/**
 * 群风控与异常干预模块 — 业务服务层
 *
 * 对应规范文档 §八「模块 5：群风控与异常干预模块」
 *
 * 业务流程：
 *   §8.1 实时监听群消息：由 qiwei 模块的 webhook 消费者完成
 *   §8.2 风险关键词库配置：CRUD 管理风险词
 *   §8.3 命中敏感词自动预警：消息内容与词库匹配 → 生成 alert
 *   §8.4 人数骤降等阈值异常：统计退群事件、零互动天数 → 生成 alert
 *   §8.5 异常提醒到企微：通过 API-14 发送
 *   §8.6 预警自动生成干预工单：alert 创建时联动生成 work_order
 *   §8.7 工单处理与关闭：更新处理记录 → 计时统计响应时长
 *   §8.8 异常处理案例知识库：已关闭工单归档为 kb_case（二期）
 */

import { AppError } from '../../../../shared/errors/app-error.js';
import type {
  RiskKeyword,
  Alert,
  AlertType,
  WorkOrder,
  WorkOrderStatus,
} from '../models/risk.model.js';

// ---------- 内存存储（TODO: 替换为数据库）----------
const keywordStore = new Map<number, RiskKeyword>();
const alertStore = new Map<number, Alert>();
const workOrderStore = new Map<number, WorkOrder>();
let nextKeywordId = 1;
let nextAlertId = 1;
let nextWorkOrderId = 1;

// ============================================================
// 风险关键词库（§8.2）
// ============================================================

/** 创建关键词 */
export function createKeyword(data: Omit<RiskKeyword, 'id' | 'createdAt'>): RiskKeyword {
  const kw: RiskKeyword = {
    id: nextKeywordId++,
    ...data,
    createdAt: new Date().toISOString(),
  };
  keywordStore.set(kw.id, kw);
  return kw;
}

/** 查询关键词列表 */
export function listKeywords(category?: string, enabled?: number): RiskKeyword[] {
  let result = Array.from(keywordStore.values());
  if (category) result = result.filter((k) => k.category === category);
  if (enabled !== undefined) result = result.filter((k) => k.enabled === enabled);
  return result;
}

/** 更新关键词 */
export function updateKeyword(id: number, data: Partial<RiskKeyword>): RiskKeyword {
  const kw = keywordStore.get(id);
  if (!kw) throw new AppError(404, 'KEYWORD_NOT_FOUND', `关键词 ID=${id} 不存在`);
  Object.assign(kw, data);
  keywordStore.set(id, kw);
  return kw;
}

/** 删除关键词 */
export function deleteKeyword(id: number): void {
  if (!keywordStore.has(id)) throw new AppError(404, 'KEYWORD_NOT_FOUND', `关键词 ID=${id} 不存在`);
  keywordStore.delete(id);
}

/**
 * 扫描消息内容，匹配风险关键词
 *
 * 实际生产环境在 webhook 消费者中对每条消息实时执行。
 *
 * @param content  - 消息文本内容
 * @param roomId   - 群 ID
 * @param messageId - 消息 ID
 * @returns 命中的预警列表（如无命中则返回空数组）
 */
export function scanMessageForKeywords(
  content: string,
  roomId: string,
  messageId: number,
): Alert[] {
  const alerts: Alert[] = [];
  const activeKeywords = listKeywords(undefined, 1);

  for (const kw of activeKeywords) {
    if (content.includes(kw.keyword)) {
      const alert = createAlert({
        roomId,
        type: 'keyword',
        level: kw.severity,
        title: `命中风险关键词"${kw.keyword}"`,
        description: `群 ${roomId} 的消息命中风险关键词"${kw.keyword}"（分类：${kw.category}）`,
        matchedKeyword: kw.keyword,
        messageId,
      });
      alerts.push(alert);
    }
  }

  return alerts;
}

// ============================================================
// 预警管理（§8.3 ~ §8.5）
// ============================================================

interface CreateAlertParams {
  roomId: string;
  type: AlertType;
  level: 1 | 2 | 3;
  title: string;
  description: string;
  matchedKeyword?: string;
  messageId?: number;
}

/** 创建预警记录 */
export function createAlert(params: CreateAlertParams): Alert {
  const now = new Date().toISOString();
  const alert: Alert = {
    id: nextAlertId++,
    roomId: params.roomId,
    type: params.type,
    level: params.level,
    title: params.title,
    description: params.description,
    matchedKeyword: params.matchedKeyword || '',
    messageId: params.messageId || 0,
    status: 'open',
    handlerId: 0,
    handleNote: '',
    workOrderId: 0,
    createdAt: now,
    handledAt: '',
  };

  alertStore.set(alert.id, alert);

  // ---- §8.6：高危预警自动生成干预工单 ----
  if (params.level >= 3) {
    const order = createWorkOrder({
      alertId: alert.id,
      title: `【自动】${params.title}`,
      description: params.description,
      assigneeId: 0, // 待分配
    });
    alert.workOrderId = order.id;
    alertStore.set(alert.id, alert);
  }

  return alert;
}

/** 查询预警列表 */
export function listAlerts(
  roomId?: string,
  type?: AlertType,
  status?: 'open' | 'handled' | 'ignored',
): Alert[] {
  let result = Array.from(alertStore.values());
  if (roomId) result = result.filter((a) => a.roomId === roomId);
  if (type) result = result.filter((a) => a.type === type);
  if (status) result = result.filter((a) => a.status === status);
  return result.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime());
}

/** 处理预警 */
export function handleAlert(
  id: number,
  status: 'handled' | 'ignored',
  handlerId: number,
  note: string,
): Alert {
  const alert = alertStore.get(id);
  if (!alert) throw new AppError(404, 'ALERT_NOT_FOUND', `预警 ID=${id} 不存在`);

  alert.status = status;
  alert.handlerId = handlerId;
  alert.handleNote = note;
  alert.handledAt = new Date().toISOString();
  alertStore.set(id, alert);
  return alert;
}

// ============================================================
// 干预工单（§8.6 ~ §8.7）
// ============================================================

interface CreateWorkOrderParams {
  alertId: number;
  title: string;
  description: string;
  assigneeId: number;
  deadline?: string;
}

/** 创建工单 */
export function createWorkOrder(params: CreateWorkOrderParams): WorkOrder {
  const now = new Date().toISOString();
  // 默认截止时间为 24h 后
  const deadline = params.deadline || new Date(Date.now() + 24 * 60 * 60 * 1000).toISOString();

  const order: WorkOrder = {
    id: nextWorkOrderId++,
    alertId: params.alertId,
    title: params.title,
    description: params.description,
    assigneeId: params.assigneeId,
    deadline,
    status: 'pending',
    handleRecord: '',
    createdAt: now,
    completedAt: '',
  };

  workOrderStore.set(order.id, order);
  return order;
}

/** 查询工单列表 */
export function listWorkOrders(status?: WorkOrderStatus, assigneeId?: number): WorkOrder[] {
  let result = Array.from(workOrderStore.values());
  if (status) result = result.filter((o) => o.status === status);
  if (assigneeId !== undefined) result = result.filter((o) => o.assigneeId === assigneeId);
  return result.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime());
}

/** 更新工单状态 */
export function updateWorkOrder(
  id: number,
  status: WorkOrderStatus,
  handleRecord?: string,
): WorkOrder {
  const order = workOrderStore.get(id);
  if (!order) throw new AppError(404, 'WORK_ORDER_NOT_FOUND', `工单 ID=${id} 不存在`);

  order.status = status;
  if (handleRecord) order.handleRecord = handleRecord;
  if (status === 'completed') order.completedAt = new Date().toISOString();
  workOrderStore.set(id, order);
  return order;
}