#!/usr/bin/env ruby

if ARGV.length != 3
  puts "Usage: fop.rb <PDF OUTPUT FILENAME> <XSLT INPUT FILENAME> <XML INPUT FILENAME>"
else
  $LOAD_PATH << File.join(File.expand_path(File.dirname(__FILE__)),'..','yajb')

  require 'yajb/jbridge'
  include JavaBridge

  fop_home = File.join(File.dirname(__FILE__),'fop-0.92beta')
  if !defined?(JBRIDGE_OPTIONS) then JBRIDGE_OPTIONS = {} end
  
  # NOTE:- the classpath separator is the unix one; ':', you'll want ';' for windows
  classpath = "$CLASSPATH:"
  classpath << Dir["#{File.join(fop_home, 'lib')}/*.jar"].join(':')
  classpath << ":#{File.join(fop_home, 'build')}/fop.jar"
  JBRIDGE_OPTIONS[:classpath] = classpath

  at_exit { JavaBridge.break_bridge }

  %w{org.apache.fop.apps.FopFactory
     org.apache.fop.apps.Fop
     org.apache.fop.apps.MimeConstants
     javax.xml.transform.TransformerFactory
     javax.xml.transform.stream.StreamSource
     javax.xml.transform.sax.SAXResult
     java.io.BufferedOutputStream
     java.io.FileOutputStream
     java.io.File}.each { |import_string| jimport import_string }

  # This is the standard xml+xsl-t pattern for using FOP. 
  # http://xmlgraphics.apache.org/fop/0.92/embedding.html
  fopFactory = :FopFactory.jclass.newInstance

  # the output file for the pdf
  out = :BufferedOutputStream.jnew(:FileOutputStream.jnew(:File.jnew(ARGV.shift)))
  fop = fopFactory.newFop(:MimeConstants.jclass.MIME_PDF, out)
  factory = :TransformerFactory.jclass.newInstance

  # the xsl-t file to transform the xml into xsl-fo
  xslt = :StreamSource.jnew(:File.jnew(ARGV.shift))
  transformer = factory.newTransformer(xslt)

  # the xmll file you want to generate a pdf from
  src = :StreamSource.jnew(:File.jnew(ARGV.shift))
  res = :SAXResult.jnew(fop.getDefaultHandler)
  transformer.transform(src, res)
  out.close

  # Of course ... instead of just args on the command line for filenames
  # to read / output to you could use java's StringReader objects to read 
  # from XML documents you've created with builder or some other ruby xml
  # generation mechanism...
end