package koboldsim

import (
	"math"

	"golang.org/x/exp/constraints"
)

// Generic helper functions not directly attached to Card Sim Engine mechanics.

// Mean calculates the mathematical mean of its arguments (the sum, divided
// by the number of elements). If it is called with no arguments, it returns
// NaN ("not a number"). If there are contradictory infinities among the
// arguments, it also returns NaN. Overflowing or underflowing can create an
// infinity.
func Mean(vals ...float64) float64 {
	if len(vals) == 0 {
		return math.NaN()
	}

	total := 0.0
	for _, x := range vals {
		total += x
	}
	return total / float64(len(vals))
}

func clamp[T constraints.Ordered](val, low, high T) T {
	if val < low {
		return low
	}
	if val > high {
		return high
	}
	return val
}