# License
#
#   Copyright (c) 2004 Koen Vervloesem. All rights reserved.
#
#   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, and/or sell copies of the Software, and to permit persons
#   to whom the Software is furnished to do so, provided that the above
#   copyright notice(s) and this permission notice appear in all copies of
#   the Software and that both the above copyright notice(s) and this
#   permission notice appear in supporting documentation.
#
#   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
#   OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
#   HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY
#   SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER
#   RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
#   CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
#   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
#   Except as contained in this notice, the name of a copyright holder
#   shall not be used in advertising or otherwise to promote the sale, use
#   or other dealings in this Software without prior written authorization
#   of the copyright holder.

require 'rpdf'
require 'image_size'

class JPEG2PDF
  include RPDF

  def initialize(pdf)
    @doc = Document.new(pdf)
    @imagenumber = 0
  end

  def add_jpeg(filename)
    jpegfile = File.open(filename)
    imagedata = jpegfile.read
    jpegfile.close
    size = ImageSize.new(imagedata)
    if(size.get_type == 'JPEG')
      width = size.get_width
      height = size.get_height
      bpc = size.get_bpc
      components = size.get_components
      if components == 1
        colorspace = :DeviceGray
      elsif components == 3
        colorspace = :DeviceRGB
      elsif components == 4
        colorspace = :DeviceCMYK
      else
        raise Exception.new("Unsupported colorspace in image #{filename}")
      end

      imagestream = PDFStream.new(imagedata, @doc)
      imagestream.dict[:Filter] = [:DCTDecode]
      imagestream.dict[:Name] = "Image#{@imagenumber}".intern

      imagedictionary = ImageDictionary.new(width, height, colorspace, bpc)
      imagestream.dict.update(imagedictionary)
	  imagestream.invalidate # write jpeg as soon as possible

      page = Page.new(@doc, @doc.pagetree)
      page[:MediaBox] = [0, 0, width, height]
      page[:Resources] = { :XObject => { "Image#{@imagenumber}".intern => imagestream } }

      contentstream = PDFStream.new("q\n#{width} 0 0 #{height} 0 0 cm\n/Image#{@imagenumber} Do\nQ", @doc)

      page[:Contents] = contentstream
      @imagenumber = @imagenumber + 1
    end
  end

  def close
    @doc.close_pdf
  end

end