package main

import (
	"flag"
	"fmt"
	"os"
	"pong/dial"
	"pong/goping"
	"strconv"
)

// 定义命令行参数对应的变量，这三个变量都是指针类型

var helpText = `usage: pong <adress> <port> [-t <timeout> -k <protocol>]
eg:
pong www.baidu.com
pong www.baidu.com 443
pong -t 1www.baidu.com 443 
pong -k udp www.baidu.com 443 
pong -a www.baidu.com -p 443 -k tcp -t 3
`

func main() {
	address := flag.String("a", "", "domain or ip address")
	port := flag.Int("p", 0, "port")
	protocol := flag.String("k", "tcp", "protocol kind")
	timeout := flag.Int("t", 1, "timeout")
	flag.Parse()

	//fmt.Println("port:", *port)
	//fmt.Println("protocol:", *protocol)

	switch flag.NArg() { //函数返回没有被解析的命令行参数的个数
	// flag.Args() 函数返回没有被解析的命令行参数
	case 0:
		if *address != "" && *port != 0 {
			dial.PortDial(*address, strconv.Itoa(*port), *protocol, *timeout)
		}
		fmt.Printf(helpText)
		os.Exit(0)
	case 1:
		if *port != 0 {
			dial.PortDial(flag.Arg(0), strconv.Itoa(*port), *protocol, *timeout)
		}
		goping.Ping(flag.Arg(0), 48)
		os.Exit(0)
	default:
		addressDial := flag.Arg(0)
		portDial := flag.Arg(1)
		if *address != "" {
			addressDial = *address
		}
		if *port != 0 {
			portDial = strconv.Itoa(*port)
		}
		dial.PortDial(addressDial, portDial, *protocol, *timeout)
	}
}