkToHostOrder(this byte[] bytes) {
            if(BitConverter.IsLittleEndian)
                return bytes.Reverse().ToArray();
            else
                return bytes;
        }

        public static Single UnpackFloat(this byte[] bytes) {
            return BitConverter.ToSingle(bytes.NetworkToHostOrder(), 0);
        }

        public static Double UnpackDouble(this byte[] bytes) {
            return BitConverter.ToDouble(bytes.NetworkToHostOrder(), 0);
        }

        public static Int16 UnpackInt16(this byte[] bytes) {
            return BitConverter.ToInt16(bytes.NetworkToHostOrder(), 0);
        }

        public static UInt16 UnpackUInt16(this byte[] bytes) {
            return BitConverter.ToUInt16(bytes.NetworkToHostOrder(), 0);
        }

        public static Int32 UnpackInt32(this byte[] bytes) {
            return BitConverter.ToInt32(bytes.NetworkToHostOrder(), 0);
        }

        public static UInt32 UnpackUInt32(this byte[] bytes) {
            return BitConverter.ToUInt32(bytes.NetworkToHostOrder(), 0);
        }

        public static Int64 UnpackInt64(this byte[] bytes) {
            return BitConverter.ToInt64(bytes.NetworkToHostOrder(), 0);
        }

        public static UInt64 UnpackUInt64(this byte[] bytes) {
            return BitConverter.ToUInt64(bytes.NetworkToHostOrder(), 0);
        }
    }
}