# Blends multiple steering behaviors into one, and returns a weighted
# acceleration from their calculations.
#
# Stores the behaviors internally as dictionaries of the form
# {
# 	behavior : GSAISteeringBehavior,
# 	weight : float
# }
class_name GSAIBlend
extends GSAISteeringBehavior

var _behaviors := []
var _accel := GSAITargetAcceleration.new()


func _init(agent: GSAISteeringAgent).(agent) -> void:
	pass


# Appends a behavior to the internal array along with its `weight`.
func add(behavior: GSAISteeringBehavior, weight: float) -> void:
	behavior.agent = agent
	_behaviors.append({behavior = behavior, weight = weight})


# Returns the behavior at the specified `index`, or an empty `Dictionary` if
# none was found.
func get_behavior_at(index: int) -> Dictionary:
	if _behaviors.size() > index:
		return _behaviors[index]
	printerr("Tried to get index " + str(index) + " in array of size " + str(_behaviors.size()))
	return {}


func _calculate_steering(blended_accel: GSAITargetAcceleration) -> void:
	blended_accel.set_zero()

	for i in range(_behaviors.size()):
		var bw: Dictionary = _behaviors[i]
		bw.behavior.calculate_steering(_accel)

		blended_accel.add_scaled_accel(_accel, bw.weight)

	blended_accel.linear = GSAIUtils.clampedv3(blended_accel.linear, agent.linear_acceleration_max)
	blended_accel.angular = clamp(
		blended_accel.angular, -agent.angular_acceleration_max, agent.angular_acceleration_max
	)