#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2007 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// 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.
#endregion

using System;
using System.Diagnostics;
using System.Collections;
using System.Globalization;
using System.Text;
using System.IO;
using PdfSharp.Drawing;
using PdfSharp.Internal;

namespace PdfSharp.Pdf.Advanced
{
  /// <summary>
  /// Contains all used images of a document.
  /// </summary>
  internal sealed class PdfImageTable : PdfResourceTable
  {
    /// <summary>
    /// Initializes a new instance of this class, which is a singleton for each document.
    /// </summary>
    public PdfImageTable(PdfDocument document) : base(document)
    {
    }

    /// <summary>
    /// Gets a PdfImage from an XImage. If no PdfImage already exists, a new one is created.
    /// </summary>
    public PdfImage GetImage(XImage image)
    {
      PdfImageTable.ImageSelector selector = image.selector;
      if (selector == null)
      {
        selector = new ImageSelector(image);
        image.selector = selector;
      }
      PdfImage pdfImage = this.images[selector] as PdfImage;
      if (pdfImage == null)
      {
        pdfImage = new PdfImage(this.owner, image);
        //pdfImage.Document = this.document;
        Debug.Assert(pdfImage.Owner == this.owner);
        this.images[selector] = pdfImage;
        //if (this.document.EarlyWrite)
        //{
        //  //pdfFont.Close(); delete 
        //  //pdfFont.AssignObjID(ref this.document.ObjectID); // BUG just test code!!!!
        //  //pdfFont.WriteObject(null);
        //}
      }
      return pdfImage;
    }

    /// <summary>
    /// Map from ImageSelector to PdfImage.
    /// </summary>
    Hashtable images = new Hashtable();

    /// <summary>
    /// A collection of information that uniquely idendifies a particular PdfImage.
    /// </summary>
    public class ImageSelector
    {
      /// <summary>
      /// Initializes a new instance of ImageSelector from an XImage.
      /// </summary>
      public ImageSelector(XImage image)
      {
        // HACK: implement a way to identify images when they are reused
        if (image.path == null)
          image.path = Guid.NewGuid().ToString();

        // HACK: just use full path to identify
        this.path = image.path.ToLower(CultureInfo.InvariantCulture);
      }

      public string Path
      {
        get {return this.path;}
        set {this.path = value;}
      }
      string path;

      public override bool Equals(object obj)
      {
        ImageSelector selector = obj as ImageSelector;
        if (obj == null)
          return false;
        return this.path == selector.path;;
      }

      public override int GetHashCode()
      {
        return this.path.GetHashCode();
      }
    }
  }
}
