class_name EnemySmall
extends EnemyBase
## 小型敌机：直线下压 + 可选横向摆动，部分会朝正下方开火。

const TEX := preload("res://assets/svg/enemy_small.svg")

var base_x := 270.0
var vy := 150.0
var sway_amp := 0.0
var sway_freq := 2.0
var phase := 0.0
var shoot := false
var bullet_speed := 250.0

var _t := 0.0
var _shoot_timer := 0.0


func setup(
	p_base_x: float,
	p_y: float,
	p_vy: float,
	p_sway_amp := 0.0,
	p_sway_freq := 2.0,
	p_phase := 0.0,
	p_shoot := false,
	p_bullet_speed := 250.0
) -> void:
	base_x = p_base_x
	position = Vector2(p_base_x, p_y)
	vy = p_vy
	sway_amp = p_sway_amp
	sway_freq = p_sway_freq
	phase = p_phase
	shoot = p_shoot
	bullet_speed = p_bullet_speed


func _ready() -> void:
	collision_layer = 4
	collision_mask = 0
	hp = 1
	score_value = 100
	hit_radius = 14.0
	var sprite := Sprite2D.new()
	sprite.texture = TEX
	# 掉落道具的敌机染成红色涂装（1942 惯例：红机掉宝）
	if drops_powerup:
		sprite.modulate = Color(1.0, 0.5, 0.4)
	add_child(sprite)
	var shape := CollisionShape2D.new()
	var capsule := CapsuleShape2D.new()
	capsule.radius = 12.0
	capsule.height = 34.0
	shape.shape = capsule
	add_child(shape)
	_shoot_timer = randf_range(1.2, 2.4)


func _process(delta: float) -> void:
	_t += delta
	position.y += vy * delta
	position.x = base_x + sin(_t * sway_freq + phase) * sway_amp
	if position.y > 1010.0 or position.x < -50.0 or position.x > 590.0:
		queue_free()
		return
	if shoot and position.y > 90.0 and position.y < 640.0:
		_shoot_timer -= delta
		if _shoot_timer <= 0.0:
			_shoot_timer = randf_range(1.8, 3.0)
			_fire_bullet(Vector2(0.0, bullet_speed))