extends CharacterBody3D

signal died(points: int)

enum State { CHASING, FLYING, STUNNED, DEAD }

var move_speed: float = 3.0
var health: int = 30
var damage_to_player: int = 8
var score_value: int = 10
var wall_damage_mult: float = 1.8
var chain_factor: float = 0.65
var stun_time: float = 0.5
var base_scale: float = 1.0

var state: State = State.CHASING
var fly_vel: Vector3 = Vector3.ZERO
var stun_timer: float = 0.0
var contact_timer: float = 0.0
var target: Node3D = null

@onready var mesh_node: MeshInstance3D = $BodyMesh
var mat: StandardMaterial3D

var COLOR_CHASE = Color(1.0, 0.28, 0.18)
var COLOR_FLY   = Color(1.0, 0.85, 0.1)
var COLOR_STUN  = Color(0.55, 0.55, 0.65)

const CONTACT_CD   = 0.7
const AIR_FRICTION = 0.86

func _ready() -> void:
	add_to_group("enemies")
	mat = mesh_node.material_override.duplicate() as StandardMaterial3D
	mesh_node.material_override = mat
	COLOR_CHASE = mat.albedo_color

func setup(type: String, wave: int) -> void:
	match type:
		"slime":
			move_speed = 2.8 + wave * 0.12
			health     = 28 + wave * 4
			score_value = 10
			damage_to_player = 8
		"bat":
			move_speed = 5.5 + wave * 0.15
			health     = 14 + wave * 2
			score_value = 15
			damage_to_player = 6
			base_scale = 0.7
			mesh_node.scale = Vector3(0.7, 0.7, 0.7)
			COLOR_CHASE = Color(0.6, 0.2, 0.8)
			mat.albedo_color = COLOR_CHASE
		"ogre":
			move_speed = 1.8 + wave * 0.08
			health     = 80 + wave * 12
			score_value = 25
			damage_to_player = 18
			base_scale = 1.5
			mesh_node.scale = Vector3(1.5, 1.5, 1.5)
			COLOR_CHASE = Color(0.3, 0.7, 0.3)
			mat.albedo_color = COLOR_CHASE

func _physics_process(delta: float) -> void:
	match state:
		State.CHASING: _chase(delta)
		State.FLYING:  _fly(delta)
		State.STUNNED: _stun_tick(delta)
		State.DEAD:    pass

func _chase(delta: float) -> void:
	if not is_instance_valid(target):
		return
	contact_timer = max(0.0, contact_timer - delta)
	var diff := target.global_position - global_position
	diff.y = 0.0
	var dist := diff.length()
	if dist < 1.0 and contact_timer <= 0.0:
		contact_timer = CONTACT_CD
		if target.has_method("take_damage"):
			target.take_damage(damage_to_player)
	if dist > 0.05:
		var dir := diff.normalized()
		velocity.x = dir.x * move_speed
		velocity.z = dir.z * move_speed
		rotation.y = lerp_angle(rotation.y, atan2(dir.x, dir.z), 8.0 * delta)
	velocity.y = 0.0
	move_and_slide()

func _fly(delta: float) -> void:
	var speed_now := Vector2(fly_vel.x, fly_vel.z).length()
	velocity = fly_vel
	velocity.y = 0.0
	move_and_slide()

	var hit_wall := false
	for i in get_slide_collision_count():
		var col := get_slide_collision(i)
		var col3d := col.get_collider() as Node3D
		if col3d == null:
			continue
		if col3d.has_meta("is_wall"):
			_take_hit(int(speed_now * wall_damage_mult))
			_wall_impact_effect()
			fly_vel = Vector3.ZERO
			velocity = Vector3.ZERO
			_enter_stun()
			hit_wall = true
			break
		elif col3d.is_in_group("enemies") and col3d != self:
			var chain_dir := col3d.global_position - global_position
			chain_dir.y = 0.0
			if chain_dir.length() > 0.01:
				col3d.call("receive_kick", chain_dir.normalized(), speed_now * chain_factor)
		elif col3d.is_in_group("player"):
			col3d.call("take_damage", int(speed_now * 0.6))

	if not hit_wall:
		fly_vel = velocity
		fly_vel.y = 0.0
		fly_vel *= pow(AIR_FRICTION, delta * 60.0)
		if Vector2(fly_vel.x, fly_vel.z).length() < 0.4:
			_enter_chase()

	mesh_node.rotation.y += delta * 10.0

func _stun_tick(delta: float) -> void:
	velocity = Vector3.ZERO
	stun_timer -= delta
	if stun_timer <= 0.0:
		_enter_chase()

func receive_kick(direction: Vector3, force: float) -> void:
	if state == State.DEAD:
		return
	fly_vel = direction * force
	fly_vel.y = 0.0
	state = State.FLYING
	mat.albedo_color = COLOR_FLY
	var tw := create_tween()
	tw.tween_property(mesh_node, "scale:y", base_scale * 0.35, 0.06)
	tw.tween_property(mesh_node, "scale:y", base_scale, 0.18)

func _enter_stun() -> void:
	state = State.STUNNED
	stun_timer = stun_time
	mat.albedo_color = COLOR_STUN
	var bs := base_scale
	var tw := create_tween()
	tw.tween_property(mesh_node, "scale", Vector3(bs * 1.6, bs * 0.25, bs * 1.6), 0.07)
	tw.tween_property(mesh_node, "scale", Vector3(bs, bs, bs), 0.22)

func _enter_chase() -> void:
	state = State.CHASING
	mat.albedo_color = COLOR_CHASE

func _take_hit(dmg: int) -> void:
	if state == State.DEAD:
		return
	health -= dmg
	if health <= 0:
		_die()

func _wall_impact_effect() -> void:
	var tw := create_tween()
	tw.tween_property(mat, "albedo_color", Color.WHITE, 0.04)
	tw.tween_property(mat, "albedo_color", COLOR_STUN, 0.12)

func _die() -> void:
	if state == State.DEAD:
		return
	state = State.DEAD
	set_physics_process(false)
	emit_signal("died", score_value)
	var tw := create_tween()
	tw.tween_property(self, "scale", Vector3(2.0, 0.05, 2.0), 0.18)
	tw.tween_property(self, "scale", Vector3(0.0, 0.0, 0.0), 0.1)
	tw.tween_callback(queue_free)