/***************************************************************************
    copyright            : (C) 2005 by Brian Nickel
                         : (C) 2006 Novell, Inc.
    email                : brian.nickel@gmail.com
                         : Aaron Bockover <abockover@novell.com>
    based on             : tbytevector.cpp from TagLib
 ***************************************************************************/

/***************************************************************************
 *   This library is free software; you can redistribute it and/or modify  *
 *   it  under the terms of the GNU Lesser General Public License version  *
 *   2.1 as published by the Free Software Foundation.                     *
 *                                                                         *
 *   This library is distributed in the hope that it will be useful, but   *
 *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
 *   Lesser General Public License for more details.                       *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this library; if not, write to the Free Software   *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
 *   USA                                                                   *
 ***************************************************************************/

using System.Collections;
using System.Collections.Generic;
using System;

namespace TagLib {
	/// <summary>
	///    Specifies the text encoding used when converting between a <see
	///    cref="string" /> and a <see cref="ByteVector" />.
	/// </summary>
	/// <remarks>
	///    This enumeration is used by <see
	///    cref="ByteVector.FromString(string,StringType)" /> and <see
	///    cref="ByteVector.ToString(StringType)" />.
	/// </remarks>
	public enum StringType {
		/// <summary>
		///    The string is to be Latin-1 encoded.
		/// </summary>
		Latin1 = 0,
		
		/// <summary>
		///    The string is to be UTF-16 encoded.
		/// </summary>
		UTF16 = 1,
		
		/// <summary>
		///    The string is to be UTF-16BE encoded.
		/// </summary>
		UTF16BE = 2,
		
		/// <summary>
		///    The string is to be UTF-8 encoded.
		/// </summary>
		UTF8 = 3,
		
		/// <summary>
		///    The string is to be UTF-16LE encoded.
		/// </summary>
		UTF16LE = 4
	}
	
	/// <summary>
	///    This class represents and performs operations on variable length
	///    list of <see cref="byte" /> elements.
	/// </summary>
	public class ByteVector : IList<byte>, IComparable<ByteVector>
	{
		/// <summary>
		///    Contains values to use in CRC calculation.
		/// </summary>
		private static uint [] crc_table = new uint[256] {
			0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
			0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
			0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
			0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
			0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
			0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
			0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
			0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
			0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
			0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
			0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
			0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
			0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
			0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
			0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
			0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
			0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
			0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
			0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
			0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
			0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
			0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
			0x5e9f46bf, 0x5a5e5b08,	0x571d7dd1, 0x53dc6066,
			0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
			0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
			0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
			0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
			0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
			0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, 
			0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
			0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
			0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a, 
			0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
			0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
			0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
			0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
			0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
			0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
			0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
			0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
			0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
			0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
			0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
			0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
			0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
			0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 
			0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, 
			0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
			0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 
			0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
			0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
			0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
			0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
			0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
			0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 
			0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
			0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
			0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
			0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
			0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
			0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
			0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c, 
			0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
			0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
		};
		
		#region Private Fields
		
		/// <summary>
		///    Contains the internal byte list.
		/// </summary>
		private List<byte> data = new List<byte>();
		
		#endregion
		
		
		
		#region Constructors
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="ByteVector" /> with a length of zero.
		/// </summary>
		public ByteVector ()
		{
		}
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="ByteVector" /> by copying the values from another
		///    instance.
		/// </summary>
		/// <param name="vector">
		///    A <see cref="ByteVector" /> object containing the bytes
		///    to be stored in the new instance.
		/// </param>
		public ByteVector (ByteVector vector)
		{
			if (vector != null)
				this.data.AddRange (vector);
		}
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="ByteVector" /> by copying the values from a
		///    specified <see cref="byte[]" />.
		/// </summary>
		/// <param name="data">
		///    A <see cref="byte[]" /> containing the bytes to be stored
		///    in the new instance.
		/// </param>
		public ByteVector (params byte [] data)
		{
			if (data != null)
				this.data.AddRange (data);
		}
		
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="ByteVector" /> by copying a specified number of
		///    values from a specified <see cref="byte[]" />.
		/// </summary>
		/// <param name="data">
		///    A <see cref="byte[]" /> containing the bytes to be stored
		///    in the new instance.
		/// </param>
		/// <param name="length">
		///    A <see cref="int" /> value specifying the number of bytes
		///    to be copied to the new instance.
		/// </param>
		/// <exception cref="ArgumentOutOfRangeException">
		///    <paramref name="length" /> is less than zero or greater
		///    than the length of the data.
		/// </exception>
		public ByteVector (byte [] data, int length)
		{
			if (length > data.Length)
				throw new ArgumentOutOfRangeException ("length",
					"Length exceeds size of data.");
			
			if (length < 0)
				throw new ArgumentOutOfRangeException ("length",
					"Length is less than zero.");
			
			if (length == data.Length) {
				this.data.AddRange (data);
			} else {
				byte [] array = new byte[length];
				System.Array.Copy (data, 0, array, 0, length);
				this.data.AddRange (array);
			}
		}
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="ByteVector" /> of specified size containing bytes
		///    with a zeroed value.
		/// </summary>
		/// <param name="size">
		///    A <see cref="int" /> value specifying the number of bytes
		///    to be stored in the new instance.
		/// </param>
		/// <remarks>
		///    Each element of the new instance will have a value of
		///    <c>0x00</c>. <see cref="ByteVector(int,byte)" /> to fill
		///    a new instance with a specified value.
		/// </remarks>
		/// <exception cref="ArgumentOutOfRangeException">
		///    <paramref name="size" /> is less than zero.
		/// </exception>
		public ByteVector (int size) : this (size, 0)
		{
		}
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="ByteVector" /> of specified size containing bytes
		///    of a specified value.
		/// </summary>
		/// <param name="size">
		///    A <see cref="int" /> value specifying the number of bytes
		///    to be stored in the new instance.
		/// </param>
		/// <param name="value">
		///    A <see cref="byte" /> value specifying the value to be
		///    stored in the new instance.
		/// </param>
		/// <exception cref="ArgumentOutOfRangeException">
		///    <paramref name="size" /> is less than zero.
		/// </exception>
		public ByteVector (int size, byte value)
		{
			if (size < 0)
				throw new ArgumentOutOfRangeException ("size",
					"Size is less than zero.");
			
			if(size == 0)
				return;
			
			byte [] data = new byte [size];
			
			for (int i = 0; i < size; i ++)
				data[i] = value;
			
			this.data.AddRange (data);
		}
		
		#endregion
		
		
		
		#region Public Properties
		
		/// <summary>
		///    Gets the data stored in the current instance.
		/// </summary>
		/// <value>
		///    A <see cref="byte[]" /> containing the data stored in the
		///    current instance.
		/// </value>
		public byte [] Data {
			get {return this.data.ToArray();}
		}
		
		/// <summary>
		///    Gets whether or not the current instance is empty.
		/// </summary>
		/// <value>
		///    A <see cref="bool" /> value indicating whether or not the
		///    current instance is empty.
		/// </value>
		public bool IsEmpty {
			get {return this.data.Count == 0;}
		}
		
		/// <summary>
		///    Gets the CRC-32 checksum of the current instance.
		/// </summary>
		/// <value>
		///    A <see cref="int" /> value containing the CRC-32 checksum
		///    of the current instance.
		/// </value>
		public uint Checksum {
			get {
				uint sum = 0;
				
				foreach(byte b in this.data)
					sum = (sum << 8) ^ crc_table
						[((sum >> 24) & 0xFF) ^ b];
				
				return sum;
			}
		}
		
		#endregion
		
		
		
		#region Public Methods
		
		/// <summary>
		///    Creates a new instance of <see cref="ByteVector" />
		///    containing a specified range of elements from the current
		///    instance.
		/// </summary>
		/// <param name="startIndex">
		///    A <see cref="int" /> value specifying the index at which
		///    to start copying elements from the current instance.
		/// </param>
		/// <param name="length">
		///    A <see cref="int" /> value specifying the number of
		///    elements to copy from the current instance.
		/// </param>
		/// <exception cref="ArgumentOutOfRangeException">
		///    <paramref name="startIndex" /> is less than zero or or
		///    equal to <see cref="Count" />. OR <paramref name="length"
		///    /> is less than zero or greater than the amount of
		///    available; data.
		/// </exception>
		public ByteVector Mid (int startIndex, int length)
		{
			if (startIndex < 0 || startIndex > Count)
				throw new ArgumentOutOfRangeException ("startIndex");
			
			if (length < 0 || startIndex + length > Count)
				throw new ArgumentOutOfRangeException ("length");
			
			if (length == 0)
				return new ByteVector ();
				
			if(startIndex + length > this.data.Count)
				length = this.data.Count - startIndex;
			
			byte [] data = new byte [length];
			
			this.data.CopyTo (startIndex, data, 0, length);
			
			return data;
		}

        public ByteVector Mid(int index)
        {
            return Mid(index, Count - index);
        }
        
        public int Find (ByteVector pattern, int offset, int byteAlign)
        {
            if (pattern == null)
               throw new ArgumentNullException ("pattern");
         
            if (pattern.Count > Count - offset)
                return -1;

            // Let's go ahead and special case a pattern of size one since that's common
            // and easy to make fast.

            if (pattern.Count == 1)
            {
                byte p = pattern [0];
                for (int i = offset; i < this.data.Count; i += byteAlign)
                    if (this [i] == p)
                        return i;
                return -1;
            }

            int [] last_occurrence = new int [256];

            for (int i = 0; i < 256; ++i)
                last_occurrence [i] = pattern.Count;

            for (int i = 0; i < pattern.Count - 1; ++i)
                last_occurrence [pattern [i]] = pattern.Count - i - 1;

            for (int i = pattern.Count - 1 + offset; i < this.data.Count; i += last_occurrence [this.data [i]])
            {
                int iBuffer = i;
                int iPattern = pattern.Count - 1;
                
                while(iPattern >= 0 && this.data [iBuffer] == pattern [iPattern])
                {
                    --iBuffer;
                    --iPattern;
                }

                if(-1 == iPattern && (iBuffer + 1 - offset) % byteAlign == 0)
                    return iBuffer + 1;
            }

            return -1;
        }

        public int Find(ByteVector pattern, int offset)
        {
            return Find(pattern, offset, 1);
        }

        public int Find(ByteVector pattern)
        {
            return Find(pattern, 0, 1);
        }
      
        public int RFind (ByteVector pattern, int offset, int byteAlign)
        {
            if (pattern == null)
                throw new ArgumentNullException ("pattern");
            
            if (pattern.Count == 0 || pattern.Count > Count - offset)
                return -1;

            // Let's go ahead and special case a pattern of size one since that's common
            // and easy to make fast.

            if (pattern.Count == 1)
            {
                byte p = pattern [0];
                for (int i = Count - offset - 1; i >= 0; i -= byteAlign)
                    if (this.data [i] == p)
                        return i;
                return -1;
            }
            
            int [] first_occurrence = new int [256];
            
            for (int i = 0; i < 256; ++i)
                first_occurrence [i] = pattern.Count;
            
            for (int i = pattern.Count - 1; i > 0; --i)
                first_occurrence [pattern [i]] = i;
            
            for (int i = Count - offset - pattern.Count; i >= 0; i -= first_occurrence [this.data [i]])
                if (ContainsAt (pattern, i) && (offset - i) % byteAlign == 0)
                    return i;
            
            return -1;
        }
        
        public int RFind(ByteVector pattern, int offset)
        {
            return RFind (pattern, offset, 1);
        }

        public int RFind(ByteVector pattern)
        {
            return RFind(pattern, 0, 1);
        }
      
        public bool ContainsAt(ByteVector pattern, int offset, 
            int patternOffset, int patternLength)
        {
            if (pattern == null)
               throw new ArgumentNullException ("pattern");
         
            if(pattern.Count < patternLength) {
                patternLength = pattern.Count;
            }

            // do some sanity checking -- all of these things are 
            // needed for the search to be valid
            if(patternLength > this.data.Count || offset >= this.data.Count || 
                patternOffset >= pattern.Count || patternLength == 0) {
                return false;
            }
            
            // loop through looking for a mismatch
            for(int i = 0; i < patternLength - patternOffset; i++) {
                if(this.data[i + offset] != pattern[i + patternOffset]) {
                    return false;
                }
            }

            return true;
        }

        public bool ContainsAt(ByteVector pattern, int offset, int patternOffset)
        {
            return ContainsAt(pattern, offset, patternOffset, Int32.MaxValue);
        }

        public bool ContainsAt(ByteVector pattern, int offset)
        {
            return ContainsAt(pattern, offset, 0);
        }
      
        public bool StartsWith(ByteVector pattern)
        {
            return ContainsAt(pattern, 0);
        }
      
        public bool EndsWith(ByteVector pattern)
        {
            if (pattern == null)
               throw new ArgumentNullException ("pattern");
         
            return ContainsAt(pattern, this.data.Count - pattern.Count);
        }

        public int EndsWithPartialMatch(ByteVector pattern)
        {
            if (pattern == null)
               throw new ArgumentNullException ("pattern");
         
            if(pattern.Count > this.data.Count) {
                return -1;
            }

            int start_index = this.data.Count - pattern.Count;

            // try to match the last n-1 bytes from the vector (where n is 
            // the pattern size) -- continue trying to match n-2, n-3...1 bytes

            for(int i = 1; i < pattern.Count; i++) {
                if(ContainsAt(pattern, start_index + i, 0, pattern.Count - i)) {
                    return start_index + i;
                }
            }

            return -1;
        }

        public void Add(ByteVector vector)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            if(vector != null) {
                this.data.AddRange(vector);
            }
        }

        public void Add(byte [] vector)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            if(vector != null) {
                this.data.AddRange(vector);
            }
        }
        
        public void Insert (int index, ByteVector vector)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            if(vector != null) {
                this.data.InsertRange (index, vector);
            }
        }
        
        public void Insert (int index, byte [] vector)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            if(vector != null) {
                this.data.InsertRange (index, vector);
            }
        }
        
        public ByteVector Resize(int size, byte padding)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            if(this.data.Count > size) {
                this.data.RemoveRange(size, this.data.Count - size);
            }
            
            while(this.data.Count < size) {
                this.data.Add (padding);
            }
            
            return this;
        }

        public ByteVector Resize(int size)
        {
            return Resize(size, 0);
        }
        
        public void RemoveRange (int index, int count)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
           this.data.RemoveRange (index, count);
        }
        #endregion
        
        #region Conversions

        public uint ToUInt(bool mostSignificantByteFirst)
        {
            uint sum = 0;
            for(int i = 0, last = Count > 4 ? 3 : Count - 1; i <= last; i++) {
                sum |= (uint)this[i] << ((mostSignificantByteFirst ? last - i : i) * 8);
            }
            return sum;
        }

        public uint ToUInt()
        {
            return ToUInt(true);
        }

        public ushort ToUShort(bool mostSignificantByteFirst)
        {
            ushort sum = 0;
            for(int i = 0, last = Count > 2 ? 1 : Count - 1; i <= last; i++) {
                sum |= (ushort)(this[i] << ((mostSignificantByteFirst ? last - i : i) * 8));
            }
            return sum;
        }

        public ushort ToUShort()
        {
            return ToUShort(true);
        }

        public ulong ToULong(bool mostSignificantByteFirst)
        {
            ulong sum = 0;
            for(int i = 0, last = Count > 8 ? 7 : Count - 1; i <= last; i++) {
                sum |= (ulong)this [i] << ((mostSignificantByteFirst ? last - i : i) * 8);
            }
            return sum;
        }

        public ulong ToULong()
        {
            return ToULong(true);
        }

        public string ToString(StringType type, int offset)
        {
            ByteVector bom = type == StringType.UTF16 && this.data.Count > 1 ? Mid(offset, 2) : null;
            string s = StringTypeToEncoding(type, bom).GetString(Data, offset, Count - offset);
            
            if(s.Length != 0 && (s[0] == 0xfffe || s[0] == 0xfeff)) { // UTF16 BOM
                return s.Substring (1);
            }
            
            return s;
        }

        public string ToString(StringType type)
        {
            return ToString (type, 0);
        }

        public override string ToString()
        {
            return ToString(StringType.UTF8);
        }
        
        public string[] ToStrings (StringType type, int offset)
        {
            return ToStrings (type, offset, int.MaxValue);
        }
		
		public string[] ToStrings (StringType type, int offset, int count)
		{
			int chunk = 0;
			int position = offset;
			
			StringCollection list = new StringCollection ();
			ByteVector separator = TextDelimiter (type);
			int align = separator.Count;
			
			while (chunk < count && position < Count) {
				int start = position;
				
				if (chunk + 1 == count) {
					position = offset + count;
				} else {
					position = Find (separator, start, align);
					
					if (position < 0)
						position = Count;
				}
				
				int length = position - start;
				
				if (length == 0) {
					list.Add (string.Empty);
				} else {
					string s = Mid (start, length).ToString (type);
					if (s.Length != 0 && (s[0] == 0xfffe || s[0] == 0xfeff)) { // UTF16 BOM
						s = s.Substring (1);
					}
					
					list.Add (s);
				}
				
				position += align;
			}
			
			return list.ToArray ();
		}
        
        #endregion
        
        #region Operators
      
        public static bool operator==(ByteVector first, ByteVector second)
        {
            if((object) first == null && (object) second == null) {
                return true;
            } else if((object) first == null || (object) second == null) {
                return false;
            }
            
            return first.Equals (second);
        }
        
        public static bool operator!=(ByteVector first, ByteVector second)
        {
           return !(first == second);
        }

        public static bool operator<(ByteVector first, ByteVector second)
        {
            if (first == null)
               throw new ArgumentNullException ("first");
            
            if (second == null)
               throw new ArgumentNullException ("second");
           
            return first.CompareTo (second) < 0;
        }

        public static bool operator<=(ByteVector first, ByteVector second)
        {
            if (first == null)
               throw new ArgumentNullException ("first");
            
            if (second == null)
               throw new ArgumentNullException ("second");
           
            return first.CompareTo (second) <= 0;
        }

        public static bool operator>(ByteVector first, ByteVector second)
        {
            if (first == null)
               throw new ArgumentNullException ("first");
            
            if (second == null)
               throw new ArgumentNullException ("second");
           
            return first.CompareTo (second) > 0;
        }

        public static bool operator>=(ByteVector first, ByteVector second)
        {
            if (first == null)
               throw new ArgumentNullException ("first");
            
            if (second == null)
               throw new ArgumentNullException ("second");
           
            return first.CompareTo (second) >= 0;
        }

        public static ByteVector operator+(ByteVector first, ByteVector second)
        {
            ByteVector sum = new ByteVector(first);
            sum.Add(second);
            return sum;
        }

        public static implicit operator ByteVector(byte value)
        {
            return new ByteVector(value);
        }

        public static implicit operator ByteVector(byte [] value)
        {
            return new ByteVector(value);
        }

        public static implicit operator ByteVector(string value)
        {
            return ByteVector.FromString(value);
        }
        
        #endregion

        #region Static Conversions

        public static ByteVector FromUInt(uint value, bool mostSignificantByteFirst)
        {
            ByteVector vector = new ByteVector();
            for(int i = 0; i < 4; i++) {
                vector.Add((byte)(value >> ((mostSignificantByteFirst ? 3 - i : i) * 8) & 0xFF));
            }
            return vector;
        }

        public static ByteVector FromUInt(uint value)
        {
            return FromUInt(value, true);
        }

        public static ByteVector FromUShort(ushort value, bool mostSignificantByteFirst)
        {
            ByteVector vector = new ByteVector();
            for(int i = 0; i < 2; i++) {
                vector.Add((byte)(value >> ((mostSignificantByteFirst ? 1 - i : i) * 8) & 0xFF));
            }
            return vector;
        }

        public static ByteVector FromUShort(ushort value)
        {
            return FromUShort(value, true);
        }

        public static ByteVector FromULong(ulong value, bool mostSignificantByteFirst)
        {
            ByteVector vector = new ByteVector();
            for(int i = 0; i < 8; i++) {
                vector.Add((byte)(value >> ((mostSignificantByteFirst ? 7 - i : i) * 8) & 0xFF));
            }
            return vector;
        }

        public static ByteVector FromULong(ulong value)
        {
            return FromULong(value, true);
        }
        
        public static ByteVector FromString(string text, StringType type, int length)
        {
            ByteVector data = new ByteVector ();
            
            if (type == StringType.UTF16)
                data.Add (new byte [] {0xff, 0xfe});
            
            if (text == null || text.Length == 0)
                return data;
            
            if (text.Length > length)
                text = text.Substring (0, length);
            
            data.Add (StringTypeToEncoding (type, null).GetBytes (text));
            
            return data;
        }

        public static ByteVector FromString(string text, StringType type)
        {
            return FromString(text, type, Int32.MaxValue);
        }

        public static ByteVector FromString(string text, int length)
        {
            return FromString(text, StringType.UTF8, length);
        }

        public static ByteVector FromString(string text)
        {
            return FromString (text, StringType.UTF8);
        }
      
        public static ByteVector FromPath (string path)
        {
            byte [] tmp_out;
            return FromPath (path, out tmp_out, false);
        }
        
        internal static ByteVector FromPath (string path, out byte [] firstChunk, bool copyFirstChunk)
        {
           return FromFile (new File.LocalFileAbstraction (path), out firstChunk, copyFirstChunk);
        }

        public static ByteVector FromFile (File.IFileAbstraction abstraction)
        {
            byte [] tmp_out;
            return FromFile (abstraction, out tmp_out, false);
        }
        
        internal static ByteVector FromFile (File.IFileAbstraction abstraction, out byte [] firstChunk, bool copyFirstChunk)
        {
           System.IO.Stream stream = abstraction.ReadStream;
           ByteVector output = FromStream (stream, out firstChunk, copyFirstChunk);
           abstraction.CloseStream (stream);
           return output;
        }

        public static ByteVector FromStream(System.IO.Stream stream)
        {
            byte [] tmp_out;
            return FromStream(stream, out tmp_out, false);
        }

        internal static ByteVector FromStream(System.IO.Stream stream, 
            out byte [] firstChunk, bool copyFirstChunk)
        {
            ByteVector vector = new ByteVector();
            byte [] bytes = new byte[4096];
            int read_size = bytes.Length;
            int bytes_read = 0;
            bool set_first_chunk = false;

            firstChunk = null;

            while(true) {
                Array.Clear(bytes, 0, bytes.Length);
                int n = stream.Read(bytes, 0, read_size);
                vector.Add(bytes);
                bytes_read += n;

                if(!set_first_chunk) {
                    if(copyFirstChunk) {
                        if(firstChunk == null || firstChunk.Length != read_size) {
                            firstChunk = new byte[read_size];
                        }

                        Array.Copy(bytes, 0, firstChunk, 0, n);
                    }
                    set_first_chunk = true;
                }

                if((bytes_read == stream.Length && stream.Length > 0) || 
                    (n < read_size && stream.Length <= 0)) {
                    break;
                }
            }

            if(stream.Length > 0 && vector.Count != stream.Length) {
                vector.Resize((int)stream.Length);
            }

            return vector;
        }
      
        #endregion
      
        #region Utilities
        
      private static readonly ReadOnlyByteVector td1 = new ReadOnlyByteVector ((int)1);
      private static readonly ReadOnlyByteVector td2 = new ReadOnlyByteVector ((int)2);
      public static ByteVector TextDelimiter (StringType type)
      {
         return (type == StringType.UTF16 || type == StringType.UTF16BE || type == StringType.UTF16LE) ? td2 : td1;
      }
        
        private static System.Text.Encoding last_utf16_encoding = System.Text.Encoding.Unicode;
        private static System.Text.Encoding StringTypeToEncoding(StringType type, ByteVector bom)
        {
            switch(type) {
                case StringType.UTF16:
                    // If we have a BOM, return the appropriate encoding.
                    // Otherwise, assume we're reading from a string that
                    // was already identified. In that case, the encoding will
                    // be stored as last_utf16_encoding;
                    if (bom == null || (bom [0] == 0xFF && bom [1] == 0xFE))
                        return (last_utf16_encoding = System.Text.Encoding.Unicode);
                    if (bom == null || (bom [1] == 0xFF && bom [0] == 0xFE))
                        return (last_utf16_encoding = System.Text.Encoding.BigEndianUnicode);
                    return last_utf16_encoding;
                case StringType.UTF16BE:
                    return System.Text.Encoding.BigEndianUnicode;
                case StringType.UTF8:
                    return System.Text.Encoding.UTF8;
                case StringType.UTF16LE:
                    return System.Text.Encoding.Unicode;
            }
            
            try
            {
               // The right format but not ECMA.
               return System.Text.Encoding.GetEncoding("latin1");
            }
            catch (ArgumentException)
            {
               return System.Text.Encoding.UTF8;
            }
        }
      
        #endregion
      
        #region System.Object
      
      public override bool Equals (object obj)
      {
         if (!(obj is ByteVector))
            return false;
         
         return Equals ((ByteVector) obj);
      }
      
      public bool Equals (ByteVector other)
      {
         return CompareTo (other) == 0;
      }
      
        public override int GetHashCode ()
        {
           unchecked
           {
              return (int) Checksum;
           }
        }
        
        #endregion
        
        #region IComparable<T>
        
        public int CompareTo (ByteVector other)
        {
           if ((object) other == null)
              throw new ArgumentNullException ("other");
           
           int diff = Count - other.Count;
           
           for(int i = 0; diff == 0 && i < Count; i ++)
              diff = this [i] - other [i];
           
           return diff;
        }
        
        #endregion
        
        #region IEnumerable<T>

        public IEnumerator<byte> GetEnumerator()
        {
            return this.data.GetEnumerator();
        }
        
        IEnumerator IEnumerable.GetEnumerator()
        {
            return this.data.GetEnumerator();
        }
        
        #endregion

        #region ICollection<T>
        
        public void Clear()
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            this.data.Clear();
        }

        public void Add(byte item)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            this.data.Add(item);
        }

        public bool Remove(byte item)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            return this.data.Remove(item);
        }
        
        public void CopyTo(byte [] array, int arrayIndex)
        {
            this.data.CopyTo(array, arrayIndex);
        }
        
        public bool Contains(byte item)
        {
            return this.data.Contains(item);
        }

        public int Count {
            get { return this.data.Count; }
        }

        public bool IsSynchronized {
            get { return false; }
        }

        public object SyncRoot {
            get { return this; }
        }
        
        #endregion
        
        #region IList<T>
        
        public void RemoveAt(int index)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            this.data.RemoveAt(index);
        }
        
        public void Insert(int index, byte item)
        {
        	   if (IsReadOnly)
               throw new NotSupportedException ("Cannot edit readonly objects.");
            
            this.data.Insert(index, item);
        }
        
        public int IndexOf(byte item)
        {
            return this.data.IndexOf(item);
        }
        
        public virtual bool IsReadOnly {
            get { return false; }
        }
        
        public virtual bool IsFixedSize {
            get { return false; }
        }
        
        public byte this[int index] {
            get { return this.data[index]; }
            set { if (IsReadOnly) throw new NotSupportedException ("Cannot edit readonly objects."); data[index] = value; }
        }
        
        #endregion
    }
}
