package utils

import (
	"errors"
	"fmt"
	"net"
	"strings"
)

// NetworkLister List all network interface available
func NetworkLister() {
	// Retrieve Interfaces
	inter, err := net.Interfaces()

	// Process errors
	if err != nil {
		println("[ERROR] An error occurred : " + err.Error())
		return
	}

	// Display items
	println("\n\nNetwork interface list :")
	for i, val := range inter {
		fmt.Printf("%d. %s\n", i, val.Name)
		addrs, _ := val.Addrs()
		for _, addr := range addrs {
			println("-- ", addr.String())
		}
	}
	print("\n")
}

// RetrieveIPv4FromInterface Retrieve the first IPv4 from an interface.
func RetrieveIPv4FromInterface(inter string) (net.IP, error) {
	ief, err := net.InterfaceByName(inter)
	addrs, err := ief.Addrs()
	if err != nil {
		return nil, err
	}
	for _, addr := range addrs {
		switch v := addr.(type) {
		case *net.IPNet:
			//if !v.IP.IsLoopback() {
			if v.IP.To4() != nil { //Verify if IP is IPV4
				return v.IP, nil
			}
			//}
		}
	}
	return nil, errors.New("no IPv4 found")
}

// IsIPv4 Check if the ip is a v4 or v6 ip
func IsIPv4(addr string) bool {
	return strings.Count(addr, ":") < 2
}