import type { EntityId } from 'db://assets/mx/module/ecs/EntityId';
import type { EcsComponent, ComponentCtor } from 'db://assets/mx/module/ecs/Component';

/** 组件存储桶的最小接口（结构类型，避免与 World 循环 import） */
export interface IComponentStorage<A extends EcsComponent> {
    forEach(fn: (id: EntityId, comp: A) => void): void;
}

/** 单组件查询视图 */
export class View1<A extends EcsComponent> {
    constructor(
        private readonly _storage: IComponentStorage<A>,
        private readonly _isAlive: (id: EntityId) => boolean,
    ) {}

    /** 遍历所有拥有该组件的存活实体 */
    forEach(fn: (id: EntityId, a: A) => void): void {
        this._storage.forEach((id, a) => {
            if (this._isAlive(id)) fn(id, a);
        });
    }
}

/** 双组件查询视图（按 ctorA 桶遍历 + 过滤 ctorB） */
export class View2<A extends EcsComponent, B extends EcsComponent> {
    constructor(
        private readonly _storageA: IComponentStorage<A>,
        private readonly _ctorB: ComponentCtor<B>,
        private readonly _getComponent: (id: EntityId, ctor: ComponentCtor<B>) => B | undefined,
        private readonly _isAlive: (id: EntityId) => boolean,
    ) {}

    /** 遍历所有同时拥有两个组件的存活实体 */
    forEach(fn: (id: EntityId, a: A, b: B) => void): void {
        this._storageA.forEach((id, a) => {
            if (!this._isAlive(id)) return;
            const b = this._getComponent(id, this._ctorB);
            if (b) fn(id, a, b);
        });
    }
}