class_name EnemyMedium
extends EnemyBase
## 中型轰炸机：从屏幕一侧横掠，正弦起伏，朝玩家方向瞄准射击。

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

var side := 1  ## 1 = 从左向右，-1 = 从右向左
var base_y := 220.0
var vx := 110.0
var fire_interval := 1.6
var bullet_speed := 235.0

var _t := 0.0
var _fire_timer := 1.0


func setup(p_side: int, p_y: float, p_vx := 110.0, p_bullet_speed := 235.0, p_fire_interval := 1.6) -> void:
	side = p_side
	base_y = p_y
	vx = p_vx
	bullet_speed = p_bullet_speed
	fire_interval = p_fire_interval
	drops_powerup = true
	position = Vector2(-70.0 if side == 1 else 610.0, base_y)


func _ready() -> void:
	collision_layer = 4
	collision_mask = 0
	hp = 6
	score_value = 400
	hit_radius = 30.0
	var sprite := Sprite2D.new()
	sprite.texture = TEX
	add_child(sprite)
	var shape := CollisionShape2D.new()
	var rect := RectangleShape2D.new()
	rect.size = Vector2(54.0, 30.0)
	shape.shape = rect
	add_child(shape)


func _process(delta: float) -> void:
	_t += delta
	position.x += vx * float(side) * delta
	position.y = base_y + sin(_t * 1.1) * 46.0
	if (side == 1 and position.x > 610.0) or (side == -1 and position.x < -70.0):
		queue_free()
		return
	_fire_timer -= delta
	if _fire_timer <= 0.0:
		_fire_timer = fire_interval
		_fire_bullet(_aim_direction() * bullet_speed)