module ActiveRecord
  module ConnectionAdapters
    module SQLServerActiveRecordExtensions
      
      def self.included(klass)
        klass.extend ClassMethods
        class << klass
          alias_method_chain :reset_column_information, :sqlserver_columns_cache_support
          alias_method_chain :add_order!, :sqlserver_unique_checking
        end
      end
      
      module ClassMethods
        
        def coerce_sqlserver_date(*attributes)
          write_inheritable_attribute :coerced_sqlserver_date_columns, Set.new(attributes.map(&:to_s))
        end
        
        def coerce_sqlserver_time(*attributes)
          write_inheritable_attribute :coerced_sqlserver_time_columns, Set.new(attributes.map(&:to_s))
        end
        
        def coerced_sqlserver_date_columns
          read_inheritable_attribute(:coerced_sqlserver_date_columns) || []
        end
        
        def coerced_sqlserver_time_columns
          read_inheritable_attribute(:coerced_sqlserver_time_columns) || []
        end
        
        def reset_column_information_with_sqlserver_columns_cache_support
          connection.instance_variable_set :@sqlserver_columns_cache, {}
          reset_column_information_without_sqlserver_columns_cache_support
        end
        
        private
        
        def add_order_with_sqlserver_unique_checking!(sql, order, scope = :auto)
          order_sql = ''
          add_order_without_sqlserver_unique_checking!(order_sql, order, scope)
          unless order_sql.blank?
            unique_order_hash = {}
            select_table_name = connection.send(:get_table_name,sql)
            select_table_name.tr!('[]','') if select_table_name
            orders_and_dirs_set = connection.send(:orders_and_dirs_set,order_sql)
            unique_order_sql = orders_and_dirs_set.inject([]) do |array,order_dir|
              ord, dir = order_dir
              ord_tn_and_cn = ord.to_s.split('.').map{|o|o.tr('[]','')}
              ord_table_name, ord_column_name = if ord_tn_and_cn.size > 1
                                                  ord_tn_and_cn
                                                else
                                                  [nil, ord_tn_and_cn.first]
                                                end
              if (ord_table_name && ord_table_name == select_table_name && unique_order_hash[ord_column_name]) || unique_order_hash[ord_column_name]
                array
              else
                unique_order_hash[ord_column_name] = true
                array << "#{ord} #{dir}".strip
              end
            end.join(', ')
            sql << " ORDER BY #{unique_order_sql}"
          end
        end
        
      end
      
    end
  end
end

ActiveRecord::Base.send :include, ActiveRecord::ConnectionAdapters::SQLServerActiveRecordExtensions