# Enemy.gd
# ─────────────────────────────────────────────────────────────────────────────
# Gegner-KI – State Machine mit NavigationAgent3D
#
# Zustände:
#   IDLE      → wartet bis Spieler in detection_range kommt
#   CHASING   → läuft via NavMesh zum Spieler
#   ATTACKING → steht, dreht sich zum Spieler, greift in attack_speed-Intervallen an
#   DEAD      → Kollision deaktiviert, Node wird nach kurzer Verzögerung entfernt
#
# Signale:
#   enemy_died(spawn_position, xp_reward)        → World.gd → Respawn + XP
#   enemy_dropped_loot(loot, world_pos)          → World.gd → Spieler → LootWindow
# ─────────────────────────────────────────────────────────────────────────────
extends CharacterBody3D

# ═══════════════════════════════════════════════════════════════
# SIGNALE
# ═══════════════════════════════════════════════════════════════

signal enemy_died(spawn_position: Vector3, xp_reward: int)
signal enemy_dropped_loot(loot: Dictionary, world_pos: Vector3)

# ═══════════════════════════════════════════════════════════════
# STATS
# ═══════════════════════════════════════════════════════════════

@export var max_hp: int = 50
@export var min_damage: int = 3
@export var max_damage: int = 7
@export var attack_range: float = 2.0
@export var attack_speed: float = 2.0   # Sekunden zwischen Angriffen
@export var move_speed: float = 3.0
@export var xp_reward: int = 20
@export var detection_range: float = 15.0
@export var loot_table: LootTable = null

var current_hp: int
var target = null  # Spieler

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# ZUSTAND
# ═══════════════════════════════════════════════════════════════

enum State { IDLE, CHASING, ATTACKING, DEAD }
var state: State = State.IDLE

var attack_cooldown: float = 0.0
var is_dead: bool = false

const GRAVITY = 9.8

# ═══════════════════════════════════════════════════════════════
# NODE-REFERENZEN
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@onready var nav_agent: NavigationAgent3D = $NavigationAgent3D
@onready var health_label: Label3D = $HealthDisplay/Label3D

# ═══════════════════════════════════════════════════════════════
# READY
# ═══════════════════════════════════════════════════════════════

func _ready():
	current_hp = max_hp
	_update_health_display()
	health_label.visible = false

	# NavigationAgent konfigurieren
	nav_agent.path_desired_distance = 0.5
	nav_agent.target_desired_distance = attack_range * 0.9

# ═══════════════════════════════════════════════════════════════
# PHYSICS PROCESS
# ═══════════════════════════════════════════════════════════════

func _physics_process(delta):
	if is_dead:
		return

	# Schwerkraft
	if not is_on_floor():
		velocity.y -= GRAVITY * delta

	# Cooldown herunterzählen
	if attack_cooldown > 0:
		attack_cooldown -= delta

	# Kein Ziel → Idle
	if target == null or not is_instance_valid(target):
		state = State.IDLE
		velocity.x = 0
		velocity.z = 0
		move_and_slide()
		return

	var distance = global_position.distance_to(target.global_position)

	match state:
		State.IDLE:
			if distance <= detection_range:
				state = State.CHASING
		State.CHASING:
			if distance <= attack_range:
				state = State.ATTACKING
				velocity.x = 0
				velocity.z = 0
			else:
				_move_toward_target()
		State.ATTACKING:
			if distance > attack_range * 1.5:
				state = State.CHASING
			else:
				velocity.x = 0
				velocity.z = 0
				_face_target()
				if attack_cooldown <= 0:
					_perform_attack()

	move_and_slide()

func _move_toward_target():
	if target == null:
		return
	nav_agent.target_position = target.global_position
	if nav_agent.is_navigation_finished():
		return
	var next_pos = nav_agent.get_next_path_position()
	var direction = (next_pos - global_position).normalized()
	direction.y = 0
	velocity.x = direction.x * move_speed
	velocity.z = direction.z * move_speed
	_face_direction(direction)

func _face_target():
	if target == null:
		return
	var dir = (target.global_position - global_position)
	dir.y = 0
	if dir.length() > 0.01:
		_face_direction(dir.normalized())

func _face_direction(dir: Vector3):
	if dir.length() > 0.01:
		rotation.y = atan2(dir.x, dir.z)

# ═══════════════════════════════════════════════════════════════
# KAMPF
# ═══════════════════════════════════════════════════════════════

func _perform_attack():
	if target == null or not is_instance_valid(target):
		return
	var damage = randi_range(min_damage, max_damage)
	target.take_damage(damage)
	attack_cooldown = attack_speed
	print(name + " greift an: " + str(damage) + " Schaden")

func take_damage(amount: int):
	if is_dead:
		return
	current_hp = clamp(current_hp - amount, 0, max_hp)
	_update_health_display()
	if current_hp <= 0:
		_die()

# ═══════════════════════════════════════════════════════════════
# HP-ANZEIGE
# ═══════════════════════════════════════════════════════════════

func show_health():
	if health_label:
		health_label.visible = true

func hide_health():
	if health_label:
		health_label.visible = false

func _update_health_display():
	if health_label:
		health_label.text = str(current_hp) + " / " + str(max_hp)

# ═══════════════════════════════════════════════════════════════
# TOD & LOOT
# ═══════════════════════════════════════════════════════════════

func _die():
	is_dead = true
	state = State.DEAD
	velocity = Vector3.ZERO
	print(name + " gestorben!")

	# Loot generieren
	if loot_table != null:
		var loot = loot_table.generate_loot()
		enemy_dropped_loot.emit(loot, global_position)

	# XP und Respawn-Signal
	enemy_died.emit(global_position, xp_reward)

	# Kollision deaktivieren und Node entfernen
	set_deferred("collision_layer", 0)
	set_deferred("collision_mask", 0)
	await get_tree().create_timer(1.5).timeout
	queue_free()