package main

import (
	"fmt"
	"log"
	"net"
	"os"
)

var (
	Args         []string
	ExampleFlag1 bool
	ipToScan     string
	portToScan   string
)

func main() {
	if len(os.Args) == 1 {
		showHelp()
		os.Exit(0)
	}
	storeArgs()

Loop:
	for i, v := range Args {
		switch v {
		case "--help", "-h":
			showHelp()
			os.Exit(0)
		case "--port", "-p":
			portToScan = Args[i+1]
		default:
			if ip := findIP(v); ip != "" {
				ipToScan = ip
				continue Loop
			}
			if Args[i-1] == "--port" || Args[i-1] == "-p" {
				continue Loop
			}
			fmt.Printf("Invalid parameter: \"%v\"\n", v)
			os.Exit(0)
		}
	}
	if ipToScan != "" {
		if portToScan != "" {
			if e := scanPort(); e != nil {
				log.Fatal(e)
			}
		} else {
			if e := scanPorts(); e != nil {
				log.Fatal(e)
			}
		}

	} else {
		fmt.Println("no ip provided")
	}
}

func findIP(s string) string {
	addr := net.ParseIP(s)
	if addr != nil {
		return s
	}
	return ""
}

func scanPort() error {
	fmt.Printf("Starting dragon-scan 0.0.1\n")
	_, err := net.Dial("tcp", ipToScan+":"+portToScan)
	if err == nil {
	}
	fmt.Printf("dragon-scan report for %v\n", ipToScan)
	return nil
}

func scanPorts() error {
	fmt.Printf("Starting dragon-scan 0.0.1\n")
	var successful []int
	for port := 0; port <= 3306; port++ {
		_, err := net.Dial("tcp", ipToScan+":"+string(port))
		if err == nil {
			successful = append(successful, port)
		}
	}
	fmt.Printf("dragon-scan report for %v\n", ipToScan)
	showPorts(successful)
	return nil
}

func showPorts(list []int) {
	for _, port := range list {
		fmt.Println(port)
	}
}

func showHelp() {
	fmt.Printf("This is where I would show the help, IF I HAD ANY!\n")
}

func storeArgs() {
	for i := 1; i < len(os.Args); i++ {
		Args = append(Args, os.Args[i])
	}
}