module Eeml

  class JsonOutput # :nodoc:

    def to_json(environment, options = { :full => true })
      hash = to_public_json_data(environment, options)
      hash.to_json
    end

    def to_public_json_data(environment, options = { :full => true })
      environment_hash = { :id => Integer(environment.identifier), #we WANT this to fail early when we start using non-numeric identifiers
                           :title => environment.title, 
                           :feed => environment.feed_url, 
                           :status => environment.status,
                           :description => environment.description,
                           :website => environment.website,
                           :email => environment.email,
                           :icon => environment.icon,
                           :version => EEML_VERSION}

      environment_hash[:updated] = environment.updated.strftime("%Y-%m-%dT%H:%M:%SZ") unless environment.updated.nil?  #TODO: was retrieved_at

      environment_hash.delete_if { |key, value| value.blank? }

      unless environment.location.nil?

        # add location data
        location_hash = { :domain => environment.location.domain,
                          :exposure => environment.location.exposure,
                          :disposition => environment.location.disposition,
                          :name => environment.location.name,
                          :ele => environment.location.elevation #currently, ele is output as a string
                        }
        location_hash[:lat] = Float(environment.location.latitude) if environment.location.latitude
        location_hash[:lon] = Float(environment.location.longitude) if environment.location.longitude

        location_hash.delete_if { |key, value| value.blank? }

        environment_hash[:location] = location_hash unless location_hash.empty?
      end

      # if :full option given, add our datastream data into the returned json
      if options[:full] == true
        datastream_array = []

        # add datastream data
        environment.datastreams.each do |datastream|
          datastream_array << datastream_to_json(datastream)
        end

        environment_hash[:datastreams] = datastream_array unless datastream_array.empty?
      end

      return environment_hash
    end
    
    protected
    def datastream_to_json(datastream)
      datastream_hash = { :id => datastream.identifier }

      datastream_hash[:tags] = datastream.tags unless datastream.tags.empty?

      value_hash = { :min_value => datastream.min_value.to_s,
                     :max_value => datastream.max_value.to_s,
                     :current_value => datastream.value.to_s }

      value_hash.delete_if { |key, value| value.blank? }

      datastream_hash[:value] = value_hash unless value_hash.empty?

      unit_hash = { :type => datastream.unit_type.to_s,
                    :symbol => datastream.unit_symbol.to_s,
                    :label => datastream.unit_value.to_s }

      unit_hash.delete_if { |key, value| value.blank? }

      datastream_hash[:unit] = unit_hash unless unit_hash.empty?

      return datastream_hash
    end



  end
end