package network

import (
	"encoding/json"
	"log"
	"net"
	"net/http"
)

type NICS struct {
	Flags              string
	HardwareAddr       string
	Index              int
	MTU                int
	IPv4Addr           string
	IPv6Addr           string
	IPv4MulticastAddrs string
	IPv6MulticastAddrs string
	Name               string
}

func GetNICInfo(w http.ResponseWriter, r *http.Request){
	interfaces, err := net.Interfaces()
	if err != nil {
		sendJSONResponse(w, err.Error())
	}
	var NICList []NICS
	for _, i := range interfaces {
		InterfaceName := i.Name
		InterfaceIPv4 := ""
		InterfaceIPv6 := ""
		Flags := i.Flags.String()
		HardwareAddr := i.HardwareAddr.String()
		Index := i.Index
		MTU := i.MTU
		IPv4MulticastAddr := ""
		IPv6MulticastAddr := ""

		if HardwareAddr == "" {
			HardwareAddr = "N/A"
		}

		Addrs, _ := i.Addrs()
		for _, addr := range Addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP
			case *net.IPAddr:
				ip = v.IP
			}
			ip = ip.To4()
			if ip != nil {
				InterfaceIPv4 = ip.String()
			} else {
				InterfaceIPv6 = ip.String()
			}
		}
		if InterfaceIPv4 == "" || InterfaceIPv4 == "<nil>" {
			InterfaceIPv4 = "N/A"
		}
		if InterfaceIPv6 == "" || InterfaceIPv6 == "<nil>" {
			InterfaceIPv6 = "N/A"
		}

		MultiAddrs, _ := i.MulticastAddrs()
		for _, addr := range MultiAddrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP
			case *net.IPAddr:
				ip = v.IP
			}
			ip = ip.To4()
			if ip != nil {
				IPv4MulticastAddr = ip.String()
			} else {
				IPv6MulticastAddr = ip.String()
			}
		}
		if IPv4MulticastAddr == "" || IPv4MulticastAddr == "<nil>" {
			IPv4MulticastAddr = "N/A"
		}
		if IPv6MulticastAddr == "" || IPv6MulticastAddr == "<nil>" {
			IPv6MulticastAddr = "N/A"
		}

		n := NICS{
			Flags:              Flags,
			HardwareAddr:       HardwareAddr,
			Index:              Index,
			MTU:                MTU,
			IPv4Addr:           InterfaceIPv4,
			IPv6Addr:           InterfaceIPv6,
			IPv4MulticastAddrs: IPv4MulticastAddr,
			IPv6MulticastAddrs: IPv6MulticastAddr,
			Name:               InterfaceName,
		}

		NICList = append(NICList, n)
	}

	var jsonData []byte
	jsonData, err = json.Marshal(NICList)
	if err != nil {
		log.Println(err)
	}
	sendJSONResponse(w, string(jsonData))
}

//Get the IP address of the NIC that can conncet to the internet
func GetOutboundIP() (net.IP, error) {
	conn, err := net.Dial("udp", "8.8.8.8:80")
	if err != nil {
		return nil, err
	}
	defer conn.Close()

	localAddr := conn.LocalAddr().(*net.UDPAddr)

	return localAddr.IP, nil
}

func GetPing(w http.ResponseWriter, r *http.Request) {
	sendJSONResponse(w, "pong")
}