# PlayerSkill (§3.8 修改 1) —— 逐行移植 CPythonPlayer 的技能三层合法性校验。
#
# 参考 REF/UserInterface/PythonPlayerSkill.cpp：
#   (a) ClickSkillSlot(dwSlotIndex)      :106  —— 槽位 / 技能数据 / 公会技路由 / 被动挡下 /
#                                                 站立技 + 开关技 toggle-off 分支
#   (b) __CanUseSkill()                  :439  —— 主角存在 / 观战 / 骑乘缺骑乘术 / actor 可行动
#   (c) __CheckSkillUsable(dwSlotIndex)  :166  —— 骑乘⇄骑乘术、安全区攻击技、瓶子、钓鱼、
#                                                 未学、武器种类、箭矢、冷却、HP/SP
#   (d) __UseSkill(dwSlotIndex)          :460  —— 编排：私人商店 / __CanUseSkill / __CheckSpecialSkill /
#                                                 toggle-active 早退 / __CheckSkillUsable / IsUsingSkill /
#                                                 目标解析（联盟 / 安全区 / 可攻击 / 尸体 / 需要目标）
#
# POC 没有 C++ 技能 proto，TSkillData 判定位全部落在 `ui/skill_table.gd`（增量 87）。
# 本类是纯校验器：不发包、不播动作，返回 { ok:bool, code:String, target_vid:int }。
# 施放路径（quickbar.activate() 的 skill 分支）在调用 M2Client.use_skill() /
# cast_skill() 之前先过 use_skill()，ok=false 时按 code 弹 OnCannotUseSkill 文案。
#
# 运行期上下文（网络下发 / net_play 本地占位）由调用方每次校验前刷新到公开字段，
# 对齐原客户端从 CInstanceBase / m_sysIs* / GetStatus() 读到的那些值。
extends RefCounted

# --- §3.8 修改 1 要求的命名常量 --------------------------------------------
const SKILL_MAX_NUM := 255              # Packet.h:2041
const SKILL_TYPE_GUILD := 3            # CPythonSkill::SKILL_TYPE_GUILD
const RIDING_SKILL_INDEX := 109        # __CanUseSkill 里硬编码的骑乘术判定 vnum
const RIDING_SKILL_MASTER_LEVEL := 20  # GetSkillLevel(109) < 20 的下限
const ITEM_EMPTY_BOTTLE := 27995       # __CheckSkillUsable / __HasItem
const ITEM_POISON_BOTTLE := 27996
const SKILL_INDEX_COMBO := 122         # PythonPlayerModule.cpp:6
const SKILL_INDEX_FISHING := 123       # PythonPlayerModule.cpp:7
const SKILL_INDEX_SUMMON := 131        # PythonPlayerModule.cpp:15（__CheckShortMana 豁免）

# code 里这几类是「原客户端也不弹文案 / 已在别处处理」，调用方不该弹 OnCannotUseSkill：
const SILENT_CODES := [
	"", "OK", "PASSIVE", "BAD_SLOT", "NO_SKILL_DATA", "GUILD_ROUTED",
	"TOGGLE_OFF", "SPECIAL_SKILL", "PRIVATE_SHOP", "RESERVED", "NO_RIDING_SKILL",
	"CANNOT_ACT", "ALREADY_CASTING",
]

var client: Object                     # M2Client
var table: RefCounted                  # SkillTable（增量 87 谓词）

# --- 运行期上下文（调用方刷新；默认取「未知 / 放行」）-----------------------
var observer_mode := false             # IsObserverMode()
var mounting := false                  # CInstanceBase::IsMountingHorse()
var in_safe := false                   # CInstanceBase::IsInSafe()
var is_fishing := false                # CInstanceBase::IsFishingMode()
var is_using_skill := false            # CInstanceBase::IsUsingSkill()
var can_act := true                    # CanProcessNetworkStatePacket（死亡/晕眩/击退 → false）
var private_shop_open := false         # IsOpenPrivateShop()
var level_limit := true                # m_sysIsLevelLimit
var cooltime_check := true             # m_sysIsCoolTime
var dash_active := false               # __CheckDashAffect
var weapon_sub_type := -1             # CInstanceBase::GetWeaponType()；-1 = 未知（跳过匹配）
var arrow_count := -1                 # 装备箭袋数量；-1 未知/无限，0 = EMPTY_ARROW
var slot_cd_end := 0.0                # 该槽本地冷却结束时刻（Time.get_ticks_msec()/1000）
var cur_sp := -1                      # GetStatus(POINT_SP)；-1 = 未知（不判 NOT_ENOUGH_SP）
var cur_hp := -1                      # GetStatus(POINT_HP)；-1 = 未知（不判 NOT_ENOUGH_HP）
var bow_distance := 0                 # GetStatus(POINT_BOW_DISTANCE) —— __GetSkillTargetRange 加成
## vid -> 主角到目标的距离 cm（已含 IS_HUGE_RACE −200 修正）；<0 = 未知。未注入则不判射程。
var target_distance := Callable()

func setup(m2client: Object, skill_table: RefCounted) -> void:
	client = m2client
	table = skill_table

# --- 小工具 --------------------------------------------------------------

func _now() -> float:
	return Time.get_ticks_msec() / 1000.0

func _ok(target_vid := 0) -> Dictionary:
	return {"ok": true, "code": "OK", "target_vid": target_vid}

# __GetSkillTargetRange —— PythonPlayerSkill.cpp:390
func _skill_target_range(skill_id: int) -> int:
	return int(table.target_range(skill_id)) + bow_distance * 100

# 射程外：不施法，交给调用方 __ReserveUseSkill（走近后再 __UseSkill）。
# charge = 参考端「蓄力技且未预约时先 __SendUseSkill(slot, 0)」。
func _out_of_range(skill_id: int, tvid: int) -> Dictionary:
	var range_cm := _skill_target_range(skill_id)
	if range_cm <= 0 or not target_distance.is_valid():
		return {}
	var distance := float(target_distance.call(tvid))
	if distance < 0.0 or distance < float(range_cm):
		return {}
	var r := _no("RESERVED", tvid)
	r["range_cm"] = range_cm
	r["charge"] = bool(table.is_charge_skill(skill_id))
	return r

func _no(code: String, target_vid := 0) -> Dictionary:
	return {"ok": false, "code": code, "target_vid": target_vid}

static func is_silent_code(code: String) -> bool:
	return SILENT_CODES.has(code)

func _main_vid() -> int:
	if client and client.has_method("get_main_vid"):
		return int(client.get_main_vid())
	return 0

func _main_entity() -> Dictionary:
	var v := _main_vid()
	if client and client.has_method("get_entity") and v != 0:
		var e: Variant = client.get_entity(v)
		if e is Dictionary:
			return e
	return {}

# GetSkillLevel(idx) / GetSkillGrade(idx) 等价：查 M2Client.get_skills()（按技能 vnum）。
func _skill_level(skill_id: int) -> int:
	if client == null or not client.has_method("get_skills"):
		return 0
	for s in client.get_skills():
		if int(s.get("id", 0)) == skill_id:
			return int(s.get("level", 0))
	return 0

func _skill_grade(skill_id: int) -> int:
	if client == null or not client.has_method("get_skills"):
		return 0
	for s in client.get_skills():
		if int(s.get("id", 0)) == skill_id:
			return int(s.get("master", 0))   # 0..3，master 即 grade
	return 0

# __HasItem(dwItemID)：扫背包（POC 无独立龙魂背包，省略那段）。
func _has_item(vnum: int) -> bool:
	if client == null or not client.has_method("get_inventory"):
		return false
	for it in client.get_inventory():
		if int(it.get("vnum", 0)) == vnum and int(it.get("count", 0)) > 0:
			return true
	return false

# __HasEnoughArrow()：原版查装备箭袋 subtype==WEAPON_ARROW；POC 用 net_play 的
# _arrow_count 占位（真值待服务端 / 后续增量）。-1 视为无限。
func _has_enough_arrow() -> bool:
	return arrow_count != 0

# __CheckRestSkillCoolTime(slot)：m_sysIsCoolTime 关 → 不在冷却；否则比本地剩余。
func _check_rest_skill_cooltime() -> bool:
	if not cooltime_check:
		return false
	return _now() < slot_cd_end

# §3.8 修改 3：NeedSP 公式经 skill_table.need_sp()（.msk NeedSPFormula）解析。
#
# __CheckShortLife（PythonPlayerSkill.cpp:354）：
#   !IsUseHPSkill()                 → false
#   dwNeedHP = GetNeedSP(eff%)      （HP 消耗也取 NeedSP，参考端怪癖）
#   dwNeedHP <= GetStatus(POINT_HP) → false  否则 true
func _check_short_life(skill_id: int) -> bool:
	if table == null or not table.has_method("need_hp"):
		return false
	if not table.is_use_hp(skill_id):
		return false
	if cur_hp < 0:                       # HP 未知 → 不误挡
		return false
	var need_hp := int(table.need_hp(skill_id, _skill_level(skill_id)))
	if need_hp < 0:                      # 公式解析不出 → 不挡
		return false
	return need_hp > cur_hp

# __CheckShortMana（PythonPlayerSkill.cpp:320）：
#   idx == c_iSkillIndex_Summon(131)          → false
#   iNeedSP = GetNeedSP(eff%) ; icurSP = GetStatus(POINT_SP)
#   !IsToggleSkill() && iNeedSP == 0          → true（"strange game data"）
#   CanUseIfNotEnough(): icurSP <= 0          → true
#   else:  iNeedSP != -1 && iNeedSP > icurSP  → true
#   否则 false
func _check_short_mana(skill_id: int) -> bool:
	if table == null or not table.has_method("need_sp"):
		return false
	if skill_id == SKILL_INDEX_SUMMON:
		return false
	if cur_sp < 0:                       # SP 未知 → 不误挡
		return false
	var need_sp := int(table.need_sp(skill_id, _skill_level(skill_id)))
	# 参考端：非开关技且 iNeedSP == 0 视为坏数据并拦截。POC 约定 need_sp() 用 -1
	# 表示「.msk 没有 NeedSPFormula」（解析不出），此时不套这条以免误挡；只有确有
	# 公式且算出 0 才按参考拦。
	if not table.is_toggle(skill_id) and need_sp == 0:
		return true
	if table.can_use_if_not_enough(skill_id):
		return cur_sp <= 0
	return need_sp != -1 and need_sp > cur_sp

func _entity_kind(e: Dictionary) -> int:
	return int(e.get("kind", int(e.get("type", -1))))

# IsAttackableInstance 的近似：PC(0) / MONSTER(2) 且未死可打。
# 帝国 / 结盟 / PK / 决斗规则归 §5.4，这里不判。
func _is_attackable(e: Dictionary) -> bool:
	if e.is_empty() or bool(e.get("dead", false)):
		return false
	return _entity_kind(e) in [0, 2]

# ========================================================================
# (a) ClickSkillSlot —— PythonPlayerSkill.cpp:106
# ========================================================================
# is_active：该槽当前是否已激活（IsSkillActive(slot)），仅开关技有意义。
func click_skill_slot(skill_id: int, is_active := false) -> Dictionary:
	# if (dwSlotIndex >= SKILL_MAX_NUM) return;
	if skill_id < 0 or skill_id >= SKILL_MAX_NUM:
		return _no("BAD_SLOT")

	# if (!GetSkillData(rkSkillInst.dwIndex, &pSkillData)) return;
	if table == null or not table.has(skill_id):
		return _no("NO_SKILL_DATA")

	# if (SKILL_TYPE_GUILD == pSkillData->byType) { UseGuildSkill(...); return; }
	if table.skill_type_of(skill_id) == SKILL_TYPE_GUILD:
		return _no("GUILD_ROUTED")

	# if (!pSkillData->IsCanUseSkill()) return;   —— 被动技，静默
	if not table.is_can_use_skill(skill_id):
		return _no("PASSIVE")

	# if (pSkillData->IsStandingSkill())
	if table.is_standing(skill_id):
		# if (IsToggleSkill() && IsSkillActive(slot)) { SendUseSkillPacket; return; }
		if table.is_toggle(skill_id) and is_active:
			if not can_act:                      # pkInstMain->IsUsingSkill() 之前的取指针失败
				return _no("CANNOT_ACT")
			if is_using_skill:
				return _no("ALREADY_CASTING")
			return _no("TOGGLE_OFF")             # toggle-off：调用方直接发 use_skill 关掉
		# __UseSkill(dwSlotIndex);
		return use_skill(skill_id, is_active)

	# 非站立技：原版还有 m_dwcurSkillSlotIndex / __IsRightButtonSkillMode 的两段式选中，
	# POC 快捷栏是一键即放，等价于 !__IsRightButtonSkillMode() 分支 -> __UseSkill。
	return use_skill(skill_id, is_active)

# ========================================================================
# (b) __CanUseSkill —— PythonPlayerSkill.cpp:439
# ========================================================================
func can_use_skill() -> Dictionary:
	# if (!NEW_GetMainActorPtr()) return false;
	if _main_vid() == 0:
		return _no("CANNOT_ACT")

	# if (IsObserverMode()) return false;
	if observer_mode:
		return _no("OBSERVER")

	# if (IsMountingHorse() && GetSkillGrade(109) < 1 && GetSkillLevel(109) < 20) return false;
	if mounting and _skill_grade(RIDING_SKILL_INDEX) < 1 \
			and _skill_level(RIDING_SKILL_INDEX) < RIDING_SKILL_MASTER_LEVEL:
		return _no("NO_RIDING_SKILL")

	# return pkInstMain->CanUseSkill();   —— 死亡 / 晕眩 / 击退 / 施法中
	if not can_act:
		return _no("CANNOT_ACT")

	return _ok()

# ========================================================================
# (c) __CheckSkillUsable —— PythonPlayerSkill.cpp:166
# ========================================================================
func check_skill_usable(skill_id: int) -> Dictionary:
	# if (!NEW_GetMainActorPtr()) return false;
	if _main_vid() == 0:
		return _no("CANNOT_ACT")

	# if (dwSlotIndex >= SKILL_MAX_NUM) return false;
	if skill_id < 0 or skill_id >= SKILL_MAX_NUM:
		return _no("BAD_SLOT")

	# if (!GetSkillData(...)) return false;
	if table == null or not table.has(skill_id):
		return _no("NO_SKILL_DATA")

	# if (IsMountingHorse() && !IsHorseSkill()) -> "NOT_HORSE_SKILL"
	if mounting and not table.is_horse_skill(skill_id):
		return _no("NOT_HORSE_SKILL")

	# if (IsHorseSkill() && !IsMountingHorse()) -> "HAVE_TO_RIDE"
	if table.is_horse_skill(skill_id) and not mounting:
		return _no("HAVE_TO_RIDE")

	# if (IsAttackSkill() && IsInSafe()) -> "IN_SAFE"
	if table.is_attack(skill_id) and in_safe:
		return _no("IN_SAFE")

	# if (!IsCanUseSkill()) return false;   —— 被动技
	if not table.is_can_use_skill(skill_id):
		return _no("PASSIVE")

	# if (IsNeedEmptyBottle() && !__HasItem(27995)) -> "NEED_EMPTY_BOTTLE"
	if table.is_need_empty_bottle(skill_id) and not _has_item(ITEM_EMPTY_BOTTLE):
		return _no("NEED_EMPTY_BOTTLE")

	# if (IsNeedPoisonBottle() && !__HasItem(27996)) -> "NEED_POISON_BOTTLE"
	if table.is_need_poison_bottle(skill_id) and not _has_item(ITEM_POISON_BOTTLE):
		return _no("NEED_POISON_BOTTLE")

	# if (IsFishingMode()) -> "REMOVE_FISHING_ROD"
	if is_fishing:
		return _no("REMOVE_FISHING_ROD")

	# if (m_sysIsLevelLimit && rkSkillInst.iLevel <= 0) -> "NOT_YET_LEARN"
	if level_limit and _skill_level(skill_id) <= 0:
		return _no("NOT_YET_LEARN")

	# if (!CanUseWeaponType(GetWeaponType())) -> "NOT_MATCHABLE_WEAPON"
	#   weapon_sub_type < 0（未知）时跳过，避免误挡。
	if weapon_sub_type >= 0 and not table.can_use_weapon_type(skill_id, weapon_sub_type):
		return _no("NOT_MATCHABLE_WEAPON")

	# if (!IsHorseSkill()) { __CheckShortArrow; if (IsNeedBow() && !__HasEnoughArrow()) ... }
	if not table.is_horse_skill(skill_id):
		if table.is_need_bow(skill_id) and not _has_enough_arrow():
			return _no("EMPTY_ARROW")

		# __CheckDashAffect 分支：冲刺 affect 下、非蓄力技才查冷却；否则查冷却 + HP + SP
		if dash_active:
			if not table.is_charge_skill(skill_id):
				if _check_rest_skill_cooltime():
					return _no("WAIT_COOLTIME")
		else:
			if _check_rest_skill_cooltime():
				return _no("WAIT_COOLTIME")
			if _check_short_life(skill_id):
				return _no("NOT_ENOUGH_HP")
			if _check_short_mana(skill_id):
				return _no("NOT_ENOUGH_SP")

	return _ok()

# ========================================================================
# (d) __UseSkill —— PythonPlayerSkill.cpp:460
# ========================================================================
func use_skill(skill_id: int, is_active := false) -> Dictionary:
	# if (IsOpenPrivateShop()) return true;   —— 静默成功但什么都不做
	if private_shop_open:
		return _no("PRIVATE_SHOP")

	# if (!__CanUseSkill()) return false;
	var b := can_use_skill()
	if not b.ok:
		return b

	# if (dwSlotIndex >= SKILL_MAX_NUM) return false;
	if skill_id < 0 or skill_id >= SKILL_MAX_NUM:
		return _no("BAD_SLOT")

	# if (__CheckSpecialSkill(rkSkillInst.dwIndex)) return true;
	if _check_special_skill(skill_id):
		return _no("SPECIAL_SKILL")

	# if (!GetSkillData(...)) return false;
	if table == null or not table.has(skill_id):
		return _no("NO_SKILL_DATA")

	# if (IsToggleSkill() && IsSkillActive(slot)) { SendUseSkillPacket; return false; }
	if table.is_toggle(skill_id) and is_active:
		return _no("TOGGLE_OFF")

	# if (!__CheckSkillUsable(dwSlotIndex)) return false;
	var c := check_skill_usable(skill_id)
	if not c.ok:
		return c

	# if (pkInstMain->IsUsingSkill()) return false;
	if is_using_skill:
		return _no("ALREADY_CASTING")

	# 目标解析（IsNeedTarget || CanChangeDirection || IsAutoSearchTarget）
	var need_target: bool = table.is_need_target(skill_id) \
			or table.can_change_direction(skill_id) \
			or table.is_auto_search_target(skill_id)
	if not need_target:
		return _ok(0)

	return _resolve_target(skill_id)

# __UseSkill 里的目标分支（PythonPlayerSkill.cpp:520-650）。
# 判目标「类型」是否合法并回传解析到的 vid；射程外回 RESERVED（带 range_cm / charge），
# 由调用方 __ReserveUseSkill。扇形·圆形多目标 SendAddFlyTargetingPacket 归 §3.4/§3.9。
func _resolve_target(skill_id: int) -> Dictionary:
	var main_vid := _main_vid()
	var tvid := 0
	if client and client.has_method("get_target"):
		tvid = int(client.get_target().get("vid", 0))

	var need_corpse: bool = table.is_need_corpse(skill_id)
	var te: Dictionary = {}
	if tvid != 0 and client and client.has_method("get_entity"):
		var e: Variant = client.get_entity(tvid)
		if e is Dictionary:
			te = e

	# --- 有目标 ---
	if not te.is_empty():
		var is_self := tvid == main_vid
		var target_dead := bool(te.get("dead", false))

		# 需要尸体的技能：目标必须已死
		if need_corpse and not target_dead:
			return _no("ONLY_FOR_CORPSE")

		if table.is_only_for_alliance(skill_id):
			if is_self:
				if not table.can_use_for_me(skill_id):
					return _no("CANNOT_USE_SELF")
				return _ok(main_vid)
			# 非自己：结盟技打友方（不可攻击的 PC）合法；打敌人不合法
			if _entity_kind(te) == 0 and not _is_attackable(te):
				# PythonPlayerSkill.cpp:560：友方 PC 在射程外 -> __ReserveUseSkill（无蓄力预发）。
				var far := _out_of_range(skill_id, tvid)
				if not far.is_empty():
					far["charge"] = false
					return far
				return _ok(tvid)
			if table.can_use_for_me(skill_id):
				return _ok(main_vid)          # 目标非法 -> 回落自身
			return _no("ONLY_FOR_ALLIANCE")
		else:
			# 攻击类：目标在安全区不可打
			if bool(te.get("in_safe", false)):
				return _no("CANNOT_ATTACK_ENEMY_IN_SAFE_AREA")
			if _is_attackable(te):
				# __ProcessEnemySkillTargetRange（PythonPlayerSkill.cpp:395）
				var far := _out_of_range(skill_id, tvid)
				if not far.is_empty():
					return far
				return _ok(tvid)
			return _no("CANNOT_ATTACK")

	# --- 无目标 ---
	if table.is_auto_search_target(skill_id):
		# NEW_GetFrontInstance 在 POC 侧没有等价物；无目标即失败。
		if not table.can_use_for_me(skill_id) and not need_corpse:
			return _no("NEED_TARGET")

	if table.can_use_for_me(skill_id):
		return _ok(main_vid)
	if need_corpse:
		return _no("ONLY_FOR_CORPSE")
	return _no("NEED_TARGET")

# __CheckSpecialSkill —— PythonPlayerSkill.cpp:950（钓鱼 123 / 连击 122）。
func _check_special_skill(skill_id: int) -> bool:
	if skill_id == SKILL_INDEX_FISHING:
		return true
	if skill_id == SKILL_INDEX_COMBO:
		return true
	return false