export_images_to_pdf.rb

require 'rubygems'
require 'prawn'
require "prawn/measurement_extensions"
require 'ruby-debug'
 
balsamiq = "/Volumes/Macintosh HD/Applications/Balsamiq Mockups.app/Contents/MacOS/Balsamiq Mockups"

# Put ignored bmml files here, one per line
ignored_files = [ 
  "blank.bmml",
  "06.01.01.Events Management.bmml"
]

output_dir = "./output"

checkpoint_file = "#{output_dir}/checkpoint"

Dir.mkdir( output_dir ) unless ( File.exists?( output_dir ) or File.directory?( output_dir ) )

class JPEG
  attr_reader :width, :height, :bits

  def initialize(file)
    if file.kind_of? IO
      examine(file)
    else
      File.open(file, 'rb') { |io| examine(io) }
    end
  end

private
  def examine(io)
    raise 'malformed JPEG' unless io.getc == 0xFF && io.getc == 0xD8 # SOI

    class << io
      def readint; (readchar << 8) + readchar; end
      def readframe; read(readint - 2); end
      def readsof; [readint, readchar, readint, readint, readchar]; end
      def next
        c = readchar while c != 0xFF
        c = readchar while c == 0xFF
        c
      end
    end

    while marker = io.next
      case marker
        when 0xC0..0xC3, 0xC5..0xC7, 0xC9..0xCB, 0xCD..0xCF # SOF markers
          length, @bits, @height, @width, components = io.readsof
          raise 'malformed JPEG' unless length == 8 + components * 3
        when 0xD9, 0xDA:  break # EOI, SOS
        when 0xFE:        @comment = io.readframe # COM
        when 0xE1:        io.readframe # APP1, contains EXIF tag
        else              io.readframe # ignore frame
      end
    end
  end
end

class Util
  def self.store obj, file_name
    marshal_dump = Marshal.dump(obj)
    file = File.new(file_name,'w')
    file.write marshal_dump
    file.close
    return obj
  end
  
  def self.load file_name
    return nil unless File.exists? file_name
    file = File.open(file_name, 'r')
    obj = Marshal.load file.read
    file.close
    return obj
  end
  
  def self.dimension_of file
    # http://snippets.dzone.com/posts/show/805
    case file
    when /\.png$/i
      IO.read( file )[0x10..0x18].unpack('LL')
    when /\.gif$/i
      IO.read( file )[6..10].unpack('SS')
    when /\.jpe?g$/i
      jpg = JPEG.new( file )
      return [ jpg.width, jpg.height ]
    end
  end
end

# remove files in Output but not in input
images = Dir.glob "#{output_dir}/*.png"
files  = Dir.glob "*.bmml" || {}
images.each do |image| 
 if files.collect{ |file| file if image.index(file) == 0 }.compact.empty?
    puts "[DELETE] #{output_dir}/{image} (old files)"
    File.delete "#{output_dir}/#{image}"
  end
end


puts "==========="
# read in checkpoint file so that we can skip already generated files that are unchanged
last_run = Util.load checkpoint_file
last_run ||= {}

#puts files
# debugger
images = []
next_run = {}
files.each do |file|
  next if ignored_files.index( file )
  
  if last_run[ file ] != File.mtime( file ) 
    puts "[ADD] #{file} (to be exported to PNG)"
    next_run[ file ] = File.mtime( file )
  else 
    puts "[REUSE] #{file} (same as last time)"
  end

  images << "#{output_dir}/#{file}.png"
end

# now export 
# images = [ "#{output_dir}/Screen shot 2010-05-24 at 12.24.02 AM.png",
#   "#{output_dir}/Screen shot 2010-05-24 at 12.22.28 AM.png",
#   "#{output_dir}/Screen shot 2010-05-25 at 2.22.01 PM.png"
# ]


next_run.each do |file, mtime|
  puts "[EXPORT] #{file}"
  cmd = %!"#{balsamiq}" export "#{File.expand_path file}" "#{File.expand_path("#{output_dir}/#{file}.png") }"!
  puts cmd
  `#{cmd}`
  break
end

# Baill out if there's no images
return if images.empty?

# Read the first image size to determine the initial layout
dim = Util.dimension_of images.first
Prawn::Document.generate( "#{output_dir}/mocks.pdf", :page_size => "A4", :page_layout => dim[1] > dim [ 0 ] ? :portrait : :landscape  ) do 

  # Append image to the pdf document 
  images.each_with_index do |img, i|
    dim = Util.dimension_of( img )
    start_new_page( :layout => dim[1] > dim [ 0 ] ? :portrait : :landscape ) if i > 0
    image img, :position => :left, :vposition => :top , :fit => bounds.top_right
  end

  # Print the page #
  number_pages "<page>", [bounds.left, 0]
  
  # build the section outline
  define_outline do
    section 'Mock', :page => 1, :closed => true do
      for i in 0...images.length 
        page i + 1, :title => images[i].split('/').last
      end
    end
  end
  
  
end