feat: implement order export to Excel with excelize library

backend/internal/api/handlers/order.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"fmt"
 	"math"
 	"net/http"
 	"strconv"
@@ -11,6 +12,7 @@ import (
 	"sale/internal/utils"
 
 	"github.com/gin-gonic/gin"
+	"github.com/xuri/excelize/v2"
 )
 
 type CartHandler struct{}
@@ -663,7 +665,99 @@ func (h *OrderHandler) Export(c *gin.Context) {
 	utils.DB.Preload("OrderItems.Product").Preload("ShippingAddress").Preload("User").
 		Order("created_at DESC").Find(&orders)
 
-	c.JSON(http.StatusOK, gin.H{"data": orders})
+	// 创建 Excel 文件
+	f := excelize.NewFile()
+	defer f.Close()
+
+	sheetName := "订单列表"
+	f.SetSheetName("Sheet1", sheetName)
+
+	// 设置表头
+	headers := []string{"订单ID", "用户名", "订单状态", "商品信息", "商品金额", "运费", "服务费", "通道费", "包装费", "国际计算手续费", "订单总额", "收货人", "联系电话", "收货地址", "快递单号", "创建时间"}
+	for i, header := range headers {
+		cell, _ := excelize.CoordinatesToCellName(i+1, 1)
+		f.SetCellValue(sheetName, cell, header)
+	}
+
+	// 设置表头样式
+	headerStyle, _ := f.NewStyle(&excelize.Style{
+		Font:      &excelize.Font{Bold: true},
+		Fill:      excelize.Fill{Type: "pattern", Color: []string{"#4472C4"}, Pattern: 1},
+		Alignment: &excelize.Alignment{Horizontal: "center", Vertical: "center"},
+	})
+	f.SetRowStyle(sheetName, 1, 1, headerStyle)
+
+	// 状态映射
+	statusMap := map[string]string{
+		"pending_payment": "待支付", "pending_confirm": "待确认", "pending_ship": "待发货",
+		"shipped": "已发货", "completed": "已完成", "refunding": "退款中", "refunded": "已退款", "cancelled": "已取消",
+	}
+
+	// 填充数据
+	for i, order := range orders {
+		row := i + 2
+
+		// 商品信息
+		var productsStr string
+		for _, item := range order.OrderItems {
+			if productsStr != "" {
+				productsStr += "; "
+			}
+			productsStr += fmt.Sprintf("%s x%d", item.Product.Name, item.Quantity)
+		}
+
+		// 收货地址
+		var addressStr string
+		if order.ShippingAddress != nil {
+			addressStr = order.ShippingAddress.Province + order.ShippingAddress.City + order.ShippingAddress.District + order.ShippingAddress.Address
+		}
+
+		// 填充单元格
+		f.SetCellValue(sheetName, fmt.Sprintf("A%d", row), order.ID)
+		f.SetCellValue(sheetName, fmt.Sprintf("B%d", row), order.User.Username)
+		f.SetCellValue(sheetName, fmt.Sprintf("C%d", row), statusMap[order.Status])
+		f.SetCellValue(sheetName, fmt.Sprintf("D%d", row), productsStr)
+		f.SetCellValue(sheetName, fmt.Sprintf("E%d", row), order.Subtotal)
+		f.SetCellValue(sheetName, fmt.Sprintf("F%d", row), order.ShippingFee)
+		f.SetCellValue(sheetName, fmt.Sprintf("G%d", row), order.ServiceFee)
+		f.SetCellValue(sheetName, fmt.Sprintf("H%d", row), order.ChannelFee)
+		f.SetCellValue(sheetName, fmt.Sprintf("I%d", row), order.PackagingFee)
+		f.SetCellValue(sheetName, fmt.Sprintf("J%d", row), order.InternationalFee)
+		f.SetCellValue(sheetName, fmt.Sprintf("K%d", row), order.TotalAmount)
+		if order.ShippingAddress != nil {
+			f.SetCellValue(sheetName, fmt.Sprintf("L%d", row), order.ShippingAddress.Name)
+			f.SetCellValue(sheetName, fmt.Sprintf("M%d", row), order.ShippingAddress.Phone)
+			f.SetCellValue(sheetName, fmt.Sprintf("N%d", row), addressStr)
+		}
+		f.SetCellValue(sheetName, fmt.Sprintf("O%d", row), order.TrackingNumber)
+		f.SetCellValue(sheetName, fmt.Sprintf("P%d", row), order.CreatedAt.Format("2006-01-02 15:04:05"))
+	}
+
+	// 设置列宽
+	f.SetColWidth(sheetName, "A", "A", 10)
+	f.SetColWidth(sheetName, "B", "B", 15)
+	f.SetColWidth(sheetName, "C", "C", 10)
+	f.SetColWidth(sheetName, "D", "D", 40)
+	f.SetColWidth(sheetName, "E", "K", 12)
+	f.SetColWidth(sheetName, "L", "M", 15)
+	f.SetColWidth(sheetName, "N", "N", 40)
+	f.SetColWidth(sheetName, "O", "O", 20)
+	f.SetColWidth(sheetName, "P", "P", 20)
+
+	// 设置响应头
+	filename := fmt.Sprintf("orders_%s.xlsx", time.Now().Format("20060102150405"))
+	c.Header("Content-Type", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
+	c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=%s", filename))
+	c.Header("Content-Transfer-Encoding", "binary")
+
+	// 写入响应
+	buf, err := f.WriteToBuffer()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to generate Excel file"})
+		return
+	}
+
+	c.Data(http.StatusOK, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", buf.Bytes())
 }
 
 func (h *OrderHandler) CancelOrder(c *gin.Context) {