netmaker/logic/util.go

// package for logicing client and server code
package logic

import (
	"crypto/rand"
	"encoding/base32"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"log/slog"
	"net"
	"net/http"
	"os"
	"reflect"
	"regexp"
	"strings"
	"time"
	"unicode"

	"github.com/blang/semver"
	"github.com/c-robinson/iplib"
	"github.com/gravitl/netmaker/database"
	"github.com/gravitl/netmaker/logger"
	"github.com/gravitl/netmaker/models"
)

// IsBase64 - checks if a string is in base64 format
// This is used to validate public keys (make sure they're base64 encoded like all public keys should be).
func IsBase64(s string) bool {
	_, err := base64.StdEncoding.DecodeString(s)
	return err == nil
}

// CheckEndpoint - checks if an endpoint is valid
func CheckEndpoint(endpoint string) bool {
	endpointarr := strings.Split(endpoint, ":")
	return len(endpointarr) == 2
}

// FileExists - checks if local file exists
func FileExists(f string) bool {
	info, err := os.Stat(f)
	if os.IsNotExist(err) {
		return false
	}
	return !info.IsDir()
}

// IsAddressInCIDR - util to see if an address is in a cidr or not
func IsAddressInCIDR(address net.IP, cidr string) bool {
	var _, currentCIDR, cidrErr = net.ParseCIDR(cidr)
	if cidrErr != nil {
		return false
	}
	return currentCIDR.Contains(address)
}

// SetNetworkNodesLastModified - sets the network nodes last modified
func SetNetworkNodesLastModified(networkName string) error {

	timestamp := time.Now().Unix()

	network, err := GetParentNetwork(networkName)
	if err != nil {
		return err
	}
	network.NodesLastModified = timestamp
	data, err := json.Marshal(&network)
	if err != nil {
		return err
	}
	err = database.Insert(networkName, string(data), database.NETWORKS_TABLE_NAME)
	if err != nil {
		return err
	}
	return nil
}

// RandomString - returns a random string in a charset
func RandomString(length int) string {
	randombytes := make([]byte, length)
	_, err := rand.Read(randombytes)
	if err != nil {
		logger.Log(0, "random string", err.Error())
		return ""
	}
	return base32.StdEncoding.EncodeToString(randombytes)[:length]
}

// StringSliceContains - sees if a string slice contains a string element
func StringSliceContains(slice []string, item string) bool {
	for _, s := range slice {
		if s == item {
			return true
		}
	}
	return false
}
func SetVerbosity(logLevel int) {
	var level slog.Level
	switch logLevel {

	case 0:
		level = slog.LevelInfo
	case 1:
		level = slog.LevelError
	case 2:
		level = slog.LevelWarn
	case 3:
		level = slog.LevelDebug

	default:
		level = slog.LevelInfo
	}
	// Create the logger with the chosen level
	handler := slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
		Level: level,
	})
	logger := slog.New(handler)
	slog.SetDefault(logger)

}

// NormalizeCIDR - returns the first address of CIDR
func NormalizeCIDR(address string) (string, error) {
	ip, IPNet, err := net.ParseCIDR(address)
	if err != nil {
		return "", err
	}
	if ip.To4() == nil {
		net6 := iplib.Net6FromStr(IPNet.String())
		IPNet.IP = net6.FirstAddress()
	} else {
		net4 := iplib.Net4FromStr(IPNet.String())
		IPNet.IP = net4.NetworkAddress()
	}
	return IPNet.String(), nil
}

// StringDifference - returns the elements in `a` that aren't in `b`.
func StringDifference(a, b []string) []string {
	mb := make(map[string]struct{}, len(b))
	for _, x := range b {
		mb[x] = struct{}{}
	}
	var diff []string
	for _, x := range a {
		if _, found := mb[x]; !found {
			diff = append(diff, x)
		}
	}
	return diff
}

// CheckIfFileExists - checks if file exists or not in the given path
func CheckIfFileExists(filePath string) bool {
	if _, err := os.Stat(filePath); os.IsNotExist(err) {
		return false
	}
	return true
}

// RemoveStringSlice - removes an element at given index i
// from a given string slice
func RemoveStringSlice(slice []string, i int) []string {
	return append(slice[:i], slice[i+1:]...)
}

// IsSlicesEqual tells whether a and b contain the same elements.
// A nil argument is equivalent to an empty slice.
func IsSlicesEqual(a, b []string) bool {
	if len(a) != len(b) {
		return false
	}
	for i, v := range a {
		if v != b[i] {
			return false
		}
	}
	return true
}

// VersionLessThan checks if v1 < v2 semantically
// dev is the latest version
func VersionLessThan(v1, v2 string) (bool, error) {
	if v1 == "dev" {
		return false, nil
	}
	if v2 == "dev" {
		return true, nil
	}
	semVer1 := strings.TrimFunc(v1, func(r rune) bool {
		return !unicode.IsNumber(r)
	})
	semVer2 := strings.TrimFunc(v2, func(r rune) bool {
		return !unicode.IsNumber(r)
	})
	sv1, err := semver.Parse(semVer1)
	if err != nil {
		return false, fmt.Errorf("failed to parse semver1 (%s): %w", semVer1, err)
	}
	sv2, err := semver.Parse(semVer2)
	if err != nil {
		return false, fmt.Errorf("failed to parse semver2 (%s): %w", semVer2, err)
	}
	return sv1.LT(sv2), nil
}

// Compare any two maps with any key and value types
func CompareMaps[K comparable, V any](a, b map[K]V) bool {
	if len(a) != len(b) {
		return false
	}

	for key, valA := range a {
		valB, ok := b[key]
		if !ok {
			return false
		}

		if !reflect.DeepEqual(valA, valB) {
			return false
		}
	}

	return true
}

func UniqueStrings(input []string) []string {
	seen := make(map[string]struct{})
	var result []string

	for _, val := range input {
		if _, ok := seen[val]; !ok {
			seen[val] = struct{}{}
			result = append(result, val)
		}
	}

	return result
}
func GetClientIP(r *http.Request) string {
	// Trust X-Forwarded-For first
	if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
		parts := strings.Split(xff, ",")
		return strings.TrimSpace(parts[0])
	}
	if xrip := r.Header.Get("X-Real-IP"); xrip != "" {
		return xrip
	}

	ip, _, err := net.SplitHostPort(r.RemoteAddr)
	if err != nil {
		return r.RemoteAddr
	}
	return ip
}

// CompareIfaceSlices compares two slices of Iface for deep equality (order-sensitive)
func CompareIfaceSlices(a, b []models.Iface) bool {
	if len(a) != len(b) {
		return false
	}
	for i := range a {
		if !compareIface(a[i], b[i]) {
			return false
		}
	}
	return true
}
func compareIface(a, b models.Iface) bool {
	return a.Name == b.Name &&
		a.Address.IP.Equal(b.Address.IP) &&
		a.Address.Mask.String() == b.Address.Mask.String() &&
		a.AddressString == b.AddressString
}

// IsFQDN checks if the given string is a valid Fully Qualified Domain Name (FQDN)
func IsFQDN(domain string) bool {
	// Basic check to ensure the domain is not empty and has at least one dot (.)
	if domain == "" || !strings.Contains(domain, ".") {
		return false
	}

	// Regular expression for validating FQDN (basic check for valid characters and structure)
	fqdnRegex := `^(?i)([a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?$`
	re := regexp.MustCompile(fqdnRegex)

	return re.MatchString(domain)
}