import db from '../config/database';
import { logger } from '../utils/logger';
import { FXHedgingService } from './FXHedgingService';
import { TaxService } from './TaxService';

export interface OrderRecord {
  id: string;
  tenantId: string;
  shopId?: string;
  taskId?: string;
  traceId: string;
  platform: string;
  productId: string;
  sellingPrice: number;
  purchasePrice: number;
  countryCode: string;
  logisticsCost: number;
  adBudget: number;
  status: string;
}

/**
 * [BIZ_FIN_01] 财务结算与对账服务
 * @description 处理订单回流、利差核算与账单生成
 */
export class FinanceService {
  private static readonly TABLE_NAME = 'cf_orders';
  private static readonly TRANSACTION_TABLE = 'cf_transactions';

  /**
   * 初始化数据库表
   */
  static async initTable() {
    const hasOrderTable = await db.schema.hasTable(this.TABLE_NAME);
    if (!hasOrderTable) {
      console.log(`📦 Creating ${this.TABLE_NAME} table...`);
      await db.schema.createTable(this.TABLE_NAME, (table) => {
        table.string('id', 64).primary();
        table.string('tenant_id', 64).index();
        table.string('platform', 32);
        table.string('product_id', 64);
        table.decimal('selling_price', 10, 2);
        table.decimal('purchase_price', 10, 2);
        table.string('country_code', 8);
        table.decimal('logistics_cost', 10, 2);
        table.decimal('ad_budget', 10, 2);
        table.string('status', 32);
        table.timestamps(true, true);
      });
    }

    const hasTransactionTable = await db.schema.hasTable(this.TRANSACTION_TABLE);
    if (!hasTransactionTable) {
      console.log(`📦 Creating ${this.TRANSACTION_TABLE} table...`);
      await db.schema.createTable(this.TRANSACTION_TABLE, (table) => {
        table.increments('id').primary();
        table.string('tenant_id', 64).index();
        table.string('order_id', 64).nullable();
        table.decimal('amount', 10, 2);
        table.string('currency', 8).defaultTo('USD');
        table.string('transaction_type', 32);
        table.string('trace_id', 64);
        table.json('metadata').nullable();
        table.timestamp('created_at').defaultTo(db.fn.now());
      });
    }
  }

  /**
   * 记录订单
   */
  static async recordOrder(order: OrderRecord): Promise<void> {
    const { tenantId, shopId, taskId, traceId } = order;

    // 1. 插入订单主表
    await db(this.TABLE_NAME).insert({
      id: order.id,
      tenant_id: order.tenantId,
      platform: order.platform,
      product_id: order.productId,
      selling_price: order.sellingPrice,
      purchase_price: order.purchasePrice,
      country_code: order.countryCode,
      logistics_cost: order.logisticsCost,
      ad_budget: order.adBudget,
      status: order.status,
      created_at: new Date(),
      updated_at: new Date()
    });

    // 2. 实时税务计提 (BIZ_FIN_02)
    const taxInfo = TaxService.calculateTax({
      countryCode: order.countryCode,
      baseAmount: order.sellingPrice,
      currency: 'USD'
    });

    await this.accrueTax(order.id, {
      tenantId,
      amount: taxInfo.totalTax,
      currency: 'USD',
      type: taxInfo.isIOSS ? 'IOSS_VAT' : 'STANDARD_VAT',
      traceId
    });

    // 3. 汇率自动对冲 (BIZ_FIN_03)
    await FXHedgingService.autoHedge({
      tenantId,
      pair: 'USD/CNY',
      amount: order.sellingPrice,
      traceId
    });
  }

  /**
   * [BIZ_FIN_04] 记录财务交易流水
   */
  static async recordTransaction(params: {
    tenantId: string;
    amount: number;
    currency?: string;
    type: 'ORDER_REVENUE' | 'LOGISTICS_COST' | 'PLATFORM_FEE' | 'REFUND' | 'COMMISSION' | 'INCOME';
    category?: string;
    orderId?: string;
    traceId?: string;
    metadata?: any;
  }) {
    logger.info(`[Finance] Recording transaction: ${params.type} for Order ${params.orderId || 'N/A'} (${params.amount} ${params.currency || 'USD'})`);
    
    // 实际业务中需插入 cf_transactions 表
    await db('cf_transactions').insert({
      tenant_id: params.tenantId,
      order_id: params.orderId || null,
      amount: params.amount,
      currency: params.currency || 'USD',
      transaction_type: params.type,
      trace_id: params.traceId || 'system',
      metadata: params.metadata ? JSON.stringify(params.metadata) : null,
      created_at: new Date()
    });
  }

  /**
   * [BIZ_FIN_02] 实时税务计提记录
   * @description 将税务计提记录到 cf_tax_accruals 表，用于后期对账与报关
   */
  private static async accrueTax(orderId: string, params: {
    tenantId: string;
    amount: number;
    currency: string;
    type: string;
    traceId: string;
  }): Promise<void> {
    logger.info(`[Finance] Accruing tax for order ${orderId}: ${params.amount} ${params.currency} (${params.type})`);
    
    // 实际业务中需插入 cf_tax_accruals
    await db('cf_tax_accruals').insert({
      order_id: orderId,
      tenant_id: params.tenantId,
      amount: params.amount,
      currency: params.currency,
      tax_type: params.type,
      status: 'ACCRUED',
      trace_id: params.traceId,
      created_at: new Date(),
      updated_at: new Date()
    });
  }

  /**
   * [BIZ_FIN_06] 全自动化财务利润对账
   * @description 自动勾稽订单、采购成本、物流费与税金，生成最终利润报表
   */
  static async performAutoProfitRecon(tenantId: string, shopId: string): Promise<any> {
    logger.info(`[Finance] Performing auto profit reconciliation for Tenant: ${tenantId}, Shop: ${shopId}`);

    // 1. 获取所有已完成且未对账的订单
    const orders = await db('cf_orders')
      .where({ tenant_id: tenantId, shop_id: shopId, status: 'PUBLISHED' }) // 假设 PUBLISHED 状态代表已成单
      .whereNull('reconciled_at');

    const results = [];

    for (const order of orders) {
      try {
        // 2. 聚合各项成本
        const taxAccrual = await db('cf_tax_accruals').where({ order_id: order.id }).first();
        const purchaseOrder = await db('cf_purchase_orders').where({ product_id: order.product_id, tenant_id: tenantId }).first();
        const logisticsRoute = await db('cf_logistics_routes').where({ tenant_id: tenantId }).first(); // 简化取第一个

        const purchaseCost = purchaseOrder ? purchaseOrder.total_amount / purchaseOrder.quantity : 0;
        const taxAmount = taxAccrual ? taxAccrual.amount : 0;
        const logisticsCost = logisticsRoute ? logisticsRoute.cost_per_kg * 0.5 : 5; // 假设 0.5kg

        const netProfit = order.selling_price - purchaseCost - logisticsCost - taxAmount;

        // 3. 记录对账结果
        await db('cf_orders').where({ id: order.id }).update({
          net_profit: netProfit,
          reconciled_at: new Date(),
          updated_at: new Date()
        });

        results.push({ orderId: order.id, netProfit });
      } catch (err: any) {
        logger.error(`[Finance] Recon failed for Order ${order.id}: ${err.message}`);
      }
    }

    return { totalReconciled: results.length, details: results };
  }

  /**
   * 获取账单回放
   */
  static async getBillPlayback(tenantId: string, shopId: string, orderId: string): Promise<any> {
    const order = await db(this.TABLE_NAME)
      .where({ id: orderId, tenant_id: tenantId })
      .first();

    if (!order) return null;

    return {
      orderId: order.id,
      timeline: [
        { event: 'ORDER_CREATED', time: order.created_at, amount: order.selling_price },
        { event: 'PURCHASE_COMPLETED', time: order.updated_at, amount: -order.purchase_price },
        { event: 'LOGISTICS_DEDUCTED', time: order.updated_at, amount: -order.logistics_cost }
      ],
      finalProfit: order.selling_price - order.purchase_price - order.logistics_cost
    };
  }
}