class DarwinCore
  class Generator
    class EmlXml

      def initialize(data, path)
        @data = data
        @path = path
        @write = 'w:utf-8'
      end

      def create
        eml_uri =  'eml://ecoinformatics.org/eml-2.1.1' + 
          ' http://rs.gbif.org/schema/eml-gbif-profile/1.0.1/eml.xsd'
        builder = Nokogiri::XML::Builder.new do |xml|
          xml.eml(packageId:      "%s/%s" % [@data[:id], timestamp],
            system:               @data[:system] || 'http://globalnames.org',
            :'xml:lang' =>         'en',
            :'xmlns:eml' =>        'eml://ecoinformatics.org/eml-2.1.1',
            :'xmlns:md' =>         'eml://ecoinformatics.org/methods-2.1.1',
            :'xmlns:proj' =>       'eml://ecoinformatics.org/project-2.1.1',
            :'xmlns:d' =>          'eml://ecoinformatics.org/dataset-2.1.1',
            :'xmlns:res' =>        'eml://ecoinformatics.org/resource-2.1.1',
            :'xmlns:dc' =>         'http://purl.org/dc/terms/',
            :'xmlns:xsi' =>        'http://www.w3.org/2001/XMLSchema-instance',
            :'xsi:schemaLocation' => 'eml_uri') do
            build_dataset(xml)
            build_additional_metadata(xml)
            xml.parent.namespace = xml.parent.namespace_definitions.first
          end
        end
        data = builder.to_xml
        f = open(File.join(@path, 'eml.xml'), @write)
        f.write(data)
        f.close
      end

      private

      def build_dataset(xml)
        xml.dataset(id: @data[:id]) do
          xml.title(@data[:title])
          xml.license(@data[:license])
          contacts = []
          build_authors(xml, contacts)
          build_metadata_providers(xml)
          xml.pubDate(Time.now.to_s)
          build_abstract(xml)
          build_contacts(xml, contacts)
        end
      end

      def build_abstract(xml)
        xml.abstract() do
          xml.para(@data[:abstract])
        end
      end

      def build_contacts(xml, contacts)
        contacts.each do |contact|
          xml.contact { xml.references(contact) }
        end
      end

      def build_metadata_providers(xml)
        @data[:metadata_providers].each_with_index do |a, i|
          xml.metadataProvider do
            build_person(xml, a)
          end
        end if @data[:metadata_providers]
      end
     
      def build_authors(xml, contacts)
        @data[:authors].each_with_index do |a, i|
          creator_id = i + 1
          contacts << creator_id
          xml.creator(id: creator_id, scope: 'document') do
            build_person(xml, a)
          end
        end
      end

      def build_additional_metadata(xml)
        xml.additionalMetadata do
          xml.metadata do
            xml.citation(@data[:citation])
            xml.resourceLogoUrl(@data[:logo_url]) if @data[:logo_url]
          end
        end
      end

      def build_person(xml, data)
        a = data
        xml.individualName do
          xml.givenName(a[:first_name])
          xml.surName(a[:last_name])
        end
        xml.organizationName(a[:organization]) if a[:organization]
        xml.positionName(a[:position]) if a[:position]
        xml.onlineUrl(a[:url]) if a[:url]
        xml.electronicMailAddress(a[:email])
      end

      def timestamp
        t = Time.now.getutc.to_a[0..5].reverse
        t[0..2].join('-') + '::' + t[-3..-1].join(':')
      end
    end
  end
end