## BossManager — Boss 阶段状态机 + 攻击模式调度（Autoload）
## Boss 实体仍在 EnemyManager SoA（渲染/受击/HP）；本管理器侧挂运行态、接管移动、驱动招式。
## 数据驱动：data/bosses.json（每 boss_type 的 move_speed / phases / attack_patterns），自载。
extends Node

const BOSSES_JSON: String = "res://data/bosses.json"

# boss_type(int) → { move_speed:float, phases:Array[Dictionary] }
var _defs: Dictionary = {}
# boss_id(int) → 运行态 Dictionary
var _active: Dictionary = {}

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

func _load_defs() -> void:
	if not FileAccess.file_exists(BOSSES_JSON):
		push_error("BossManager: 缺失 res://data/bosses.json")
		return
	var data = JSON.parse_string(FileAccess.get_file_as_string(BOSSES_JSON))
	if not (data is Dictionary):
		push_error("BossManager: bosses.json 格式错误")
		return
	_defs.clear()
	for k in data:
		_defs[int(k)] = data[k]

## wave_manager._spawn_boss 生成 SoA Boss 后调用
func register_boss(boss_id: int, boss_type: int, max_hp: float, wave: int) -> void:
	var def: Dictionary = _defs.get(boss_type, {})
	var phases: Array = def.get("phases", [])
	_active[boss_id] = {
		"boss_type": boss_type,
		"max_hp": max_hp,
		"wave": wave,
		"move_speed": float(def.get("move_speed", 100.0)),
		"phase": 0,
		"phases": phases,
		"pattern_index": 0,
		"cooldown": 1.0,        # 入场后短暂延迟再起手
		"action": {},           # 进行中招式（空=无）
		"spiral_phase": 0.0,    # spiral 招式的累积旋转角
	}
	EnemyManager.register_external_mover(boss_id)
	if not phases.is_empty():
		_emit_phase(boss_id, 0)

func _physics_process(delta: float) -> void:
	if _active.is_empty():
		return
	for boss_id in _active.keys():
		if not EnemyManager.has_entity(boss_id):
			continue
		var st: Dictionary = _active[boss_id]
		_check_phase(boss_id, st)
		_tick_movement(boss_id, st, delta)
		_tick_action(boss_id, st, delta)

# 阶段切换：HP% 跨入更深阶段（phases 按 hp_threshold 降序，取满足阈值的最深项）
func _check_phase(boss_id: int, st: Dictionary) -> void:
	var hp_pct: float = EnemyManager.get_hp_percent(boss_id)
	var phases: Array = st["phases"]
	var target: int = int(st["phase"])
	for i in phases.size():
		if hp_pct <= float(phases[i].get("hp_threshold", 1.0)):
			target = i
	if target > int(st["phase"]):
		st["phase"] = target
		st["pattern_index"] = 0
		st["cooldown"] = 0.5
		st["action"] = {}
		_summon_adds(boss_id, int(phases[target].get("summon_adds", 0)))
		_emit_phase(boss_id, target)

func _emit_phase(boss_id: int, phase: int) -> void:
	EventBus.emit(EventID.BOSS_PHASE_CHANGED, {
		"boss_id": boss_id, "boss_type": int(_active[boss_id]["boss_type"]), "phase": phase})

func _summon_adds(boss_id: int, n: int) -> void:
	if n <= 0:
		return
	var boss_pos: Vector2 = EnemyManager.get_pos_by_id(boss_id)
	for i in n:
		var ang: float = TAU * float(i) / float(n)
		var off: Vector2 = Vector2(cos(ang), sin(ang)) * 80.0
		EnemyManager.spawn_enemy(boss_pos + off, 40.0, EnemyManager.Type.FAST)

func _cur_phase(st: Dictionary) -> Dictionary:
	var phases: Array = st["phases"]
	if phases.is_empty():
		return {}
	return phases[clampi(int(st["phase"]), 0, phases.size() - 1)]

# 移动：无「接管移动」的招式在进行时，朝玩家缓慢漂移
func _tick_movement(boss_id: int, st: Dictionary, delta: float) -> void:
	var action: Dictionary = st["action"]
	if not action.is_empty() and bool(action.get("controls_move", false)):
		return
	var pos: Vector2 = EnemyManager.get_pos_by_id(boss_id)
	var player: Vector2 = PlayerManager.get_position()
	var spd: float = float(st["move_speed"]) * float(_cur_phase(st).get("move_speed_mult", 1.0))
	var to: Vector2 = player - pos
	if to.length() > 1.0:
		pos += to.normalized() * spd * delta
		EnemyManager.set_entity_pos(boss_id, pos)

# 招式推进：有进行中招式 → 推进；否则冷却到点 → 起手下一招式
func _tick_action(boss_id: int, st: Dictionary, delta: float) -> void:
	var action: Dictionary = st["action"]
	if not action.is_empty():
		_advance_action(boss_id, st, action, delta)
		return
	st["cooldown"] = float(st["cooldown"]) - delta
	if float(st["cooldown"]) > 0.0:
		return
	var patterns: Array = _cur_phase(st).get("attack_patterns", [])
	if patterns.is_empty():
		st["cooldown"] = 1.0
		return
	var idx: int = int(st["pattern_index"]) % patterns.size()
	st["pattern_index"] = int(st["pattern_index"]) + 1
	_start_pattern(boss_id, st, patterns[idx])

# 招式起手（Task 7/8 补齐分支）；未知 kind 兜底置冷却
func _start_pattern(boss_id: int, st: Dictionary, p: Dictionary) -> void:
	st["cooldown"] = float(p.get("cooldown", 2.0))

# 招式推进（Task 8 补齐三段式）；骨架版直接结束
func _advance_action(boss_id: int, st: Dictionary, action: Dictionary, delta: float) -> void:
	st["action"] = {}

func _on_enemy_killed(payload: Dictionary) -> void:
	var id: int = int(payload.get("entity_id", -1))
	if not _active.has(id):
		return
	var st: Dictionary = _active[id]
	EnemyManager.unregister_external_mover(id)
	EventBus.emit(EventID.BOSS_KILLED, {
		"boss_id": id, "boss_type": int(st["boss_type"]), "wave": int(st["wave"])})
	_active.erase(id)

func get_active_boss_count() -> int:
	return _active.size()

func get_phase(boss_id: int) -> int:
	return int(_active.get(boss_id, {}).get("phase", -1))

func reset() -> void:
	for id in _active.keys():
		EnemyManager.unregister_external_mover(id)
	_active.clear()