import { ecs } from "../../../../extensions/oops-plugin-framework/assets/libs/ecs/ECS";
import { Vec3 } from "cc";
import { HeroAttrsComp } from "./HeroAttrsComp";
import { HeroViewComp } from "./HeroViewComp";
import { BuffsList, SkillConfig, SkillKind, SkillSet, TGroup } from "../common/config/SkillSet";
import { Skill } from "../skill/Skill";
import { smc } from "../common/SingletonModuleComp";
import { GameConst } from "../common/config/GameConst";
import { oops } from "db://oops-framework/core/Oops";
import { GameEvent } from "../common/config/GameEvent";

/**
 * ==================== 自动施法系统 ====================
 * 
 * 职责：
 * 1. 检测可施放的技能
 * 2. 根据策略自动施法（AI）
 * 3. 选择目标
 * 4. 添加施法请求标记
 * 
 * 设计理念：
 * - 负责"何时施法"的决策
 * - 通过添加 CSRequestComp 触发施法
 * - 可被玩家输入系统或AI系统复用
 * - 支持多种AI策略
 */
@ecs.register('SCastSystem')
export class SCastSystem extends ecs.ComblockSystem implements ecs.ISystemUpdate {
    debugMode: boolean = false;  // 是否启用调试模式
    private readonly emptyCastPlan = { skillId: 0, targets: [] as HeroViewComp[], isFriendly: false };
    
    filter(): ecs.IMatcher {
        return ecs.allOf(HeroAttrsComp, HeroViewComp);
    }

    update(e: ecs.Entity): void {
        if(!smc.mission.play ) return;
        if(smc.mission.pause) return
        const heroAttrs = e.get(HeroAttrsComp);
        const heroView = e.get(HeroViewComp);
        if (!heroAttrs || !heroView || !heroView.node) return;
        if (heroAttrs.is_dead || heroAttrs.is_reviving || heroAttrs.isStun() || heroAttrs.isFrost()) return;
        heroAttrs.updateCD(this.dt);
        if (!heroAttrs.is_atking) return;
        const castPlan = this.pickCastSkill(heroAttrs, heroView);
        if (castPlan.skillId === 0 || castPlan.targets.length === 0) return;
        this.castSkill(e, castPlan, heroAttrs, heroView);
    }

    private pickCastSkill(heroAttrs: HeroAttrsComp, heroView: HeroViewComp): { skillId: number; targets: HeroViewComp[]; isFriendly: boolean } {
        const skillCandidates = [heroAttrs.skill_id, heroAttrs.atk_id];
        for (const s_uuid of skillCandidates) {
            if (!s_uuid) continue;
            const config = SkillSet[s_uuid];
            if (!config) continue;
            const isMainSkill = s_uuid === heroAttrs.skill_id;
            if (isMainSkill && !heroAttrs.can_skill) continue;
            if (!isMainSkill && !heroAttrs.can_atk) continue;
            if (this.isFriendlySkill(config.TGroup)) {
                return { skillId: s_uuid, targets: [heroView], isFriendly: true };
            }
            if (!heroAttrs.enemy_in_cast_range) continue;
            const target = this.resolveCombatTarget(heroAttrs);
            if (!target) continue;
            return { skillId: s_uuid, targets: [target], isFriendly: false };
        }
        return this.emptyCastPlan;
    }

    private castSkill(entity: ecs.Entity, castPlan: { skillId: number; targets: HeroViewComp[]; isFriendly: boolean }, heroAttrs: HeroAttrsComp, heroView: HeroViewComp) {
        const s_uuid = castPlan.skillId;
        const config = SkillSet[s_uuid];
        if (!config) return;
        heroView.playSkillEffect(s_uuid);
        const isMainSkill = s_uuid === heroAttrs.skill_id;
        
        // 优先使用技能配置的前摇时间，否则使用全局默认值
        // 注意：这里仍然是基于时间的延迟，受帧率波动影响。
        // 若需精确同步，建议在动画中添加帧事件并在 HeroViewComp 中监听。
        const delay = config.ready > 0 ? config.ready : GameConst.Battle.SKILL_CAST_DELAY;
        
        heroView.scheduleOnce(() => {
            if (!heroView.node || !heroView.node.isValid || heroAttrs.is_dead) return;
            if (castPlan.isFriendly) {
                oops.message.dispatchEvent(GameEvent.CastHeroSkill, {
                    casterEid: entity.eid,
                    s_uuid,
                    fac: heroAttrs.fac,
                    targetEids: castPlan.targets.map(target => target.ent?.eid).filter((eid): eid is number => typeof eid === "number")
                });
                return;
            }
            const validTargets = this.filterValidTargets(castPlan.targets);
            if (validTargets.length === 0) return;
            this.applyPrimaryEffect(entity, s_uuid, config, heroView, validTargets);
            this.applyExtraEffects(config, validTargets);
        }, delay);
        if (isMainSkill) {
            heroAttrs.triggerSkillCD();
        } else {
            heroAttrs.triggerAtkCD();
        }
    }

    private createSkillEntity(s_uuid: number, caster: HeroViewComp, targetPos: Vec3) {
        if (!caster.node || !caster.node.isValid) return;
        const parent = caster.node.parent;
        if (!parent) return;
        const skill = ecs.getEntity<Skill>(Skill);
        skill.load(caster.node.position.clone(), parent, s_uuid, targetPos.clone(), caster, 0);
    }

    private applyPrimaryEffect(casterEntity: ecs.Entity, s_uuid: number, config: SkillConfig, heroView: HeroViewComp, targets: HeroViewComp[]) {
        const kind = config.kind ?? SkillKind.Damage;
        if (kind === SkillKind.Damage) {
            if (config.ap > 0) {
                this.createSkillEntity(s_uuid, heroView, targets[0].node.position);
            }
            return;
        }
        for (const target of targets) {
            if (!target.ent) continue;
            const model = target.ent.get(HeroAttrsComp);
            if (!model || model.is_dead) continue;
            if (kind === SkillKind.Heal && config.ap !== 0) {
                model.add_hp(config.ap, false);
            } else if (kind === SkillKind.Shield && config.ap !== 0) {
                model.add_shield(config.ap, false);
            }
        }
    }

    private applyExtraEffects(config: SkillConfig, targets: HeroViewComp[]) {
        for (const target of targets) {
            if (!target.ent) continue;
            const model = target.ent.get(HeroAttrsComp);
            if (!model || model.is_dead) continue;
            if (config.buffs) {
                for (const buffId of config.buffs) {
                    const buffConf = BuffsList[buffId];
                    if (buffConf) {
                        model.addBuff(buffConf);
                    }
                }
            }

            if (config.debuffs) {
                for (const buffId of config.debuffs) {
                    const buffConf = BuffsList[buffId];
                    if (buffConf) {
                        model.addBuff(buffConf);
                    }
                }
            }
        }
    }

    private filterValidTargets(targets: HeroViewComp[]): HeroViewComp[] {
        return targets.filter(target => {
            if (!target || !target.node || !target.node.isValid) return false;
            if (!target.ent) return false;
            const model = target.ent.get(HeroAttrsComp);
            if (!model || model.is_dead || model.is_reviving) return false;
            return true;
        });
    }

    private isFriendlySkill(group: TGroup): boolean {
        return group === TGroup.Self || group === TGroup.Team || group === TGroup.Ally;
    }

    private resolveCombatTarget(heroAttrs: HeroAttrsComp): HeroViewComp | null {
        if (heroAttrs.combat_target_eid <= 0) return null;
        const targetEntity = ecs.getEntityByEid(heroAttrs.combat_target_eid);
        if (!targetEntity) return null;
        const targetAttrs = targetEntity.get(HeroAttrsComp);
        const targetView = targetEntity.get(HeroViewComp);
        if (!targetAttrs || !targetView || !targetView.node || !targetView.node.isValid) return null;
        if (targetAttrs.is_dead || targetAttrs.is_reviving) return null;
        if (targetAttrs.fac === heroAttrs.fac) return null;
        return targetView;
    }
}