import { logger } from '../utils/logger';
import { FeatureGovernanceService } from '../core/governance/FeatureGovernanceService';
import { AIService } from './AIService';

interface RecommendationInput {
  tenantId: string;
  shopId?: string;
  taskId?: string;
  traceId: string;
  businessType: 'TOC' | 'TOB';
  recommendationType: 'PRODUCT' | 'PROMOTION' | 'SUPPLIER' | 'LOGISTICS' | 'PRICING';
  context: Record<string, any>;
  userId?: string;
  productId?: string;
  categoryId?: string;
}

interface RecommendationItem {
  id: string;
  name: string;
  score: number;
  relevance: number;
  confidence: number;
  attributes: Record<string, any>;
}

interface RecommendationOutput {
  recommendations: RecommendationItem[];
  totalCount: number;
  confidence: number;
  reasoning: string;
  executionPath: 'AUTO' | 'REVIEW' | 'MANUAL';
}

export class IntelligentRecommendation {
  /**
   * 获取智能推荐
   */
  static async getRecommendations(input: RecommendationInput): Promise<RecommendationOutput> {
    logger.info(`[IntelligentRecommendation] Getting recommendations - type: ${input.recommendationType}, tenantId: ${input.tenantId}`);

    try {
      // 检查功能开关
      if (!(await FeatureGovernanceService.isEnabled('INTELLIGENT_RECOMMENDATION', input.tenantId))) {
        return this.getDefaultRecommendations(input);
      }

      // 根据推荐类型执行不同的推荐逻辑
      switch (input.recommendationType) {
        case 'PRODUCT':
          return this.getProductRecommendations(input);
        case 'PROMOTION':
          return this.getPromotionRecommendations(input);
        case 'SUPPLIER':
          return this.getSupplierRecommendations(input);
        case 'LOGISTICS':
          return this.getLogisticsRecommendations(input);
        case 'PRICING':
          return this.getPricingRecommendations(input);
        default:
          return this.getDefaultRecommendations(input);
      }
    } catch (error: any) {
      logger.error(`[IntelligentRecommendation] Recommendation failed: ${error.message}`);
      return this.getDefaultRecommendations(input);
    }
  }

  /**
   * 获取产品推荐
   */
  private static async getProductRecommendations(input: RecommendationInput): Promise<RecommendationOutput> {
    const { context, userId, productId, categoryId } = input;

    // 模拟产品推荐数据
    const mockProducts = [
      {
        id: '1',
        name: 'Smart Watch Pro',
        score: 0.95,
        relevance: 0.9,
        confidence: 0.85,
        attributes: {
          category: 'Electronics',
          price: 299.99,
          rating: 4.8,
          sales: 1200
        }
      },
      {
        id: '2',
        name: 'Wireless Earbuds',
        score: 0.88,
        relevance: 0.85,
        confidence: 0.8,
        attributes: {
          category: 'Electronics',
          price: 149.99,
          rating: 4.6,
          sales: 2500
        }
      },
      {
        id: '3',
        name: 'Fitness Tracker',
        score: 0.82,
        relevance: 0.8,
        confidence: 0.75,
        attributes: {
          category: 'Fitness',
          price: 89.99,
          rating: 4.5,
          sales: 1800
        }
      }
    ];

    // 过滤和排序推荐
    let recommendations = mockProducts;
    
    // 如果提供了产品ID，推荐相关产品
    if (productId) {
      recommendations = recommendations.filter(p => p.id !== productId);
    }

    // 如果提供了分类ID，推荐同分类产品
    if (categoryId) {
      recommendations = recommendations.filter(p => p.attributes.category === categoryId);
    }

    // 排序推荐
    recommendations.sort((a, b) => b.score - a.score);

    return {
      recommendations: recommendations.slice(0, 5),
      totalCount: recommendations.length,
      confidence: 0.85,
      reasoning: 'Recommended products based on relevance, popularity, and rating.',
      executionPath: 'AUTO'
    };
  }

  /**
   * 获取促销推荐
   */
  private static async getPromotionRecommendations(input: RecommendationInput): Promise<RecommendationOutput> {
    const { context, userId } = input;

    // 模拟促销推荐数据
    const mockPromotions = [
      {
        id: '1',
        name: 'Black Friday Sale',
        score: 0.92,
        relevance: 0.9,
        confidence: 0.88,
        attributes: {
          type: 'Discount',
          discount: 0.2,
          startDate: new Date(),
          endDate: new Date(Date.now() + 7 * 24 * 60 * 60 * 1000)
        }
      },
      {
        id: '2',
        name: 'Flash Sale',
        score: 0.85,
        relevance: 0.85,
        confidence: 0.82,
        attributes: {
          type: 'Time-limited',
          discount: 0.3,
          startDate: new Date(),
          endDate: new Date(Date.now() + 24 * 60 * 60 * 1000)
        }
      },
      {
        id: '3',
        name: 'Buy One Get One Free',
        score: 0.78,
        relevance: 0.8,
        confidence: 0.75,
        attributes: {
          type: 'Bundle',
          discount: 0.5,
          startDate: new Date(),
          endDate: new Date(Date.now() + 3 * 24 * 60 * 60 * 1000)
        }
      }
    ];

    // 排序推荐
    const recommendations = mockPromotions.sort((a, b) => b.score - a.score);

    return {
      recommendations: recommendations.slice(0, 3),
      totalCount: recommendations.length,
      confidence: 0.82,
      reasoning: 'Recommended promotions based on timing, discount level, and relevance.',
      executionPath: 'REVIEW'
    };
  }

  /**
   * 获取供应商推荐
   */
  private static async getSupplierRecommendations(input: RecommendationInput): Promise<RecommendationOutput> {
    const { context, productId } = input;

    // 模拟供应商推荐数据
    const mockSuppliers = [
      {
        id: '1',
        name: 'Global Electronics Inc.',
        score: 0.94,
        relevance: 0.92,
        confidence: 0.88,
        attributes: {
          category: 'Electronics',
          reliability: 0.95,
          price: 0.8,
          deliveryTime: 3
        }
      },
      {
        id: '2',
        name: 'Fast Delivery Co.',
        score: 0.87,
        relevance: 0.85,
        confidence: 0.83,
        attributes: {
          category: 'General',
          reliability: 0.9,
          price: 0.75,
          deliveryTime: 2
        }
      },
      {
        id: '3',
        name: 'Quality Products Ltd.',
        score: 0.82,
        relevance: 0.8,
        confidence: 0.78,
        attributes: {
          category: 'Electronics',
          reliability: 0.92,
          price: 0.85,
          deliveryTime: 4
        }
      }
    ];

    // 排序推荐
    const recommendations = mockSuppliers.sort((a, b) => b.score - a.score);

    return {
      recommendations: recommendations.slice(0, 3),
      totalCount: recommendations.length,
      confidence: 0.85,
      reasoning: 'Recommended suppliers based on reliability, price, and delivery time.',
      executionPath: 'REVIEW'
    };
  }

  /**
   * 获取物流推荐
   */
  private static async getLogisticsRecommendations(input: RecommendationInput): Promise<RecommendationOutput> {
    const { context } = input;

    // 模拟物流推荐数据
    const mockLogistics = [
      {
        id: '1',
        name: 'Express Delivery',
        score: 0.93,
        relevance: 0.9,
        confidence: 0.88,
        attributes: {
          type: 'Express',
          cost: 25,
          deliveryTime: 2,
          reliability: 0.95
        }
      },
      {
        id: '2',
        name: 'Standard Shipping',
        score: 0.85,
        relevance: 0.85,
        confidence: 0.82,
        attributes: {
          type: 'Standard',
          cost: 15,
          deliveryTime: 5,
          reliability: 0.9
        }
      },
      {
        id: '3',
        name: 'Economy Shipping',
        score: 0.78,
        relevance: 0.8,
        confidence: 0.75,
        attributes: {
          type: 'Economy',
          cost: 10,
          deliveryTime: 7,
          reliability: 0.85
        }
      }
    ];

    // 排序推荐
    const recommendations = mockLogistics.sort((a, b) => b.score - a.score);

    return {
      recommendations: recommendations.slice(0, 3),
      totalCount: recommendations.length,
      confidence: 0.83,
      reasoning: 'Recommended logistics options based on cost, delivery time, and reliability.',
      executionPath: 'AUTO'
    };
  }

  /**
   * 获取定价推荐
   */
  private static async getPricingRecommendations(input: RecommendationInput): Promise<RecommendationOutput> {
    const { context, productId } = input;

    // 模拟定价推荐数据
    const mockPricing = [
      {
        id: '1',
        name: 'Premium Pricing',
        score: 0.88,
        relevance: 0.9,
        confidence: 0.85,
        attributes: {
          price: 399.99,
          margin: 0.4,
          competitiveness: 0.7,
          salesProjection: 50
        }
      },
      {
        id: '2',
        name: 'Competitive Pricing',
        score: 0.92,
        relevance: 0.92,
        confidence: 0.88,
        attributes: {
          price: 349.99,
          margin: 0.3,
          competitiveness: 0.85,
          salesProjection: 80
        }
      },
      {
        id: '3',
        name: 'Value Pricing',
        score: 0.85,
        relevance: 0.85,
        confidence: 0.82,
        attributes: {
          price: 299.99,
          margin: 0.2,
          competitiveness: 0.95,
          salesProjection: 120
        }
      }
    ];

    // 排序推荐
    const recommendations = mockPricing.sort((a, b) => b.score - a.score);

    return {
      recommendations: recommendations.slice(0, 3),
      totalCount: recommendations.length,
      confidence: 0.85,
      reasoning: 'Recommended pricing strategies based on margin, competitiveness, and sales projection.',
      executionPath: 'REVIEW'
    };
  }

  /**
   * 获取默认推荐
   */
  private static getDefaultRecommendations(input: RecommendationInput): RecommendationOutput {
    return {
      recommendations: [],
      totalCount: 0,
      confidence: 0.5,
      reasoning: 'Using default recommendations due to feature disabled or error',
      executionPath: 'MANUAL'
    };
  }

  /**
   * 评估推荐效果
   */
  static async evaluateRecommendations(recommendationId: string, feedback: {
    clicked: boolean;
    purchased: boolean;
    rating?: number;
  }): Promise<{
    effectiveness: number;
    improvement: number;
    insights: string[];
  }> {
    logger.info(`[IntelligentRecommendation] Evaluating recommendations: ${recommendationId}`);

    try {
      // 计算推荐效果
      let effectiveness = 0;
      if (feedback.purchased) {
        effectiveness = 1.0;
      } else if (feedback.clicked) {
        effectiveness = 0.5;
      } else if (feedback.rating) {
        effectiveness = feedback.rating / 5;
      }

      return {
        effectiveness,
        improvement: 0.1,
        insights: [
          'Improve relevance scoring for product recommendations',
          'Enhance personalization based on user behavior',
          'Optimize recommendation timing and frequency'
        ]
      };
    } catch (error: any) {
      logger.error(`[IntelligentRecommendation] Evaluation failed: ${error.message}`);
      return {
        effectiveness: 0.5,
        improvement: 0,
        insights: []
      };
    }
  }
}
