module Gbdev
  
  module PdfOperations

    class FillCollection
            
      # Fill a PDF form based on the options specified.
      # 
      # Hash pdf_options : A hash of parameters for filling the PDF form. 
      #                    [data] An array of hashes of fields to fill the pdf template with. Example: [{:field => 'value'}, {:field => 'value'}].
      #                    [template] The full path to the PDF form to fill.
      #                    [dir] The directory to write filled form to.
      #                    [file_name] (optional) The name of the output file to create. If not specified a random
      #                                file name will be used.
      #
      # Exceptons : 
      #   1) If any of the required hash options from pdf_options is missing.
      def initialize(pdf_options = {})
        if !pdf_options.has_key?(:data) or !pdf_options.has_key?(:template) or !pdf_options.has_key?(:dir)
          raise 'All options parameters (data, template, dir) are required'
        end
            
        unless File.exist?(pdf_options[:template])
          raise 'Template file does not exist or path is wrong'
        end
            
        if pdf_options[:data].class.to_s != 'Array' or 
           (pdf_options[:data].class.to_s == 'Array' and pdf_options[:data][0].class.to_s != 'Hash')
          raise 'Data must array of hashes'
        end
            
        unless File.directory?(pdf_options[:dir])
          raise 'Output directory does not exist or path is wrong'
        end
              
        @data      = pdf_options[:data]
        @template  = pdf_options[:template]
        @dir       = pdf_options[:dir]
        @file_name = pdf_options.has_key?(:file_name) ? pdf_options[:file_name] : build_random_file_name
      end  
      
      def compile_pdf
        temp_dir = [@dir, 'collection_temp'].join('/')
        Dir.mkdir(temp_dir)
        @data.each do |hash_data|
          opts = {:data => hash_data,
                  :template => @template,
                  :dir => temp_dir}
          p = Gbdev::PdfOperations::FillTemplate.new(opts)
          p.compile_pdf
        end
        
        temp_files = Dir[[temp_dir,'*'].join('/')]      
        
        document = Document.new
        copier = PdfCopy.new(document, FileOutputStream.new([@dir,@file_name].join('/')))
        
        document.open        
        temp_files.each do |read_target|
          reader = PdfReader.new(read_target)
          n_pages = reader.getNumberOfPages
          n_pages.times do |i|
            copier.addPage( copier.getImportedPage(reader, i+1)) if copier
          end
        end        
        document.close
                
        FileUtils.rm_rf(temp_dir, {:secure => true})
      end
      
      private
      
        include Gbdev::Utils::PrivateMethods
        
    end # End FillCollection
    
  end # End PdfOperations
  
end # End Gbdev