import { Provide } from '@midwayjs/core';
import { BaseService, CoolCommException } from '@cool-midway/core';
import { InjectEntityModel } from '@midwayjs/typeorm';
import { Repository } from 'typeorm';
import { CrmLeadEntity } from '../entity/lead';
import { CrmLeadAuditEntity } from '../entity/audit';

/**
 * 自动回收执行结果接口
 */
export interface AutoRecycleResult {
  recycledCount: number;
  leadIds: number[];
}

/**
 * 团队线索公海池流转与自动分配服务
 * 负责线索公海回收、超时自动扫描回收、销售原子防并发抢单、管理员指派及全链路审计追踪
 */
@Provide()
export class CrmLeadPoolService extends BaseService {
  @InjectEntityModel(CrmLeadEntity)
  crmLeadEntity: Repository<CrmLeadEntity>;

  @InjectEntityModel(CrmLeadAuditEntity)
  crmLeadAuditEntity: Repository<CrmLeadAuditEntity>;

  /**
   * 将线索退回/手动置入公海池
   * @param leadId 线索主键 ID
   * @param reason 退回公海原因说明
   */
  async recycleToPool(
    leadId: number,
    reason?: string
  ): Promise<CrmLeadEntity> {
    const id = Number(leadId);
    if (!id) {
      throw new CoolCommException('缺少线索 ID', 400);
    }

    const lead = await this.crmLeadEntity.findOne({ where: { id } });
    if (!lead) {
      throw new CoolCommException('潜客线索不存在', 404);
    }

    const oldUserId = lead.userId ?? null;
    lead.isPool = true;
    lead.userId = null;
    const saved = await this.crmLeadEntity.save(lead);

    const audit = new CrmLeadAuditEntity();
    audit.leadId = id;
    audit.action = 'recycle';
    audit.fromUserId = oldUserId;
    audit.toUserId = null;
    audit.reason = reason || '手动退回公海池';
    await this.crmLeadAuditEntity.save(audit);

    return saved;
  }

  /**
   * 定时扫描超过指定天数未跟进的线索，自动批量归入公海池
   * @param inactivityDays 未跟进超期天数阈值
   */
  async scanAndAutoRecycle(inactivityDays: number): Promise<AutoRecycleResult> {
    if (!inactivityDays || inactivityDays <= 0) {
      return { recycledCount: 0, leadIds: [] };
    }

    const thresholdMs = inactivityDays * 24 * 60 * 60 * 1000;
    const now = Date.now();
    const thresholdDate = new Date(now - thresholdMs);

    let toRecycle: CrmLeadEntity[] = [];

    if (this.crmLeadEntity && typeof this.crmLeadEntity.createQueryBuilder === 'function') {
      toRecycle = await this.crmLeadEntity
        .createQueryBuilder('lead')
        .where('lead.is_pool = :isPool', { isPool: false })
        .andWhere('lead.status NOT IN (:...excluded)', { excluded: ['won', 'archived'] })
        .andWhere(
          '(COALESCE(lead.last_follow_up_time, lead.update_time, lead.create_time) <= :thresholdDate)',
          { thresholdDate }
        )
        .take(500)
        .getMany();
    } else {
      const allLeads = await this.crmLeadEntity.find({ where: { isPool: false } } as any);
      for (const lead of allLeads || []) {
        if (lead.isPool) continue;
        if (lead.status === 'won' || lead.status === 'archived') continue;
        const followUp = lead.lastFollowUpTime || lead.updateTime || lead.createTime;
        if (!followUp) continue;
        const diff = now - new Date(followUp).getTime();
        if (diff >= thresholdMs) {
          toRecycle.push(lead);
        }
      }
    }

    const recycledIds: number[] = [];
    for (const lead of toRecycle) {
      const oldUserId = lead.userId ?? null;
      lead.isPool = true;
      lead.userId = null;
      await this.crmLeadEntity.save(lead);
      recycledIds.push(Number(lead.id));

      const audit = new CrmLeadAuditEntity();
      audit.leadId = Number(lead.id);
      audit.action = 'auto_recycle';
      audit.fromUserId = oldUserId;
      audit.toUserId = null;
      audit.reason = `超过 ${inactivityDays} 天未跟进自动回收至公海池`;
      await this.crmLeadAuditEntity.save(audit);
    }

    return { recycledCount: recycledIds.length, leadIds: recycledIds };
  }

  /**
   * 销售成员从公海池抢单/领用 (CAS 原子性防并发保护)
   * @param leadId 线索 ID
   * @param userId 认领销售人员 ID
   */
  async claimLead(leadId: number, userId: number): Promise<CrmLeadEntity> {
    const id = Number(leadId);
    const targetUid = Number(userId);

    if (!id) {
      throw new CoolCommException('缺少线索 ID', 400);
    }
    if (!targetUid) {
      throw new CoolCommException('缺少领用销售人员 ID', 400);
    }

    // 检查线索是否存在
    const existing = await this.crmLeadEntity.findOne({ where: { id } });
    if (!existing) {
      throw new CoolCommException('潜客线索不存在', 404);
    }

    if (!existing.isPool || existing.userId) {
      throw new CoolCommException('该线索已被其他销售认领或不在公海池', 409);
    }

    // 原子性条件更新：仅在线索仍在公海时方可更新
    const updateResult = await this.crmLeadEntity.update(
      { id, isPool: true },
      { isPool: false, userId: targetUid }
    );

    if (!updateResult || updateResult.affected === 0) {
      throw new CoolCommException('该线索已被其他销售认领或不在公海池', 409);
    }

    const updated = await this.crmLeadEntity.findOne({ where: { id } });
    const resultLead = updated || existing;
    resultLead.isPool = false;
    resultLead.userId = targetUid;

    // 记录领用审计日志
    const audit = new CrmLeadAuditEntity();
    audit.leadId = id;
    audit.action = 'claim';
    audit.operatorId = targetUid;
    audit.fromUserId = null;
    audit.toUserId = targetUid;
    audit.reason = '销售公海抢单领用';
    await this.crmLeadAuditEntity.save(audit);

    return resultLead;
  }

  /**
   * 管理员指定派发分配线索
   * @param leadId 线索 ID
   * @param targetUserId 目标销售成员 ID
   * @param assignerId 管理员/操作人 ID
   */
  async assignLead(
    leadId: number,
    targetUserId: number,
    assignerId?: number
  ): Promise<CrmLeadEntity> {
    const id = Number(leadId);
    const targetUid = Number(targetUserId);

    if (!id) {
      throw new CoolCommException('缺少线索 ID', 400);
    }
    if (!targetUid) {
      throw new CoolCommException('缺少目标销售人员 ID', 400);
    }

    const lead = await this.crmLeadEntity.findOne({ where: { id } });
    if (!lead) {
      throw new CoolCommException('潜客线索不存在', 404);
    }

    const oldUserId = lead.userId ?? null;
    lead.userId = targetUid;
    lead.isPool = false;
    const saved = await this.crmLeadEntity.save(lead);

    const audit = new CrmLeadAuditEntity();
    audit.leadId = id;
    audit.action = 'assign';
    audit.operatorId = assignerId ? Number(assignerId) : null;
    audit.fromUserId = oldUserId;
    audit.toUserId = targetUid;
    audit.reason = '管理员指定派发线索';
    await this.crmLeadAuditEntity.save(audit);

    return saved;
  }

  /**
   * 查询指定线索的全生命周期流转审计追踪日志
   * @param leadId 线索 ID
   */
  async getAuditLogs(leadId: number): Promise<CrmLeadAuditEntity[]> {
    const id = Number(leadId);
    if (!id) return [];

    return await this.crmLeadAuditEntity.find({
      where: { leadId: id },
    });
  }
}