#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 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.Text;
using System.IO;
using PdfSharp.Pdf.Advanced;
using PdfSharp.Pdf.IO;

namespace PdfSharp.Pdf.Annotations
{
  /// <summary>
  /// Represents the annotations array of a page.
  /// </summary>
  public sealed class PdfAnnotations : PdfArray
  {
    internal PdfAnnotations(PdfDocument document)
      : base(document)
    {
    }

    internal PdfAnnotations(PdfArray array)
      : base(array)
    {
    }

    /// <summary>
    /// Adds the specified annotation.
    /// </summary>
    /// <param name="annotation">The annotation.</param>
    public void Add(PdfAnnotation annotation)
    {
      annotation.Document = this.Owner;
      this.Owner.irefTable.Add(annotation);
      Elements.Add(annotation.Reference);
    }

    /// <summary>
    /// Removes an annotation from the document.
    /// </summary>
    public void Remove(PdfAnnotation annotation)
    {
      if (annotation.Owner != Owner)
        throw new InvalidOperationException("The annotation does not belong to this document.");

      Owner.Internals.RemoveObject(annotation);
      Elements.Remove(annotation.Reference);
    }

    /// <summary>
    /// Removes all the annotations from the current page.
    /// </summary>
    public void Clear()
    {
      for (int idx = Count - 1; idx >= 0; idx--)
        Page.Annotations.Remove(page.Annotations[idx]);
    }

    //public void Insert(int index, PdfAnnotation annotation)
    //{
    //  annotation.Document = this.Document;
    //  this.annotations.Insert(index, annotation);
    //}

    /// <summary>
    /// Gets the number of annoations in this collection.
    /// </summary>
    public int Count
    {
      get { return Elements.Count; }
    }

    /// <summary>
    /// Gets the <see cref="PdfSharp.Pdf.Annotations.PdfAnnotation"/> at the specified index.
    /// </summary>
    public PdfAnnotation this[int index]
    {
      get
      {
        PdfReference iref = null;
        PdfDictionary dict = null;
        PdfItem item = Elements[index];
        if ((iref = item as PdfReference) != null)
        {
          Debug.Assert(iref.Value is PdfDictionary, "Reference to dictionary expected.");
          dict = (PdfDictionary)iref.Value;
        }
        else
        {
          Debug.Assert(item is PdfDictionary, "Dictionary expected.");
          dict = (PdfDictionary)item;
        }
        PdfAnnotation annotation = dict as PdfAnnotation;
        if (annotation == null)
        {
          annotation = new PdfGenericAnnotation(dict);
          if (iref == null)
            Elements[index] = annotation;
        }
        return annotation;
      }
    }

    //public PdfAnnotation this[int index]
    //{
    //  get 
    //  {
    //      //DMH 6/7/06
    //      //Broke this out to simplfy debugging
    //      //Use a generic annotation to access the Meta data
    //      //Assign this as the parent of the annotation
    //      PdfReference r = Elements[index] as PdfReference;
    //      PdfDictionary d = r.Value as PdfDictionary;
    //      PdfGenericAnnotation a = new PdfGenericAnnotation(d);
    //      a.Collection = this;
    //      return a;
    //  }
    //}

    /// <summary>
    /// Gets the page the annotations belongs to.
    /// </summary>
    internal PdfPage Page
    {
      get { return this.page; }
      set { this.page = value; }
    }
    PdfPage page;

    /// <summary>
    /// Fixes the /P element in imported annotation.
    /// </summary>
    internal static void FixImportedAnnotation(PdfPage page)
    {
      PdfArray annots = page.Elements.GetArray(PdfPage.Keys.Annots);
      if (annots != null)
      {
        int count = annots.Elements.Count;
        for (int idx=0;idx<count;idx++)
        {
          PdfDictionary annot = annots.Elements.GetDictionary(idx);
          if (annot != null && annot.Elements.Contains("/P"))
            annot.Elements["/P"] = page.Reference;
        }
      }
    }

    /// <summary>
    /// Returns an enumerator that iterates through a collection.
    /// </summary>
    public override IEnumerator GetEnumerator()
    {
      return new AnnotationsIterator(this);
    }

    class AnnotationsIterator : IEnumerator
    {
      PdfAnnotations annotations;
      int index;

      public AnnotationsIterator(PdfAnnotations annotations)
      {
        this.annotations = annotations;
        this.index = -1;
      }

      public object Current
      {
        get { return this.annotations[this.index]; }
      }

      public bool MoveNext()
      {
        return ++this.index < this.annotations.Count;
      }

      public void Reset()
      {
        this.index = -1;
      }
    }
  }
}