package main

import (
	"fmt"
	"io"
	"net"
	"os"
)

// 客户端接收文件的示例函数
func ReceiveFile(conn net.Conn, filename string, filesize int64) error {
	file, err := os.Create(filename)
	if err != nil {
		return err
	}
	defer file.Close()

	var received int64 = 0
	buf := make([]byte, 4096)
	for received < filesize {
		n, err := conn.Read(buf)
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}
		file.Write(buf[:n])
		received += int64(n)
	}
	fmt.Printf("文件 %s 接收完成，共 %d 字节\n", filename, received)
	return nil
}

// 客户端发送文件的示例函数
func SendFile(conn net.Conn, filepath string) error {
	file, err := os.Open(filepath)
	if err != nil {
		return err
	}
	defer file.Close()

	buf := make([]byte, 4096)
	for {
		n, err := file.Read(buf)
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}
		_, err = conn.Write(buf[:n])
		if err != nil {
			return err
		}
	}
	fmt.Printf("文件 %s 发送完成\n", filepath)
	return nil
}