class ActiveModel::Validations::NumericalityValidator

def allow_only_integer?(record)
  case options[:only_integer]
  when Symbol
    record.send(options[:only_integer])
  when Proc
    options[:only_integer].call(record)
  else
    options[:only_integer]
  end
end

def check_validity!
  keys = CHECKS.keys - [:odd, :even]
  options.slice(*keys).each do |option, value|
    unless value.is_a?(Numeric) || value.is_a?(Proc) || value.is_a?(Symbol)
      raise ArgumentError, ":#{option} must be a number, a symbol or a proc"
    end
  end
end

def filtered_options(value)
  filtered = options.except(*RESERVED_OPTIONS)
  filtered[:value] = value
  filtered
end

def is_integer?(raw_value)
  /\A[+-]?\d+\z/ === raw_value.to_s
end

def is_number?(raw_value)
  !parse_raw_value_as_a_number(raw_value).nil?
rescue ArgumentError, TypeError
  false
end

def parse_raw_value_as_a_number(raw_value)
  return raw_value.to_i if is_integer?(raw_value)
  Kernel.Float(raw_value) if raw_value !~ /\A0[xX]/
end

def record_attribute_changed_in_place?(record, attr_name)
  record.respond_to?(:attribute_changed_in_place?) &&
    record.attribute_changed_in_place?(attr_name.to_s)
end

def validate_each(record, attr_name, value)
  before_type_cast = :"#{attr_name}_before_type_cast"
  raw_value = record.send(before_type_cast) if record.respond_to?(before_type_cast) && record.send(before_type_cast) != value
  raw_value ||= value
  if record_attribute_changed_in_place?(record, attr_name)
    raw_value = value
  end
  unless is_number?(raw_value)
    record.errors.add(attr_name, :not_a_number, filtered_options(raw_value))
    return
  end
  if allow_only_integer?(record) && !is_integer?(raw_value)
    record.errors.add(attr_name, :not_an_integer, filtered_options(raw_value))
    return
  end
  if raw_value.is_a?(Numeric)
    value = raw_value
  else
    value = parse_raw_value_as_a_number(raw_value)
  end
  options.slice(*CHECKS.keys).each do |option, option_value|
    case option
    when :odd, :even
      unless value.to_i.send(CHECKS[option])
        record.errors.add(attr_name, option, filtered_options(value))
      end
    else
      case option_value
      when Proc
        option_value = option_value.call(record)
      when Symbol
        option_value = record.send(option_value)
      end
      unless value.send(CHECKS[option], option_value)
        record.errors.add(attr_name, option, filtered_options(value).merge!(count: option_value))
      end
    end
  end
end