module GenericFormFor
  module Inputs
    module Base
      module Validations
        
        def required?
          options.key?(:required) ? options[:required] : required_from_validations?
        end

        def required_from_validations?
          @required_from_validations ||= object.class.validators_on(method).any? { |v| v.kind_of? ActiveModel::Validations::PresenceValidator } if object.class.respond_to?(:validators_on)
        end
        
        def limits_from_validations
          @limits_from_validations ||= object.class.validators_on(method).map { |v| v.options if v.kind_of? ActiveModel::Validations::NumericalityValidator }.compact.first if object.class.respond_to?(:validators_on)
        end
        
        def minimal_number
          return nil unless min = limits_from_validations
          min[:greater_than_or_equal_to] || (min[:greater_than] ?  min[:greater_than] + decimals.to_f : nil)
        end
        
        
        def maximal_number
          return nil unless max = limits_from_validations
          max[:less_than_or_equal_to] || (max[:less_than] ?  max[:less_than] - decimals.to_f : nil)
        end
        
        def limit
          column.try(:limit)
        end
        
        def decimals
          return 1 if column.try(:type) == :integer
          scale = column.try(:scale).to_f
          scale == 0 ? nil : "0.#{"0"*(scale-1)}1"
        end
        
      end
    end
  end
end