# require 'image_popup'

# Methods to look into Sonyericsson mobile phone theme (THM) files.
# Author:: Peter Kofler, www.code-cop.org
# Copyright (c) 2009, Peter Kofler, licensed under BSD License.
module SonyEricssonDesign

  EXTENSION = '.thm'
  # Standby_image = main image
  # Desktop_image = the menu selection
  # Popup_image = little image
  MAIN_IMAGE = 'Standby_image'

  attr_reader :items

  # Helper class to hold the data from the thm file structure.
  class ThmItem < Struct.new(:name, :numbers, :stuff, :body)
    # Length of the content in bytes.
    def body_len
      numbers[3]
    end
    # Full name of the the content file.
    alias to_s name
    # Extension of the content file.
    def extension
      name.scan(/\.[^.]+$/)[0]
    end
    def save_with_basename(basename)
      save(basename + extension)
    end
    def save(filename=name)
      File.open(filename, 'wb') { |io| io.write body }
    end
    def delete(filename=name)
      File.delete(filename)
    end
  end

  # Scan folder _dirname_ for all thm files. Do not check subfolders.
  def scan_for_thms(dirname)
    current = Dir.getwd
    Dir.chdir dirname
    files = Dir["*#{EXTENSION}"].collect { |name| "#{dirname}/#{name}" }
    Dir.chdir current
    files
  end

  # If the given block evaluates to +true+ print the _msg_ and return evaluation result.
  def warn?(msg)
    if yield
      puts "WARNING: #{msg}"
      true
    else
      false
    end
  end

  # Read thm _file_ and return the list of +ThmItem+ items. Stop at broken or unknown items.
  def read_thm(file)
    items = []

    data = File.open(file, 'rb') { |io| io.read }
    max = data.size

    ofs = 0
    while ofs < max do
      d = ThmItem.new

      #0000h ... null terminated string with name of file
      break if warn?("short data - no name") { ofs + 0x63 >= max }
      d.name = data[ofs..ofs+0x63].strip
      # p d.name
      break if warn?("invalid data - empty name") { d.name.empty? }

      #0064h ... some numbers in octal separated by blanks and nulls, lengths = [7, 7, 7, 11, 11, 7, 1]
      break if warn?("short data in #{d.name} - no numbers") { ofs + 0x100 >= max }
      # p [ofs.to_s , ':'] + data[ofs+0x64..ofs+0x100].scan(/[0-7]+/)
      d.numbers = data[ofs+0x64..ofs+0x100].scan(/[0-7]+/).collect { |n| n.strip.to_i(8) }
      # p d.numbers
      break if warn?("invalid data in #{d.name} - no length #{d.numbers.join('/')}") { !d.body_len || d.body_len == 0 }

      #0101h ... ustar 0x00 00W850
      #0129h ... nogroup
      break if warn?("short data in #{d.name} - no stuff") { ofs + 0x1ff >= max }
      d.stuff  = data[ofs+0x101..ofs+0x1ff].strip.scan(/[^\000]+/)
      # p d.stuff

      #0200h ... data
      break if warn?("short data in #{d.name} - no content") { ofs + 0x200 + d.body_len > max }
      d.body = data[ofs + 0x200..ofs + 0x200 + d.body_len - 1]
      # puts d.body

      items << d

      ofs += 0x200 + d.body_len
      while ofs<max && data[ofs]==0 do
        ofs += 1
      end
    end

    @items = items
  end

  # Return the theme xml file content. Mainly it's called Theme.xml, but somtimes not.
  def theme_xml
    xml = @items.find { |i| i.name == 'Theme.xml' }

    # sometimes the Theme.xml is not called that way.
    unless xml
      xml = @items.find { |i| i.name =~ /\.xml$/ }
    end

    raise "no Theme.xml (or other xml) found" unless xml
    xml
  end

  # Return the item of the main image defined in the theme.xml by the _tag_
  def find_main_image(tag=MAIN_IMAGE)
    xml = theme_xml

    main_image_name = xml.body.scan(/<#{tag} Source="([^"]+)"\/>/)[0][0]
    raise "main image (#{tag}) link not found" unless main_image_name

    main_image = @items.find { |i| i.name == main_image_name }
    raise "main image #{main_image_name} content not found" unless main_image

    main_image
  end

  #  # Open a popup and show the main image.
  #  def show_main_image
  #    main_image = find_main_image
  #    begin
  #      main_image.save
  #      ImagePopup.new(main_image.name).display
  #    ensure
  #      main_image.delete
  #    end
  #  end

  # Save the main image with the same name as the thm _thmname_ to disk.
  def save_main_images(thmname)
    n = MAIN_IMAGE
    main_image = find_main_image(n)
    main_image.save_with_basename(thmname.scan(/^(.+)\./)[0][0] + '_' + n)
  end

end

if __FILE__ == $0

  include SonyEricssonDesign

  path = ARGV[0]
  if path.nil?
    print "#{File.basename $0} <folder>\n\n"
    print "extracts the #{MAIN_IMAGE} out of all Ericsson Theme files in the given <folder> for preview"
    exit(1)
  end

  scan_for_thms(path).each do |thm|
    begin
      puts "working on #{thm}"
      read_thm(thm)
      #show_main_image
      save_main_images(thm)

    rescue
      puts $!
    end
  end

end