/**
 * MatchStore（规范 §131）
 *
 * 职责：
 *   - 维护今日推荐列表（游标分页 + 加载状态）
 *   - 维护 Mutual Matches（互相喜欢）列表
 *   - 维护我喜欢 / 喜欢我 计数（计数仅作徽标提示，不暴露具体身份）
 *   - 处理 Like/Pass/Block/Unmatch/成功牵手双确认 等动作
 *
 * 不变量（AGENTS.md）：
 *   - 第 2 条：Required 不可自动放宽——推荐列表完全由后端按 PartnerPreference 过滤，
 *     前端不做任何"放宽条件再查"的逻辑。
 *   - 第 4 条：Block 即时禁止互动——block 成功后，本地立即从推荐/Mutual 列表移除该用户。
 *   - 第 5 条：红娘不可替用户 Like——本 Store 只暴露当前用户操作 Like/Pass 的接口。
 *   - 第 6 条：成功牵手必须双确认——requestSuccess 与 confirmSuccess 分两次调用，
 *     Store 内部维护 successPendingMatchIds 表示谁正在等待对方确认。
 *   - 第 6 条（隐式）：单向意向不泄露——A Like B 但 B 未 Mutual 时，
 *     getLikers 不在 Store 中暴露 B 的具体身份（仅后端返回的脱敏字段）。
 */
const BaseStore = require('./baseStore');
const { matchService, recommendationService } = require('../services');
const { RECOMMENDATION_STATE, RELATION_STATUS } = require('../constants');

class MatchStore extends BaseStore {
  constructor() {
    super({
      /** @type {import('../types').Recommendation[]} */
      recommendations: [],
      /** @type {RECOMMENDATION_STATE[keyof RECOMMENDATION_STATE]} */
      recState: RECOMMENDATION_STATE.IDLE,
      recCursor: null,
      dailyRemaining: 0,

      /** @type {import('../types').Conversation[]} */
      mutualList: [],
      mutualCursor: null,
      mutualHasMore: true,

      /** 我喜欢的人列表（缘分中心 Tab） */
      likedList: [],
      likedCursor: null,
      likedHasMore: true,

      /** 喜欢我的人列表（缘分中心 Tab，仅脱敏字段） */
      likersList: [],
      likersCursor: null,
      likersHasMore: true,

      /** 黑名单列表（脱敏） */
      blockedList: [],
      blockedCursor: null,
      blockedHasMore: true,

      likersCount: 0,
      likedByMeCount: 0,

      /** 正在等待对方确认成功牵手的 matchId 集合 */
      successPendingMatchIds: [],

      lastError: null,
    });
    /** 进行中的 action 防重锁，key=userId/matchId */
    this._actionLocks = new Set();
  }

  /** 获取今日推荐（首次） */
  async fetchRecommendations() {
    if (this.state.recState === RECOMMENDATION_STATE.LOADING) return;
    this.setState({ recState: RECOMMENDATION_STATE.LOADING, lastError: null });
    try {
      const result = await recommendationService.getRecommendations({ pageSize: 10 });
      const items = result.items || [];
      this.setState({
        recommendations: items,
        recCursor: result.nextCursor || null,
        dailyRemaining: result.dailyRemaining ?? 0,
        recState: items.length === 0 ? RECOMMENDATION_STATE.EMPTY : RECOMMENDATION_STATE.LOADED,
      });
      return result;
    } catch (err) {
      this.setState({ recState: RECOMMENDATION_STATE.ERROR, lastError: err });
      throw err;
    }
  }

  /** 加载更多推荐 */
  async loadMoreRecommendations() {
    if (this.state.recState === RECOMMENDATION_STATE.LOADING) return;
    if (!this.state.recCursor) {
      this.setState({ recState: RECOMMENDATION_STATE.FINISHED });
      return;
    }
    this.setState({ recState: RECOMMENDATION_STATE.LOADING });
    try {
      const result = await recommendationService.getRecommendations({
        cursor: this.state.recCursor,
        pageSize: 10,
      });
      const items = result.items || [];
      this.setState({
        recommendations: [...this.state.recommendations, ...items],
        recCursor: result.nextCursor || null,
        dailyRemaining: result.dailyRemaining ?? this.state.dailyRemaining,
        recState: items.length === 0 ? RECOMMENDATION_STATE.FINISHED : RECOMMENDATION_STATE.LOADED,
      });
    } catch (err) {
      this.setState({ recState: RECOMMENDATION_STATE.ERROR, lastError: err });
      throw err;
    }
  }

  /**
   * Like 一个用户
   * @param {string} userId
   * @returns {Promise<import('../types').LikeResult>}
   *         mutualMatch=true 表示刚刚达成双向匹配，调用方应跳转会话页或弹提示
   */
  async like(userId) {
    if (this._actionLocks.has(`like:${userId}`)) return;
    this._actionLocks.add(`like:${userId}`);
    try {
      const result = await matchService.like(userId);
      // 从推荐列表移除（无论是否 Mutual，已经做出判断）
      this.setState({
        recommendations: this.state.recommendations.filter((r) => r.userId !== userId),
      });
      return result;
    } finally {
      this._actionLocks.delete(`like:${userId}`);
    }
  }

  /**
   * 取消喜欢
   * 注意：Mutual 后通常不能直接取消，后端会返回 MATCH_REQUIRED
   */
  async unlike(userId) {
    if (this._actionLocks.has(`unlike:${userId}`)) return;
    this._actionLocks.add(`unlike:${userId}`);
    try {
      await matchService.unlike(userId);
      // 推荐/匹配列表不变，后端 relationship 变 neutral
    } finally {
      this._actionLocks.delete(`unlike:${userId}`);
    }
  }

  /** Pass（单向意向，对方不收到通知） */
  async pass(userId) {
    if (this._actionLocks.has(`pass:${userId}`)) return;
    this._actionLocks.add(`pass:${userId}`);
    try {
      await matchService.pass(userId);
      this.setState({
        recommendations: this.state.recommendations.filter((r) => r.userId !== userId),
      });
    } finally {
      this._actionLocks.delete(`pass:${userId}`);
    }
  }

  /**
   * 拉黑用户（Block 优先级最高，AGENTS 第 4 条）
   * 拉黑后：本地从推荐/Mutual 列表移除；调用方应跳离当前用户详情页。
   * 跨 Store 副作用由 stores/index.js 编排：通知 messageStore 标记会话不可发消息。
   */
  async block(userId, reason) {
    if (this._actionLocks.has(`block:${userId}`)) return;
    this._actionLocks.add(`block:${userId}`);
    try {
      await matchService.block(userId, reason ? { reason } : {});
      this.setState({
        recommendations: this.state.recommendations.filter((r) => r.userId !== userId),
        mutualList: this.state.mutualList.filter(
          (c) => c.targetUserId !== userId && c.conversationId !== userId,
        ),
      });
      return { relationStatus: RELATION_STATUS.BLOCKED };
    } finally {
      this._actionLocks.delete(`block:${userId}`);
    }
  }

  /** 解除拉黑 */
  async unblock(userId) {
    if (this._actionLocks.has(`unblock:${userId}`)) return;
    this._actionLocks.add(`unblock:${userId}`);
    try {
      return await matchService.unblock(userId);
    } finally {
      this._actionLocks.delete(`unblock:${userId}`);
    }
  }

  /** 拉取 Mutual Matches 列表 */
  async fetchMutualList(params = {}) {
    const result = await matchService.getMutualList(params);
    this.setState({
      mutualList: result.items || [],
      mutualCursor: result.nextCursor || null,
      mutualHasMore: !!result.nextCursor,
    });
    return result;
  }

  /** 加载更多 Mutual Matches */
  async loadMoreMutualList() {
    if (!this.state.mutualCursor || !this.state.mutualHasMore) return;
    const result = await matchService.getMutualList({ cursor: this.state.mutualCursor });
    this.setState({
      mutualList: [...this.state.mutualList, ...(result.items || [])],
      mutualCursor: result.nextCursor || null,
      mutualHasMore: !!result.nextCursor,
    });
    return result;
  }

  /**
   * 拉取我喜欢的人列表（缘分中心 Tab）
   * AGENTS 第 6 条（隐式）：单向意向不泄露——本列表为"我"视角，可查看自己喜欢的人。
   */
  async fetchLikedList(params = {}) {
    const result = await matchService.getLikedByMe(params);
    this.setState({
      likedList: result.items || [],
      likedCursor: result.nextCursor || null,
      likedHasMore: !!result.nextCursor,
    });
    return result;
  }

  /** 加载更多我喜欢的人 */
  async loadMoreLikedList() {
    if (!this.state.likedCursor || !this.state.likedHasMore) return;
    const result = await matchService.getLikedByMe({ cursor: this.state.likedCursor });
    this.setState({
      likedList: [...this.state.likedList, ...(result.items || [])],
      likedCursor: result.nextCursor || null,
      likedHasMore: !!result.nextCursor,
    });
    return result;
  }

  /**
   * 拉取喜欢我的人列表（缘分中心 Tab）
   * AGENTS 第 6 条：单向意向不泄露——后端仅返回脱敏字段（昵称/年龄/地区/是否已 Mutual），
   * Store 不做任何二次身份还原。
   */
  async fetchLikersList(params = {}) {
    const result = await matchService.getLikers(params);
    this.setState({
      likersList: result.items || [],
      likersCursor: result.nextCursor || null,
      likersHasMore: !!result.nextCursor,
      likersCount: result.totalCount ?? this.state.likersCount,
    });
    return result;
  }

  /** 加载更多喜欢我的人 */
  async loadMoreLikersList() {
    if (!this.state.likersCursor || !this.state.likersHasMore) return;
    const result = await matchService.getLikers({ cursor: this.state.likersCursor });
    this.setState({
      likersList: [...this.state.likersList, ...(result.items || [])],
      likersCursor: result.nextCursor || null,
      likersHasMore: !!result.nextCursor,
    });
    return result;
  }

  /**
   * 拉取黑名单列表（黑名单管理页）
   * 返回字段已脱敏，不含对方手机号/身份证等敏感信息。
   */
  async fetchBlockedList(params = {}) {
    const result = await matchService.getBlockedList(params);
    this.setState({
      blockedList: result.items || [],
      blockedCursor: result.nextCursor || null,
      blockedHasMore: !!result.nextCursor,
    });
    return result;
  }

  /** 加载更多黑名单 */
  async loadMoreBlockedList() {
    if (!this.state.blockedCursor || !this.state.blockedHasMore) return;
    const result = await matchService.getBlockedList({ cursor: this.state.blockedCursor });
    this.setState({
      blockedList: [...this.state.blockedList, ...(result.items || [])],
      blockedCursor: result.nextCursor || null,
      blockedHasMore: !!result.nextCursor,
    });
    return result;
  }

  /** 拉取喜欢我的人计数（不暴露具体身份） */
  async fetchLikersCount() {
    const result = await matchService.getLikers({ pageSize: 1 });
    this.setState({ likersCount: result.totalCount || 0 });
    return result.totalCount || 0;
  }

  /** 拉取我喜欢的人计数 */
  async fetchLikedByMeCount() {
    const result = await matchService.getLikedByMe({ pageSize: 1 });
    this.setState({ likedByMeCount: (result.items || []).length });
    return result;
  }

  /**
   * 解除匹配（AGENTS 第 4 条：解除后双方会话立即停用）
   * @param {string} matchId
   */
  async unmatch(matchId) {
    if (this._actionLocks.has(`unmatch:${matchId}`)) return;
    this._actionLocks.add(`unmatch:${matchId}`);
    try {
      await matchService.unmatch(matchId);
      this.setState({
        mutualList: this.state.mutualList.filter((c) => c.conversationId !== matchId),
      });
    } finally {
      this._actionLocks.delete(`unmatch:${matchId}`);
    }
  }

  /**
   * 发起成功牵手请求（AGENTS 第 6 条：双确认第一步）
   * @param {string} matchId
   * @returns {Promise<{ successRequestId: string, expiresAt: number, status: string }>}
   */
  async requestSuccess(matchId) {
    if (this._actionLocks.has(`success-req:${matchId}`)) return;
    this._actionLocks.add(`success-req:${matchId}`);
    try {
      const result = await matchService.requestSuccess(matchId);
      this.setState({
        successPendingMatchIds: [...new Set([...this.state.successPendingMatchIds, matchId])],
      });
      return result;
    } finally {
      this._actionLocks.delete(`success-req:${matchId}`);
    }
  }

  /**
   * 确认成功牵手（双确认第二步，仅被请求方调用）
   * @param {string} matchId
   */
  async confirmSuccess(matchId) {
    if (this._actionLocks.has(`success-confirm:${matchId}`)) return;
    this._actionLocks.add(`success-confirm:${matchId}`);
    try {
      const result = await matchService.confirmSuccess(matchId);
      // 成功后从 pending 列表移除
      this.setState({
        successPendingMatchIds: this.state.successPendingMatchIds.filter((id) => id !== matchId),
      });
      return result;
    } finally {
      this._actionLocks.delete(`success-confirm:${matchId}`);
    }
  }
}

const matchStore = new MatchStore();
module.exports = matchStore;