table.rb

class Table
  # Checks if the table is available for a given time range.
  # 
  # @param [Hash(Symbol => DateTime)] params
  #
   def available_at?(params)
     if (params[:at].class != DateTime); raise ArgumentError, "Provide a DateTime for :at";end;
     if (params[:ending].class != DateTime); raise ArgumentError, "Provide a DateTime for :ending";end;

     return false if
      (TableBooking.all(:at.lte => params[:at], :ending.gte => params[:ending]) +
      TableBooking.all(:at.gte => params[:at], :at.lte => params[:ending]) +
      TableBooking.all(:ending.gte => params[:at], :ending.lte => params[:ending])).count > 0
     true
   end 

end