using System;
using System.Collections;
using System.Net;
using System.Linq;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;

namespace SBRL.Utilities
{
	public static class Utilities
	{
		public static IEnumerable<IPAddress> GetLocalIps()
		{
			IPHostEntry entries = Dns.GetHostEntry(Dns.GetHostName());
			return (from ipAddr in entries.AddressList
			        where !IPAddress.IsLoopback(ipAddr)
			        select ipAddr).ToList();
		}

		public static string EscapeString(string str)
		{
			StringBuilder result = new StringBuilder(str);
			foreach(KeyValuePair<string, string> kvp in replacementPairs)
				result.Replace(kvp.Key, kvp.Value);

			return result.ToString();
		}

		private static Dictionary<string, string> replacementPairs = new Dictionary<string, string>()
		{
			["\n"] = @"\n",
			["\t"] = @"\t"
		};

		/// <summary>
		/// Concatenates a pair of buffers into a single long buffer.
		/// </summary>
		/// <param name="A">The first buffer to concatenate.</param>
		/// <param name="B">The second buffer to concatenate.</param>
		/// <returns>The concatenated buffers.</returns>
		public static byte[] ConcatBuffers(byte[] A, byte[] B)
		{
			byte[] result = new byte[A.Length + B.Length];
			Buffer.BlockCopy(A, 0, result, 0, A.Length);
			Buffer.BlockCopy(B, 0, result, A.Length, B.Length);
			return result;
		}
	}
}