package main

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

type Client struct {
	ServerIp   string
	ServerPort int
	Name       string
	conn       net.Conn
	flag       int // 当前client模式
}

func NewClient(serverIp string, serverPort int) *Client {
	// 创建客户端对象
	client := &Client{
		ServerIp:   serverIp,
		ServerPort: serverPort,
		flag:       999,
	}
	// 连接server
	conn, err := net.Dial("tcp", fmt.Sprintf("%s:%d", serverIp, serverPort))
	if err != nil {
		fmt.Println("net.Dial error: ", err)
		return nil
	}
	client.conn = conn

	// 返回对象
	return client
}

// 处理server回应的消息,直接显示到标准输出
func (client *Client) DealResponse() {
	// 一旦client.conn 有数据,就直接copy到标准输出上
	io.Copy(os.Stdout, client.conn)
}

func (client *Client) menu() bool {
	var flag int
	fmt.Println("1. 公聊模式")
	fmt.Println("2. 私聊模式")
	fmt.Println("3. 更新用户名")
	fmt.Println("0. 退出")

	fmt.Scanln(&flag)
	if flag >= 0 && flag <= 3 {
		client.flag = flag
		return true
	} else {
		fmt.Println(">>>>>请输入合法的数字<<<<<")
		return false
	}
}

func (client *Client) PublicChat() {
	// 提示用户输入消息
	var chatMsg string
	fmt.Println(">>>>>请输入聊天内容,exit退出")
	fmt.Scanln(&chatMsg)

	for chatMsg != "exit" {
		// 发给服务器

		// 消息不为空则发送
		if len(chatMsg) != 0 {
			sendMsg := chatMsg + "\n"
			_, err := client.conn.Write([]byte(sendMsg))
			if err != nil {
				fmt.Println("conn Write err:", err)
				break
			}
		}

		chatMsg = ""
		fmt.Println(">>>>>请输入聊天内容,exit退出")
		fmt.Scanln(&chatMsg)
	}
}

func (client *Client) UpdateName() bool {
	fmt.Println(">>>>>请输入用户名")
	fmt.Scanln(&client.Name)
	sendMsg := "rename|" + client.Name + "\n"
	_, err := client.conn.Write([]byte(sendMsg))
	if err != nil {
		fmt.Println("conn.Write error:", err)
		return false
	}
	return true
}

func (client *Client) Run() {
	for client.flag != 0 {
		for client.menu() != true {

		}
		// 根据不同的模式处理不同的业务
		switch client.flag {
		case 1:
			// 公聊模式
			fmt.Println("公聊模式选择")
			client.PublicChat()
			break
		case 2:
			// 私聊模式
			fmt.Println("私聊模式选择")
			break
		case 3:
			// 更新用户名
			client.UpdateName()
			break
		}
	}
}

var serverIp string
var serverPort int

func init() {
	flag.StringVar(&serverIp, "ip", "127.0.0.1", "set server ip address(default 127.0.0.1)")
	flag.IntVar(&serverPort, "port", 8888, "set server port(default 8888)")
}
func main() {
	// 命令行解析
	flag.Parse()

	client := NewClient(serverIp, serverPort)
	if client == nil {
		fmt.Println(">>>>> connection fail")
		return
	}
	// 单独开启一个goroutine处理server返回大的消息
	go client.DealResponse()
	fmt.Println(">>>>> connection success")
	client.Run()
}