#region PDFsharp - A .NET library for processing PDF

//

// Authors:

//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)

//

// Copyright (c) 2005-2009 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 PdfSharp.Internal;

using PdfSharp.Pdf.IO;

using PdfSharp.Pdf.Internal;



namespace PdfSharp.Pdf.Filters

{

  /// <summary>

  /// Applies standard filters to streams.

  /// </summary>

  public static class Filtering

  {

    /// <summary>

    /// Gets the filter specified by the case sensitive name.

    /// </summary>

    public static Filter GetFilter(string filterName)

    {

      if (filterName.StartsWith("/"))

        filterName = filterName.Substring(1);



      // Some tools use abbreviations

      switch (filterName)

      {

        case "ASCIIHexDecode":

        case "AHx":

          if (Filtering.asciiHexDecode == null)

            Filtering.asciiHexDecode = new ASCIIHexDecode();

          return Filtering.asciiHexDecode;



        case "ASCII85Decode":

        case "A85":

          if (Filtering.ascii85Decode == null)

            Filtering.ascii85Decode = new ASCII85Decode();

          return Filtering.ascii85Decode;



        case "LZWDecode":

        case "LZW":

          if (Filtering.lzwDecode == null)

            Filtering.lzwDecode = new LzwDecode();

          return Filtering.lzwDecode;



        case "FlateDecode":

        case "Fl":

          if (Filtering.flateDecode == null)

            Filtering.flateDecode = new FlateDecode();

          return Filtering.flateDecode;



        //case "RunLengthDecode":

        //  if (Filtering.RunLengthDecode == null)

        //    Filtering.RunLengthDecode = new RunLengthDecode();

        //  return Filtering.RunLengthDecode;

        //

        //case "CCITTFaxDecode":

        //  if (Filtering.CCITTFaxDecode == null)

        //    Filtering.CCITTFaxDecode = new CCITTFaxDecode();

        //  return Filtering.CCITTFaxDecode;

        //

        //case "JBIG2Decode":

        //  if (Filtering.JBIG2Decode == null)

        //    Filtering.JBIG2Decode = new JBIG2Decode();

        //  return Filtering.JBIG2Decode;

        //

        //case "DCTDecode":

        //  if (Filtering.DCTDecode == null)

        //    Filtering.DCTDecode = new DCTDecode();

        //  return Filtering.DCTDecode;

        //

        //case "JPXDecode":

        //  if (Filtering.JPXDecode == null)

        //    Filtering.JPXDecode = new JPXDecode();

        //  return Filtering.JPXDecode;

        //

        //case "Crypt":

        //  if (Filtering.Crypt == null)

        //    Filtering.Crypt = new Crypt();

        //  return Filtering.Crypt;



        case "RunLengthDecode":

        case "CCITTFaxDecode":

        case "JBIG2Decode":

        case "DCTDecode":

        case "JPXDecode":

        case "Crypt":

          Debug.WriteLine("Filter not implemented: " + filterName);

          return null;

      }

      throw new NotImplementedException("Unknown filter: " + filterName);

    }



    /// <summary>

    /// Gets the filter singleton.

    /// </summary>

    public static ASCIIHexDecode ASCIIHexDecode

    {

      get

      {

        if (Filtering.asciiHexDecode == null)

          Filtering.asciiHexDecode = new ASCIIHexDecode();

        return Filtering.asciiHexDecode;

      }

    }

    static ASCIIHexDecode asciiHexDecode;



    /// <summary>

    /// Gets the filter singleton.

    /// </summary>

    public static ASCII85Decode ASCII85Decode

    {

      get

      {

        if (Filtering.ascii85Decode == null)

          Filtering.ascii85Decode = new ASCII85Decode();

        return Filtering.ascii85Decode;

      }

    }

    static ASCII85Decode ascii85Decode;



    /// <summary>

    /// Gets the filter singleton.

    /// </summary>

    public static LzwDecode LzwDecode

    {

      get

      {

        if (Filtering.lzwDecode == null)

          Filtering.lzwDecode = new LzwDecode();

        return Filtering.lzwDecode;

      }

    }

    static LzwDecode lzwDecode;



    /// <summary>

    /// Gets the filter singleton.

    /// </summary>

    public static FlateDecode FlateDecode

    {

      get

      {

        if (Filtering.flateDecode == null)

          Filtering.flateDecode = new FlateDecode();

        return Filtering.flateDecode;

      }

    }

    static FlateDecode flateDecode;



    //runLengthDecode

    //ccittFaxDecode

    //jbig2Decode

    //dctDecode

    //jpxDecode

    //crypt



    /// <summary>

    /// Encodes the data with the specified filter.

    /// </summary>

    public static byte[] Encode(byte[] data, string filterName)

    {

      Filter filter = GetFilter(filterName);

      if (filter != null)

        return filter.Encode(data);

      return null;

    }



    /// <summary>

    /// Encodes a raw string with the specified filter.

    /// </summary>

    public static byte[] Encode(string rawString, string filterName)

    {

      Filter filter = GetFilter(filterName);

      if (filter != null)

        return filter.Encode(rawString);

      return null;

    }



    /// <summary>

    /// Decodes the data with the specified filter.

    /// </summary>

    public static byte[] Decode(byte[] data, string filterName, FilterParms parms)

    {

      Filter filter = GetFilter(filterName);

      if (filter != null)

        return filter.Decode(data, parms);

      return null;

    }



    /// <summary>

    /// Decodes the data with the specified filter.

    /// </summary>

    public static byte[] Decode(byte[] data, string filterName)

    {

      Filter filter = GetFilter(filterName);

      if (filter != null)

        return filter.Decode(data, null);

      return null;

    }



    /// <summary>

    /// Decodes the data with the specified filter.

    /// </summary>

    public static byte[] Decode(byte[] data, PdfItem filterItem)

    {

      byte[] result = null;

      if (filterItem is PdfName)

      {

        Filter filter = GetFilter(filterItem.ToString());

        if (filter != null)

          result = filter.Decode(data);

      }

      else if (filterItem is PdfArray)

      {

        PdfArray array = (PdfArray)filterItem;

        foreach (PdfItem item in array)

          data = Filtering.Decode(data, item);

        result = data;

      }

      return result;

    }



    /// <summary>

    /// Decodes to a raw string with the specified filter.

    /// </summary>

    public static string DecodeToString(byte[] data, string filterName, FilterParms parms)

    {

      Filter filter = GetFilter(filterName);

      if (filter != null)

        return filter.DecodeToString(data, parms);

      return null;

    }



    /// <summary>

    /// Decodes to a raw string with the specified filter.

    /// </summary>

    public static string DecodeToString(byte[] data, string filterName)

    {

      Filter filter = GetFilter(filterName);

      if (filter != null)

        return filter.DecodeToString(data, null);

      return null;

    }

  }

}