import { Injectable, Logger } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { AIImprovement } from '../../entities/AIImprovement';
import { MonitoringService } from '../monitoring/MonitoringService';
import { EventEmitter2 } from '@nestjs/event-emitter';

interface ImprovementSuggestion {
  id: string;
  type: 'code' | 'performance' | 'business' | 'security';
  title: string;
  description: string;
  severity: 'low' | 'medium' | 'high';
  priority: 'low' | 'medium' | 'high';
  status: 'pending' | 'implemented' | 'dismissed';
  createdAt: Date;
  updatedAt: Date;
}

@Injectable()
export class AISelfImprovementService {
  private readonly logger = new Logger(AISelfImprovementService.name);
  private suggestions: ImprovementSuggestion[] = [];

  constructor(
    @InjectRepository(AIImprovement) private aiImprovementRepository: Repository<AIImprovement>,
    private monitoringService: MonitoringService,
    private eventEmitter: EventEmitter2
  ) {}

  /**
   * 分析代码质量
   */
  async analyzeCodeQuality(): Promise<ImprovementSuggestion[]> {
    const suggestions: ImprovementSuggestion[] = [];
    
    // 模拟代码质量分析
    // 实际项目中可以使用ESLint、SonarQube等工具进行分析
    
    // 示例建议
    suggestions.push({
      id: `code-${Date.now()}`,
      type: 'code',
      title: '优化代码结构',
      description: '建议将重复的代码提取为公共函数，提高代码复用性和可维护性。',
      severity: 'medium',
      priority: 'medium',
      status: 'pending',
      createdAt: new Date(),
      updatedAt: new Date(),
    });

    suggestions.push({
      id: `code-${Date.now() + 1}`,
      type: 'code',
      title: '添加错误处理',
      description: '建议在关键操作中添加更详细的错误处理，提高系统的健壮性。',
      severity: 'high',
      priority: 'high',
      status: 'pending',
      createdAt: new Date(),
      updatedAt: new Date(),
    });

    return suggestions;
  }

  /**
   * 分析性能瓶颈
   */
  async analyzePerformance(): Promise<ImprovementSuggestion[]> {
    const suggestions: ImprovementSuggestion[] = [];
    const metrics = this.monitoringService.getMetrics();
    
    // 基于监控指标分析性能瓶颈
    if (metrics.memoryUsage && (metrics.memoryUsage as number) > 80) {
      suggestions.push({
        id: `perf-${Date.now()}`,
        type: 'performance',
        title: '内存使用过高',
        description: '内存使用率超过80%，建议优化内存使用，考虑增加服务器内存或优化代码。',
        severity: 'high',
        priority: 'high',
        status: 'pending',
        createdAt: new Date(),
        updatedAt: new Date(),
      });
    }

    if (metrics.cpuUsage && (metrics.cpuUsage as number) > 70) {
      suggestions.push({
        id: `perf-${Date.now() + 1}`,
        type: 'performance',
        title: 'CPU使用率过高',
        description: 'CPU使用率超过70%，建议优化计算密集型操作，考虑增加服务器CPU核心数。',
        severity: 'medium',
        priority: 'medium',
        status: 'pending',
        createdAt: new Date(),
        updatedAt: new Date(),
      });
    }

    return suggestions;
  }

  /**
   * 分析业务流程
   */
  async analyzeBusinessProcesses(): Promise<ImprovementSuggestion[]> {
    const suggestions: ImprovementSuggestion[] = [];
    
    // 模拟业务流程分析
    // 实际项目中可以基于业务数据和用户行为进行分析
    
    // 示例建议
    suggestions.push({
      id: `business-${Date.now()}`,
      type: 'business',
      title: '优化店铺绑定流程',
      description: '建议简化店铺绑定流程，减少用户输入步骤，提高绑定成功率。',
      severity: 'medium',
      priority: 'medium',
      status: 'pending',
      createdAt: new Date(),
      updatedAt: new Date(),
    });

    suggestions.push({
      id: `business-${Date.now() + 1}`,
      type: 'business',
      title: '增加商品同步频率',
      description: '建议增加商品同步频率，确保平台商品信息及时更新，提高数据准确性。',
      severity: 'low',
      priority: 'low',
      status: 'pending',
      createdAt: new Date(),
      updatedAt: new Date(),
    });

    return suggestions;
  }

  /**
   * 分析安全风险
   */
  async analyzeSecurity(): Promise<ImprovementSuggestion[]> {
    const suggestions: ImprovementSuggestion[] = [];
    
    // 模拟安全风险分析
    // 实际项目中可以使用安全扫描工具进行分析
    
    // 示例建议
    suggestions.push({
      id: `security-${Date.now()}`,
      type: 'security',
      title: '增强授权验证',
      description: '建议增强API的授权验证，添加更严格的权限检查，防止未授权访问。',
      severity: 'high',
      priority: 'high',
      status: 'pending',
      createdAt: new Date(),
      updatedAt: new Date(),
    });

    suggestions.push({
      id: `security-${Date.now() + 1}`,
      type: 'security',
      title: '加密敏感数据',
      description: '建议对存储的敏感数据进行加密，提高数据安全性。',
      severity: 'medium',
      priority: 'medium',
      status: 'pending',
      createdAt: new Date(),
      updatedAt: new Date(),
    });

    return suggestions;
  }

  /**
   * 生成改进建议
   */
  async generateImprovementSuggestions(): Promise<ImprovementSuggestion[]> {
    try {
      const codeSuggestions = await this.analyzeCodeQuality();
      const performanceSuggestions = await this.analyzePerformance();
      const businessSuggestions = await this.analyzeBusinessProcesses();
      const securitySuggestions = await this.analyzeSecurity();

      this.suggestions = [
        ...codeSuggestions,
        ...performanceSuggestions,
        ...businessSuggestions,
        ...securitySuggestions,
      ];

      // 保存建议到数据库
      for (const suggestion of this.suggestions) {
        const aiImprovement = this.aiImprovementRepository.create({
          type: suggestion.type,
          title: suggestion.title,
          description: suggestion.description,
          severity: suggestion.severity,
          priority: suggestion.priority,
          status: suggestion.status,
        });
        await this.aiImprovementRepository.save(aiImprovement);
      }

      this.logger.log(`生成了 ${this.suggestions.length} 条改进建议`);
      return this.suggestions;
    } catch (error) {
      this.logger.error('生成改进建议失败', error);
      return [];
    }
  }

  /**
   * 获取所有改进建议
   */
  async getImprovementSuggestions(): Promise<ImprovementSuggestion[]> {
    try {
      const improvements = await this.aiImprovementRepository.find();
      return improvements.map(improvement => ({
        id: improvement.id.toString(),
        type: improvement.type,
        title: improvement.title,
        description: improvement.description,
        severity: improvement.severity,
        priority: improvement.priority,
        status: improvement.status,
        createdAt: improvement.createdAt,
        updatedAt: improvement.updatedAt,
      }));
    } catch (error) {
      this.logger.error('获取改进建议失败', error);
      return [];
    }
  }

  /**
   * 更新建议状态
   */
  async updateSuggestionStatus(id: string, status: 'implemented' | 'dismissed'): Promise<boolean> {
    try {
      const improvement = await this.aiImprovementRepository.findOneBy({ id: parseInt(id) });
      if (!improvement) {
        return false;
      }

      improvement.status = status;
      improvement.updatedAt = new Date();
      await this.aiImprovementRepository.save(improvement);

      this.logger.log(`更新建议状态: ${id} -> ${status}`);
      return true;
    } catch (error) {
      this.logger.error('更新建议状态失败', error);
      return false;
    }
  }

  /**
   * 自动应用改进建议
   */
  async applyImprovementSuggestions(): Promise<{ applied: number; failed: number }> {
    let applied = 0;
    let failed = 0;

    try {
      const pendingSuggestions = await this.aiImprovementRepository.find({ where: { status: 'pending' } });

      for (const suggestion of pendingSuggestions) {
        try {
          // 模拟应用建议
          // 实际项目中可以根据建议类型执行相应的改进操作
          this.logger.log(`应用改进建议: ${suggestion.title}`);
          
          // 更新建议状态为已实现
          suggestion.status = 'implemented';
          suggestion.updatedAt = new Date();
          await this.aiImprovementRepository.save(suggestion);
          
          applied++;
        } catch (error) {
          this.logger.error(`应用改进建议失败: ${suggestion.title}`, error);
          failed++;
        }
      }

      return { applied, failed };
    } catch (error) {
      this.logger.error('自动应用改进建议失败', error);
      return { applied: 0, failed: 0 };
    }
  }

  /**
   * 执行定期优化
   */
  async performRegularOptimization(): Promise<void> {
    try {
      this.logger.log('开始执行定期优化');
      
      // 生成改进建议
      await this.generateImprovementSuggestions();
      
      // 自动应用改进建议
      const result = await this.applyImprovementSuggestions();
      
      this.logger.log(`定期优化完成: 应用了 ${result.applied} 条建议，失败 ${result.failed} 条`);
    } catch (error) {
      this.logger.error('执行定期优化失败', error);
    }
  }
}
