module Voyager
  module Holdings
    class Item
      attr_reader :holding_id, :item_count, :temp_locations, :item_status
      
      # Item class initializing method
      # Populates instance variables from the mfhd:mfhdRecord node.
      #
      # * *Args*    :
      #   - +xml_node+ -> mfhd:mfhdRecord node
      #
      def initialize(xml_node)   
      
        @holding_id = xml_node.attributes["mfhdId"].value
        # the item collecction
        item = xml_node.at_css("mfhd|itemCollection")
        # number of item records
        @item_count = item.at_css("item|itemCount").content
        @temp_locations = parse_for_temp_locations(item)  # array
        @item_status = parse_for_circ_status(item, @item_count)  # hash
        
      end
      
      private
      
      # Isolates item:itemLocation nodes in the mfhd:itemCollection and
      # extracts information on items in temp locations.
      #
      # * *Args*    :
      #   - +item+ -> mfhd:itemCollection node
      # * *Returns* :
      #   - An array of messages for items found in temp locations
      #   - An empty array if there are no items in temp locations
      #
      def parse_for_temp_locations(item)
        
        # item:itemLocation nodes
        # reject nodes that do not have the tmpLoc attribute set
        itemLocation = item.css("item|itemLocation").reject { |loc| loc.at_css("item|itemLocationData[@name='tmpLoc']").content.empty? }
        
        return [] unless itemLocation.length > 0
        
        messages = []
        
        itemLocation.each do |loc|
          # label is descriptive information for items; optional
          label = []
          ['itemEnum', 'itemChron','itemYear', 'itemCaption', 'itemFreeText'].each do |type|
            loc_data = loc.at_css("item|itemLocationData[@name=#{type}]")
            label << loc_data.content unless loc_data.content.empty?
          end
          # generate message
          if label.empty?
            messages << "Shelved in " + loc.at_css("item|itemLocationData[@name='tempLocation']").content
          else
            messages << label.join(" ") + " Shelved in " + loc.at_css("item|itemLocationData[@name='tempLocation']").content
          end
        end
        
        messages
        
      end
      
      # Isolates item:itemRecord nodes in the mfhd:itemCollection,
      # determines circulation status and generates messages
      #
      # * *Args*    :
      #   - +item+ -> mfhd:itemCollection node
      #   - +item_count+ -> count of item records
      # * *Returns* :
      #   - Hash containing overall circulation status and a list of circulation messages
      #     { :status => overall item status, :messages => [ one or more circulation messages ] }
      #   - Possible statuses are: 'none', 'available', 'not_available', 'some_avaialble'
      #   - An additional status, 'online', is set in the Record class
      #
      def parse_for_circ_status(item,item_count)
        
        # no items = no status available
        if item_count == "0"
          return {:status => 'none', :messages => ['No item status available'] }
        end

        # item:itemRecord nodes
        itemRecord = item.css("item|itemRecord")
        
        # generate an arry of hashes for ease of handling
        records = itemRecord.collect do |record|
          data = {}
          record.css("item|itemData").each do |rec|
            data[rec.attr("name").to_sym] = rec.content
          end
          data
        end

        # determine overall status
        status = determine_status(records,item_count)
        # generate messages
        messages = generate_messages(records)

        return {:status => status, :messages => messages }
        
      end
      
      # Set the overall circulation status
      #
      # * *Args*    :
      #   - +records+ -> Array of hashes for data in item:itemRecord nodes
      #   - +item_count+ -> count of item records
      # * *Returns* :
      #   - Overall circulation status
      #
      def determine_status(records,item_count)
        
        # this may need to be refined
        # statusCode = 1 in first (and only) record means nothing has a item status set
        # assume available
        status = 'available'
        # if statusCode > 1 some item status is set so some item is not available; 11 (returned) is the exception
        if records.first[:statusCode].to_i > 1 && records.first[:statusCode].to_i != 11
          # if the number of records (item:itemRecord nodes) with statusCodes > 1 equals the total number of items
          # everything is unavailable; otherwise, only some items are unavailable
          if records.length == item_count.to_i
            status = 'not_available'
          else
            status = 'some_available'
          end
        end
        
        status
          
      end
      
      # Generate circulation messages
      #
      # * *Args*    :
      #   - +records+ -> Array of hashes for data in item:itemRecord nodes
      # * *Returns* :
      #   - Array of circulation messages
      #
      def generate_messages(records)
        
        messages = []
        
        records.each do |record|
          # messages differ based on whether there is a request count
          if record[:requestCount] == '0'
            messages << generate_message_no_requests(record)
          else
            messages << generate_message_requests(record)
          end
          
        end
        
        messages
        
      end
      
      # Generate message from a record (item:itemRecord node)
      # No request count
      #
      # * *Args*    :
      #   - +record+ -> Hash of data from an item:itemRecord node
      # * *Returns* :
      #   - Formatted message
      #
      def generate_message_no_requests(record)
        
        # label is descriptive information for items; optional
        labels = []
        [:enumeration, :chronology, :year, :caption, :text].each do |type|
          labels << record[type] unless record[type].empty?
        end
        labels.empty? ? label = '' : label = labels.join(' ') + ' '
        
        datetime = record[:statusDate].split(' ') # split into date/time
        
        message = ''
        
        # status patron message otherwise a regular message
        if record[:patronGroupCode].strip.match(/^(IND|MIS|ACO)/)
        
          message = record[:lastName].strip + ' ' + record[:firstName].strip
          
        else
        
          case record[:statusCode]
          when '1'
            message = 'Not checked out'
          when '2'
            message = "Checked out, due #{datetime.join(' ')} - Recall, or try Borrow Direct or ILL."
          when '3'
            message = "Checked out, due #{datetime.join(' ')} - Recall, or try Borrow Direct or ILL."
          when '4'
            message = "Overdue as of #{datetime.join(' ')} - Recall, or try Borrow Direct."
          when '5'
            message = "Requests: #{record[:requestCount]}"
          when '6'
            message = "Requests: #{record[:requestCount]}"
          when '7'
            message = "On hold at #{record[:holdLocation]}. Try Borrow Direct or ILL."
          when '8'
            message = "In transit #{datetime[0]}. Place a hold request."
          when '9'
            message = "In transit to #{record[:holdLocation]} #{datetime[0]}. Place a hold request."
          when '10'
            message = "In transit to #{record[:holdLocation]} #{datetime[0]}. Place a hold request."
          when '11'
            message = "Returned #{datetime[0]}"
          when '12'
            message = "Missing #{datetime[0]}. Try Borrow Direct or ILL."
          when '13'
            message = "Unavailable #{datetime[0]}. Try Borrow Direct or ILL."
          when '14'
            message = "Unavailable #{datetime[0]}. Try Borrow Direct or ILL."
          when '18'
            message = "Sent to bindery for 1 month on #{datetime[0]}. Try Borrow Direct or ILL."
          when '21'
            message = "Scheduled"
          when '22'
            message = "In Process #{datetime[0]}. Place an In Process item request."
          when '23'
            message = "Requested"
          when '24'
            message = "Requested"
          when '25'
            message = "Requested"
          else
            message = "Unknown"
          end
        
        end
        
        # add label
        message.insert(0, label) unless label.empty?
 
        return message
 
      end
      
      # Generate message from a record (item:itemRecord node)
      # Request count
      #
      # * *Args*    :
      #   - +record+ -> Hash of data from an item:itemRecord node
      # * *Returns* :
      #   - Formatted message
      #
      def generate_message_requests(record)
        
        # label is descriptive information for items; optional
        labels = []
        [:enumeration, :chronology, :year, :caption, :text].each do |type|
          labels << record[type] unless record[type].empty?
        end
        labels.empty? ? label = '' : label = labels.join(' ') + ' '
        
        datetime = record[:statusDate].split(' ') # split into date/time
        
        message = ''
        
        # status patron message otherwise regular message
        if record[:patronGroupCode].strip.match(/^(IND|MIS|ACO)/)
        
          message = record[:lastName].strip + ' ' + record[:firstName].strip
          
        else
        
          case record[:statusCode]
          when '1'
            message = "Not checked out (Requests: #{record[:requestCount]})"
          when '2'
            message = "Checked out, due #{datetime.join(' ')} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '3'
            message = "Checked out, due #{datetime.join(' ')} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '4'
            message = "Overdue as of #{datetime.join(' ')} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '5'
            message = "Checked out, due #{datetime.join(' ')} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '6'
            message = "Checked out, due #{datetime.join(' ')} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '7'
            message = "On hold at #{record[:holdLocation]} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '8'
            message = "In transit #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct"
          when '9'
            message = "In transit to #{record[:holdLocation]} #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct."
          when '10'
            message = "In transit to #{record[:holdLocation]} #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct"
          when '11'
            message = "Returned #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '12'
            message = "Missing #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '13'
            message = "Unavailable #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '14'
            message = "Unavailable #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '18'
            message = "Sent to bindery for 1 month on #{datetime[0]} (Requests: #{record[:requestCount]}). Try Borrow Direct or ILL."
          when '21'
            message = "Scheduled (Requests: #{record[:requestCount]})"
          when '22'
            message = "In Process #{datetime[0]} (Requests: #{record[:requestCount]}). Place an In Process item request."
          when '23'
            message = "Requests: #{record[:requestCount]}"
          when '24'
            message = "Requests: #{record[:requestCount]}"
          when '25'
            message = "Requests: #{record[:requestCount]}"
          else
            message = "Unknown"
          end
        
        end
        
        # add label
        message.insert(0, label) unless label.empty?
 
        return message
 
      end
      
    end
  end
end