class_name DamageEvent
extends RefCounted
## The one typed payload for every hit in the game — a bull goring a matador, a bear slam popping
## the bull, a thrown spear landing. It replaces the scattered, stringly Object.call(&"take_sword_hit",
## "gored") paths: an emitter (a Hitbox) fills one of these and hands it to the target's
## receive_damage(event). One shape to read, log and type-check, instead of four call conventions.
##
## It serves both victim models the game already has: the bull, which dies on one clean hit
## (lethal + cause + hit_position), and an enemy, which is launched/ragdolled by an impulse
## (knockback_dir · knockback_strength + knock_up). A given hit just leaves the fields it doesn't
## use at their defaults.

enum Cause { GENERIC, GORED, MAULED, THROWN, SLAMMED, KICKED, DASHED }

## Who dealt the hit — for attribution and for ignoring self-overlap. May be null.
var source: Node = null
## What kind of hit; drives the victim's reaction (blood/vignette/FX) and any future resistances.
var cause: Cause = Cause.GENERIC
## World contact point, so impact FX spawn where the hit actually landed.
var hit_position: Vector3 = Vector3.ZERO
## Planar push direction (need not be normalised). Vector3.ZERO = no horizontal knockback.
var knockback_dir: Vector3 = Vector3.ZERO
## Impulse magnitude behind knockback_dir — the enemy launch/ragdoll strength.
var knockback_strength: float = 0.0
## Upward launch in m/s (an overhead smash pop, a leap-slam outer ring). 0 = a grounded hit.
var knock_up: float = 0.0
## One clean hit ends the run for the bull; most enemy-dealt hits are lethal to it. Enemies that
## are merely launched (not killed) by the bull's abilities set this false.
var lethal: bool = true


static func make(kind: Cause, at: Vector3, src: Node = null) -> DamageEvent:
	var e := DamageEvent.new()
	e.cause = kind
	e.hit_position = at
	e.source = src
	return e


## The single entry point every attacker uses to wound a target: build the typed event and hand it
## to receive_damage(). Falls back to the legacy string call for any target not yet migrated, so a
## caller never has to branch on which contract the victim speaks. `knock_up_v` is the already-shaped
## pop (0 = grounded); callers that scale it by distance compute it before calling.
static func deal(target: Node, kind: Cause, at: Vector3, src: Node = null, knock_up_v: float = 0.0) -> void:
	if target == null:
		return
	if target.has_method(&"receive_damage"):
		var event := make(kind, at, src)
		event.knock_up = knock_up_v
		target.call(&"receive_damage", event)
		return
	if target.has_method(&"take_sword_hit"):
		target.call(&"take_sword_hit", make(kind, at, src).cause_name(), at)
		if knock_up_v > 0.0 and target.has_method(&"apply_knock_up"):
			target.call(&"apply_knock_up", knock_up_v)


## Lower-case name of the cause, for logs and for the bull's existing cause-keyed reactions
## ("gored" / "mauled" / "thrown") during the migration off string causes.
func cause_name() -> String:
	return String(Cause.keys()[cause]).to_lower()


## Maps a legacy cause string onto the enum, so a Hitbox's exported damage_cause round-trips
## exactly (gored/mauled/thrown are the only ones in use). Unknown strings fall back to GENERIC.
static func cause_from(text: String) -> Cause:
	match text.to_lower():
		"gored":
			return Cause.GORED
		"mauled":
			return Cause.MAULED
		"thrown":
			return Cause.THROWN
		"slammed":
			return Cause.SLAMMED
		"kicked":
			return Cause.KICKED
		"dashed":
			return Cause.DASHED
	return Cause.GENERIC