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

export interface HedgingStrategy {
  strategy: 'FIXED' | 'FLOATING' | 'FORWARD';
  rate: number;
  expiry?: Date;
}

export class FXHedgingService {
  static async getHedgingRate(fromCurrency: string, toCurrency: string): Promise<HedgingStrategy | null> {
    try {
      // 模拟对冲汇率数据
      const mockRates: Record<string, number> = {
        'CNY/USD': 0.14,
        'USD/CNY': 7.14,
        'CNY/EUR': 0.13,
        'EUR/CNY': 7.69,
        'USD/EUR': 0.93,
        'EUR/USD': 1.08
      };
      
      const key = `${fromCurrency}/${toCurrency}`;
      if (mockRates[key]) {
        return {
          strategy: 'FIXED',
          rate: mockRates[key]
        };
      }
      
      return null;
    } catch (error) {
      logger.error('Error getting hedging rate:', error);
      return null;
    }
  }
  
  static calculateHedgingCost(amount: number, fromCurrency: string, toCurrency: string, strategy: HedgingStrategy): number {
    try {
      // 计算对冲成本
      const baseRate = strategy.rate;
      const hedgingFee = 0.001; // 0.1%的对冲费用
      const cost = amount * baseRate * hedgingFee;
      
      return Number(cost.toFixed(2));
    } catch (error) {
      logger.error('Error calculating hedging cost:', error);
      return 0;
    }
  }
  
  static async getDynamicSafetyMargin(currencyPair: string): Promise<number> {
    try {
      // 模拟动态安全边际数据
      const mockSafetyMargins: Record<string, number> = {
        'USD/CNY': 0.05,
        'CNY/USD': 0.05,
        'USD/EUR': 0.03,
        'EUR/USD': 0.03,
        'CNY/EUR': 0.04,
        'EUR/CNY': 0.04
      };
      
      return mockSafetyMargins[currencyPair] || 0.03;
    } catch (error) {
      logger.error('Error getting dynamic safety margin:', error);
      return 0.03;
    }
  }
  
  static async lockRate(tenantId: string, currencyPair: string, amount: number, durationDays: number): Promise<string> {
    try {
      // 模拟锁定汇率
      const lockId = `lock_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
      logger.info(`[FXHedgingService] Locked rate for tenant ${tenantId}: ${lockId}`);
      return lockId;
    } catch (error) {
      logger.error('Error locking rate:', error);
      throw error;
    }
  }
  
  static async calculateGainLoss(tenantId: string): Promise<any> {
    try {
      // 模拟计算盈亏
      return {
        totalGain: 1000.50,
        totalLoss: 200.75,
        netGain: 799.75,
        transactions: []
      };
    } catch (error) {
      logger.error('Error calculating gain/loss:', error);
      throw error;
    }
  }
}