/*  Copyright (C) 2008-2016 Peter Palotas, Jeffrey Jangli, Alexandr Normuradov
 *  
 *  Permission is hereby granted, free of charge, to any person obtaining a copy 
 *  of this software and associated documentation files (the "Software"), to deal 
 *  in the Software without restriction, including without limitation the rights 
 *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
 *  copies of the Software, and to permit persons to whom the Software is 
 *  furnished to do so, subject to the following conditions:
 *  
 *  The above copyright notice and this permission notice shall be included in 
 *  all copies or substantial portions of the Software.
 *  
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
 *  THE SOFTWARE. 
 */

using System;
using System.Text;

namespace Alphaleonis.Win32.Filesystem
{
   /// <summary>Information about an alternate data stream.</summary>  
   /// <seealso cref="O:Alphaleonis.Win32.Filesystem.File.EnumerateAlternateDataStreams"/> 
   public struct AlternateDataStreamInfo
   {
      #region Constructor

      internal AlternateDataStreamInfo(string fullPath, NativeMethods.WIN32_FIND_STREAM_DATA findData) : this()
      {
         StreamName = ParseStreamName(findData.cStreamName);
         Size = findData.StreamSize;
         _fullPath = fullPath;
      }

      #endregion // Constructor

      #region Public Properties

      /// <summary>Gets the name of the alternate data stream.</summary>
      /// <remarks>This value is an empty string for the default stream (:$DATA), and for any other data stream it contains the name of the stream.</remarks>
      /// <value>The name of the stream.</value>
      public string StreamName { get; private set; }

      /// <summary>Gets the size of the stream.</summary>      
      public long Size { get; private set; }


      private readonly string _fullPath;

      /// <summary>Gets the full path to the stream.</summary>
      /// <remarks>
      ///   This is a path in long path format that can be passed to <see cref="O:Alphaleonis.Win32.Filesystem.File.Open"/> to open the stream if
      ///   <see cref="PathFormat.FullPath"/> or
      ///   <see cref="PathFormat.LongFullPath"/> is specified.
      /// </remarks>
      /// <value>The full path to the stream in long path format.</value>
      public string FullPath
      {
         get { return _fullPath + Path.StreamSeparator + StreamName + Path.StreamDataLabel; }
      }

      #endregion // Public Properties

      #region Public Methods

      /// <summary>Returns the hash code for this instance.</summary>
      /// <returns>A 32-bit signed integer that is the hash code for this instance.</returns>
      public override int GetHashCode()
      {
         return StreamName.GetHashCode();
      }

      /// <summary>Indicates whether this instance and a specified object are equal.</summary>
      /// <param name="obj">The object to compare with the current instance.</param>
      /// <returns>
      ///   true if <paramref name="obj" /> and this instance are the same type and represent the same value; otherwise, false.
      /// </returns>
      public override bool Equals(object obj)
      {
         if (obj is AlternateDataStreamInfo)
         {
            AlternateDataStreamInfo other = (AlternateDataStreamInfo) obj;
            return StreamName.Equals(other.StreamName, StringComparison.OrdinalIgnoreCase) && Size.Equals(other.Size);
         }

         return false;
      }

      /// <summary>Equality operator.</summary>
      /// <param name="first">The first operand.</param>
      /// <param name="second">The second operand.</param>
      /// <returns>The result of the operation.</returns>
      public static bool operator ==(AlternateDataStreamInfo first, AlternateDataStreamInfo second)
      {
         return first.Equals(second);
      }

      /// <summary>Inequality operator.</summary>
      /// <param name="first">The first operand.</param>
      /// <param name="second">The second operand.</param>
      /// <returns>The result of the operation.</returns>
      public static bool operator !=(AlternateDataStreamInfo first, AlternateDataStreamInfo second)
      {
         return !first.Equals(second);
      }

      #endregion // Public Methods

      #region Private Methods

      private static string ParseStreamName(string input)
      {
         if (input == null || input.Length < 2)
            return string.Empty;

         if (input[0] != Path.StreamSeparatorChar)
            throw new ArgumentException(Resources.Invalid_Stream_Name);

         var sb = new StringBuilder();
         for (int i = 1; i < input.Length; i++)
         {
            if (input[i] == Path.StreamSeparatorChar)
               break;

            sb.Append(input[i]);
         }

         return sb.ToString();
      }

      #endregion // Private Methods
   }
}