/**
 * [OP-ST004] 多商户性能测试服务
 * @description 测试多商户系统的性能，分析并发情况下的系统表现
 * @version 1.0
 */
export class MerchantPerformanceTest {
  /**
   * 执行多商户性能测试
   * @param params 测试参数
   * @param traceInfo 追踪信息
   * @returns 性能测试结果
   */
  public static async runPerformanceTest(params: {
    concurrentMerchants: number;
    testDuration: number; // 测试持续时间（秒）
    operationsPerSecond: number;
  }, traceInfo: {
    tenantId: string;
    shopId: string;
    taskId: string;
    traceId: string;
    businessType: 'TOC' | 'TOB';
  }): Promise<{
    testId: string;
    startTime: string;
    endTime: string;
    concurrentMerchants: number;
    operationsPerSecond: number;
    results: {
      averageResponseTime: number;
      throughput: number;
      errorRate: number;
      maxResponseTime: number;
      p95ResponseTime: number;
      p99ResponseTime: number;
    };
  }> {
    // 生成测试ID
    const testId = `PT-${Date.now()}`;
    const startTime = new Date().toISOString();

    // 模拟性能测试过程
    console.log(`[MerchantPerformanceTest] 开始性能测试 - ID: ${testId}, 并发商户数: ${params.concurrentMerchants}`, {
      ...traceInfo,
      testId
    });

    // 模拟测试执行
    await new Promise(resolve => setTimeout(resolve, params.testDuration * 1000));

    // 生成模拟性能数据
    const responseTimes: number[] = [];
    for (let i = 0; i < params.concurrentMerchants * params.operationsPerSecond * params.testDuration; i++) {
      // 生成正态分布的响应时间
      const responseTime = this.generateNormalDistribution(150, 50);
      responseTimes.push(responseTime);
    }

    // 计算性能指标
    responseTimes.sort((a, b) => a - b);
    const totalOperations = responseTimes.length;
    const errorCount = Math.floor(totalOperations * 0.01); // 1% 错误率

    const results = {
      averageResponseTime: responseTimes.reduce((sum, time) => sum + time, 0) / responseTimes.length,
      throughput: totalOperations / params.testDuration,
      errorRate: errorCount / totalOperations,
      maxResponseTime: Math.max(...responseTimes),
      p95ResponseTime: responseTimes[Math.floor(responseTimes.length * 0.95)],
      p99ResponseTime: responseTimes[Math.floor(responseTimes.length * 0.99)]
    };

    const endTime = new Date().toISOString();

    // 记录测试完成日志
    console.log(`[MerchantPerformanceTest] 性能测试完成 - ID: ${testId}, 吞吐量: ${results.throughput.toFixed(2)} ops/s`, {
      ...traceInfo,
      testId,
      results
    });

    return {
      testId,
      startTime,
      endTime,
      concurrentMerchants: params.concurrentMerchants,
      operationsPerSecond: params.operationsPerSecond,
      results
    };
  }

  /**
   * 生成正态分布的随机数
   * @param mean 均值
   * @param stdDev 标准差
   * @returns 随机数
   */
  private static generateNormalDistribution(mean: number, stdDev: number): number {
    let u = 0, v = 0;
    while (u === 0) u = Math.random();
    while (v === 0) v = Math.random();
    const num = Math.sqrt(-2.0 * Math.log(u)) * Math.cos(2.0 * Math.PI * v);
    return Math.max(0, mean + num * stdDev);
  }

  /**
   * 生成性能报告
   * @param testId 测试ID
   * @param traceInfo 追踪信息
   * @returns 性能报告
   */
  public static async generatePerformanceReport(testId: string, traceInfo: {
    tenantId: string;
    shopId: string;
    taskId: string;
    traceId: string;
    businessType: 'TOC' | 'TOB';
  }): Promise<{
    reportId: string;
    testId: string;
    timestamp: string;
    summary: string;
    performanceMetrics: any;
    bottlenecks: string[];
    recommendations: string[];
  }> {
    // 生成报告ID
    const reportId = `PR-${Date.now()}`;
    const timestamp = new Date().toISOString();

    // 模拟性能数据
    const performanceMetrics = {
      system: {
        cpuUsage: 65,
        memoryUsage: 72,
        diskI/O: 45,
        networkThroughput: 120
      },
      application: {
        averageResponseTime: 180,
        throughput: 850,
        errorRate: 0.01,
        maxResponseTime: 550,
        p95ResponseTime: 320,
        p99ResponseTime: 480
      },
      database: {
        queryTime: 80,
        connectionPoolUsage: 60,
        cacheHitRate: 75
      }
    };

    // 生成瓶颈分析
    const bottlenecks: string[] = [];
    if (performanceMetrics.system.cpuUsage > 70) {
      bottlenecks.push('CPU使用率过高');
    }
    if (performanceMetrics.system.memoryUsage > 80) {
      bottlenecks.push('内存使用过高');
    }
    if (performanceMetrics.application.p95ResponseTime > 300) {
      bottlenecks.push('P95响应时间过长');
    }
    if (performanceMetrics.database.queryTime > 100) {
      bottlenecks.push('数据库查询时间过长');
    }

    // 生成建议
    const recommendations: string[] = [];
    if (bottlenecks.length > 0) {
      recommendations.push('优化系统资源配置');
      recommendations.push('考虑数据库索引优化');
      recommendations.push('实施缓存策略');
      recommendations.push('优化代码逻辑');
    } else {
      recommendations.push('保持当前系统配置');
      recommendations.push('定期进行性能测试');
    }

    // 生成摘要
    const summary = `系统性能良好，平均响应时间 ${performanceMetrics.application.averageResponseTime}ms，吞吐量 ${performanceMetrics.application.throughput} ops/s`;

    // 记录报告生成日志
    console.log(`[MerchantPerformanceTest] 生成性能报告 - ID: ${reportId}, 测试: ${testId}`, {
      ...traceInfo,
      reportId
    });

    return {
      reportId,
      testId,
      timestamp,
      summary,
      performanceMetrics,
      bottlenecks,
      recommendations
    };
  }

  /**
   * 执行负载测试
   * @param params 测试参数
   * @param traceInfo 追踪信息
   * @returns 负载测试结果
   */
  public static async runLoadTest(params: {
    merchantIds: string[];
    rampUpTime: number; //  ramp-up时间（秒）
    steadyStateTime: number; // 稳定状态时间（秒）
    operationsPerSecond: number;
  }, traceInfo: {
    tenantId: string;
    shopId: string;
    taskId: string;
    traceId: string;
    businessType: 'TOC' | 'TOB';
  }): Promise<{
    loadTestId: string;
    startTime: string;
    endTime: string;
    merchantCount: number;
    results: Array<{
      phase: 'ramp-up' | 'steady-state';
      throughput: number;
      averageResponseTime: number;
      errorRate: number;
    }>;
  }> {
    // 生成负载测试ID
    const loadTestId = `LT-${Date.now()}`;
    const startTime = new Date().toISOString();

    console.log(`[MerchantPerformanceTest] 开始负载测试 - ID: ${loadTestId}, 商户数: ${params.merchantIds.length}`, {
      ...traceInfo,
      loadTestId
    });

    // 模拟ramp-up阶段
    await new Promise(resolve => setTimeout(resolve, params.rampUpTime * 1000));

    // 模拟steady-state阶段
    await new Promise(resolve => setTimeout(resolve, params.steadyStateTime * 1000));

    // 生成测试结果
    const results = [
      {
        phase: 'ramp-up' as const,
        throughput: params.operationsPerSecond * 0.7,
        averageResponseTime: 200,
        errorRate: 0.005
      },
      {
        phase: 'steady-state' as const,
        throughput: params.operationsPerSecond,
        averageResponseTime: 250,
        errorRate: 0.01
      }
    ];

    const endTime = new Date().toISOString();

    // 记录测试完成日志
    console.log(`[MerchantPerformanceTest] 负载测试完成 - ID: ${loadTestId}`, {
      ...traceInfo,
      loadTestId
    });

    return {
      loadTestId,
      startTime,
      endTime,
      merchantCount: params.merchantIds.length,
      results
    };
  }
}