# dragon_lair_system.gd —— Metin2 40250 冰龙贝兰-塞陶挑战巢穴 1:1
# 对照 40250 服务端 dragon_lair.quest, dungeon.cpp, char_battle.cpp, mob 2493, NPC 30121
class_name DragonLairSystem
extends RefCounted

signal dungeon_started(time_limit: float)
signal metin_destroyed(metin_vnum: int, metin_name: String)
signal minions_spawned(count: int, mob_vnum: int)
signal dragon_hp_changed(current_hp: int, max_hp: int)
signal dragon_defeated(drops: Array)
signal dungeon_failed(reason: String)

const NPC_GHOST_OF_SURA := 30121   # 修罗鬼魂
const ITEM_TWISTED_KEY := 30179    # 扭曲钥匙
const KEY_REQUIRED_COUNT := 3
const MIN_LEVEL := 75
const TIME_LIMIT := 3600.0         # 60 分钟限时

const BOSS_VNUM := 2493            # 贝兰-塞陶 (Beran-Setaou)
const BOSS_MAX_HP := 800000
const BOSS_BASE_ATK := 1800
const BOSS_BASE_DEF := 650

const METIN_TABLE: Dictionary = {
	8031: {"name": "傲慢之石", "desc": "提供 30% 物理抗性减免"},
	8032: {"name": "寂寞之石", "desc": "提供生命自然恢复"},
	8033: {"name": "平静之石", "desc": "提供 30% 魔法抗性减免"},
	8034: {"name": "复仇之石", "desc": "提供 40% 攻击力增幅"}
}

var is_active: bool = false
var remaining_time: float = 0.0
var dragon_hp: int = 0
var dragon_max_hp: int = BOSS_MAX_HP
var is_dragon_alive: bool = false
var active_metins: Dictionary = {}  # vnum -> bool (true = alive)
var active_minions: Array = []
var regen_timer: float = 0.0

# 进入冰龙巢穴 (通过 NPC 30121 验证)
func enter_lair(player_level: int, inventory: Array) -> Dictionary:
	if player_level < MIN_LEVEL:
		return {
			"ok": false,
			"reason": "LEVEL_TOO_LOW",
			"msg": "你的等级不足 75 级，无法承受冰龙巢穴的严寒！"
		}

	# 检查背包中的 3 把扭曲钥匙 (30179)
	var key_slots: Array = []
	var total_keys: int = 0
	for i in range(inventory.size()):
		var item = inventory[i]
		if item != null and int(item.get("vnum", 0)) == ITEM_TWISTED_KEY:
			var cnt: int = int(item.get("count", 1))
			total_keys += cnt
			key_slots.append({"slot": i, "count": cnt})

	if total_keys < KEY_REQUIRED_COUNT:
		return {
			"ok": false,
			"reason": "MISSING_KEYS",
			"current_keys": total_keys,
			"required_keys": KEY_REQUIRED_COUNT,
			"msg": "进入冰龙巢穴需要 3 把扭曲钥匙！你当前拥有 %d 把。" % total_keys
		}

	# 扣除 3 把扭曲钥匙
	var needed: int = KEY_REQUIRED_COUNT
	for ks in key_slots:
		var slot_idx: int = ks["slot"]
		var available: int = ks["count"]
		if available <= needed:
			needed -= available
			inventory[slot_idx] = null
		else:
			inventory[slot_idx]["count"] = available - needed
			needed = 0
		if needed <= 0:
			break

	# 初始化巢穴状态
	is_active = true
	remaining_time = TIME_LIMIT
	dragon_hp = BOSS_MAX_HP
	dragon_max_hp = BOSS_MAX_HP
	is_dragon_alive = true
	active_minions.clear()
	regen_timer = 0.0

	# 刷新 4 块龙神魔石
	active_metins.clear()
	for vnum in METIN_TABLE.keys():
		active_metins[vnum] = true

	dungeon_started.emit(remaining_time)

	return {
		"ok": true,
		"time_limit": remaining_time,
		"dragon_hp": dragon_hp,
		"metins": active_metins.duplicate(),
		"msg": "已使用 3 把扭曲钥匙，成功开启冰龙巢穴！限时 60 分钟！"
	}

# 获取当前冰龙实际攻击力 (受 8034 复仇之石影响)
func get_dragon_atk() -> int:
	var atk := BOSS_BASE_ATK
	if active_metins.get(8034, false):
		atk = int(atk * 1.4) # +40% ATK
	return atk

# 获取当前冰龙防御力
func get_dragon_def() -> int:
	return BOSS_BASE_DEF

# 击破魔石机制
func destroy_metin(metin_vnum: int) -> Dictionary:
	if not is_active:
		return {"ok": false, "reason": "DUNGEON_NOT_ACTIVE"}

	if not active_metins.get(metin_vnum, false):
		return {"ok": false, "reason": "METIN_ALREADY_DESTROYED"}

	active_metins[metin_vnum] = false
	var mname: String = METIN_TABLE[metin_vnum]["name"]

	# 击破魔石唤醒 4 只塞陶龙宫护卫 (vnum: 2401)
	var spawn_count := 4
	for i in range(spawn_count):
		active_minions.append({"vnum": 2401, "hp": 30000})

	metin_destroyed.emit(metin_vnum, mname)
	minions_spawned.emit(spawn_count, 2401)

	return {
		"ok": true,
		"metin_vnum": metin_vnum,
		"metin_name": mname,
		"remaining_metins": get_alive_metin_count(),
		"spawned_minions": spawn_count,
		"msg": "【%s】已被击破！对应龙神加成已破除，但唤醒了龙宫护卫！" % mname
	}

# 获取存活魔石数量
func get_alive_metin_count() -> int:
	var count := 0
	for v in active_metins.values():
		if v:
			count += 1
	return count

# 对冰龙造成伤害
func apply_damage(raw_dmg: int, is_magic: bool = false) -> Dictionary:
	if not is_active or not is_dragon_alive:
		return {"ok": false, "reason": "DRAGON_NOT_ALIVE"}

	var def := get_dragon_def()
	var net_dmg: float = max(1, raw_dmg - def)

	# 8031 傲慢之石减免 30% 物理伤害
	if not is_magic and active_metins.get(8031, false):
		net_dmg *= 0.70

	# 8033 平静之石减免 30% 魔法伤害
	if is_magic and active_metins.get(8033, false):
		net_dmg *= 0.70

	var final_dmg := int(round(net_dmg))
	dragon_hp = max(0, dragon_hp - final_dmg)

	dragon_hp_changed.emit(dragon_hp, dragon_max_hp)

	# 击杀冰龙判定
	if dragon_hp <= 0:
		is_dragon_alive = false
		is_active = false
		var drops := _generate_dragon_drops()
		dragon_defeated.emit(drops)
		return {
			"ok": true,
			"killed": true,
			"net_dmg": final_dmg,
			"remaining_hp": 0,
			"drops": drops,
			"msg": "【冰龙贝兰-塞陶】已被彻底击败！龙鳞与龙爪散落一地！"
		}

	return {
		"ok": true,
		"killed": false,
		"net_dmg": final_dmg,
		"remaining_hp": dragon_hp,
		"hp_ratio": float(dragon_hp) / float(dragon_max_hp)
	}

# 逐帧更新 (计时与 8032 寂寞之石生命回复)
func update(dt: float) -> void:
	if not is_active:
		return

	remaining_time -= dt
	if remaining_time <= 0.0:
		is_active = false
		is_dragon_alive = false
		dungeon_failed.emit("TIME_OUT")
		return

	# 8032 寂寞之石：每 5 秒为冰龙回复 2% 最大生命 (16000 HP)
	if is_dragon_alive and active_metins.get(8032, false):
		regen_timer += dt
		if regen_timer >= 5.0:
			regen_timer = 0.0
			var heal_amount := int(BOSS_MAX_HP * 0.02)
			dragon_hp = mini(BOSS_MAX_HP, dragon_hp + heal_amount)
			dragon_hp_changed.emit(dragon_hp, dragon_max_hp)

# 生成冰龙掉落物 (71123 龙鳞, 71129 龙爪, 50186 水龙宝箱)
func _generate_dragon_drops() -> Array:
	var drops: Array = []

	# 1. 必掉史诗升阶材料：龙鳞 (71123)
	drops.append({
		"vnum": 71123,
		"name": "龙鳞",
		"count": randi_range(1, 2)
	})

	# 2. 必掉史诗升阶材料：龙爪 (71129)
	drops.append({
		"vnum": 71129,
		"name": "龙爪",
		"count": randi_range(1, 2)
	})

	# 3. 必掉水龙专属宝箱 (50186)
	drops.append({
		"vnum": 50186,
		"name": "贝兰-塞陶宝箱",
		"count": 1
	})

	# 4. 必掉灵魂之石 (50513)
	drops.append({
		"vnum": 50513,
		"name": "灵魂之石",
		"count": 1
	})

	# 5. 大额金币掉落
	drops.append({
		"vnum": 1,
		"name": "金币",
		"count": randi_range(150000, 300000)
	})

	return drops