extends CharacterBody2D

@export_category("移动参数")
@export var double_press_interval := 0.3
@export var move_speed: float = 75.0
@export var acceleration: float = 600.0
@export var deceleration: float = 800.0
@export var jump_velocity: float = -190.0


@onready var sprite: Sprite2D = $Sprite2D

var flying : bool = false
var last_space_press_time := -1000

func _physics_process(delta: float) -> void:

	if !flying:
		apply_gravity(delta)
		handle_jump()
	else:
		handle_vertical_movement(delta)
	
	handle_horizontal_movement(delta)
	update_sprite_direction()
	move_and_slide()

func apply_gravity(delta: float) -> void:
	if not is_on_floor():
		velocity += get_gravity() * delta

func handle_vertical_movement(delta:float) -> void:
	var direction := Input.get_axis("squat", "jump")
	var target_speed := direction * jump_velocity
	
	if direction != 0.0:
		velocity.y = move_toward(
				velocity.y,
				target_speed,
				acceleration * delta
		)
	else:
		velocity.y = move_toward(
				velocity.y,
				0.0,
				acceleration * delta
		)
	
func handle_horizontal_movement(delta: float) -> void:
	var direction := Input.get_axis("move_left", "move_right")
	var target_speed := direction * move_speed

	if direction != 0.0:
		velocity.x = move_toward(
				velocity.x,
				target_speed,
				acceleration * delta
		)
	else:
		velocity.x = move_toward(
				velocity.x,
				0.0,
				deceleration * delta
		)

func handle_jump() -> void:
	if Input.is_action_just_pressed("jump") and is_on_floor():
		velocity.y = jump_velocity

func update_sprite_direction() -> void:
	if velocity.x != 0.0:
		sprite.flip_h = velocity.x < 0.0
		
func _unhandled_input(event: InputEvent) -> void:
	if event.is_action_pressed("fly") and !event.is_echo():
		handle_space_pressed()
	if event.is_action_pressed("dash") and not is_dashing:
		start_dash()
	
func handle_space_pressed() -> void:
	var current_time := Time.get_ticks_msec()
	var elapsed_time := current_time - last_space_press_time

	if elapsed_time <= double_press_interval * 1000.0:
		flying = not flying
		last_space_press_time = -1000
	else:
		last_space_press_time = current_time


signal died 
signal health_changed(current: int, max_hp: int)
@export var max_hp: int = 3
@export var knockback_force: float = 150.0
var hp : int
func _ready() -> void:
	hp = max_hp
	health_changed.emit(hp, max_hp)

func take_damage():
	hp -= 1
	hp = max(hp, 0)
	health_changed.emit(hp, max_hp) 
	 
	apply_knockback()
	
	sprite.modulate = Color(1, 0, 0)          # 变红
	await get_tree().create_timer(0.5).timeout # 等 0.5 秒
	sprite.modulate = Color(1, 1, 1) 
	
	
	if hp <= 0:
		died.emit()
		queue_free() 
		
func apply_knockback():
	# 取当前水平运动方向，反方向给速度
	var dir = sign(velocity.x)   # -1 或 1
	if dir == 0:
		dir = -1   # 静止时默认往左击退
	velocity.x = -dir * knockback_force
	velocity.y = -100  

func _on_spikes_01_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血") # Replace with function body.


func _on_spikes_03_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血") # Replace with function body.


func _on_spikes_02_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血") # Replace with function body.

func _on_spikes_05_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血")
	
func _on_spikes_04_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血")



signal coin_changed(total: int)   # 金币变化时通知 UI

var coins: int = 0

func add_coin(amount: int = 1) -> void:
	coins += amount
	coin_changed.emit(coins)
	print("金币：", coins)

		
@export var dash_speed: float = 600.0   # 闪现速度
@export var dash_time: float = 0.1      # 持续时间（秒）
var is_dashing := false



func start_dash():
	is_dashing = true
	# 朝当前面朝方向闪现
	var dir = 1 if not sprite.flip_h else -1
	velocity.x = dir * dash_speed
	velocity.y = 0
	await get_tree().create_timer(dash_time).timeout
	velocity.x = 0
	is_dashing = false


func _on_spikes_06_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血")# Replace with function body.


func _on_spikes_07_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血") # Replace with function body.


func _on_spikes_08_body_entered(body: Node2D) -> void:
	if body.has_method("take_damage"):
			body.take_damage()
	print("你受伤了，还剩",hp,"点血") # Replace with function body.