class_name AnalyticalRegionalUpdates
extends RefCounted


static func linear_value(
	current_value: float,
	rate_per_tick: float,
	elapsed_ticks: int,
	minimum: float = -INF,
	maximum: float = INF
) -> float:
	if elapsed_ticks <= 0 or not is_finite(current_value) or not is_finite(rate_per_tick):
		return clampf(current_value, minimum, maximum)
	return clampf(current_value + rate_per_tick * elapsed_ticks, minimum, maximum)


static func exponential_value(
	current_value: float,
	multiplier_per_tick: float,
	elapsed_ticks: int,
	minimum: float = -INF,
	maximum: float = INF
) -> float:
	if (
		elapsed_ticks <= 0
		or not is_finite(current_value)
		or not is_finite(multiplier_per_tick)
		or multiplier_per_tick < 0.0
	):
		return clampf(current_value, minimum, maximum)
	return clampf(current_value * pow(multiplier_per_tick, elapsed_ticks), minimum, maximum)


static func periodic_occurrences(
	first_due_tick: int, interval_ticks: int, through_tick: int
) -> int:
	if first_due_tick < 0 or interval_ticks <= 0 or through_tick < first_due_tick:
		return 0
	return (through_tick - first_due_tick) / interval_ticks + 1


static func transfer_amount(
	available: float,
	demand: float,
	rate_per_tick: float,
	elapsed_ticks: int,
	loss_fraction: float = 0.0
) -> Dictionary:
	var sent := minf(
		maxf(available, 0.0),
		minf(maxf(demand, 0.0), maxf(rate_per_tick, 0.0) * maxi(elapsed_ticks, 0))
	)
	var received := sent * (1.0 - clampf(loss_fraction, 0.0, 1.0))
	return {
		"sent": sent,
		"received": received,
		"remaining_available": maxf(available - sent, 0.0),
		"remaining_demand": maxf(demand - received, 0.0),
	}