package main

import (
	"flag"
	"github.com/gosnmp/gosnmp"
	"log"
	"os"
	"time"
)

func main() {
	sendVersion := flag.Int("sv", 2, "Send trap version")
	flag.Parse()

	target := "47.92.151.165"
	var port uint16 = 9162

	switch *sendVersion {
	case 1:
		sendV1(target, port)
	case 3:
		sendV3(target, port)
	default:
		sendV2c(target, port)
	}
}

func sendV2c(target string, port uint16) {
	gosnmp.Default.Target = target
	gosnmp.Default.Port = port
	gosnmp.Default.Version = gosnmp.Version2c

	trap := gosnmp.SnmpTrap{
		Variables: getTestPdus(),
	}

	err := gosnmp.Default.Connect()
	if err != nil {
		log.Fatalf("Connect() err: %v", err)
	}
	defer gosnmp.Default.Conn.Close()

	_, err = gosnmp.Default.SendTrap(trap)
	if err != nil {
		log.Fatalf("SendTrap() err: %v", err)
	}
}

func sendV1(target string, port uint16) {
	gosnmp.Default.Target = target
	gosnmp.Default.Port = port
	gosnmp.Default.Version = gosnmp.Version1

	trap := gosnmp.SnmpTrap{
		Variables:    getTestPdus(),
		Enterprise:   ".1.3.6.1.6.3.1.1.5.1",
		AgentAddress: "127.0.0.1",
		GenericTrap:  0,
		SpecificTrap: 0,
		Timestamp:    300,
	}

	err := gosnmp.Default.Connect()
	if err != nil {
		log.Fatalf("Connect() err: %v", err)
	}
	defer gosnmp.Default.Conn.Close()

	_, err = gosnmp.Default.SendTrap(trap)
	if err != nil {
		log.Fatalf("SendTrap() err: %v", err)
	}
}

func sendV3(target string, port uint16) {
	// Default is a pointer to a GoSNMP struct that contains sensible defaults
	// eg port 161, community public, etc

	params := &gosnmp.GoSNMP{
		Target:        target,
		Port:          port,
		Version:       gosnmp.Version3,
		Timeout:       time.Duration(30) * time.Second,
		SecurityModel: gosnmp.UserSecurityModel,
		MsgFlags:      gosnmp.AuthPriv,
		Logger:        log.New(os.Stdout, "", 0),
		SecurityParameters: &gosnmp.UsmSecurityParameters{
			UserName:                 "user",
			AuthoritativeEngineID:    "1234",
			AuthenticationProtocol:   gosnmp.SHA,
			AuthenticationPassphrase: "password",
			PrivacyProtocol:          gosnmp.DES,
			PrivacyPassphrase:        "password",
		},
	}

	err := params.Connect()
	if err != nil {
		log.Fatalf("Connect() err: %v", err)
	}
	defer params.Conn.Close()

	trap := gosnmp.SnmpTrap{
		Variables: getTestPdus(),
	}

	_, err = params.SendTrap(trap)
	if err != nil {
		log.Fatalf("SendTrap() err: %v", err)
	}
}

func getTestPdus() []gosnmp.SnmpPDU {
	return []gosnmp.SnmpPDU{
		{
			Name: ".1.3.6.1.4.1.318.1.1.4.4.2.1.3.5",
			Type: gosnmp.Integer,
			Value: 100,
		},
		{
			Name:  ".1.3.6.1.6.3.1.1.4.1.0",
			Type:  gosnmp.ObjectIdentifier,
			Value: ".1.3.6.1.6.3.1.1.5.1",
		},
		{
			Name:  "1.3.6.1.2.1.1.6",
			Type:  gosnmp.OctetString,
			Value: "Oval Office",
		},
		{
			Name: "1.3.6.1.2.1.1.3.0",
			Type: gosnmp.TimeTicks,
			Value: uint32(time.Now().Unix()),
		},
	}
}