import { PhysicsSystem2D } from 'cc';

/**
 * 2D 物理开关唯一入口。
 *
 * 根因：广告 / 离局 / 分辨率稳定等各自 `enable = false` 再按本地 wasEnabled 恢复，
 * 快照会互相覆盖，最终永久关物理 → 子弹无碰撞 → 怪不掉血。
 *
 * 规则：任一 reason 挂起则关；集合空才开。开战/离局走 beginBattle/endBattle。
 */
export class Physics2DGate {
    private static _reasons = new Set<string>();

    static readonly VideoAd = 'videoAd';

    static suspend(reason: string): void {
        if (!reason) return;
        this._reasons.add(reason);
        PhysicsSystem2D.instance.enable = false;
    }

    static resume(reason: string): void {
        if (!reason) return;
        this._reasons.delete(reason);
        this._applyEnable();
    }

    static isSuspended(reason?: string): boolean {
        if (reason) return this._reasons.has(reason);
        return this._reasons.size > 0;
    }

    private static _applyEnable(): void {
        const on = this._reasons.size === 0;
        PhysicsSystem2D.instance.enable = on;
        if (on) PhysicsSystem2D.instance.maxSubSteps = 1;
    }

    /** 进入战斗：清空挂起并开物理 */
    static beginBattle(): void {
        this._reasons.clear();
        PhysicsSystem2D.instance.enable = true;
        PhysicsSystem2D.instance.maxSubSteps = 1;
    }

    /** 离开战斗：清空其它挂起并关物理（避免离局后广告回调误开） */
    static endBattle(): void {
        this._reasons.clear();
        PhysicsSystem2D.instance.enable = false;
    }
}