/**
 * 小区管理模块 — 业务服务层
 *
 * 对应规范文档：
 *   §5.5「录入小区基础档案」
 *   §5.6「维护小区—群—门店对应关系」
 *
 * 业务规则：
 *   1. 小区户数无法从 QiWe 自动获取，需人工录入
 *   2. 群与小区/门店的绑定关系禁止自动猜测——必须人工确认
 *   3. 未绑定群在看板中标记为「待维护」
 *   4. 报表按小区/门店聚合时，通过绑定表 INNER JOIN
 */

import { AppError } from '../../../../shared/errors/app-error.js';
import type {
  Community,
  CreateCommunityRequest,
  CommunityRoomBinding,
  CreateBindingRequest,
} from '../models/community.model.js';

// ---------- 内存存储（TODO: 替换为数据库）----------
const communityStore = new Map<number, Community>();
const bindingStore = new Map<number, CommunityRoomBinding>();
let nextCommunityId = 1;
let nextBindingId = 1;

// ============================================================
// 小区档案 CRUD
// ============================================================

/**
 * 录入小区基础档案
 *
 * 户数是触达率计算的分母，必须准确。
 * 房价、交房时间等字段供看板和经营分析使用。
 */
export function createCommunity(data: CreateCommunityRequest): Community {
  const now = new Date().toISOString();
  const community: Community = {
    id: nextCommunityId++,
    name: data.name,
    totalHouseholds: data.totalHouseholds,
    avgPrice: data.avgPrice || 0,
    deliveryYear: data.deliveryYear || 0,
    storeId: data.storeId,
    address: data.address || '',
    remark: data.remark || '',
    createdAt: now,
    updatedAt: now,
  };

  communityStore.set(community.id, community);
  return community;
}

/**
 * 查询小区列表（支持按门店筛选）
 */
export function listCommunities(storeId?: number): Community[] {
  let result = Array.from(communityStore.values());
  if (storeId !== undefined) {
    result = result.filter((c) => c.storeId === storeId);
  }
  return result;
}

/**
 * 查询单个小区详情
 */
export function getCommunityById(id: number): Community {
  const community = communityStore.get(id);
  if (!community) {
    throw new AppError(404, 'COMMUNITY_NOT_FOUND', `小区 ID=${id} 不存在`);
  }
  return community;
}

/**
 * 更新小区信息
 */
export function updateCommunity(id: number, data: Partial<CreateCommunityRequest>): Community {
  const community = getCommunityById(id);

  if (data.name !== undefined) community.name = data.name;
  if (data.totalHouseholds !== undefined) community.totalHouseholds = data.totalHouseholds;
  if (data.avgPrice !== undefined) community.avgPrice = data.avgPrice;
  if (data.deliveryYear !== undefined) community.deliveryYear = data.deliveryYear;
  if (data.storeId !== undefined) community.storeId = data.storeId;
  if (data.address !== undefined) community.address = data.address;
  if (data.remark !== undefined) community.remark = data.remark;
  community.updatedAt = new Date().toISOString();

  communityStore.set(id, community);
  return community;
}

/**
 * 删除小区
 */
export function deleteCommunity(id: number): void {
  getCommunityById(id);
  communityStore.delete(id);

  // 同时清理关联的绑定关系
  for (const [key, binding] of bindingStore) {
    if (binding.communityId === id) {
      bindingStore.delete(key);
    }
  }
}

// ============================================================
// 小区-群-门店绑定
// ============================================================

/**
 * 创建小区-群-门店绑定关系
 *
 * 业务约束：
 *   - 同一个 roomId 不可重复绑定到不同的小区
 *   - 绑定禁止自动猜测，必须人工确认
 *
 * @throws {AppError} 当 roomId 已被绑定时
 */
export function createBinding(data: CreateBindingRequest): CommunityRoomBinding {
  // 检查 roomId 是否已绑定
  for (const binding of bindingStore.values()) {
    if (binding.roomId === data.roomId) {
      throw new AppError(
        409,
        'BINDING_DUPLICATE',
        `群 ${data.roomId} 已绑定到小区 ID=${binding.communityId}，不可重复绑定`,
      );
    }
  }

  const binding: CommunityRoomBinding = {
    id: nextBindingId++,
    communityId: data.communityId,
    roomId: data.roomId,
    storeId: data.storeId,
    createdAt: new Date().toISOString(),
  };

  bindingStore.set(binding.id, binding);
  return binding;
}

/**
 * 查询绑定关系列表（按小区或门店筛选）
 */
export function listBindings(communityId?: number, storeId?: number): CommunityRoomBinding[] {
  let result = Array.from(bindingStore.values());
  if (communityId !== undefined) {
    result = result.filter((b) => b.communityId === communityId);
  }
  if (storeId !== undefined) {
    result = result.filter((b) => b.storeId === storeId);
  }
  return result;
}

/**
 * 删除绑定关系（解绑）
 */
export function deleteBinding(id: number): void {
  const binding = bindingStore.get(id);
  if (!binding) {
    throw new AppError(404, 'BINDING_NOT_FOUND', `绑定 ID=${id} 不存在`);
  }
  bindingStore.delete(id);
}

/**
 * 按 roomId 查询绑定（用于合规等模块关联查询）
 */
export function getBindingByRoomId(roomId: string): CommunityRoomBinding | undefined {
  for (const binding of bindingStore.values()) {
    if (binding.roomId === roomId) {
      return binding;
    }
  }
  return undefined;
}