import type { BattleSession } from 'db://assets/mx/module/battle';
import { TeamComp, UnitMetaComp } from 'db://assets/mx/module/battle/ecs/Components';
import type { GlyphHeroBind } from 'db://assets/mx/module/merge';
import type { EntityId } from 'db://assets/mx/module/ecs';
import { ConstNumType } from '../../game/GameDataEnums';
import { TableNames } from '../../game/ConfigTableData';
import type { Player } from '../../game/Player';
import { parseLegacyMonsterId, parseMonsterUnitDefId } from '../config/MonsterHpCalculator';
import { findCompositionForEntity, findGridIndexForEntity } from '../runtime/DeployEntityQuery';
import type { ProjectBattleHandle } from '../runtime/BattleRuntime';
import type { MapManager } from '../map/legacy/MapManager';
import { setupTowerCombat } from './TowerCombatSetup';
import { getTowerLoadoutService } from './TowerLoadoutService';
import { WeaponComposeConfigProvider } from '../bag/WeaponComposeConfigProvider';
import { getBattleGameGlobalAttackSpeedHost } from './BattleGameGlobalAttackSpeedHost';
import { getBattleGameGlobalAttackRangeHost } from './BattleGameGlobalAttackRangeHost';

/** 某怪物上造成过伤害的塔 */
interface VictimHits {
    /** 受伤怪物 */
    victim: EntityId;
    /** 打过该怪的塔（去重） */
    casters: EntityId[];
}

/** 塔当前累计经验 */
interface TowerExp {
    /** 塔实体 */
    entityId: EntityId;
    /** 当前经验（可结余） */
    exp: number;
}

/**
 * 已部署攻击单位的击杀/助攻经验与升级。
 * 上限走 Hero.level_limit；所需经验走 Hero.exp。
 */
export class TowerExpHost {
    private static _inst: TowerExpHost | null = null;

    private readonly _hits: VictimHits[] = [];
    private readonly _exps: TowerExp[] = [];

    /** 单例 */
    static get(): TowerExpHost {
        if (!TowerExpHost._inst) TowerExpHost._inst = new TowerExpHost();
        return TowerExpHost._inst;
    }

    /** 开局/结束清空 */
    clear(): void {
        this._hits.length = 0;
        this._exps.length = 0;
    }

    /**
     * 记录塔对怪物造成的伤害（任意伤害类型）。
     * @param caster 伤害来源
     * @param target 受伤目标
     * @param amount 实际伤害
     */
    onDamage(caster: EntityId, target: EntityId, amount: number): void {
        if (!(amount > 0) || !(caster > 0) || !(target > 0)) return;
        if (!getTowerLoadoutService().getLoadout(caster)) return;
        const hits = this._hitsOf(target);
        if (this._indexOfId(hits.casters, caster) >= 0) return;
        hits.casters.push(caster);
    }

    /**
     * 怪物死亡：击杀塔加 Monster.exp，其余打过该怪的塔加助攻经验。
     * @param battle 对局句柄
     * @param killer 致命一击来源（可为 0）
     * @param victim 死亡怪物
     */
    onKilled(battle: ProjectBattleHandle, killer: EntityId, victim: EntityId): void {
        if (!(victim > 0)) return;
        const killExp = this._monsterKillExp(battle, victim);
        const assistExp = this._assistExp();
        const hits = this._takeHits(victim);
        if (killer > 0 && getTowerLoadoutService().getLoadout(killer) && killExp > 0) {
            this._addExp(battle, killer, killExp);
        }
        if (!(assistExp > 0)) {
            return;
        }
        for (let i = 0; i < hits.length; i++) {
            const caster = hits[i];
            if (caster === killer) continue;
            if (!getTowerLoadoutService().getLoadout(caster)) continue;
            this._addExp(battle, caster, assistExp);
        }
    }

    /**
     * 实体回收：清伤害归属与经验。
     * @param entityId 塔或怪物
     */
    forget(entityId: EntityId): void {
        if (!(entityId > 0)) return;
        this._removeHitsVictim(entityId);
        this._stripCaster(entityId);
        const expIdx = this._expIndex(entityId);
        if (expIdx >= 0) this._exps.splice(expIdx, 1);
    }

    /**
     * 给塔加经验并尝试连升。
     * @param battle 对局句柄
     * @param entityId 塔
     * @param amount 本次经验
     */
    private _addExp(battle: ProjectBattleHandle, entityId: EntityId, amount: number): void {
        const loadout = getTowerLoadoutService().getLoadout(entityId);
        if (!loadout) return;
        const hero = gg.data.table.getTableData<ITableHero>(TableNames.Hero, loadout.weapon1Id);
        if (!hero) {
            console.log('[TowerExp] Hero 缺失', loadout.weapon1Id);
            return;
        }
        const max = WeaponComposeConfigProvider.instance.getMaxWeaponLevel(loadout.weapon1Id);
        if (loadout.level >= max) return;
        const need = this._needExp(hero, loadout.level);
        if (!(need > 0)) return;

        const rec = this._expOf(entityId);
        rec.exp += amount;
        let level = loadout.level;
        while (level < max) {
            const step = this._needExp(hero, level);
            if (!(step > 0) || rec.exp < step) break;
            // MapUpgraded → DeploySync 会按字绑定 restoreExp；须先写回再升级，升级后按升级前快照扣经验
            const expBefore = rec.exp;
            this._syncBindFromBattle(battle, entityId);
            if (!this._tryLevelUp(battle, entityId)) {
                rec.exp = expBefore;
                break;
            }
            rec.exp = expBefore - step;
            const next = getTowerLoadoutService().getLoadout(entityId);
            level = next?.level ?? level + 1;
        }
        this._syncBindFromBattle(battle, entityId);
    }

    /**
     * 写棋盘等级并重建战斗数值。
     * @param battle 对局句柄
     * @param entityId 塔
     */
    private _tryLevelUp(battle: ProjectBattleHandle, entityId: EntityId): boolean {
        const session = battle.session;
        if (!session.world.isAlive(entityId)) return false;
        const loadout = getTowerLoadoutService().getLoadout(entityId);
        if (!loadout) return false;
        const team = session.world.getComponent(entityId, TeamComp);
        const player = battle.getPlayer(team?.ownerId ?? 0);
        const map = battle.Map;
        if (!player || !map) {
            console.log('[TowerExp] 升级缺少玩家或地图', entityId);
            return false;
        }
        const gridIndex = findGridIndexForEntity(entityId, player, session, map);
        if (gridIndex == null) {
            console.log('[TowerExp] 升级找不到格子', entityId);
            return false;
        }
        const merge = player.bagSession?.merge;
        if (!merge) {
            console.log('[TowerExp] 升级缺少 MergeSession', entityId, player.playerId);
            return false;
        }
        const reason = merge.applyBattleBuffUnitLevelUp(gridIndex, 1);
        if (reason != null) {
            console.log('[TowerExp] 升级被拒绝', entityId, reason);
            return false;
        }
        const refreshed = findCompositionForEntity(entityId, player, session, map);
        const newLevel = refreshed?.level ?? loadout.level + 1;
        setupTowerCombat(session, entityId, loadout.weapon1Id, newLevel, player);
        return true;
    }

    /**
     * 补足当前等级升下一级剩余经验（已满则加 0 并走统一升级扣经验）。
     * @param battle 对局句柄
     * @param entityId 塔实体
     */
    grantRemainingExpForNextLevel(battle: ProjectBattleHandle, entityId: EntityId): boolean {
        const loadout = getTowerLoadoutService().getLoadout(entityId);
        if (!loadout) return false;
        const hero = gg.data.table.getTableData<ITableHero>(TableNames.Hero, loadout.weapon1Id);
        if (!hero) {
            console.log('[TowerExp] Hero 缺失', loadout.weapon1Id);
            return false;
        }
        const max = WeaponComposeConfigProvider.instance.getMaxWeaponLevel(loadout.weapon1Id);
        if (loadout.level >= max) return false;
        const need = this._needExp(hero, loadout.level);
        if (!(need > 0)) return false;

        const cur = this.getExp(entityId);
        // 已满也走 _addExp（加 0），保证扣经验与 MapUpgraded 对账一致
        this._addExp(battle, entityId, cur < need ? need - cur : 0);
        return true;
    }

    /**
     * 查询塔当前累计经验（未记录则 0）。
     * @param entityId 塔实体
     */
    getExp(entityId: EntityId): number {
        const idx = this._expIndex(entityId);
        return idx >= 0 ? this._exps[idx].exp : 0;
    }

    /**
     * 清空塔累计经验（授仙箓降级组合字武将等）。
     * @param entityId 塔实体
     */
    clearExp(entityId: EntityId): void {
        if (!(entityId > 0)) return;
        const expIdx = this._expIndex(entityId);
        if (expIdx >= 0) this._exps.splice(expIdx, 1);
    }

    /**
     * 恢复拆开前的经验（重组后新实体）。
     * @param entityId 塔实体
     * @param exp 绑定快照经验
     */
    restoreExp(entityId: EntityId, exp: number): void {
        if (!(entityId > 0) || !(exp > 0)) return;
        this._expOf(entityId).exp = exp;
    }

    /**
     * 把当前英雄状态写到组合内每个字上。
     * @param session 战斗会话
     * @param player 玩家
     * @param map 地图
     * @param entityId 塔实体
     */
    syncBindToGlyphs(session: BattleSession, player: Player, map: MapManager, entityId: EntityId): void {
        const compose = findCompositionForEntity(entityId, player, session, map);
        if (!compose) return;
        const bind = this.captureBind(session, entityId);
        if (!bind) return;
        player.bagSession?.merge.writeCompositionHeroBind(compose, bind);
    }

    /**
     * 按字上的绑定恢复经验与 Buff。
     * @param session 战斗会话
     * @param entityId 新实体
     * @param bind 绑定快照
     */
    restoreBindToEntity(session: BattleSession, entityId: EntityId, bind: GlyphHeroBind): void {
        this.restoreExp(entityId, bind.exp);
        getBattleGameGlobalAttackSpeedHost().restore(session, entityId, bind.aspd);
        getBattleGameGlobalAttackRangeHost().restore(session, entityId, bind.range);
    }

    /**
     * 从已部署实体采集绑定快照。
     * @param session 战斗会话
     * @param entityId 塔实体
     */
    captureBind(session: BattleSession, entityId: EntityId): GlyphHeroBind | null {
        const loadout = getTowerLoadoutService().getLoadout(entityId);
        if (!loadout) return null;
        if (!session.world.isAlive(entityId)) return null;
        return {
            weapon1Id: loadout.weapon1Id,
            level: loadout.level,
            exp: this.getExp(entityId),
            aspd: getBattleGameGlobalAttackSpeedHost().snapshot(entityId),
            range: getBattleGameGlobalAttackRangeHost().snapshot(entityId),
        };
    }

    /**
     * 从对局句柄同步绑定到字。
     * @param battle 对局
     * @param entityId 塔实体
     */
    private _syncBindFromBattle(battle: ProjectBattleHandle, entityId: EntityId): void {
        const session = battle.session;
        if (!session.world.isAlive(entityId)) return;
        const team = session.world.getComponent(entityId, TeamComp);
        const player = battle.getPlayer(team?.ownerId ?? 0);
        const map = battle.Map;
        if (!player || !map) return;
        this.syncBindToGlyphs(session, player, map, entityId);
    }

    /**
     * 当前等级升下一级所需经验。
     * @param hero Hero 行
     * @param level 当前等级
     */
    private _needExp(hero: ITableHero, level: number): number {
        return needTowerExpForLevel(hero, level);
    }

    /**
     * 怪物击杀经验。
     * @param battle 对局句柄
     * @param victim 死亡怪物
     */
    private _monsterKillExp(battle: ProjectBattleHandle, victim: EntityId): number {
        const meta = battle.session.world.getComponent(victim, UnitMetaComp);
        if (!meta?.unitDefId) {
            console.log('[TowerExp] 击杀目标无 unitDefId', victim);
            return 0;
        }
        const parsed = parseMonsterUnitDefId(meta.unitDefId);
        const monsterId = parsed?.monsterId ?? parseLegacyMonsterId(meta.unitDefId);
        if (!(monsterId > 0)) {
            console.log('[TowerExp] 无法解析怪物 id', meta.unitDefId);
            return 0;
        }
        const row = gg.data.table.getTableData<ITableMonster>(TableNames.Monster, monsterId);
        if (!row) {
            console.log('[TowerExp] Monster 缺失', monsterId);
            return 0;
        }
        const exp = Number(row.exp);
        if (!Number.isFinite(exp) || exp < 0) {
            console.log('[TowerExp] Monster.exp 非法', monsterId, row.exp);
            return 0;
        }
        return exp;
    }

    /** 常量表助攻经验 */
    private _assistExp(): number {
        const row = gg.data.table.getConstData(ConstNumType.AssistExp);
        if (!row) {
            console.log('[TowerExp] Const 助攻经验缺失', ConstNumType.AssistExp);
            return 0;
        }
        const exp = Number(row.para);
        if (!Number.isFinite(exp) || exp < 0) {
            console.log('[TowerExp] Const 助攻经验非法', row.para);
            return 0;
        }
        return exp;
    }

    /**
     * 取并移除某怪的伤害名单。
     * @param victim 怪物
     */
    private _takeHits(victim: EntityId): EntityId[] {
        const idx = this._hitsIndex(victim);
        if (idx < 0) return [];
        const casters = this._hits[idx].casters;
        this._hits.splice(idx, 1);
        return casters;
    }

    /**
     * 取得或创建某怪的伤害名单。
     * @param victim 怪物
     */
    private _hitsOf(victim: EntityId): VictimHits {
        const idx = this._hitsIndex(victim);
        if (idx >= 0) return this._hits[idx];
        const rec: VictimHits = { victim, casters: [] };
        this._hits.push(rec);
        return rec;
    }

    /**
     * 取得或创建塔经验。
     * @param entityId 塔
     */
    private _expOf(entityId: EntityId): TowerExp {
        const idx = this._expIndex(entityId);
        if (idx >= 0) return this._exps[idx];
        const rec: TowerExp = { entityId, exp: 0 };
        this._exps.push(rec);
        return rec;
    }

    /**
     * 移除某怪的伤害名单。
     * @param victim 怪物
     */
    private _removeHitsVictim(victim: EntityId): void {
        const idx = this._hitsIndex(victim);
        if (idx >= 0) this._hits.splice(idx, 1);
    }

    /**
     * 从所有伤害名单去掉某塔。
     * @param caster 塔
     */
    private _stripCaster(caster: EntityId): void {
        for (let i = 0; i < this._hits.length; i++) {
            const list = this._hits[i].casters;
            const idx = this._indexOfId(list, caster);
            if (idx >= 0) list.splice(idx, 1);
        }
    }

    /**
     * 伤害名单下标。
     * @param victim 怪物
     */
    private _hitsIndex(victim: EntityId): number {
        for (let i = 0; i < this._hits.length; i++) {
            if (this._hits[i].victim === victim) return i;
        }
        return -1;
    }

    /**
     * 塔经验下标。
     * @param entityId 塔
     */
    private _expIndex(entityId: EntityId): number {
        for (let i = 0; i < this._exps.length; i++) {
            if (this._exps[i].entityId === entityId) return i;
        }
        return -1;
    }

    /**
     * 线性查找实体 id。
     * @param list 列表
     * @param id 目标
     */
    private _indexOfId(list: readonly EntityId[], id: EntityId): number {
        for (let i = 0; i < list.length; i++) {
            if (list[i] === id) return i;
        }
        return -1;
    }
}

/**
 * 当前等级升下一级所需经验（Hero.exp）。
 * @param hero Hero 行
 * @param level 当前等级
 */
export function needTowerExpForLevel(hero: ITableHero, level: number): number {
    const arr = hero.exp;
    if (!arr || arr.length === 0) return 0;
    const need = Number(arr[level - 1]);
    if (!Number.isFinite(need) || need <= 0) {
        console.log('[TowerExp] Hero.exp 缺级', hero.id, level);
        return 0;
    }
    return need;
}

/** 局内经验宿主 */
export function getTowerExpHost(): TowerExpHost {
    return TowerExpHost.get();
}