import db from '../config/database';
import { logger } from '../utils/logger';
import { DecisionExplainabilityEngine } from '../core/ai/DecisionExplainabilityEngine';

export interface PackageItem {
  skuId: string;
  weight: number;
  dimensions: { l: number; w: number; h: number };
}

/**
 * [BIZ_OPS_146] 智能包裹拆分/合包优化建议 (Bundle)
 * @description 核心逻辑：基于首重与续重运费模板，自动识别多个订单合包或单个大订单拆分的成本优势，降低单均运费。
 */
export class PackingOptimizer {
  /**
   * 优化包裹方案 (BIZ_OPS_146)
   */
  static async optimizePacking(tenantId: string, orderIds: string[]): Promise<any> {
    logger.info(`[PackingOptimizer] Analyzing bundling options for ${orderIds.length} orders, Tenant: ${tenantId}`);

    try {
      // 1. 获取订单商品详情 (模拟)
      const items: PackageItem[] = [
        { skuId: 'SKU_A', weight: 0.4, dimensions: { l: 10, w: 10, h: 5 } },
        { skuId: 'SKU_B', weight: 0.3, dimensions: { l: 8, w: 8, h: 4 } }
      ];

      // 2. 运费计算对比 (模拟逻辑)
      // 假设：单包运费 15，合包运费 22
      const separateCost = 15 * 2;
      const bundledCost = 22;
      const savings = separateCost - bundledCost;

      if (savings > 0) {
        const advice = `Bundling Opportunity: Combining these ${orderIds.length} orders into a single package saves ${savings.toFixed(2)} in freight costs. ` +
          `Estimated total weight: 0.7kg.`;

        // 3. [UX_XAI_01] 记录决策证据链
        await DecisionExplainabilityEngine.logDecision({
          tenantId,
          module: 'LOGISTICS_COST_OPTIMIZATION',
          resourceId: orderIds.join(','),
          decisionType: 'BUNDLE_OPTIMIZATION_SUGGESTION',
          causalChain: advice,
          factors: [
            { name: 'PotentialSavings', value: savings, weight: 0.8, impact: 'POSITIVE' },
            { name: 'TotalWeight', value: 0.7, weight: 0.2, impact: 'NEUTRAL' }
          ],
          traceId: 'packing-opt-' + Date.now()
        });

        return { success: true, savings, advice, status: 'PENDING_REVIEW' };
      }

      return { success: true, message: 'Current separate shipping is optimal' };
    } catch (err: any) {
      logger.error(`[PackingOptimizer][WARN] Optimization failed: ${err.message}`);
      return { success: false, error: err.message };
    }
  }
}