class_name EnemyBase
extends Area2D
## 敌机基类：血量、受击闪白、死亡结算与爆炸。

var hp := 1
var score_value := 100
var dead := false
var drops_powerup := false
## 激光命中判定的近似半径（水平覆盖 + 垂直截断）
var hit_radius := 16.0


func apply_damage(dmg: int) -> void:
	if dead:
		return
	hp -= dmg
	if hp <= 0:
		dead = true
		_die()
	else:
		_flash()


func _die() -> void:
	_spawn_drop()
	var game := get_tree().get_first_node_in_group("game") as Game
	if game != null:
		game.add_score(score_value)
		game.spawn_explosion(global_position, 1.0)
	queue_free()


## 死亡时按标记掉落道具（可能在物理信号回调中调用，需延迟入树）。
## forced 为 -1 时随机 P/B（各 50%）。
func _spawn_drop(forced := -1) -> void:
	if not drops_powerup:
		return
	var container := get_tree().get_first_node_in_group("powerups")
	if container == null:
		return
	var pickup := Powerup.new()
	pickup.position = global_position
	if forced >= 0:
		pickup.kind = forced
	else:
		pickup.kind = Powerup.Kind.BOMB if randf() < 0.5 else Powerup.Kind.POWER
	container.call_deferred("add_child", pickup)


func _flash() -> void:
	modulate = Color(3.0, 3.0, 3.0)
	create_tween().tween_property(self, "modulate", Color.WHITE, 0.12)


## 朝玩家方向的单位向量；玩家不存在或不活跃时朝正下方
func _aim_direction() -> Vector2:
	var game := get_tree().get_first_node_in_group("game") as Game
	if game != null and is_instance_valid(game.player) and game.player.active:
		var to_player: Vector2 = game.player.global_position - global_position
		if to_player.length() > 1.0:
			return to_player.normalized()
	return Vector2.DOWN


## 向敌方弹幕容器发射一发子弹
func _fire_bullet(velocity: Vector2, muzzle_offset := Vector2(0.0, 14.0)) -> void:
	var container := get_tree().get_first_node_in_group("enemy_bullets")
	if container == null:
		return
	var bullet := EnemyBullet.new()
	bullet.velocity = velocity
	container.add_child(bullet)
	bullet.global_position = global_position + muzzle_offset