module Voyager
  module Holdings
    class Record
      attr_reader :holding_id, :location_name, :call_number, :summary_holdings, :notes_852, :notes_866, :notes,
                  :shelving_title, :supplements, :indexes, :reproduction_note, :urls, :item_count, :temp_locations,
                  :item_status, :orders, :current_issues, :services, :bibid

      # Record class initializing method
      # Populates instance variables from the mfhd:marcRecord node of the mfhd:mfhdRecord node.
      # Also instantiates Otem and Order classes for the mfhd:mfhdRecord node.
      #
      # * *Args*    :
      #   - +xml_node+ -> mfhd:mfhdRecord node
      #
      def initialize(xml_node)
        @bibid = xml_node.attributes["bibId"].value
        @holding_id = xml_node.attributes["mfhdId"].value
        @location_name = xml_node.at_css("mfhd|mfhdData[@name='locationDisplayName']").content
        # marc record node
        marc = xml_node.at_css("mfhd|marcRecord")

        # 852 holdings tag node
        tag852 = marc.at_css("slim|datafield[@tag='852']")
        # 866 holdings tag node
        tag866 = marc.css("slim|datafield[@tag='866']")

        @call_number = parse_call_number(tag852)    # string
        @summary_holdings = parse_summary_holdings(tag866)  # array
        @notes_852 = parse_notes_852(tag852)    # array
        @notes_866 = parse_notes_866(tag866)    # array
        # combine notes into a single array
        @notes = @notes_852 + @notes_866        # array
        @shelving_title = parse_shelving_title(tag852)  # string
        @supplements = parse_supplements(marc)    # array
        @indexes = parse_indexes(marc)    # array
        @reproduction_note = parse_reproduction_note(marc)    #string
        @urls = parse_urls(marc)    # array of hashes
        
        # information from item level records
        item = Item.new(xml_node)

        @item_count = item.item_count
        @temp_locations = item.temp_locations
        @item_status = item.item_status
        
        # special case for single temp location
        if @item_count == '1' && (not @temp_locations.empty?)
          # temp location begins 'Shelved in' if it is not for a part
          if @temp_locations.first.match(/^Shelved/)
            # remove 'Shelved in' and replace location_name
            @location_name = @temp_locations.first.gsub(/^Shelved in /, '')
            @temp_locations.clear
          end
        end
        
        # set item status for online items
        if @location_name.match(/^Online/)
          @item_status[:status] = 'online'
          @item_status[:messages].clear
        end
        
        # information from order/receipt records
        order = Order.new(xml_node)
        
        @current_issues = order.current_issues
        @orders = order.orders
        
        # add available services
        @services = determine_services(@location_name,@call_number,@item_status,@orders,@bibid)
        
      end

      # Collect data from all variables into a hash
      #
      # * *Returns* :
      #   - Hash
      #
      def to_hash
        {
          :bibid => @bibid,
          :holding_id => @holding_id,
          :location_name => @location_name,
          :call_number => @call_number,
          :shelving_title => @shelving_title,
          :summary_holdings => @summary_holdings,
          :supplements => @supplements,
          :indexes => @indexes,
          :notes => @notes,
          :reproduction_note => @reproduction_note,
          :urls => @urls,
          :item_count => @item_count,
          :temp_locations => @temp_locations,
          :item_status => @item_status,
          :services => @services,
          :current_issues => @current_issues,
          :orders => @orders
        }
      end

      private
      
      # Extract call number
      #
      # * *Args*    :
      #   - +tag852+ -> 852 field node; not repeatable
      # * *Returns* :
      #   - Call number string
      #
      def parse_call_number(tag852)
        
        g = tag852.at_css("slim|subfield[@code='g']")
        h = tag852.at_css("slim|subfield[@code='h']")
        i = tag852.at_css("slim|subfield[@code='i']")
        k = tag852.at_css("slim|subfield[@code='k']")
        m = tag852.at_css("slim|subfield[@code='m']")
        
        # subfields need to be output in this order even though they may not appear in this order
        [k,g,h,i,m].compact.collect { |subfield| subfield.content }.join(" ")

      end
      
      # Extract summary holdings from 866 field
      #
      # * *Args*    :
      #   - +tag866+ -> 866 field node; repeatable
      # * *Returns* :
      #   - Array of summary holdings statements
      #   - Empty array if there are no summary holdings
      #
      def parse_summary_holdings(tag866)
        
        return [] unless tag866
        
        summary = tag866.collect do |field|
          field.at_css("slim|subfield[@code='a']")
        end
        
        summary.compact.collect { |subfield| subfield.content.strip }
          
      end
      
      # Extract public notes from 852 field, subfield z
      #
      # * *Args*    :
      #   - +tag852+ -> 852 field node; not repeatable
      # * *Returns* :
      #   - Array of note statements
      #   - Empty array if there are no notes
      #
      def parse_notes_852(tag852)
        
        subz = tag852.css("slim|subfield[@code='z']")

        return [] unless subz
        
        # there can be multiple z's
        subz.collect { |subfield| subfield.content }

      end
      
      # Extract public notes from 866 fields, subfield z
      #
      # * *Args*    :
      #   - +tag866+ -> 866 field node; repeatable
      # * *Returns* :
      #   - Array of note statements
      #   - Empty array if there are no notes
      #
      def parse_notes_866(tag866)
        
        return [] unless tag866
        
        notes = tag866.collect do |field|
          field.at_css("slim|subfield[@code='z']")
        end
        
        notes.compact.collect { |subfield| subfield.content }

      end
      
      # Extract shelving title
      #
      # * *Args*    :
      #   - +tag852+ -> 852 field node; not repeatable
      # * *Returns* :
      #   - Shelving title string
      #
      def parse_shelving_title(tag852)
        
        subl = tag852.at_css("slim|subfield[@code='l']")
        subl ? subl.content : ''
      
      end

      # Extract supplement holdings from field 867
      #
      # * *Args*    :
      #   - +marc+ -> mfhd:marcRecord node
      # * *Returns* :
      #   - Array of supplement holdings statements
      #   - Empty array if there are no summary holdings
      #      
      def parse_supplements(marc)
        
        tag867 = marc.css("slim|datafield[@tag='867']")
        
        return [] unless tag867
        
        supplements = tag867.collect do |field|
          field.at_css("slim|subfield[@code='a']")
        end
        
        supplements.compact.collect { |subfield| subfield.content }
        
      end
      
      # Extract index holdings from field 868
      #
      # * *Args*    :
      #   - +marc+ -> mfhd:marcRecord node
      # * *Returns* :
      #   - Array of index holdings statements
      #   - Empty array if there are no summary holdings
      #      
      def parse_indexes(marc)
        
        tag868 = marc.css("slim|datafield[@tag='868']")
        
        return [] unless tag868
        
        indexes = tag868.collect do |field|
          field.at_css("slim|subfield[@code='a']")
        end
        
        indexes.compact.collect { |subfield| subfield.content }
        
      end
      
      # Extract reproduction note from field 843
      #
      # * *Args*    :
      #   - +marc+ -> mfhd:marcRecord node
      # * *Returns* :
      #   - Reproduction note string
      #      
      def parse_reproduction_note(marc)
        
        tag843 = marc.at_css("slim|datafield[@tag='843']")
        
        return '' unless tag843
        
        # collect subfields in input order; only ouput certain subfields
        tag843.css("slim|subfield").collect { |subfield| subfield.content if subfield.attr("code").match(/[abcdefmn3]/)}.join(' ')

      end
      
      # Extract URLs from 856 fields in the marc holdings record
      #
      # * *Args*    :
      #   - +marc+ -> mfhd:marcRecord node
      # * *Returns* :
      #   - Array of hashes for urls
      #     { :url => url, :link_text => link text }
      #   - Empty array if there are no urls in the holdings record
      # Note: there may be urls in the bib record.
      #
      def parse_urls(marc)
        
        tag856 = marc.css("slim|datafield[@tag='856']")
        
        return [] unless tag856
        
        urls = []
        
        tag856.each do |field|
          
          # only process idicators 40
          if field.attr("ind1") == '4' and field.attr("ind2") == '0'
            
            subu = field.at_css("slim|subfield[@code='u']")
            subz = field.at_css("slim|subfield[@code='z']")
            sub3 = field.at_css("slim|subfield[@code='3']")
 
            # only process if there is a url
            if subu
            
              url = subu.content
              
              link_text = [sub3, subz].compact.collect { |subfield| subfield.content }

              if link_text.empty?
                link_text << url
              end
              
              urls << { :url => url, :link_text => link_text.join(' ') }
            
            end
          end
        end
        
        urls

      end
      
      def determine_services(location_name,call_number,item_status,orders,bibid)
        
        services = []
        
        unless orders.empty?
          orders.each do |order|
            parms = ORDER_STATUS_CODES[order[:status_code]]
            raise "Status code not found in config/order_status_codes.yml" unless parms
            services << parms['services'] unless parms['services'].nil?
          end
          return services.flatten.uniq
        end
        
        services << scan_message(location_name)
        
        status = item_status[:status]
        messages = item_status[:messages]
        
        case status
        when 'online'
        when 'none'
          services << 'in_process' if call_number.match(/in process/i)
        when 'available'
          services << process_available(location_name,bibid)
        when 'some_available'
          services << process_some_available(location_name,bibid,messages)
        when 'not_available'
          services << scan_messages(messages)
        else
        end
        
        services.flatten.uniq
        
      end
      
      def process_available(location_name,bibid)
        # offsite
        if location_name.match(/^Offsite/) &&
            HTTPClient.new.get_content("http://www.columbia.edu/cgi-bin/cul/lookupNBX?" + bibid) == "1"
          return ['offsite']
        end
        # precat
        if location_name.match(/^Precat/)
           return ['precat']
        end
        return []
      end
      
      def process_some_available(location_name,bibid,messages)
        
        services = []
        # offsite
        if location_name.match(/^Offsite/) &&
            HTTPClient.new.get_content("http://www.columbia.edu/cgi-bin/cul/lookupNBX?" + bibid) == "1"
          services << 'offsite'
        end
        
        services << scan_messages(messages)

        services
        
      end
      
      def scan_messages(messages)
        services = []
        messages.each do |message|
          # status patrons
          if message[:status_code] == 'sp'
            services << scan_message(message[:long_message])
          else
            parms = ITEM_STATUS_CODES[message[:status_code]]
            raise "Status code not found in config/order_status_codes.yml" unless parms
            services << parms['services'] unless parms['services'].nil?
          end
        end
        services
      end
      
      
      def scan_message(message)

        out = []
        out << 'recall_hold' if message =~ /Recall/i
        out << 'recall_hold' if message =~ /hold /
        out << 'borrow_direct' if message =~ /Borrow/
        out << 'ill' if message =~ /ILL/
        out << 'in_process' if message =~ /In Process/

        out

      end
      
    end
    
  end
end