import { Knex } from 'knex';
import { db } from '../database';

export class BlacklistEffectivenessService {
  /**
   * 分析黑名单效果
   * @param params 分析参数
   * @param traceInfo 追踪信息
   * @returns 分析结果
   */
  public static async analyzeBlacklistEffectiveness(
    params: {
      timeRange: { start: string; end: string };
      blacklistIds?: string[];
      metrics?: string[];
    },
    traceInfo: {
      tenantId: string;
      shopId: string;
      taskId: string;
      traceId: string;
      businessType: 'TOC' | 'TOB';
    }
  ): Promise<{
    timestamp: string;
    timeRange: { start: string; end: string };
    metrics: {
      totalBlacklistCount: number;
      newAdditions: number;
      removals: number;
      activeBlacklistCount: number;
      preventionRate: number;
      falsePositiveRate: number;
      returnRateReduction: number;
      refundRateReduction: number;
    };
    insights: string[];
  }> {
    try {
      const timestamp = new Date().toISOString();
      
      // 模拟分析数据
      const metrics = {
        totalBlacklistCount: Math.floor(Math.random() * 500) + 100,
        newAdditions: Math.floor(Math.random() * 50) + 10,
        removals: Math.floor(Math.random() * 20) + 5,
        activeBlacklistCount: Math.floor(Math.random() * 400) + 80,
        preventionRate: (Math.random() * 30 + 60).toFixed(2),
        falsePositiveRate: (Math.random() * 10 + 2).toFixed(2),
        returnRateReduction: (Math.random() * 15 + 5).toFixed(2),
        refundRateReduction: (Math.random() * 12 + 3).toFixed(2),
      };
      
      // 生成洞察
      const insights = [
        `黑名单总数为 ${metrics.totalBlacklistCount}，期间新增 ${metrics.newAdditions} 个，移除 ${metrics.removals} 个`,
        `黑名单预防率为 ${metrics.preventionRate}%，有效阻止了潜在的恶意交易`,
        `误报率为 ${metrics.falsePositiveRate}%，在可接受范围内`,
        `退货率下降了 ${metrics.returnRateReduction}%，退款率下降了 ${metrics.refundRateReduction}%`,
        `当前活跃黑名单数量为 ${metrics.activeBlacklistCount}，占总数的 ${((metrics.activeBlacklistCount / metrics.totalBlacklistCount) * 100).toFixed(1)}%`,
      ];
      
      return {
        timestamp,
        timeRange: params.timeRange,
        metrics,
        insights,
      };
    } catch (error) {
      console.error('Error analyzing blacklist effectiveness:', error);
      throw new Error('Failed to analyze blacklist effectiveness');
    }
  }

  /**
   * 生成黑名单效果分析报告
   * @param params 报告参数
   * @param traceInfo 追踪信息
   * @returns 分析报告
   */
  public static async generateEffectivenessReport(
    params: {
      timeRange: { start: string; end: string };
      reportType: 'weekly' | 'monthly' | 'quarterly' | 'yearly';
      includeRecommendations?: boolean;
    },
    traceInfo: {
      tenantId: string;
      shopId: string;
      taskId: string;
      traceId: string;
      businessType: 'TOC' | 'TOB';
    }
  ): Promise<{
    reportId: string;
    timestamp: string;
    timeRange: { start: string; end: string };
    reportType: string;
    summary: string;
    metrics: {
      totalBlacklistCount: number;
      newAdditions: number;
      removals: number;
      activeBlacklistCount: number;
      preventionRate: number;
      falsePositiveRate: number;
      returnRateReduction: number;
      refundRateReduction: number;
    };
    trends: Array<{
      metric: string;
      currentValue: number;
      previousValue: number;
      change: number;
      trend: 'up' | 'down' | 'stable';
    }>;
    recommendations: string[];
  }> {
    try {
      const reportId = `EFFECTIVENESS-REPORT-${Date.now()}`;
      const timestamp = new Date().toISOString();
      
      // 分析黑名单效果
      const analysis = await this.analyzeBlacklistEffectiveness(params, traceInfo);
      
      // 生成摘要
      const summary = `黑名单效果分析报告 (${params.reportType}) - ${params.timeRange.start} 至 ${params.timeRange.end}`;
      
      // 生成趋势数据
      const trends = [
        {
          metric: '预防率',
          currentValue: parseFloat(analysis.metrics.preventionRate),
          previousValue: parseFloat((Math.random() * 5 + parseFloat(analysis.metrics.preventionRate) - 2.5).toFixed(2)),
          change: 0,
          trend: 'stable' as 'up' | 'down' | 'stable',
        },
        {
          metric: '误报率',
          currentValue: parseFloat(analysis.metrics.falsePositiveRate),
          previousValue: parseFloat((Math.random() * 3 + parseFloat(analysis.metrics.falsePositiveRate) - 1.5).toFixed(2)),
          change: 0,
          trend: 'stable' as 'up' | 'down' | 'stable',
        },
        {
          metric: '退货率下降',
          currentValue: parseFloat(analysis.metrics.returnRateReduction),
          previousValue: parseFloat((Math.random() * 4 + parseFloat(analysis.metrics.returnRateReduction) - 2).toFixed(2)),
          change: 0,
          trend: 'stable' as 'up' | 'down' | 'stable',
        },
        {
          metric: '退款率下降',
          currentValue: parseFloat(analysis.metrics.refundRateReduction),
          previousValue: parseFloat((Math.random() * 3 + parseFloat(analysis.metrics.refundRateReduction) - 1.5).toFixed(2)),
          change: 0,
          trend: 'stable' as 'up' | 'down' | 'stable',
        },
      ];
      
      // 计算趋势变化
      trends.forEach(trend => {
        trend.change = parseFloat((trend.currentValue - trend.previousValue).toFixed(2));
        if (trend.change > 0.5) {
          trend.trend = 'up';
        } else if (trend.change < -0.5) {
          trend.trend = 'down';
        } else {
          trend.trend = 'stable';
        }
      });
      
      // 生成建议
      const recommendations = [
        '建议定期审查黑名单，移除已改善行为的买家',
        '建议优化黑名单规则，减少误报率',
        '建议增加黑名单数据来源，提高识别准确率',
        '建议建立黑名单共享机制，与其他商家合作',
        '建议定期更新黑名单效果分析，持续优化策略',
      ];
      
      return {
        reportId,
        timestamp,
        timeRange: params.timeRange,
        reportType: params.reportType,
        summary,
        metrics: {
          ...analysis.metrics,
          preventionRate: parseFloat(analysis.metrics.preventionRate),
          falsePositiveRate: parseFloat(analysis.metrics.falsePositiveRate),
          returnRateReduction: parseFloat(analysis.metrics.returnRateReduction),
          refundRateReduction: parseFloat(analysis.metrics.refundRateReduction),
        },
        trends,
        recommendations,
      };
    } catch (error) {
      console.error('Error generating effectiveness report:', error);
      throw new Error('Failed to generate effectiveness report');
    }
  }

  /**
   * 评估黑名单ROI
   * @param params 评估参数
   * @param traceInfo 追踪信息
   * @returns ROI评估结果
   */
  public static async evaluateBlacklistROI(
    params: {
      timeRange: { start: string; end: string };
      includeCosts?: boolean;
    },
    traceInfo: {
      tenantId: string;
      shopId: string;
      taskId: string;
      traceId: string;
      businessType: 'TOC' | 'TOB';
    }
  ): Promise<{
    timestamp: string;
    timeRange: { start: string; end: string };
    roi: number;
    benefits: {
      preventedLosses: number;
      reducedReturns: number;
      reducedRefunds: number;
      improvedCustomerExperience: number;
    };
    costs: {
      implementation: number;
      maintenance: number;
      falsePositiveCosts: number;
    };
    paybackPeriod: number;
  }> {
    try {
      const timestamp = new Date().toISOString();
      
      // 模拟ROI数据
      const benefits = {
        preventedLosses: Math.random() * 50000 + 20000,
        reducedReturns: Math.random() * 15000 + 5000,
        reducedRefunds: Math.random() * 10000 + 3000,
        improvedCustomerExperience: Math.random() * 5000 + 2000,
      };
      
      const costs = {
        implementation: Math.random() * 5000 + 2000,
        maintenance: Math.random() * 3000 + 1000,
        falsePositiveCosts: Math.random() * 2000 + 500,
      };
      
      const totalBenefits = Object.values(benefits).reduce((sum, value) => sum + value, 0);
      const totalCosts = Object.values(costs).reduce((sum, value) => sum + value, 0);
      const roi = totalCosts > 0 ? ((totalBenefits - totalCosts) / totalCosts) * 100 : 0;
      const paybackPeriod = totalBenefits > 0 ? totalCosts / (totalBenefits / 12) : 0;
      
      return {
        timestamp,
        timeRange: params.timeRange,
        roi: parseFloat(roi.toFixed(2)),
        benefits,
        costs,
        paybackPeriod: parseFloat(paybackPeriod.toFixed(2)),
      };
    } catch (error) {
      console.error('Error evaluating blacklist ROI:', error);
      throw new Error('Failed to evaluate blacklist ROI');
    }
  }

  /**
   * 获取黑名单趋势分析
   * @param params 趋势分析参数
   * @param traceInfo 追踪信息
   * @returns 趋势分析结果
   */
  public static async getBlacklistTrends(
    params: {
      timeRange: { start: string; end: string };
      interval: 'daily' | 'weekly' | 'monthly';
      metrics: string[];
    },
    traceInfo: {
      tenantId: string;
      shopId: string;
      taskId: string;
      traceId: string;
      businessType: 'TOC' | 'TOB';
    }
  ): Promise<{
    timestamp: string;
    timeRange: { start: string; end: string };
    interval: string;
    trends: Array<{
      date: string;
      metrics: Record<string, number>;
    }>;
  }> {
    try {
      const timestamp = new Date().toISOString();
      const trends = [];
      
      // 生成趋势数据
      const startDate = new Date(params.timeRange.start);
      const endDate = new Date(params.timeRange.end);
      const currentDate = new Date(startDate);
      
      while (currentDate <= endDate) {
        const dateStr = currentDate.toISOString().split('T')[0];
        
        const metrics: Record<string, number> = {};
        if (params.metrics.includes('blacklistCount')) {
          metrics.blacklistCount = Math.floor(Math.random() * 100) + 50;
        }
        if (params.metrics.includes('preventionRate')) {
          metrics.preventionRate = parseFloat((Math.random() * 20 + 60).toFixed(2));
        }
        if (params.metrics.includes('falsePositiveRate')) {
          metrics.falsePositiveRate = parseFloat((Math.random() * 5 + 2).toFixed(2));
        }
        if (params.metrics.includes('returnRateReduction')) {
          metrics.returnRateReduction = parseFloat((Math.random() * 10 + 5).toFixed(2));
        }
        
        trends.push({
          date: dateStr,
          metrics,
        });
        
        // 增加时间间隔
        if (params.interval === 'daily') {
          currentDate.setDate(currentDate.getDate() + 1);
        } else if (params.interval === 'weekly') {
          currentDate.setDate(currentDate.getDate() + 7);
        } else if (params.interval === 'monthly') {
          currentDate.setMonth(currentDate.getMonth() + 1);
        }
      }
      
      return {
        timestamp,
        timeRange: params.timeRange,
        interval: params.interval,
        trends,
      };
    } catch (error) {
      console.error('Error getting blacklist trends:', error);
      throw new Error('Failed to get blacklist trends');
    }
  }
}
