import { _decorator, Component, Label, Sprite } from 'cc';

const { ccclass, property } = _decorator;

/**
 * PlayerInfoView: 响应式视图组件(自包含,便于 Cocos 编辑器挂载)。
 *
 * 设计取舍:不 import framework/store-binder,让本组件保持"纯 cc.Component 子类 +
 * 极简内联 binder"的单文件结构,方便通过 funplay-cocos-mcp 的 mount 流程挂到 prefab
 * (挂脚本路径与持久化限制见 memory `prefab-persist-mount-script` /
 * `cocos-mcp-mount-script-path`)。
 *
 * 实际订阅契约与 framework/ui/store-binder 一致:
 * - bindTo(binder) 接收外部 binder 实例
 * - 调用方持有 binder,内部 subscribe + 自动刷新 Label.string
 *
 * 后续如需让 framework/store-binder 与本组件复用同一份逻辑,可把 subscribe
 * 抽到一个 cc-agnostic 的 pure module;目前以"单文件自包含"落地,优先确保编辑器挂载稳定。
 */

/** 内联极简 binder(语义与 framework/ui/store-binder 对齐) */
interface ViewBinder {
  bind<T>(store: ViewStore<T>, slot: string, cb: (value: T) => void): void;
  unbindAll(): void;
}

/** 极简 store 契约:暴露 subscribe 与 value */
interface ViewStore<T> {
  subscribe(cb: (value: T, prev: T) => void): () => void;
  value: T;
}

function createViewBinder(): ViewBinder {
  const unsubs: Array<() => void> = [];
  return {
    bind<T>(store: ViewStore<T>, _slot: string, cb: (value: T) => void) {
      // 首次同步:bind 时立即用当前 value 跑一次 callback
      try { cb(store.value); }
      catch (e) { console.error('[PlayerInfoView] initial callback error:', e); }
      const unsub = store.subscribe((value) => cb(value));
      unsubs.push(unsub);
    },
    unbindAll() {
      while (unsubs.length > 0) {
        const u = unsubs.pop();
        try { u?.(); } catch { /* 退订隔离 */ }
      }
    },
  };
}

@ccclass('PlayerInfoView')
export class PlayerInfoView extends Component {
  @property(Label)
  nicknameLabel: Label = null!;

  @property(Label)
  beanLabel: Label = null!;

  @property(Sprite)
  avatarSprite: Sprite = null!;

  private binder: ViewBinder | null = null;
  private session: { player: { state: ViewStore<any> } } | null = null;

  /**
   * 由场景初始化代码调用,把视图绑定到 session.player.state。
   * 调用方负责传入 session(典型用法:PlatformSession)。
   *
   * 兼容性:session.player.state 需有 subscribe/value 两个成员——framework
   * 的 ReadonlyReactive<T> 已具备。
   */
  bindTo(session: { player: { state: ViewStore<any> } }): void {
    this.unbindIfNeeded();
    this.session = session;
    this.binder = createViewBinder();
    this.binder.bind(session.player.state, 'state', (p: any) => this.applyPlayer(p));
  }

  onDestroy(): void { this.unbindIfNeeded(); }

  /** 公共方法:外部可直接驱动 UI */
  applyPlayer(p: { nickname: string; bean: number; avatar: string }): void {
    if (this.nicknameLabel) this.nicknameLabel.string = p.nickname ?? '';
    if (this.beanLabel) this.beanLabel.string = String(p.bean ?? 0);
    // avatar 加载留给业务侧扩展
  }

  private unbindIfNeeded(): void {
    this.binder?.unbindAll();
    this.binder = null;
    this.session = null;
  }
}