/*
  Copyright 2008-2012 Stefano Chizzolini. http://www.pdfclown.org

  Contributors:
    * Stefano Chizzolini (original code developer, http://www.stefanochizzolini.it)

  This file should be part of the source code distribution of "PDF Clown library" (the
  Program): see the accompanying README files for more info.

  This Program is free software; you can redistribute it and/or modify it under the terms
  of the GNU Lesser General Public License as published by the Free Software Foundation;
  either version 3 of the License, or (at your option) any later version.

  This Program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY,
  either expressed or implied; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the License for more details.

  You should have received a copy of the GNU Lesser General Public License along with this
  Program (see README files); if not, go to the GNU website (http://www.gnu.org/licenses/).

  Redistribution and use, with or without modification, are permitted provided that such
  redistributions retain the above copyright notice, license and disclaimer, along with
  this list of conditions.
*/

using org.pdfclown.bytes;
using org.pdfclown.documents;
using org.pdfclown.documents.contents.xObjects;
using org.pdfclown.objects;

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

namespace org.pdfclown.documents.interaction.annotations
{
  /**
    <summary>Appearance states [PDF:1.6:8.4.4].</summary>
  */
  [PDF(VersionEnum.PDF12)]
  public sealed class AppearanceStates
    : PdfObjectWrapper<PdfDataObject>,
      IDictionary<PdfName,FormXObject>
  {
    #region dynamic
    #region fields
    private Appearance appearance;

    private PdfName statesKey;
    #endregion

    #region constructors
    internal AppearanceStates(
      PdfName statesKey,
      Appearance appearance
      ) : base(appearance.BaseDataObject[statesKey])
    {
      this.appearance = appearance;
      this.statesKey = statesKey;
    }
    #endregion

    #region interface
    #region public
    /**
      <summary>Gets the appearance associated to these states.</summary>
    */
    public Appearance Appearance
    {get{return appearance;}}

    public override object Clone(
      Document context
      )
    {throw new NotImplementedException();} // TODO: verify appearance reference.

//TODO
  /**
    Gets the key associated to a given value.
  */
//   public PdfName GetKey(
//     FormXObject value
//     )
//   {return BaseDataObject.GetKey(value.BaseObject);}

    #region IDictionary
    public void Add(
      PdfName key,
      FormXObject value
      )
    {EnsureDictionary()[key] = value.BaseObject;}

    public bool ContainsKey(
      PdfName key
      )
    {
      PdfDataObject baseDataObject = BaseDataObject;
      if(baseDataObject == null) // No state.
        return false;
      else if(baseDataObject is PdfStream) // Single state.
        return (key == null);
      else // Multiple state.
        return ((PdfDictionary)baseDataObject).ContainsKey(key);
    }

    public ICollection<PdfName> Keys
    {get{throw new NotImplementedException();}}

    public bool Remove(
      PdfName key
      )
    {
      PdfDataObject baseDataObject = BaseDataObject;
      if(baseDataObject == null) // No state.
        return false;
      else if(baseDataObject is PdfStream) // Single state.
      {
        if(key == null)
        {
          BaseObject = null;
          appearance.BaseDataObject.Remove(statesKey);
          return true;
        }
        else // Invalid key.
          return false;
      }
      else // Multiple state.
        return ((PdfDictionary)baseDataObject).Remove(key);
    }

    public FormXObject this[
      PdfName key
      ]
    {
      get
      {
        PdfDataObject baseDataObject = BaseDataObject;
        if(baseDataObject == null) // No state.
          return null;
        else if(key == null)
        {
          if(baseDataObject is PdfStream) // Single state.
            return FormXObject.Wrap(BaseObject);
          else // Multiple state, but invalid key.
            return null;
        }
        else // Multiple state.
          return FormXObject.Wrap(((PdfDictionary)baseDataObject)[key]);
      }
      set
      {
        if(key == null) // Single state.
        {
          BaseObject = value.BaseObject;
          appearance.BaseDataObject[statesKey] = BaseObject;
        }
        else // Multiple state.
        {EnsureDictionary()[key] = value.BaseObject;}
      }
    }

    public bool TryGetValue(
      PdfName key,
      out FormXObject value
      )
    {
      value = this[key];
      return (value != null || ContainsKey(key));
    }

    public ICollection<FormXObject> Values
    {get{throw new NotImplementedException();}}

    #region ICollection
    void ICollection<KeyValuePair<PdfName,FormXObject>>.Add(
      KeyValuePair<PdfName,FormXObject> entry
      )
    {Add(entry.Key,entry.Value);}

    public void Clear(
      )
    {EnsureDictionary().Clear();}

    bool ICollection<KeyValuePair<PdfName,FormXObject>>.Contains(
      KeyValuePair<PdfName,FormXObject> entry
      )
    {
      PdfDataObject baseDataObject = BaseDataObject;
      if(baseDataObject == null) // No state.
        return false;
      else if(baseDataObject is PdfStream) // Single state.
        return ((FormXObject)entry.Value).BaseObject.Equals(BaseObject);
      else // Multiple state.
        return entry.Value.Equals(this[entry.Key]);
    }

    public void CopyTo(
      KeyValuePair<PdfName,FormXObject>[] entries,
      int index
      )
    {throw new NotImplementedException();}

    public int Count
    {
      get
      {
        PdfDataObject baseDataObject = BaseDataObject;
        if(baseDataObject == null) // No state.
          return 0;
        else if(baseDataObject is PdfStream) // Single state.
          return 1;
        else // Multiple state.
          return ((PdfDictionary)baseDataObject).Count;
      }
    }

    public bool IsReadOnly
    {get{return false;}}

    public bool Remove(
      KeyValuePair<PdfName,FormXObject> entry
      )
    {throw new NotImplementedException();}

    #region IEnumerable<KeyValuePair<PdfName,FormXObject>>
    IEnumerator<KeyValuePair<PdfName,FormXObject>> IEnumerable<KeyValuePair<PdfName,FormXObject>>.GetEnumerator(
      )
    {
      PdfDataObject baseDataObject = BaseDataObject;
      if(baseDataObject == null) // No state.
      { /* NOOP. */ }
      else if(baseDataObject is PdfStream) // Single state.
      {
        yield return new KeyValuePair<PdfName,FormXObject>(
          null,
          FormXObject.Wrap(BaseObject)
          );
      }
      else // Multiple state.
      {
        foreach(KeyValuePair<PdfName,PdfDirectObject> entry in ((PdfDictionary)baseDataObject))
        {
          yield return new KeyValuePair<PdfName,FormXObject>(
            entry.Key,
            FormXObject.Wrap(entry.Value)
            );
        }
      }
    }

    #region IEnumerable
    IEnumerator IEnumerable.GetEnumerator(
      )
    {return ((IEnumerable<KeyValuePair<PdfName,FormXObject>>)this).GetEnumerator();}
    #endregion
    #endregion
    #endregion
    #endregion
    #endregion
    #endregion

    #region private
    private PdfDictionary EnsureDictionary(
      )
    {
      PdfDataObject baseDataObject = BaseDataObject;
      if(!(baseDataObject is PdfDictionary))
      {
        /*
          NOTE: Single states are erased as they have no valid key
          to be consistently integrated within the dictionary.
        */
        BaseObject = ((PdfDirectObject)(baseDataObject = new PdfDictionary()));
        appearance.BaseDataObject[statesKey] = (PdfDictionary)baseDataObject;
      }
      return (PdfDictionary)baseDataObject;
    }
    #endregion
    #endregion
  }
}