package main

import (
	"bytes"
	"encoding/base64"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
	"os"
	"runtime"
	"time"
)

type Incident struct {
	AppID            string `json:"app_id"`
	Resource         string `json:"resource"`
	Node             string `json:"node"`
	ShortDescription string `json:"short_description"`
	MetricName       string `json:"metric_name"`
	MessageKey       string `json:"message_key"`
	MetricValue      string `json:"metric_value"`
	Source           string `json:"source"`
	Description      string `json:"description"`
	EventClass       string `json:"event_class"`
	Severity         int    `json:"severity"`
	Type             string `json:"type"`
	AssignmentGroup  string `json:"assignment_group"`
	Environment      string `json:"environment"`
}

// ValidAuthMethods defines the allowed authentication methods.
//var ValidAuthMethods = []string{"no-auth", "basic", "ntlm"}

var (
	sha1ver   string // sha1 revision used to build the program
	buildTime string // when the executable was built
)

/*
// ValidateAuthMethod checks if the provided auth method is valid.
func ValidateAuthMethod(authMethod string) error {
	for _, validMethod := range ValidAuthMethods {
		if authMethod == validMethod {
			return nil
		}
	}
	return errors.New("invalid authentication method: " + authMethod)
}
*/

func prettyPrint(args ...interface{}) {
	var caller string

	timeNow := time.Now().Format("01-02-2006 15:04:05")
	prefix := fmt.Sprintf("[%s] %s -- ", "PrettyPrint", timeNow)
	_, fileName, fileLine, ok := runtime.Caller(1)

	if ok {
		caller = fmt.Sprintf("%s:%d", fileName, fileLine)
	} else {
		caller = ""
	}

	log.Printf("\n%s%s\n", prefix, caller)

	if len(args) == 2 {
		label := args[0]
		value := args[1]

		s, _ := json.MarshalIndent(value, "", "\t")
		fmt.Printf("%s%s: %s\n", prefix, label, string(s))
	} else {
		s, _ := json.MarshalIndent(args, "", "\t")
		log.Printf("%s%s\n", prefix, string(s))
	}
}

func main() {
	// Command line flags for the vCenter connection
	snowURL := flag.String("url", "https://server.domain.example/api/global/em/inbound_event", "The URL of the SNOW endpoint")
	snowUser := flag.String("user", "username", "The username to use when authenticating to SNOW")
	snowPass := flag.String("password", "password", "The password to use when authenticating to SNOW")
	proxyURL := flag.String("p-url", "", "The URL of the SNOW endpoint, including protocol and port. Eg http://proxy.domain.example:8080")

	// proxyUser := flag.String("p-user", "", "The username to use when authenticating to the proxy")
	// proxyPass := flag.String("p-pass", "", "The password to use when authenticating to the proxy")
	// proxyDomain := flag.String("p-domain", "", "The domain to use when authenticating to the proxy with NTLM authentication")
	payload := flag.String("payload", "{}", "The JSON formatted payload to send to SNOW")

	flag.Parse()

	// Print logs to file
	f, err := os.OpenFile("log.txt", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
	if err != nil {
		log.Fatalf("error opening file: %v", err)
	}
	defer f.Close()
	log.SetOutput(f)

	//log.Printf("Starting execution. Built on %s from sha1 %s\n", buildTime, sha1ver)

	/*
		if err := ValidateAuthMethod(*proxyType); err != nil {
			log.Fatalf("error validating auth method '%s': %s\n", *proxyType, err)
		} else {
			fmt.Println("Valid auth method:", *proxyType)
		}
	*/

	// Validate the incoming payload
	var incident Incident
	if err := json.Unmarshal([]byte(*payload), &incident); err != nil {
		fmt.Printf("Error unmarshaling JSON: %s\n", err)
		os.Exit(1)
	} else {
		prettyPrint(incident)
	}

	// Configure proxy transport
	var transport http.RoundTripper = http.DefaultTransport
	if *proxyURL != "" {
		proxy, err := url.Parse(*proxyURL)
		if err != nil {
			fmt.Println("Invalid proxy URL:", err)
			return
		}

		// Base transport with proxy
		// baseTransport := &http.Transport{Proxy: http.ProxyURL(proxy)}
		transport = &http.Transport{Proxy: http.ProxyURL(proxy)}

		/*
			// If NTLM credentials are provided, wrap the transport
			if *proxyUser != "" && *proxyPass != "" {
				// create a dialer
				dialer := &net.Dialer{
					Timeout:   30 * time.Second,
					KeepAlive: 30 * time.Second,
				}

				// wrap dial context with NTLM
				ntlmDialContext := ntlm.NewNTLMProxyDialContext(dialer, *proxy, *proxyUser, *proxyPass, *proxyDomain, nil)

				transport = &http.Transport{
					Proxy:       nil, // !!! IMPORTANT, do not set proxy here !!!
					DialContext: ntlmDialContext,
				}
			} else {
				transport = baseTransport
			}
		*/
	}

	// Create HTTP client with custom transport
	client := &http.Client{
		Transport: transport,
	}

	// Create the request
	req, err := http.NewRequest("POST", *snowURL, bytes.NewBuffer([]byte(*payload)))
	if err != nil {
		log.Println("Error creating request:", err)
		return
	}

	// Set headers
	req.Header.Set("Content-Type", "application/json")

	// Add Basic Authentication for target URL
	if *snowUser != "" && *snowPass != "" {
		basicAuth := base64.StdEncoding.EncodeToString([]byte(*snowUser + ":" + *snowPass))
		req.Header.Set("Authorization", "Basic "+basicAuth)
	}

	// Send the request
	resp, err := client.Do(req)
	if err != nil {
		log.Println("Error sending request:", err)
		return
	}
	defer resp.Body.Close()

	// Read response
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		log.Println("Error reading response:", err)
		return
	}

	// Print response
	log.Println("Response Status:", resp.Status)
	fmt.Println(string(body))
}