Updated Cacoo implementation

gistfile1.rb

require 'json'
require 'time'
require_relative '../api/diagram'

module Asciidoctor
  module Diagram
    # @private
    module Cacoo
      def self.get_diagram_metadata(diagram_id, api_key)
        # NOTE: See API document at https://cacoo.com/lang/en/api and
        # https://cacoo.com/lang/en/api_image
        unless @diagrams
          diagrams = JSON.parse(get("/api/v1/diagrams.json?apiKey=#{api_key}"))
          @diagrams = diagrams['result'].each_with_object({}) { |d, h| h[d['diagramId']] = d }
        end

        @diagrams[diagram_id]
      end

      def self.get_diagram(diagram_id, api_key)
        # NOTE: See API document at https://cacoo.com/lang/en/api and
        # https://cacoo.com/lang/en/api_image
        get("/api/v1/diagrams/#{diagram_id}.png?apiKey=#{api_key}")
      end

      def self.get(url)
        https = Net::HTTP.new('cacoo.com', 443)
        https.use_ssl = true
        https.start do
          response = https.get(url)
          raise "Cacoo response status code was #{response.code}" if response.code != '200'
          response.body
        end
      end

      class Source < API::DiagramSource
        attr_accessor :diagram_id
        attr_accessor :api_key

        def initialize(diagram_id, api_key)
          @diagram_id = diagram_id
          @api_key = api_key
        end

        def image_name
          "cacoo-#{diagram_id}"
        end

        def code
          diagram_id
        end

        def should_process?(image_file, image_metadata)
          Time.rfc2822(cacoo_metadata['updated']) < Time.rfc2822(image_metadata['updated'])
        end

        def create_image_metadata
          { 'updated' => cacoo_metadata['updated'] }
        end

        def cacoo_metadata
          Cacoo.get_diagram_metadata(diagram_id, api_key)
        end
      end
    end

    class CacooBlockMacroProcessor < API::DiagramBlockMacroProcessor
      register_format(:png, :image) do |parent, source|
        Cacoo.cacoo(source.code, source.api_key)
      end

      def create_source(parent, target, attributes)
        api_key = ENV['CACOO_API_KEY'] || parent.document.attributes('cacoo_api_key')
        raise "Please specify your Cacoo API key using the CACOO_API_KEY environment variable or cacoo_api_key document attribute" unless api_key
        Cacoo::Source.new(target.strip, api_key)
      end
    end
  end
end