using System;
using System.Collections.Generic;
using System.Net;
using System.Net.NetworkInformation;
using System.Text;
using System.Web;

namespace TBF.BenchControl.Network.Adapter
{
	/// <summary>
	/// Class for the storing information about a network adapter.
	/// </summary>
	public class AdapterInfo
	{
		public string Description;		/// Description of the network adapter.
		public IPAddress IPAddress;		/// IP address of the network adapter.
		public IPAddress NetMask;		/// Mask of the network adapter.

		/// Constructor
		public AdapterInfo(string description)
		{
			Description = description;
		}

		public IPAddress GetBroadcastAddress()
		{
			byte[] ipAdressBytes = IPAddress.GetAddressBytes();
			byte[] subnetMaskBytes = NetMask.GetAddressBytes();

			if (ipAdressBytes.Length != subnetMaskBytes.Length)
				throw new ArgumentException("Lengths of IP address and subnet mask do not match.");

			byte[] broadcastAddress = new byte[ipAdressBytes.Length];
			for (int i = 0; i < broadcastAddress.Length; i++)
			{
				broadcastAddress[i] = (byte)(ipAdressBytes[i] | (subnetMaskBytes[i] ^ 255));
			}

			return new IPAddress(broadcastAddress);
		}

		///------------------------------------------------------
		/// Static members and functions
		///------------------------------------------------------

		/// <summary>
		/// Private list of the available network adapters.
		/// </summary>
		static List<AdapterInfo> netAdapters;

		/// <summary>
		/// Retrieves the list of network adapters.
		/// Never returns 'null', calls RefreshNetAdaptersInfo() the first time it is used.
		/// If you want to refresh the list of the network adapters later, explicitly call
		/// the RefreshNetAdaptersInfo() method.
		/// </summary>
		public static List<AdapterInfo> NetAdapters
		{
			get
			{
				if (netAdapters == null) RefreshNetAdaptersInfo();
				return netAdapters;
			}
		}

		/// <summary>
		/// Refreshes the information about network adapters stored in the netAdapters list.
		/// </summary>
		public static void RefreshNetAdaptersInfo()
		{
			if (netAdapters == null) netAdapters = new List<AdapterInfo>();
			else netAdapters.Clear();

			NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();
			foreach (NetworkInterface adapter in nics)
			{
				AdapterInfo info = new AdapterInfo(adapter.Description);
				netAdapters.Add(info);

				IPInterfaceProperties properties = adapter.GetIPProperties();
				if (properties == null)
					continue;
				UnicastIPAddressInformationCollection uniCast = properties.UnicastAddresses;
				if (uniCast == null)
					continue;
				foreach (UnicastIPAddressInformation uni in uniCast)
				{
					if (info == null)
					{
						info = new AdapterInfo(adapter.Description);
						netAdapters.Add(info);
					}
					info.IPAddress = uni.Address;
					if (uni.IPv4Mask != null) info.NetMask = uni.IPv4Mask;
					info = null;
				}
			}
		}

		/// <summary>
		/// Gets the loopback network adapter.
		/// </summary>
		public static AdapterInfo LoopbackAdapter
		{
			get
			{
				List<AdapterInfo> adapters = NetAdapters;
				foreach (AdapterInfo a in adapters)
				{
					if (a.IPAddress != null && a.IPAddress.Equals(IPAddress.Loopback)) return a;
				}
				return null;
			}
		}

		/// <summary>
		/// Gets the default network adapter - the first one which his not a loopback adapter.
		/// Network adapters with IP address have preference, adapters without IP address
		/// (like an unconnected wireless adapter) are used just when there is no adapter with IP.
		///
		/// Default adapter is used when none was specified in the configuration file
		/// and it is used to initialize Options-General dialog-tab.
		/// </summary>
		public static AdapterInfo DefaultAdapter
		{
			get
			{
				List<AdapterInfo> adapters = NetAdapters;		/// Make a copy to avoid interference
				AdapterInfo adapterWithoutIP = null;			/// Use this one if there is no other better adapter
				foreach (AdapterInfo a in adapters)
				{
					if (!a.IPAddress.Equals(IPAddress.Loopback))
					{
						if (a.IPAddress != null) return a;
						else if (adapterWithoutIP == null) adapterWithoutIP = a;
					}
				}
				return adapterWithoutIP == null ? LoopbackAdapter : adapterWithoutIP;
			}
		}

		/// <summary>
		/// Get network adapter info from the description string.
		/// </summary>
		/// <param name="description">Description</param>
		/// <returns>AdapterInfo object reference</returns>
		public static AdapterInfo GetNetAdapter(string description)
		{
			List<AdapterInfo> adapters = NetAdapters;

			foreach (AdapterInfo a in adapters)
			{
				if (a.Description != description ||
					a.IPAddress == null ||
					a.IPAddress.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6 ||
					a.IPAddress.Equals(IPAddress.Loopback) ||
					a.NetMask == null)
				{
					continue;
				}
				return a;
			}

			return DefaultAdapter;
		}

		/// <summary>
		/// Encodes the given string as URL parameter.
		/// </summary>
		/// <param name="pathToEncode">String to be encoded.</param>
		/// <returns>String encoded as the URL parameter.</returns>
		public static string UrlPathEncode(string pathToEncode)
		{
			StringBuilder sb = new StringBuilder(pathToEncode.Length * 3);

			sb.Append(pathToEncode);

			// % must be first!!!
			sb.Replace("%", "%" + Convert.ToInt32('%').ToString("X2"));
			// ?, & and / are not convertable by HttpUtility.UrlPathEncode
			sb.Replace("?", "%" + Convert.ToInt32('?').ToString("X2"));
			sb.Replace("&", "%" + Convert.ToInt32('&').ToString("X2"));
			sb.Replace("/", "%" + Convert.ToInt32('/').ToString("X2"));
			// Additional chars. E.g.: # didn't work in the path passed to the Uri class. "c:\\sour#ce\\my # proj".
			sb.Replace("#", "%" + Convert.ToInt32('#').ToString("X2"));
			// Backslash must be removed because it is not accepted by Uri class when passing path into it. E.g.: "C:%5Csource" is not acceptable.
			//sb.Replace("\\", "%" + Convert.ToInt32('\\').ToString("X2"));
			//// I removed following chars because I do not know if it is good idea to replace them (see previous line with '\\' char).
			sb.Replace("\r", "%" + Convert.ToInt32('\r').ToString("X2"));
			sb.Replace("\n", "%" + Convert.ToInt32('\n').ToString("X2"));
			sb.Replace("\t", "%" + Convert.ToInt32('\t').ToString("X2"));

			string s = sb.ToString();
			s = HttpUtility.UrlPathEncode(s);
			//sb.Length = 0;
			//sb.Append(HttpUtility.UrlPathEncode(s));
			//for (int i = 0; i < sb.Length; i += 3)
			//{
			//    char c = sb[i];
			//    if (c == '%')
			//        continue;
			//    sb[i] = '%';
			//    sb.Insert(i + 1, Convert.ToUInt64(c).ToString("X2"));
			//}
			return s;
		}
	}
}