import type { EntityId } from 'db://assets/mx/module/ecs';
import type { Skill } from '../skill/Skill';
import type { SkillPresentationContext } from '../skill/SkillPresentationTypes';
import type { SkillVisualChannel } from './SkillVisualChannel';
import type { ISkillPresenter } from './SkillPresenter';

/** 待发射飞剑 */
interface FlySwordPending {
    /** 施法者 */
    caster: EntityId;
    /** Ability id */
    abilityId: string;
    /** 目标 */
    target: EntityId;
    /** 伤害倍率 */
    scale: number;
    /** atk_buff1 */
    buff1: string;
    /** atk_buff2 */
    buff2: string;
    /** 距发射（秒） */
    wait: number;
    /** 表现通道 */
    channel: SkillVisualChannel;
}

let _host: FlySwordHost | null = null;

/** 飞剑交错发射宿主 */
export function getFlySwordHost(): FlySwordHost {
    if (!_host) _host = new FlySwordHost();
    return _host;
}

/**
 * atk_type=10 飞剑线：按间隔依次发射，落地伤由 BowAtkHost 结算。
 */
export class FlySwordHost {
    private readonly _pending: FlySwordPending[] = [];

    /**
     * 排队发射。
     * @param channel 表现通道
     * @param ctx 表现上下文
     * @param scale 伤害倍率
     * @param intervalSec 邻剑间隔
     * @param maxCount 最多发射数
     */
    begin(channel: SkillVisualChannel, ctx: SkillPresentationContext, scale: number, intervalSec: number, maxCount: number): void {
        const buff1 = String(ctx.params.buff1 ?? '');
        const buff2 = String(ctx.params.buff2 ?? '');
        const targets = ctx.targets;
        let launched = 0;
        for (let i = 0; i < targets.length && launched < maxCount; i++) {
            const tid = targets[i];
            if (!(tid > 0)) continue;
            this._pending.push({
                caster: ctx.caster,
                abilityId: ctx.abilityId,
                target: tid,
                scale,
                buff1,
                buff2,
                wait: launched * Math.max(0, intervalSec),
                channel,
            });
            launched += 1;
        }
        if (launched <= 0) {
            console.log('[FlySword] 无有效目标', ctx.params.skillId);
            return;
        }
        this.tick(0);
    }

    /**
     * 推进排队发射。
     * @param dt 逻辑秒
     */
    tick(dt: number): void {
        if (this._pending.length <= 0) return;
        for (let i = this._pending.length - 1; i >= 0; i--) {
            const p = this._pending[i];
            p.wait -= dt;
            if (p.wait > 0) continue;
            this._pending.splice(i, 1);
            if (!p.channel.launchFlySword(p.caster, p.abilityId, p.target, p.scale, p.buff1, p.buff2)) {
                console.log('[FlySword] 发射失败', p.target);
            }
        }
    }

    /**
     * 卸下施法者排队。
     * @param caster 塔实体
     */
    cancelCaster(caster: EntityId): void {
        for (let i = this._pending.length - 1; i >= 0; i--) {
            if (this._pending[i].caster === caster) this._pending.splice(i, 1);
        }
    }

    /** 清空全部排队 */
    abortAll(): void {
        this._pending.length = 0;
    }
}

/**
 * 飞剑武器主动：瞬发，实例化飞剑.prefab 飞向目标，落地结算。
 */
export class FlySwordAtkPresenter implements ISkillPresenter {
    present(ctx: SkillPresentationContext, host: Skill): void {
        if (!ctx.isAlive) {
            ctx.finish();
            return;
        }
        const raw = String(ctx.params.atkPara ?? '').split(',');
        const count = Math.floor(Number(String(raw[0] ?? '').trim()) || 0);
        const intervalSec = Number(String(raw[1] ?? '').trim());
        const wan = Number(String(raw[2] ?? '').trim());
        if (!(count > 0) || !Number.isFinite(intervalSec) || intervalSec < 0 || !Number.isFinite(wan) || !(wan > 0)) {
            console.log('[FlySwordAtkPresenter] atk_para 无效', ctx.params.skillId, ctx.params.atkPara);
            ctx.finish();
            return;
        }
        const skillKind = String(ctx.params.skillKind ?? '');
        const followWeapon = skillKind === 'weapon' || host.visualChannel.useWeapon;
        if (followWeapon) host.visualChannel.ensureWeapon();
        const seq = host.beginPresentationCast(ctx);
        if (!(seq > 0)) return;
        host.disarmAnimComplete();
        getFlySwordHost().begin(host.visualChannel, ctx, wan / 10000, intervalSec, count);
        ctx.releasePresentationLock();
        host.finishPresentationCast(seq, false);
    }
}