class Dry::Types::Default

def self.[](value)
  if value.respond_to?(:call)
    Callable
  else
    self
  end
end

def call_safe(input = Undefined, &)
  if input.equal?(Undefined)
    evaluate
  else
    Undefined.default(type.call_safe(input, &)) { evaluate }
  end
end

def call_unsafe(input = Undefined)
  if input.equal?(Undefined)
    evaluate
  else
    Undefined.default(type.call_unsafe(input)) { evaluate }
  end
end

def callable? = false

def constrained(...) = type.constrained(...).default(value)

def default? = true

def initialize(type, value, **)
  super
  @value = value
end

def try(input = Undefined, &)
  if input.equal?(Undefined)
    success(evaluate)
  else
    type.try(input)
  end
end

def valid?(value = Undefined) = Undefined.equal?(value) || super