import db from '../config/database';
import { AuditService } from './AuditService';
import { AIService } from './AIService';
import { SovereigntyIdentityService } from './SovereigntyIdentityService';
import { FeatureGovernanceService } from '../core/governance/FeatureGovernanceService';

/**
 * [BIZ_SOV_03] 跨境资金主权结算协议 (Sovereignty Settlement)
 * 负责基于租户 DID 身份进行跨国、跨币种的直接主权结算，绕过传统银行中转
 */
export class SovereigntySettlementService {
  /**
   * 发起主权结算
   */
  static async initiateSettlement(
    tenantId: string, 
    amount: number, 
    currency: string, 
    traceId: string
  ): Promise<string | null> {
    // Feature Flag Check
    if (!(await FeatureGovernanceService.isEnabled('BIZ_SOV_SETTLEMENT', tenantId))) {
      return null;
    }
    // 1. 获取租户主权身份 DID
    const identity = await SovereigntyIdentityService.getIdentity(tenantId);
    if (!identity) {
      throw new Error('Sovereignty Identity not initialized');
    }

    // 2. 调用 AGI 结算引擎生成结算证明 (模拟主权区块链交互)
    const settlementHash = 'SETTLE-' + Math.random().toString(36).substring(7).toUpperCase();

    await db.transaction(async (trx) => {
      // 3. 记录结算单
      const [id] = await trx('cf_sovereignty_payouts').insert({
        tenant_id: tenantId,
        amount,
        currency,
        settlement_hash: settlementHash,
        status: 'PENDING'
      });

      // 4. 模拟主权网关回调执行
      await this.executeSettlement(id, tenantId, traceId);

      // 审计记录
      await AuditService.log({
        tenantId: tenantId,
        userId: 'SYSTEM',
        module: 'SOVEREIGNTY_SETTLEMENT',
        action: 'SOVEREIGNTY_SETTLEMENT_CREATED',
        resourceType: 'FINANCE_PAYOUT',
        resourceId: id.toString(),
        traceId: traceId,
        afterSnapshot: JSON.stringify({ amount, currency, settlementHash }),
        result: 'success',
        source: 'node',
        metadata: { did: identity.did }
      });
    });

    return settlementHash;
  }

  /**
   * 执行结算 (V27.0 Sovereignty Flow)
   */
  private static async executeSettlement(payoutId: number, tenantId: string, traceId: string): Promise<void> {
    // 模拟结算成功
    await db('cf_sovereignty_payouts')
      .where({ id: payoutId })
      .update({
        status: 'SETTLED',
        updated_at: db.fn.now()
      });

    await AuditService.log({
      tenantId: tenantId,
      userId: 'SYSTEM',
      module: 'SOVEREIGNTY_SETTLEMENT',
      action: 'SOVEREIGNTY_SETTLEMENT_EXECUTED',
      resourceType: 'FINANCE_PAYOUT',
      resourceId: payoutId.toString(),
      traceId: traceId,
      afterSnapshot: JSON.stringify({ status: 'SETTLED' }),
      result: 'success',
      source: 'node',
      metadata: { timestamp: new Date().toISOString() }
    });
  }

  /**
   * 获取租户所有主权结算记录
   */
  static async getSettlementHistory(tenantId: string) {
    return await db('cf_sovereignty_payouts')
      .where({ tenant_id: tenantId })
      .orderBy('created_at', 'desc');
  }
}
