extends Resource
class_name MeleeAttack

## Config + logic for one melee swing (punch, kick, or a real weapon later).
## Swap the resource + viewmodel and you have a new weapon; movement never changes.
##
## Hit detection is a forgiving SPHERE query against the physics space, fired from
## the camera center (crosshair) so you don't have to pixel-aim. intersect_shape is
## NOT distance-sorted, so we pick the collider nearest the camera and act on it.
##
## Godot 4.7 GDScript 2.0. Verified: PhysicsShapeQueryParameters3D, SphereShape3D,
## PhysicsDirectSpaceState3D.intersect_shape, apply_impulse(impulse, rel_pos).

@export var reach: float = 1.8      ## distance in front of the camera the hit sphere sits
@export var radius: float = 0.38    ## fat sphere so melee is forgiving, not pixel-precise
@export var impulse: float = 6.0    ## smash strength handed to Smashable.smash()
@export var knockback: float = 3.0  ## central/off-center impulse for plain RigidBody3D props
@export var cooldown: float = 0.28  ## seconds between swings with this attack

## Run the hit test and apply effects.
##   caster : the player (supplies the physics world + a self-exclude RID)
##   origin : camera world position
##   dir    : camera forward (normalized), i.e. -camera.global_transform.basis.z
## Returns the node hit (Smashable or RigidBody3D) or null. Safe to call only from
## _physics_process — that's where direct_space_state is guaranteed valid.
func strike(caster: Node3D, origin: Vector3, dir: Vector3, exclude: Array = []) -> Node:
	var space := caster.get_world_3d().direct_space_state
	if space == null:
		return null

	var sphere := SphereShape3D.new()
	sphere.radius = radius

	var params := PhysicsShapeQueryParameters3D.new()
	params.shape = sphere
	params.transform = Transform3D(Basis.IDENTITY, origin + dir * reach)
	params.collide_with_bodies = true
	params.collide_with_areas = false
	params.exclude = exclude   # [caster.get_rid()] so the fat sphere never self-hits

	var hits := space.intersect_shape(params, 8)
	if hits.is_empty():
		return null

	# intersect_shape is unsorted — pick the collider nearest the camera so a swing
	# hits the first thing in front, not something behind it.
	var best: Node = null
	var best_d := INF
	for h in hits:
		var col = h.get("collider")
		if col == null or not (col is Node3D):
			continue
		var d: float = (col.global_position - origin).length_squared()
		if d < best_d:
			best_d = d
			best = col

	if best == null:
		return null

	# Smashable extends RigidBody3D, so this check MUST come first or we'd only
	# knock it around and never shatter it.
	if best is Smashable:
		best.smash(dir * impulse)
	elif best is RigidBody3D:
		# off-center impulse (relative to center of mass) so props tumble, not glide
		var hit_pos: Vector3 = origin + dir * reach
		best.apply_impulse(dir * knockback, hit_pos - best.global_position)
	return best