Rakefile

# CollectionBuilder-CSV helper tasks

require 'csv'

###############################################################################
# TASK: deploy
###############################################################################

desc "Build site with production env"
task :deploy do
  ENV["JEKYLL_ENV"] = "production"
  exec("bundle exec jekyll build")
end

###############################################################################
# Helper Functions
###############################################################################

$ensure_dir_exists = ->(dir) { if !Dir.exists?(dir) then Dir.mkdir(dir) end }

def prompt_user_for_confirmation message
  response = nil
  while true do
    # Use print instead of puts to avoid trailing \n.
    print "#{message} (Y/n): "
    $stdout.flush
    response =
      case STDIN.gets.chomp.downcase
      when "", "y"
        true
      when "n"
        false
      else
        nil
      end
    if response != nil
      return response
    end
    puts "Please enter \"y\" or \"n\""
  end
end

###############################################################################
# TASK: generate_derivatives
###############################################################################

desc "Generate derivative image files from collection objects"
task :generate_derivatives, [:thumbs_size, :small_size, :density, :missing, :im_executable] do |t, args|

  # set default arguments 
  args.with_defaults(
    :thumbs_size => "400x400",
    :small_size => "800x800",
    :density => "300",
    :missing => "true",
    :im_executable => "magick",
  )

  # set the folder locations
  objects_dir = "objects"
  thumb_image_dir = "objects/thumbs"
  small_image_dir = "objects/small"

  # Ensure that the output directories exist.
  [thumb_image_dir, small_image_dir].each &$ensure_dir_exists

  # support these file types
  EXTNAME_TYPE_MAP = {
    '.tiff' => :image,
    '.tif' => :image,  
    '.jpg' => :image,
    '.png' => :image,
    '.pdf' => :pdf
  }

  # CSV output
  list_name = File.join([objects_dir, "object_list.csv"])
  field_names = "object_location,image_small,image_thumb".split(",")
  # open file
  CSV.open(list_name, "w") do |csv|
    # write the header fields 
    csv << field_names

    # Iterate over files in objects directory.
    Dir.glob(File.join([objects_dir, '*'])).each do |filename|
      # Ignore subdirectories.
      if File.directory? filename
        next
      end
      # Ignore README
      if File.basename(filename) == "README.md"
        next
      end

      # Determine the file type and skip if unsupported.
      extname = File.extname(filename).downcase
      file_type = EXTNAME_TYPE_MAP[extname]
      if !file_type
        puts "Skipping file with unsupported extension: #{filename}"
        csv << ["/" + filename,nil,nil]
        next
      end

      # Define the file-type-specific ImageMagick command prefix.
      cmd_prefix =
        case file_type
        when :image then "#{args.im_executable} #{filename}"
        when :pdf then "#{args.im_executable} -density #{args.density} #{filename}[0]"
        end

      # Get the lowercase filename without any leading path and extension.
      base_filename = File.basename(filename)[0..-(extname.length + 1)].downcase

      # Generate the thumb image.
      thumb_filename=File.join([thumb_image_dir, "#{base_filename}_th.jpg"])
      if args.missing == 'false' or !File.exists?(thumb_filename)
        puts "Creating: #{thumb_filename}";
        system("#{cmd_prefix} -resize #{args.thumbs_size} -flatten #{thumb_filename}")
      else
        puts "Skipping: #{thumb_filename} already exists"
      end

      # Generate the small image.
      small_filename = File.join([small_image_dir, "#{base_filename}_sm.jpg"])
      if args.missing == 'false' or !File.exists?(small_filename)
        puts "Creating: #{small_filename}";
        system("#{cmd_prefix} -resize #{args.small_size} -flatten #{small_filename}")
      else
        puts "Skipping: #{small_filename} already exists"
      end
      csv << ["/"+filename,"/"+small_filename,"/"+thumb_filename]
    end
  end
  puts "\e[32mSee '#{list_name}' for list of objects and derivatives created.\e[0m"
end