///////////////////////////////////////////////////////////////////////////////
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//

using System;
using System.Collections;
using System.Diagnostics;
using System.Text;

using Microsoft.SingSharp;
using Microsoft.Singularity;
using Microsoft.Singularity.Channels;

#if ENABLE_GENERICS
using System.Collections.Generic;
#endif

namespace Smb.Shared
{
	/*static*/ sealed class Util
	{
		private Util() {}

		public static void ShowExceptionDebug(Exception! ex, string! msg)
		{
			DebugStub.WriteLine(msg);
			ShowExceptionDebug(ex);
		}
		
		public static void ShowExceptionDebug(Exception! ex)
		{
			for (Exception current = ex; current != null; current = current.InnerException) {
				Type! exType = current.GetType();
				DebugStub.WriteLine(String.Format("{0}: {1}", exType.FullName, ex.Message));
			}
		}

		public static string! ToStringDelete([Claims]char[]! in ExHeap exstring)
		{
			string! str = Bitter.ToString2(exstring);
			delete exstring;
			return str;
		}

	#if ENABLE_GENERICS
		public static T[]! GetSubArray<T>(T[]! arr, int index, int length)
		{
			T[] result = new T[length];
			Array.Copy(arr, index, result, 0, length);
			return result;
		}
	#else
		public static byte[]! GetSubArray(byte[]! arr, int index, int length)
			requires index >= 0;
			requires index + length <= arr.Length;
			ensures result.Length == length;
		{
			byte[] result = new byte[length];
			Array.Copy(arr, index, result, 0, length);
			return result;
		}
	
	#endif

		public const string HexDigits = "0123456789abcdef";

		public static byte[]! HexStringToByteArray(string! str)
		{
			if ((str.Length % 2) != 0)
				throw new Exception("Input string cannot be odd in length.");

			byte[]! result = new byte[str.Length / 2];
			for (int i = 0; i < result.Length; i++)
			{
				byte high = CharToHex(str[i * 2]);
				byte low = CharToHex(str[i * 2 + 1]);
				result[i] = (byte)((high << 4) | low);
			}

			return result;
		}

		/*
		 * Stupid C#!
		 */
	#if ENABLE_GENERICS && false
		static int CompareArraySpans<T>(T[] array1, int offset1, T[] array2, int offset2, int length)
		{
			for (int i = 0; i < length; i++)
			{
				T element1 = array1[i];
				T element2 = array2[i];
				if (element1 < element2)
					return -1;
				if (element1 > element2)
					return 1;
			}

			return 0;
		}
	#endif
		public static int CompareArraySpans(byte[]! array1, int offset1, byte[]! array2, int offset2, int length)
		{
			for (int i = 0; i < length; i++)
			{
				byte element1 = array1[i];
				byte element2 = array2[i];
				if (element1 < element2)
					return -1;
				if (element1 > element2)
					return 1;
			}

			return 0;
		}

		public static void DumpBuffer(byte[]! buffer)
		{
			DumpBuffer(buffer, 0, buffer.Length);
		}

	#if ENABLE_GENERICS
		public static void DumpBuffer(ArraySpan<byte> span)
		{
			DumpBuffer(span.ContainingArray, span.Offset, span.Length);
		}
	#else
		public static void DumpBuffer(ArraySpan_byte span)
		{
			DumpBuffer(span.ContainingArray, span.Offset, span.Length);
		}
	#endif

		public static void DumpBuffer(byte[]! buffer, int index, int length)
		{
			StringBuilder line = new StringBuilder();

			for (int i = 0; i < length; i += 0x10)
			{
				line.Length = 0;
				line.AppendFormat("{0:x04}: ", i);

				for (int j = 0; j < 0x10; j++)
				{

					if (i + j < length)
					{
						line.Append(" ");
						byte b = buffer[index + i + j];
						line.Append((Char)HexDigits[b >> 4]);
						line.Append((Char)HexDigits[b & 0xf]);
					}
					else
					{
						line.Append("   ");
					}
				}

				line.Append(" : ");
				for (int j = 0; j < 0x10; j++)
				{

					if (i + j < length)
					{
						byte b = buffer[index + i + j];
						if (b >= 32 && b <= 127)
						{
							line.Append((Char)b);
						}
						else
						{
							line.Append(".");
						}
					}
					else
					{
						break;
					}
				}

				DebugStub.WriteLine(line.ToString());
			}
		}

		public static void DumpBuffer(byte[]! in ExHeap buffer)
		{
			DumpBuffer(buffer, 0, buffer.Length);
		}

		public static void DumpBuffer(byte[]! in ExHeap buffer, int index, int length)
		{
			StringBuilder line = new StringBuilder();

			for (int i = 0; i < length; i += 0x10)
			{
				line.Length = 0;
				line.AppendFormat("{0:x04}: ", i);

				for (int j = 0; j < 0x10; j++)
				{

					if (i + j < length)
					{
						line.Append(" ");
						byte b = buffer[index + i + j];
						line.Append((Char)HexDigits[b >> 4]);
						line.Append((Char)HexDigits[b & 0xf]);
					}
					else
					{
						line.Append("   ");
					}
				}

				line.Append(" : ");
				for (int j = 0; j < 0x10; j++)
				{

					if (i + j < length)
					{
						byte b = buffer[index + i + j];
						if (b >= 32 && b <= 127)
						{
							line.Append((Char)b);
						}
						else
						{
							line.Append(".");
						}
					}
					else
					{
						break;
					}
				}

				DebugStub.WriteLine(line.ToString());
			}
		}

	#if ENABLE_GENERICS
		public static void CheckArraySpan<T>(T[] arr, int offset, int length)
		{
			if (arr == null)
				throw new Exception("Array cannot be null.");
			if (offset < 0)
				throw new Exception("Array offset cannot be negative.");
			if (length < 0)
				throw new Exception("Array span length cannot be negative.");
			if (offset + length > arr.Length)
				throw new Exception("Array span exceeds size of array");
		}
	#endif


		static void DumpHashtable(Hashtable! table)
		{
			try {
				DebugStub.WriteLine("Hashtable:");

				DebugStub.WriteLine("Keys:");
				foreach (Object key in table.Keys)
				{
					if (key == null)
						DebugStub.WriteLine("    null");
					else {
						Type keyType = key.GetType();
						string keyTypeName = keyType.FullName;
						string keyText = key.ToString();
						DebugStub.WriteLine(String.Format("    ({0}) {1}", keyTypeName, keyText));
					}
				}

				try {
					DebugStub.WriteLine("Keys: (from array)");
					object[]! keys = new object[table.Keys.Count];
					table.Keys.CopyTo(keys, 0);
					foreach (Object key2 in keys) {
						if (key2 == null)
							DebugStub.WriteLine("    null");
						else {
							Type keyType2 = key2.GetType();
							string keyTypeName2 = keyType2.FullName;
							string keyText2 = key2.ToString();
							DebugStub.WriteLine(String.Format("    ({0}) {1}", keyTypeName2, keyText2));
						}
					}
				} catch (Exception ex) {
					DebugStub.WriteLine("Fault occurred while reading keys from array.");
					Util.ShowExceptionDebug(ex);
				}

				DebugStub.WriteLine("Values:");
				foreach (Object value in table.Values)
				{
					if (value == null)
						DebugStub.WriteLine("    null");
					else {
						Type valueType = value.GetType();
						string valueTypeName = valueType.FullName;
						string valueText = value.ToString();
						DebugStub.WriteLine(String.Format("    ({0}) {1}", valueTypeName, valueText));
					}
				}
			} catch (Exception ex) {
				Util.ShowExceptionDebug(ex);
			}
		}
	
	
        public static string! ByteArrayToString(byte[]! buffer, int index, int length)
        {
            StringBuilder sb = new StringBuilder(length * 2);
            for (int i = 0; i < length; i++)
            {
                byte b = buffer[index + i];
                sb.Append(HexDigits[b >> 4]);
                sb.Append(HexDigits[b & 0xf]);
            }
            return sb.ToString();
        }

        public static string! ByteArrayToStringHex(byte[]! buffer)
        {
            return ByteArrayToString(buffer, 0, buffer.Length);
        }

        public static string! ByteArrayToStringBitsBe(byte[]! buffer)
        {
            return ByteArrayToStringBitsBe(buffer, 0, buffer.Length);
        }

        public static string! ByteArrayToStringBitsBe(byte[]! buffer, int index, int length)
        {
            StringBuilder sb = new StringBuilder(length * 2);
            sb.Append("be ");
            for (int i = 0; i < length; i++)
            {
                if (i > 0)
                    sb.Append('.');

                byte b = buffer[index + i];

                for (int bit = 7; bit >= 0; bit--)
                {
                    byte value = (byte)(b & (1 << bit));
                    sb.Append(value != 0 ? '1' : '0');
                }
            }
            return sb.ToString();
        }

        public static string! ByteArrayToStringBitsLe(byte[]! buffer)
        {
            return ByteArrayToStringBitsLe(buffer, 0, buffer.Length);
        }

        public static string! ByteArrayToStringBitsLe(byte[]! buffer, int index, int length)
        {
            StringBuilder sb = new StringBuilder(length * 2);
            sb.Append("le ");
            for (int i = 0; i < length; i++)
            {
                if (i > 0)
                    sb.Append('.');

                byte b = buffer[index + i];

                for (int bit = 0; bit < 8; bit++)
                {
                    byte value = (byte)(b & (1 << bit));
                    sb.Append(value != 0 ? '1' : '0');
                }
            }
            return sb.ToString();
        }

        static byte CharToHex(char c)
        {
            if (c >= '0' && c <= '9')
                return (byte)(c - '0');
            if (c >= 'a' && c <= 'f')
                return (byte)(c - 'a' + 10);
            if (c >= 'A' && c <= 'F')
                return (byte)(c - 'A' + 10);
            throw new ArgumentException("Invalid hex char");
        }

	
		public static int Align4(int value)
		{
			return (value + 3) & ~3;
		}
		
		public static int Align2(int value)
		{
			return (value + 1) & ~1;
		}
		
		public static string! YesNoString(bool value)
		{
			return value ? "Yes" : "No";
		}
	}
    
	class NotImplementedException : Exception
	{
		public NotImplementedException()
			: base("Not Implemented")
		{}
	}
	
	class UnsatisfiableReceiveException : Exception
	{
		public UnsatisfiableReceiveException()
			: base("A 'switch receive' statement could not be satisfied.")
		{}
		
		public UnsatisfiableReceiveException(string! msg)
			: base(msg)
		{}
		
	}

}