require "isbn"

module Saber
  module Task
    # Generate meta data file. 
    #
    # Usage
    # -----
    #
    #     Task["generate"].invoke(:generate, ["ebook", ["harry_potter", isbn], ...])
    #     > generate Hello.epub.yml data file.
    #
    class Generate < Base
      include Thor::Actions

      def self.source_paths
        ["#{Rc.p.home}/templates"]
      end

      source_root "#{Rc.p.root}/templates"

      desc "generate", "generate"
      def generate(type, *filenames)
        template_file = find_in_source_paths("#{type}.yml")

        filenames.each {|filename, isbn|
          isbn = ISBN.thirteen(isbn) rescue nil
          Saber.ui.say "Populating {#{isbn}} #{filename} ..."
          dest = "#{filename}.yml" 

          if isbn
            require "yaml"
            populate = {}
            data = YAML.load_file(template_file)
            data.merge! Book.populate(isbn, filename)
            data.merge! YAML.load_file("#{Rc.p.database}/#{isbn}.yml") if Pa.exists?("#{Rc.p.database}/#{isbn}.yml")

            # tags
            if data["tags"]
              Tracker.trackers.each {|name, tracker_class|
                if data["#{name}.tags"].nil? and tracker_class.method_defined?(:convert_tags)
                  tracker = tracker_class.new(options)
                  data["#{name}.tags"] = tracker.convert_tags(*data["tags"].split(/, */)).join(", ")
                end
              }
            end

            create_file dest, YAML.dump(data)
          else
            copy_file template_file, dest
          end
        }
      end
    end
  end
end