const (
	// C is the speed of light in a vacuum, m/s.
	C = 299792458
	// G is the gravitation constant, m^3/kg/s^2.
	G = 6.67408e-11
	// Hubble is Hubble's Constant, hertz.
	Hubble = 2.2e-18
	// UTemp is a low estimate for the temperature of cosmic background radiation, kelvin.
	UTemp = 2.7
	// Boltzmann is Boltzmann's constant, J/K.
	Boltzmann = 1.3806503e-23
	// Planck is Planck's Constant, J*s.
	Planck = 6.62607015e-35

	// UMass is the mass of the observable universe.
	UMass = C * C * C / (2 * G * Hubble)
	// Bremermann is Bremermann's limit.
	Bremermann = C * C / Planck

	// DefaultEntropy is the number of bits of entropy to target if no target entropy is provided.
	DefaultEntropy = 256
)

var (
	ErrMissingValue = errors.New("not enough given values")
	ErrMissingEMT   = fmt.Errorf("%w: missing energy, mass, and/or time", ErrMissingValue)
	ErrMissingPE    = fmt.Errorf("%w: missing password and/or entropy", ErrMissingValue)
)

type Givens struct {
	Password         string
	Entropy          float64
	Energy           float64
	Mass             float64 // mass used to build a computer or convert to energy
	Time             float64 // Duration of the attack, in seconds.
	Temperature      float64 // Duration of the attack, in seconds.
	EnergyPerGuess   float64
	Power            float64
	GuessesPerSecond float64
}