## WaveManager — 波次管理（Autoload: WaveManager）
## S6 内容：Wave 1~20 完整配置（敌人原型/精英寻路/Mini Boss W8/Final Boss W20）
## 设计参考：game_design.md §3.3（W1-5 数值 / W6-10 机制 / W11-20 弹幕）、§4.5 Boss
extends Node

enum WaveState { IDLE = 0, BATTLE = 1, COMPLETE = 2 }

var current_wave:   int = 0
var wave_state:     int = WaveState.IDLE
var enemies_alive:  int = 0
var _wave_start_time: float = 0.0

const ARENA_RADIUS: float = 700.0
const MAX_WAVE: int = 20

## Boss 追踪
var _boss_id:      int   = -1
var _boss_max_hp:  float = 0.0
var _boss_phase:   int   = 0
var _boss_wave:    bool  = false

## 波次配置表：纯数据驱动，唯一来源 data/waves.json（游戏设计器「波次」面板维护）
## 字段：count, hp, type, elite, gold, xp, boss(-1=无 / 4=MiniBoss / 5=Boss)
var WAVE_CONFIG: Array = []

const WAVES_JSON: String = "res://data/waves.json"

func _ready() -> void:
	EventBus.subscribe(EventID.ENEMY_KILLED, _on_enemy_killed)
	_load_json_waves()

## 数据驱动：从 data/waves.json 加载波次表
func _load_json_waves() -> void:
	if not FileAccess.file_exists(WAVES_JSON):
		push_error("WaveManager: 缺失 res://data/waves.json（无波次配置）")
		return
	var data = JSON.parse_string(FileAccess.get_file_as_string(WAVES_JSON))
	if data is Array and not data.is_empty():
		WAVE_CONFIG = data
	else:
		push_error("WaveManager: waves.json 格式错误（应为非空数组）")

func _physics_process(_delta: float) -> void:
	if _boss_wave and _boss_id >= 0:
		_update_boss_phase()

## 开始指定波次（由 CombatManager 调用）
func start_wave(wave_num: int) -> void:
	current_wave = wave_num
	wave_state   = WaveState.BATTLE
	_wave_start_time = Time.get_ticks_msec() / 1000.0
	_boss_id = -1
	_boss_phase = 0
	_boss_wave = false
	var cfg: Dictionary = _get_wave_config(wave_num)
	enemies_alive = int(cfg["count"])
	_spawn_wave_enemies(cfg)
	if int(cfg.get("boss", -1)) >= 0:
		_spawn_boss(int(cfg["boss"]), wave_num)
	EventBus.emit(EventID.GAME_STATE_CHANGED, {"from": "SHOP", "to": "BATTLE", "wave": wave_num})
	print("[WaveManager] Wave %d 开始：%d 杂兵 + %d 精英%s" % [
		wave_num, int(cfg["count"]), int(cfg.get("elite", 0)),
		("（Boss！）" if int(cfg.get("boss", -1)) >= 0 else "")])

func _spawn_wave_enemies(cfg: Dictionary) -> void:
	# 难度乘子：怪物数量（挑战×1.2）、怪物血量（初学者×0.7）
	var count: int   = int(round(int(cfg["count"]) * SettingsManager.wave_count_mult()))
	var hp:    float = float(cfg["hp"]) * SettingsManager.enemy_hp_mult()
	var etype: int   = int(cfg.get("type", 0))
	# enemies_alive 已按 cfg.count 初始化，按难度修正差额
	enemies_alive += count - int(cfg["count"])
	for _i in count:
		EnemyManager.spawn_enemy(_ring_pos(), hp, etype)
	# W15+ 精英：带 NavigationAgent2D 寻路（ADR-A4），更高血量
	var elites: int = int(cfg.get("elite", 0))
	for _e in elites:
		EnemyManager.spawn_enemy(_ring_pos(), hp * 2.5, EnemyManager.Type.ELITE, true)
	enemies_alive += elites  # 精英计入存活

func _spawn_boss(boss_type: int, wave_num: int) -> void:
	# Boss 基础血量由 SettingsManager（balance.json 可调）提供 × 难度乘子
	var hp: float = SettingsManager.get_boss_base_hp(boss_type) * SettingsManager.boss_hp_mult()
	_boss_max_hp = hp
	# Boss 在玩家上方稍远处入场
	_boss_id = EnemyManager.spawn_enemy(Vector2(0.0, -ARENA_RADIUS * 0.8), hp, boss_type)
	_boss_wave = true
	_boss_phase = 1
	enemies_alive += 1
	EventBus.emit(EventID.BOSS_SPAWNED, {
		"boss_id": _boss_id, "boss_type": boss_type, "wave": wave_num, "max_hp": hp})
	print("[WaveManager] Boss 入场！type=%d hp=%.0f (wave %d)" % [boss_type, hp, wave_num])

## Boss 阶段：HP 跨越阈值时进阶并召唤援军（简化 AI，game_design §4.5）
func _update_boss_phase() -> void:
	if not EnemyManager.has_entity(_boss_id):
		return
	var frac: float = EnemyManager.get_hp_percent(_boss_id)
	var target_phase: int = 1
	if frac <= 0.33:
		target_phase = 3
	elif frac <= 0.66:
		target_phase = 2
	if target_phase > _boss_phase:
		_boss_phase = target_phase
		_on_boss_phase_enter(target_phase)

func _on_boss_phase_enter(phase: int) -> void:
	# 进阶召唤一批援军施压（Phase 2/3）
	var add_count: int = 4 + phase * 2
	var boss_pos: Vector2 = EnemyManager.get_pos_by_id(_boss_id)
	for _i in add_count:
		var off := Vector2(randf_range(-120, 120), randf_range(-120, 120))
		var aid: int = EnemyManager.spawn_enemy(boss_pos + off, 40.0, EnemyManager.Type.FAST)
		if aid >= 0:
			enemies_alive += 1
	EventBus.emit(EventID.GAME_STATE_CHANGED, {"from": "BATTLE", "to": "BOSS_PHASE_%d" % phase})
	print("[WaveManager] Boss 进入 Phase %d，召唤 %d 援军" % [phase, add_count])

func _ring_pos() -> Vector2:
	var angle: float = randf() * TAU
	var radius: float = randf_range(250.0, ARENA_RADIUS)
	return Vector2(cos(angle) * radius, sin(angle) * radius)

func _on_enemy_killed(payload: Dictionary) -> void:
	if wave_state != WaveState.BATTLE:
		return
	var killed_id: int = int(payload.get("entity_id", -1))
	# Boss 波：Boss 死亡即通关本波（援军为附赠）
	if _boss_wave and killed_id == _boss_id:
		_complete_wave()
		return
	enemies_alive -= 1
	if enemies_alive <= 0 and not _boss_wave:
		_complete_wave()

func _complete_wave() -> void:
	if wave_state != WaveState.BATTLE:
		return
	wave_state = WaveState.COMPLETE
	_boss_wave = false
	_boss_id = -1
	var cfg: Dictionary = _get_wave_config(current_wave)
	PlayerStats.gain_gold(int(cfg["gold"]))
	PlayerStats.gain_xp(int(cfg["xp"]))
	var elapsed: float = Time.get_ticks_msec() / 1000.0 - _wave_start_time
	EventBus.emit(EventID.WAVE_COMPLETE, {"wave": current_wave, "elapsed_sec": elapsed})
	print("[WaveManager] Wave %d 完成！奖励: %dG, %d XP" % [current_wave, int(cfg["gold"]), int(cfg["xp"])])

func _get_wave_config(wave_num: int) -> Dictionary:
	var idx: int = clamp(wave_num - 1, 0, WAVE_CONFIG.size() - 1)
	var base: Dictionary = WAVE_CONFIG[idx].duplicate()
	# 超过 W20（Endless）：数值膨胀
	if wave_num > MAX_WAVE:
		var extra: int = wave_num - MAX_WAVE
		base["count"] = int(base["count"]) + extra * 6
		base["hp"]    = float(base["hp"]) * pow(1.12, extra)
		base["gold"]  = int(base["gold"]) + extra * 8
		base["xp"]    = int(base["xp"]) + extra * 12
		base["boss"]  = -1  # Endless 不重复终 Boss
	return base

func get_wave_count(wave_num: int) -> int:
	return int(_get_wave_config(wave_num)["count"])

func is_boss_wave(wave_num: int) -> bool:
	return int(_get_wave_config(wave_num).get("boss", -1)) >= 0

func reset() -> void:
	current_wave  = 0
	wave_state    = WaveState.IDLE
	enemies_alive = 0
	_boss_id = -1
	_boss_phase = 0
	_boss_wave = false