module Exlibris
  module Aleph
    # ==Overview
    # Provides access to the Aleph Record REST API.
    class Record < Rest
      attr_reader :bib_library, :record_id

      # Creates an instance of Exlibris::Aleph::Record for the given :bib_library and :record_id
      def initialize(bib_library, record_id, uri)
        @record_id = record_id
        raise "Initialization error in #{self.class}. Missing record id." if @record_id.nil?
        @bib_library = bib_library
        raise "Initialization error in #{self.class}. Missing bib library." if @bib_library.nil?
        super(uri)
        @uri = @uri+ "/record/#{bib_library}#{record_id}"
        # Format :xml parses response as a hash.
        # Eventually I'd like this to be the default since it raises exceptions for invalid XML.
        # self.class.format :xml
        # Format :html does no parsing, just passes back raw XML for parsing by client
        self.class.format :html
      end

      # Returns an XML string representation of a bib.  
      # Every method call refreshes the data from the underlying API.
      # Raises and exception if there are errors.
      # Returns a HTTParty::Response.
      def bib
        @response = self.class.get(@uri+ "?view=full")
        raise "Error getting bib from Aleph REST APIs. #{error}" unless error.nil?
        return @response
      end

      # Returns an array of items. Each item is represented as an HTTParty hash. 
      # Every method call refreshes the data from the underlying API.
      # Raises an exception if the response is not valid XML or there are errors.
      # Returns a HTTParty::Response.
      def items
        @items = []
        self.class.format :xml
        # Since we're parsing xml, this will raise an error
        # if the response isn't xml.
        @response = self.class.get(@uri+ "/items?view=full")
        self.class.format :html
        raise "Error getting items from Aleph REST APIs. #{error}" if not error.nil? or 
          @response.nil? or @response["get_item_list"].nil? or @response["get_item_list"]["items"].nil?
        item_list = @response["get_item_list"]["items"]["item"]
        @items.push(item_list) if item_list.instance_of?(Hash)
        item_list.each {|item|@items.push(item)} if item_list.instance_of?(Array)
        Rails.logger.warn("No items returned from Aleph in #{self.class}.") if @items.empty?
        return @items
      end

      # Returns an XML string representation of holdings 
      # Every method call refreshes the data from the underlying API.
      # Raises and exception if there are errors.
      # Returns a HTTParty::Response.
      def holdings
        @response = self.class.get(@uri+ "/holdings?view=full")
        raise "Error getting holdings from Aleph REST APIs. #{error}" unless error.nil?
        return @response
      end
    end
  end
end