go-common/examples/excel_example.go

package main

import (
	"fmt"
	"log"
	"net/http"
	"time"

	"git.toowon.com/jimmy/go-common/excel"
	"git.toowon.com/jimmy/go-common/factory"
	"git.toowon.com/jimmy/go-common/tools"
)

// User 用户结构体示例
type User struct {
	ID        int       `json:"id"`
	Name      string    `json:"name"`
	Email     string    `json:"email"`
	CreatedAt time.Time `json:"created_at"`
	Status    int       `json:"status"`
}

func main() {
	// 创建工厂（可选，Excel导出不需要配置）
	fac, err := factory.NewFactoryFromFile("./config/example.json")
	if err != nil {
		// Excel导出不需要配置，可以传nil
		fac = factory.NewFactory(nil)
	}

	// 示例1：导出结构体切片到文件
	fmt.Println("=== Example 1: Export Struct Slice to File ===")
	example1(fac)

	// 示例2：导出到HTTP响应
	fmt.Println("\n=== Example 2: Export to HTTP Response ===")
	example2(fac)

	// 示例3：使用格式化函数
	fmt.Println("\n=== Example 3: Export with Format Functions ===")
	example3(fac)

	// 示例4：使用ExportData接口
	fmt.Println("\n=== Example 4: Export with ExportData Interface ===")
	example4(fac)
}

// 示例1：导出结构体切片到文件
func example1(fac *factory.Factory) {
	users := []User{
		{ID: 1, Name: "Alice", Email: "alice@example.com", CreatedAt: time.Now(), Status: 1},
		{ID: 2, Name: "Bob", Email: "bob@example.com", CreatedAt: time.Now().Add(-24 * time.Hour), Status: 1},
		{ID: 3, Name: "Charlie", Email: "charlie@example.com", CreatedAt: time.Now().Add(-48 * time.Hour), Status: 0},
	}

	columns := []factory.ExportColumn{
		{Header: "ID", Field: "ID", Width: 10},
		{Header: "姓名", Field: "Name", Width: 20},
		{Header: "邮箱", Field: "Email", Width: 30},
		{Header: "创建时间", Field: "CreatedAt", Width: 20},
		{Header: "状态", Field: "Status", Width: 10},
	}

	err := fac.ExportToExcelFile("users.xlsx", "用户列表", columns, users)
	if err != nil {
		log.Printf("Failed to export to file: %v", err)
	} else {
		fmt.Println("Excel file exported successfully: users.xlsx")
	}
}

// 示例2：导出到HTTP响应
func example2(fac *factory.Factory) {
	// 模拟HTTP响应
	w := &mockResponseWriter{}

	users := []User{
		{ID: 1, Name: "Alice", Email: "alice@example.com", CreatedAt: time.Now(), Status: 1},
		{ID: 2, Name: "Bob", Email: "bob@example.com", CreatedAt: time.Now(), Status: 1},
	}

	columns := []factory.ExportColumn{
		{Header: "ID", Field: "ID"},
		{Header: "姓名", Field: "Name"},
		{Header: "邮箱", Field: "Email"},
	}

	// 设置HTTP响应头
	w.Header().Set("Content-Type", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
	w.Header().Set("Content-Disposition", "attachment; filename=users.xlsx")

	err := fac.ExportToExcel(w, "用户列表", columns, users)
	if err != nil {
		log.Printf("Failed to export to HTTP response: %v", err)
	} else {
		fmt.Printf("Excel exported to HTTP response successfully, size: %d bytes\n", len(w.data))
	}
}

// 示例3：使用格式化函数
func example3(fac *factory.Factory) {
	users := []User{
		{ID: 1, Name: "Alice", Email: "alice@example.com", CreatedAt: time.Now(), Status: 1},
		{ID: 2, Name: "Bob", Email: "bob@example.com", CreatedAt: time.Now().Add(-24 * time.Hour), Status: 0},
	}

	columns := []factory.ExportColumn{
		{Header: "ID", Field: "ID", Width: 10},
		{Header: "姓名", Field: "Name", Width: 20},
		{Header: "邮箱", Field: "Email", Width: 30},
		{
			Header: "创建时间",
			Field:  "CreatedAt",
			Width:  20,
			Format: excel.AdaptTimeFormatter(tools.FormatDateTime), // 使用适配器直接调用tools函数
		},
		{
			Header: "状态",
			Field:  "Status",
			Width:  10,
			Format: func(value interface{}) string {
				// 自定义格式化函数
				if status, ok := value.(int); ok {
					if status == 1 {
						return "启用"
					}
					return "禁用"
				}
				return ""
			},
		},
	}

	err := fac.ExportToExcelFile("users_formatted.xlsx", "用户列表", columns, users)
	if err != nil {
		log.Printf("Failed to export with format: %v", err)
	} else {
		fmt.Println("Excel file exported with format successfully: users_formatted.xlsx")
	}
}

// 示例4：使用ExportData接口
func example4(fac *factory.Factory) {
	// 创建实现了ExportData接口的数据对象
	exportData := &UserExportData{
		users: []User{
			{ID: 1, Name: "Alice", Email: "alice@example.com", CreatedAt: time.Now(), Status: 1},
			{ID: 2, Name: "Bob", Email: "bob@example.com", CreatedAt: time.Now(), Status: 1},
		},
	}

	// 使用接口方法获取列定义和数据
	columns := exportData.GetExportColumns()

	err := fac.ExportToExcelFile("users_interface.xlsx", "用户列表", columns, exportData)
	if err != nil {
		log.Printf("Failed to export with interface: %v", err)
	} else {
		fmt.Println("Excel file exported with interface successfully: users_interface.xlsx")
	}
}

// UserExportData 实现了ExportData接口的用户导出数据
type UserExportData struct {
	users []User
}

// GetExportColumns 获取导出列定义
func (d *UserExportData) GetExportColumns() []excel.ExportColumn {
	return []excel.ExportColumn{
		{Header: "ID", Field: "ID", Width: 10},
		{Header: "姓名", Field: "Name", Width: 20},
		{Header: "邮箱", Field: "Email", Width: 30},
		{
			Header: "创建时间",
			Field:  "CreatedAt",
			Width:  20,
			Format: excel.AdaptTimeFormatter(tools.FormatDateTime),
		},
		{
			Header: "状态",
			Field:  "Status",
			Width:  10,
			Format: func(value interface{}) string {
				if status, ok := value.(int); ok {
					if status == 1 {
						return "启用"
					}
					return "禁用"
				}
				return ""
			},
		},
	}
}

// GetExportRows 获取导出数据行
func (d *UserExportData) GetExportRows() [][]interface{} {
	rows := make([][]interface{}, 0, len(d.users))
	for _, user := range d.users {
		row := []interface{}{
			user.ID,
			user.Name,
			user.Email,
			user.CreatedAt,
			user.Status,
		}
		rows = append(rows, row)
	}
	return rows
}

// mockResponseWriter 模拟HTTP响应写入器（用于示例）
type mockResponseWriter struct {
	header http.Header
	data   []byte
}

func (w *mockResponseWriter) Header() http.Header {
	if w.header == nil {
		w.header = make(http.Header)
	}
	return w.header
}

func (w *mockResponseWriter) Write(data []byte) (int, error) {
	w.data = append(w.data, data...)
	return len(data), nil
}

func (w *mockResponseWriter) WriteHeader(statusCode int) {
	// 模拟实现
}