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!
  options.slice(*COMPARE_CHECKS.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
  options.slice(*RANGE_CHECKS.keys).each do |option, value|
    unless value.is_a?(Range)
      raise ArgumentError, ":#{option} must be a range"
    end
  end
end

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

def is_hexadecimal_literal?(raw_value)
  HEXADECIMAL_REGEX.match?(raw_value.to_s)
end

def is_integer?(raw_value)
  INTEGER_REGEX.match?(raw_value.to_s)
end

def is_number?(raw_value, precision, scale)
  !parse_as_number(raw_value, precision, scale).nil?
rescue ArgumentError, TypeError
  false
end

def option_as_number(record, option_value, precision, scale)
  parse_as_number(option_value(record, option_value), precision, scale)
end

def parse_as_number(raw_value, precision, scale)
  if raw_value.is_a?(Float)
    parse_float(raw_value, precision, scale)
  elsif raw_value.is_a?(BigDecimal)
    round(raw_value, scale)
  elsif raw_value.is_a?(Numeric)
    raw_value
  elsif is_integer?(raw_value)
    raw_value.to_i
  elsif !is_hexadecimal_literal?(raw_value)
    parse_float(Kernel.Float(raw_value), precision, scale)
  end
end

def parse_float(raw_value, precision, scale)
  round(raw_value, scale).to_d(precision)
end

def prepare_value_for_validation(value, record, attr_name)
  return value if record_attribute_changed_in_place?(record, attr_name)
  came_from_user = :"#{attr_name}_came_from_user?"
  if record.respond_to?(came_from_user)
    if record.public_send(came_from_user)
      raw_value = record.public_send(:"#{attr_name}_before_type_cast")
    elsif record.respond_to?(:read_attribute)
      raw_value = record.read_attribute(attr_name)
    end
  else
    before_type_cast = :"#{attr_name}_before_type_cast"
    if record.respond_to?(before_type_cast)
      raw_value = record.public_send(before_type_cast)
    end
  end
  raw_value || value
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 round(raw_value, scale)
  scale ? raw_value.round(scale) : raw_value
end

def validate_each(record, attr_name, value, precision: Float::DIG, scale: nil)
  unless is_number?(value, precision, scale)
    record.errors.add(attr_name, :not_a_number, **filtered_options(value))
    return
  end
  if allow_only_integer?(record) && !is_integer?(value)
    record.errors.add(attr_name, :not_an_integer, **filtered_options(value))
    return
  end
  value = parse_as_number(value, precision, scale)
  options.slice(*RESERVED_OPTIONS).each do |option, option_value|
    if NUMBER_CHECKS.include?(option)
      unless value.to_i.public_send(NUMBER_CHECKS[option])
        record.errors.add(attr_name, option, **filtered_options(value))
      end
    elsif RANGE_CHECKS.include?(option)
      unless value.public_send(RANGE_CHECKS[option], option_value)
        record.errors.add(attr_name, option, **filtered_options(value).merge!(count: option_value))
      end
    elsif COMPARE_CHECKS.include?(option)
      option_value = option_as_number(record, option_value, precision, scale)
      unless value.public_send(COMPARE_CHECKS[option], option_value)
        record.errors.add(attr_name, option, **filtered_options(value).merge!(count: option_value))
      end
    end
  end
end