class_name Player
extends Area2D
## 玩家战机：移动钳制、无敌闪烁与受击。
## Variant.FIGHTER：机枪弹幕（PlayerBullet）。
## Variant.FUNNEL：机体+浮游炮持续激光；按 focus(I) 浮游炮聚拢合体粗激光。

signal hit

enum Variant { FIGHTER, FUNNEL }

const SPEED := 340.0
const FIRE_INTERVAL := 0.13
const INVULN_ON_RESPAWN := 2.5
const WEAPON_LEVEL_MAX := 4
const BOMBS_MAX := 5
const BOMB_INVULN := 1.0
const TEX := preload("res://assets/art/P-38.png")
const TEX_FUNNEL := preload("res://assets/svg/plane_funnel.svg")
const FUNNEL_TEX := preload("res://assets/svg/funnel.svg")

const PLANE_LASER_DPS := 18.0
const FUNNEL_LASER_DPS := 7.0
const FOCUS_MULT := 1.5
const FOCUS_SPEED_MULT := 0.5
const PLANE_MUZZLE := Vector2(0.0, -30.0)
## 侧身帧切换：三帧贴图（平飞/左倾/右倾），机头始终垂直
const BANK_LERP := 12.0
const BANK_ENTER := 0.45
const BANK_EXIT := 0.25
## 展开阵列（左侧三槽，右侧镜像）：错开的三角编队
const FUNNEL_SPREAD_LEFT: Array[Vector2] = [
	Vector2(-36.0, -4.0),
	Vector2(-62.0, -22.0),
	Vector2(-40.0, -46.0),
]
const FUNNEL_FOCUS_X := 12.0

var variant: Variant = Variant.FIGHTER
var weapon_level := 1
var bombs := 2
var fire_timer := 0.0
var invuln := 0.0
var active := true
var sprite: Sprite2D

var _bank := 0.0
var _bank_state := 0
var _tex_neutral: Texture2D
var _tex_bank_left: Texture2D
var _tex_bank_right: Texture2D

var _funnels: Array[Node2D] = []
var _funnel_beams: Array[LaserBeam] = []
var _plane_beam: LaserBeam
var _focus_beam: LaserBeam


func _ready() -> void:
	collision_layer = 1
	collision_mask = 4 | 8 | 16
	sprite = Sprite2D.new()
	if variant == Variant.FUNNEL:
		_tex_neutral = _load_optional_texture("res://assets/art/plane_funnel.png")
		if _tex_neutral == null:
			_tex_neutral = TEX_FUNNEL
		_tex_bank_left = _load_optional_texture("res://assets/art/plane_funnel-bank-left.png")
		_tex_bank_right = _load_optional_texture("res://assets/art/plane_funnel-bank-right.png")
	else:
		_tex_neutral = TEX
		_tex_bank_left = _load_optional_texture("res://assets/art/P-38-bank-left.png")
		_tex_bank_right = _load_optional_texture("res://assets/art/P-38-bank-right.png")
	sprite.texture = _tex_neutral
	add_child(sprite)
	var shape := CollisionShape2D.new()
	var capsule := CapsuleShape2D.new()
	capsule.radius = 13.0
	capsule.height = 44.0
	shape.shape = capsule
	add_child(shape)
	area_entered.connect(_on_area_entered)
	if variant == Variant.FUNNEL:
		_plane_beam = _make_beam(PLANE_LASER_DPS, 5.0, Color(0.6, 0.85, 1.0), PLANE_MUZZLE)
		_focus_beam = _make_beam(0.0, 16.0, Color(0.92, 0.98, 1.0), PLANE_MUZZLE)
		_sync_funnels()


func _make_beam(p_dps: float, p_width: float, p_color: Color, offset: Vector2) -> LaserBeam:
	var beam := LaserBeam.new()
	beam.dps = p_dps
	beam.width = p_width
	beam.color = p_color
	beam.position = offset
	add_child(beam)
	return beam


func _process(delta: float) -> void:
	if not active:
		return
	var direction := Input.get_vector("move_left", "move_right", "move_up", "move_down")
	# 聚焦合体期间：威力换机动，移动速度减半（仍可移动）
	var speed := SPEED
	if variant == Variant.FUNNEL and Input.is_action_pressed("fire") and Input.is_action_pressed("focus"):
		speed *= FOCUS_SPEED_MULT
	position += direction * speed * delta

	# 侧身帧：带迟滞的三态切换（左倾/平飞/右倾），纯贴图切换、机头不歪
	var dir_x := clampf(direction.x, -1.0, 1.0)
	_bank = lerpf(_bank, dir_x, minf(BANK_LERP * delta, 1.0))
	if _bank_state == 0:
		if _bank > BANK_ENTER:
			_bank_state = 1
		elif _bank < -BANK_ENTER:
			_bank_state = -1
	elif absf(_bank) < BANK_EXIT:
		_bank_state = 0
	match _bank_state:
		-1:
			if _tex_bank_left != null:
				sprite.texture = _tex_bank_left
		1:
			if _tex_bank_right != null:
				sprite.texture = _tex_bank_right
		_:
			sprite.texture = _tex_neutral
	position.x = clampf(position.x, 22.0, 518.0)
	position.y = clampf(position.y, 90.0, 930.0)

	if variant == Variant.FIGHTER:
		fire_timer -= delta
		if Input.is_action_pressed("fire") and fire_timer <= 0.0:
			fire_timer = FIRE_INTERVAL
			_fire()
	else:
		_update_funnel_weapons(delta)

	if Input.is_action_just_pressed("bomb") and active and bombs > 0:
		use_bomb()

	if invuln > 0.0:
		invuln -= delta
		sprite.modulate.a = 1.0 if fmod(invuln * 8.0, 2.0) < 1.0 else 0.3
	else:
		sprite.modulate.a = 1.0


## 浮游炮机体武器：常态机体激光 + 各浮游炮激光；按 I 聚焦合体粗激光。
## 合体总威力 = 散开总威力 × FOCUS_MULT。
func _update_funnel_weapons(delta: float) -> void:
	var firing := Input.is_action_pressed("fire")
	var focus := firing and Input.is_action_pressed("focus")
	_plane_beam.active = firing and not focus
	_focus_beam.active = focus
	if focus:
		_focus_beam.dps = (PLANE_LASER_DPS + float(_funnels.size()) * FUNNEL_LASER_DPS) * FOCUS_MULT
	for beam in _funnel_beams:
		beam.active = firing and not focus
	for i in _funnels.size():
		var left := i % 2 == 0
		var rank := i / 2
		var target: Vector2
		if focus:
			target = Vector2(-FUNNEL_FOCUS_X if left else FUNNEL_FOCUS_X, -28.0 - 20.0 * float(rank))
		else:
			var slot: Vector2 = FUNNEL_SPREAD_LEFT[rank]
			target = slot if left else Vector2(-slot.x, slot.y)
		var funnel: Node2D = _funnels[i]
		funnel.position = funnel.position.lerp(target, minf(10.0 * delta, 1.0))


## 按当前火力等级同步浮游炮数量（每侧 level-1 台）
func _sync_funnels() -> void:
	if variant != Variant.FUNNEL:
		return
	var wanted := (weapon_level - 1) * 2
	while _funnels.size() > wanted:
		var removed: Node2D = _funnels.pop_back()
		_funnel_beams.pop_back()
		removed.queue_free()
	while _funnels.size() < wanted:
		var funnel := Node2D.new()
		var icon := Sprite2D.new()
		icon.texture = FUNNEL_TEX
		funnel.add_child(icon)
		var beam := LaserBeam.new()
		beam.dps = FUNNEL_LASER_DPS
		beam.width = 4.0
		beam.color = Color(0.45, 0.9, 1.0)
		beam.position = Vector2(0.0, -8.0)
		funnel.add_child(beam)
		add_child(funnel)
		funnel.position = Vector2(0.0, 20.0)
		_funnels.append(funnel)
		_funnel_beams.append(beam)


func _fire() -> void:
	var container := get_tree().get_first_node_in_group("player_bullets")
	if container == null:
		return
	match weapon_level:
		1:
			_spawn_volley(container, [-11.0, 11.0], Vector2.UP)
		2:
			_spawn_volley(container, [-17.0, -6.0, 6.0, 17.0], Vector2.UP)
		3:
			_spawn_volley(container, [-17.0, -6.0, 6.0, 17.0], Vector2.UP)
			_spawn_bullet(container, Vector2(-22.0, -4.0), Vector2.UP.rotated(deg_to_rad(-12.0)))
			_spawn_bullet(container, Vector2(22.0, -4.0), Vector2.UP.rotated(deg_to_rad(12.0)))
		_:
			# L4：6 直射 + 双道 22° 斜射 + 30° 斜射
			_spawn_volley(container, [-25.0, -15.0, -5.0, 5.0, 15.0, 25.0], Vector2.UP)
			_spawn_bullet(container, Vector2(-32.0, -4.0), Vector2.UP.rotated(deg_to_rad(-22.0)))
			_spawn_bullet(container, Vector2(-32.0, 6.0), Vector2.UP.rotated(deg_to_rad(-22.0)))
			_spawn_bullet(container, Vector2(32.0, -4.0), Vector2.UP.rotated(deg_to_rad(22.0)))
			_spawn_bullet(container, Vector2(32.0, 6.0), Vector2.UP.rotated(deg_to_rad(22.0)))
			_spawn_bullet(container, Vector2(-20.0, 10.0), Vector2.UP.rotated(deg_to_rad(-30.0)))
			_spawn_bullet(container, Vector2(20.0, 10.0), Vector2.UP.rotated(deg_to_rad(30.0)))


func _spawn_volley(container: Node, x_offsets: Array, dir: Vector2) -> void:
	for x in x_offsets:
		_spawn_bullet(container, Vector2(x, -8.0), dir)


func _spawn_bullet(container: Node, offset: Vector2, dir: Vector2) -> void:
	var bullet := PlayerBullet.new()
	bullet.direction = dir
	container.add_child(bullet)
	bullet.global_position = global_position + offset


func _collect_powerup(pickup: Powerup) -> void:
	pickup.queue_free()
	match pickup.kind:
		Powerup.Kind.BOMB:
			var game := get_tree().get_first_node_in_group("game") as Game
			bombs = mini(bombs + 1, BOMBS_MAX)
			if game != null:
				game.notify_bomb_pickup()
		_:
			if weapon_level < WEAPON_LEVEL_MAX:
				weapon_level += 1
				_sync_funnels()
			else:
				var game := get_tree().get_first_node_in_group("game") as Game
				if game != null:
					game.add_score(500)


## 投放炸弹：清屏伤害 + 清除敌弹 + 白闪光效 + 短暂无敌
func use_bomb() -> void:
	if not active or bombs <= 0:
		return
	bombs -= 1
	invuln = maxf(invuln, BOMB_INVULN)
	var game := get_tree().get_first_node_in_group("game") as Game
	if game != null:
		game.detonate_bomb()


func _on_area_entered(area: Area2D) -> void:
	if area is Powerup:
		_collect_powerup(area)
		return
	if not active or invuln > 0.0:
		return
	if area is EnemyBullet:
		area.queue_free()
		emit_signal("hit")
	elif area is EnemyBase:
		emit_signal("hit")


## 被击中后的消隐（禁用碰撞需延迟，避免在物理回调中直接修改）；火力降一级
func die() -> void:
	active = false
	weapon_level = maxi(1, weapon_level - 1)
	_sync_funnels()
	if _plane_beam != null:
		_plane_beam.active = false
	if _focus_beam != null:
		_focus_beam.active = false
	for beam in _funnel_beams:
		beam.active = false
	visible = false
	set_deferred("monitoring", false)


## 复活并给予无敌时间
func respawn(pos: Vector2) -> void:
	position = pos
	active = true
	visible = true
	invuln = INVULN_ON_RESPAWN
	fire_timer = 0.0
	_bank = 0.0
	_bank_state = 0
	sprite.texture = _tex_neutral
	set_deferred("monitoring", true)


## 可选素材：文件存在才加载（侧身帧未生成时回退平飞帧）
func _load_optional_texture(path: String) -> Texture2D:
	if not ResourceLoader.exists(path):
		return null
	return load(path) as Texture2D