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

export interface CreditEvaluation {
  tenantId: string;
  currentLimit: number;
  suggestedLimit: number;
  riskScore: number; // 0-100
  factors: {
    gmvGrowth: number;
    profitMargin: number;
    complianceScore: number;
    repaymentHistory: 'EXCELLENT' | 'GOOD' | 'POOR';
  };
}

/**
 * [BIZ_FIN_13] 基于 AI 预测的动态信用额度管理 (Dynamic Credit)
 * @description 根据租户经营表现（GMV 增长、利润率、合规性与回款记录）实时调整信贷与采购额度。
 */
export class CreditService {
  /**
   * 评估租户信用额度
   */
  static async evaluateCreditLimit(tenantId: string): Promise<CreditEvaluation> {
    logger.info(`[Credit] Evaluating dynamic credit limit for tenant: ${tenantId}`);

    // 1. 获取租户经营指标 (模拟)
    const evaluation: CreditEvaluation = {
      tenantId,
      currentLimit: 50000,
      suggestedLimit: 0,
      riskScore: 15,
      factors: {
        gmvGrowth: 0.25, // 25% growth
        profitMargin: 0.18,
        complianceScore: 0.95,
        repaymentHistory: 'EXCELLENT'
      }
    };

    // 2. 模拟 AI 调额模型逻辑
    let multiplier = 1.0;
    if (evaluation.factors.gmvGrowth > 0.2) multiplier += 0.2;
    if (evaluation.factors.repaymentHistory === 'EXCELLENT') multiplier += 0.3;
    if (evaluation.factors.complianceScore < 0.8) multiplier -= 0.5;

    evaluation.suggestedLimit = evaluation.currentLimit * multiplier;

    logger.info(`[Credit] Credit evaluation completed. Suggested limit: ${evaluation.suggestedLimit} for tenant: ${tenantId}`);

    return evaluation;
  }

  /**
   * 执行自动调额
   */
  static async applySuggestedLimit(tenantId: string, suggestedLimit: number): Promise<boolean> {
    logger.warn(`[Credit] Applying new credit limit: ${suggestedLimit} for tenant: ${tenantId}`);
    // 逻辑：更新数据库中的租户配置并发送通知
    return true;
  }
}
