class_name EnemyShip
extends EnemyBase
## 驱逐舰：随海面航行（比地面稍快），舰桥瞄准玩家射击。

const TEX := preload("res://assets/svg/ship.svg")
const MUZZLE := Vector2(0.0, 0.0)

var difficulty := 1.0
var scroll_speed := 160.0
var fire_interval := 2.4
var bullet_speed := 230.0

var _fire_timer := 0.0


func setup(p_x: float, p_y: float, p_difficulty := 1.0) -> void:
	position = Vector2(p_x, p_y)
	difficulty = p_difficulty
	scroll_speed = 150.0 + 20.0 * p_difficulty
	fire_interval = maxf(1.6, 2.4 / p_difficulty)
	bullet_speed = 230.0 * p_difficulty


func _ready() -> void:
	# 层 32：海面单位——玩家子弹可命中，但玩家机体不与其碰撞（飞越上空）
	collision_layer = 32
	collision_mask = 0
	hp = 8
	score_value = 800
	hit_radius = 46.0
	var sprite := Sprite2D.new()
	sprite.texture = TEX
	add_child(sprite)
	var shape := CollisionShape2D.new()
	var rect := RectangleShape2D.new()
	rect.size = Vector2(38.0, 112.0)
	shape.shape = rect
	add_child(shape)
	_fire_timer = randf_range(1.0, 2.2)


func _process(delta: float) -> void:
	position.y += scroll_speed * delta
	if position.y > 1100.0:
		queue_free()
		return
	if position.y > 60.0 and position.y < 760.0:
		_fire_timer -= delta
		if _fire_timer <= 0.0:
			_fire_timer = fire_interval
			_fire_bullet(_aim_direction() * bullet_speed, MUZZLE)