import { logger } from '../utils/logger';

export interface ComplianceContext {
  tenantId: string;
  operationId: string;
  operationType: 'PAYMENT' | 'SHIPMENT' | 'DATA_EXPORT' | 'AUTH_CHANGE';
  metadata: any;
}

export interface ComplianceOutcome {
  isAllowed: boolean;
  blockedAt: 'NONE' | 'REGULATORY' | 'INTERNAL_POLICY' | 'RISK_CONTROL';
  reason?: string;
  remediation?: string;
  traceId: string;
}

/**
 * [BIZ_GOV_01] 多级合规门禁系统 (Compliance Gate)
 * @description 构建多维度的业务合规性自动审查与拦截机制，支持全球贸易合规、企业政策、风控与安全门禁的自动执行。
 */
export class ComplianceGateService {
  /**
   * 业务合规性多级审查
   */
  static async checkCompliance(ctx: ComplianceContext): Promise<ComplianceOutcome> {
    const traceId = `comp-gate-${ctx.tenantId}-${Date.now()}`;
    logger.info(`[ComplianceGate] Initiating multi-level check for: ${ctx.operationType} (${ctx.operationId})`);

    // 1. 第一级：全球法规合规 (Regulatory Compliance)
    if (this.isSanctionedRegion(ctx.metadata.region)) {
      logger.error(`[ComplianceGate] Blocked at REGULATORY level: Sanctioned region ${ctx.metadata.region}`);
      return { 
        isAllowed: false, 
        blockedAt: 'REGULATORY', 
        reason: `Operation involves a sanctioned region: ${ctx.metadata.region}`, 
        traceId 
      };
    }

    // 2. 第二级：内部业务政策 (Internal Policy)
    if (!this.meetsInternalPolicy(ctx)) {
      logger.warn(`[ComplianceGate] Blocked at INTERNAL_POLICY level for tenant ${ctx.tenantId}`);
      return { 
        isAllowed: false, 
        blockedAt: 'INTERNAL_POLICY', 
        reason: 'Operation violates internal business policy (e.g., margin red-line or address restriction)', 
        remediation: 'Contact your Manager for policy override.',
        traceId 
      };
    }

    // 3. 第三级：风险控制门禁 (Risk Control)
    if (this.isHighRisk(ctx)) {
      logger.warn(`[ComplianceGate] Blocked at RISK_CONTROL level: High fraud/risk score`);
      return { 
        isAllowed: false, 
        blockedAt: 'RISK_CONTROL', 
        reason: 'Risk score exceeds threshold (Potential fraud or credit risk)', 
        remediation: 'Verify customer identity or complete secondary KYC.',
        traceId 
      };
    }

    logger.info(`[ComplianceGate] Compliance check PASSED for: ${ctx.operationType} (${ctx.operationId})`);
    return { isAllowed: true, blockedAt: 'NONE', traceId };
  }

  /**
   * 模拟全球贸易禁运/合规地区校验
   */
  private static isSanctionedRegion(region?: string): boolean {
    const sanctioned = ['SY', 'KP', 'IR', 'CU']; // 模拟禁运名单 (ISO 3166-1 alpha-2)
    return !!region && sanctioned.includes(region);
  }

  /**
   * 校验内部业务政策 (如利润率、地址限制)
   */
  private static meetsInternalPolicy(ctx: ComplianceContext): boolean {
    // 逻辑：如果操作是付款且金额巨大，则必须满足特定条件
    if (ctx.operationType === 'PAYMENT' && ctx.metadata.amount > 100000) {
      // 实际场景应校验租户限额、审批链状态等
      return false;
    }
    return true;
  }

  /**
   * 风险控制模型：基于图反欺诈 (BIZ_AUDIT_04) 或历史信用分 (BIZ_AUDIT_05)
   */
  private static isHighRisk(ctx: ComplianceContext): boolean {
    // 逻辑：如果来自高风险 IP 或具有异常交易指纹
    const riskScore = ctx.metadata.riskScore || 0;
    return riskScore > 85; // 模拟风险阈值
  }

  /**
   * 异步记录合规决策
   */
  static async logComplianceDecision(outcome: ComplianceOutcome) {
    logger.debug(`[ComplianceGate] Logged outcome: ${JSON.stringify(outcome)}`);
    // 存入审计表以供未来合规审计 (Audit Trail)
  }
}
