import db from '../config/database';
import { AuditService } from './AuditService';
import { AIService } from './AIService';

/**
 * [BIZ_FIN_21] 跨租户机密利润共享对账 (Confidential Profit Sharing)
 * 负责在租户间（如联合集采、交叉分销）进行利润共享，利用同态加密技术在不暴露明文利润的情况下完成对账
 */
export class ConfidentialSharingService {
  /**
   * 提交机密利润数据并请求对账
   */
  static async submitConfidentialProfit(
    tenantId: string, 
    partnerTenantId: string, 
    profitAmount: number, 
    sharingRatio: number,
    traceId: string
  ): Promise<void> {
    // 1. 同态加密利润数据 (模拟加密过程)
    const encryptedData = `HE-ENC-${profitAmount * 1.5}-${Math.random().toString(36).substring(7)}`;
    const settlementProof = 'PROOF-' + Math.random().toString(36).substring(7).toUpperCase();

    await db.transaction(async (trx) => {
      // 2. 记录机密对账单
      const [id] = await trx('cf_confidential_sharing').insert({
        tenant_id: tenantId,
        partner_tenant_id: partnerTenantId,
        encrypted_profit_data: encryptedData,
        sharing_ratio: sharingRatio,
        settlement_proof: settlementProof
      });

      // 3. 审计记录
      await AuditService.log({
        tenant_id: tenantId,
        action: 'CONFIDENTIAL_PROFIT_SUBMITTED',
        target_type: 'FINANCE_SHARING',
        target_id: id.toString(),
        trace_id: traceId,
        new_data: JSON.stringify({ partnerTenantId, sharingRatio }),
        metadata: JSON.stringify({ settlementProof })
      });
    });
  }

  /**
   * 执行机密对账结算 (BIZ_FIN_21)
   */
  static async executeConfidentialSettlement(
    sharingId: number, 
    tenantId: string, 
    traceId: string
  ): Promise<number> {
    const record = await db('cf_confidential_sharing').where({ id: sharingId }).first();
    if (!record) throw new Error('Sharing record not found');

    // 1. 利用 AGI 节点进行同态计算 (模拟在不解密的情况下计算应分利润)
    const calculatedShare = await AIService.calculateConfidentialShare(record.encrypted_profit_data, record.sharing_ratio);

    await db.transaction(async (trx) => {
      // 2. 更新结算证明
      await trx('cf_confidential_sharing').where({ id: sharingId }).update({
        updated_at: db.fn.now()
      });

      // 3. 审计记录
      await AuditService.log({
        tenant_id: tenantId,
        action: 'CONFIDENTIAL_SETTLEMENT_COMPLETED',
        target_type: 'FINANCE_SHARING',
        target_id: sharingId.toString(),
        trace_id: traceId,
        new_data: JSON.stringify({ calculatedShare }),
        metadata: JSON.stringify({ sharingId })
      });
    });

    return calculatedShare;
  }

  /**
   * 获取租户所有机密共享历史
   */
  static async getSharingHistory(tenantId: string) {
    return await db('cf_confidential_sharing')
      .where({ tenant_id: tenantId })
      .orWhere({ partner_tenant_id: tenantId })
      .orderBy('created_at', 'desc');
  }
}