package utilities

import "math"

// Bisect takes a known-good low and known-bad high value as the bounds
// to bisect, and a function to test each value for success or failure.
// If the function succeeds, the value is adjusted toward the maximum,
// and if the function fails, the value is adjusted toward the minimum.
// The final value is returned when the difference between the success
// and the failure is less than or equal to the acceptance threshold
// (usually 1, for integers).
func Bisect[T Number](low, high, threshold T, tryFunc func(val T) bool) T {
	lastSuccess := low
	lastFailure := high
	currVal := low

	for T(math.Abs(float64(lastFailure-lastSuccess))) > threshold {
		success := tryFunc(currVal)
		adjustment := (lastFailure - lastSuccess) / 2
		if success {
			lastSuccess = currVal
		} else {
			lastFailure = currVal
			adjustment = -adjustment
		}

		currVal += adjustment
	}

	return currVal
}