import type { Skill } from '../skill/Skill';
import type { SkillPresentationContext } from '../skill/SkillPresentationTypes';
import type { ISkillPresenter } from './SkillPresenter';
import {
    FallbackAtkPresenter,
    InstantAtkPresenter,
    LineMultiHitAtkPresenter,
    LineRectAtkPresenter,
    ProjectileAtkPresenter,
    ScatterPierceAtkPresenter,
    SequentialSingleAtkPresenter,
    SummonAtkPresenter,
    VolleyArrowAtkPresenter,
} from './AtkTypePresenters';

/**
 * 技能表现路由：Skill.skill 额外效果头优先，其次 skillId，否则 atk_type。
 * 三槽（普攻/英雄主动/武器主动）共用。
 */
export class SkillPresenterRouter {
    private static _inst: SkillPresenterRouter | null = null;

    /** 单例 */
    static get instance(): SkillPresenterRouter {
        if (!this._inst) {
            this._inst = new SkillPresenterRouter();
            this._inst._registerBuiltin();
        }
        return this._inst;
    }

    private readonly _bySkillId: { id: number; presenter: ISkillPresenter }[] = [];
    private readonly _byAtkType: { type: number; presenter: ISkillPresenter }[] = [];
    private readonly _byExtra: { type: number; presenter: ISkillPresenter }[] = [];
    private _fallback: ISkillPresenter = new FallbackAtkPresenter();

    /** 按 skillId 注册特殊表现 */
    registerSkillId(skillId: number, presenter: ISkillPresenter): void {
        const id = Math.floor(Number(skillId) || 0);
        if (id <= 0) {
            console.log('[SkillPresenterRouter] skillId 无效', skillId);
            return;
        }
        const idx = this._findSkillIndex(id);
        if (idx >= 0) this._bySkillId[idx].presenter = presenter;
        else this._bySkillId.push({ id, presenter });
    }

    /**
     * 按 Skill.skill 头类型注册额外效果表现。
     * @param extraType skill 字段第一段
     * @param presenter 表现
     */
    registerExtraSkill(extraType: number, presenter: ISkillPresenter): void {
        const type = Math.floor(Number(extraType) || 0);
        if (type <= 0) {
            console.log('[SkillPresenterRouter] extraSkill 类型无效', extraType);
            return;
        }
        for (let i = 0; i < this._byExtra.length; i++) {
            if (this._byExtra[i].type === type) {
                this._byExtra[i].presenter = presenter;
                return;
            }
        }
        this._byExtra.push({ type, presenter });
    }

    /** 按 atk_type 注册通用表现 */
    registerAtkType(atkType: number, presenter: ISkillPresenter): void {
        const type = Math.floor(Number(atkType) || 0);
        const idx = this._findTypeIndex(type);
        if (idx >= 0) this._byAtkType[idx].presenter = presenter;
        else this._byAtkType.push({ type, presenter });
    }

    /** 分发表现 */
    dispatch(ctx: SkillPresentationContext, host: Skill): void {
        if (!ctx.isAlive) return;
        const extraRaw = String(
            ctx.params.extraSkill
            ?? (String(ctx.params.skillKind ?? '') === 'normal' ? '' : ctx.params.skillRaw)
            ?? '',
        ).trim();
        if (extraRaw) {
            const extraHead = Math.floor(Number(extraRaw.split(',')[0]) || 0);
            const extraPres = this._findExtraPresenter(extraHead);
            if (extraPres) {
                extraPres.present(ctx, host);
                return;
            }
        }
        const skillId = Math.floor(Number(ctx.params.skillId ?? ctx.baseAtkId) || 0);
        const byId = this._findSkillPresenter(skillId);
        if (byId) {
            byId.present(ctx, host);
            return;
        }
        const atkHead = Math.floor(Number(ctx.params.atkTypeHead ?? ctx.params.atkType) || 0);
        const byType = this._findTypePresenter(atkHead);
        if (byType) {
            byType.present(ctx, host);
            return;
        }
        this._fallback.present(ctx, host);
    }

    private _registerBuiltin(): void {
        const instant = new InstantAtkPresenter();
        const lineRect = new LineRectAtkPresenter();
        const lineMulti = new LineMultiHitAtkPresenter();
        const summon = new SummonAtkPresenter();
        this.registerAtkType(1, instant);
        this.registerAtkType(2, lineRect);
        this.registerAtkType(3, instant);
        this.registerAtkType(5, lineMulti);
        this.registerAtkType(14, lineMulti);
        this.registerAtkType(16, lineMulti);
        this.registerAtkType(15, instant);
        this.registerAtkType(6, instant);
        this.registerAtkType(7, instant);
        this.registerAtkType(10, new SequentialSingleAtkPresenter());
        this.registerAtkType(8, summon);
        this.registerAtkType(11, summon);
        const projectile = new ProjectileAtkPresenter();
        this.registerAtkType(4, projectile);
        this.registerAtkType(12, new ScatterPierceAtkPresenter());
        this.registerAtkType(17, new ScatterPierceAtkPresenter());
        this.registerAtkType(13, new VolleyArrowAtkPresenter());
    }

    private _findSkillIndex(id: number): number {
        for (let i = 0; i < this._bySkillId.length; i++) {
            if (this._bySkillId[i].id === id) return i;
        }
        return -1;
    }

    private _findTypeIndex(type: number): number {
        for (let i = 0; i < this._byAtkType.length; i++) {
            if (this._byAtkType[i].type === type) return i;
        }
        return -1;
    }

    private _findSkillPresenter(id: number): ISkillPresenter | null {
        const idx = this._findSkillIndex(id);
        return idx >= 0 ? this._bySkillId[idx].presenter : null;
    }

    private _findTypePresenter(type: number): ISkillPresenter | null {
        const idx = this._findTypeIndex(type);
        return idx >= 0 ? this._byAtkType[idx].presenter : null;
    }

    /**
     * 按 extra skill 头查找表现。
     * @param type skill 第一段
     */
    private _findExtraPresenter(type: number): ISkillPresenter | null {
        for (let i = 0; i < this._byExtra.length; i++) {
            if (this._byExtra[i].type === type) return this._byExtra[i].presenter;
        }
        return null;
    }
}