utils.go

package utils

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	mathrand "math/rand"
	"net/http"
	"net/url"
	"os"
	"os/user"
	"path/filepath"
	"reflect"
	"regexp"
	"runtime"
	"strconv"
	"strings"

	log "github.com/sirupsen/logrus"
)

// transforms the keys of a Map recursively with the given transform function
func TransformMapKeys(input map[string]interface{}, transformFunc func(string) string) map[string]interface{} {
	output := make(map[string]interface{})
	for k, v := range input {
		transformedKey := transformFunc(k)
		value, ok := v.(map[string]interface{})
		if !ok {
			output[transformedKey] = v
		} else {
			output[transformedKey] = TransformMapKeys(value, transformFunc)
		}
	}
	return output
}

// unmarshal returns parses the JSON config data and stores the value in the reference to result
func Unmarshal(obj string, result interface{}) error {
	obj = strings.TrimSpace(obj)
	err := json.Unmarshal([]byte(obj), result)
	if err != nil {
		if e, ok := err.(*json.SyntaxError); ok {
			return ErrUnmarshalSyntax(err, e.Offset)
		}
		if e, ok := err.(*json.UnmarshalTypeError); ok {
			return ErrUnmarshalType(err, e.Value)
		}
		if e, ok := err.(*json.UnsupportedTypeError); ok {
			return ErrUnmarshalUnsupportedType(err, e.Type)
		}
		if e, ok := err.(*json.UnsupportedValueError); ok {
			return ErrUnmarshalUnsupportedValue(err, e.Value)
		}
		if e, ok := err.(*json.InvalidUnmarshalError); ok {
			return ErrUnmarshalInvalid(err, e.Type)
		}
		return ErrUnmarshal(err)
	}
	return nil
}

// getBool function returns the boolean config data
func GetBool(key string) (bool, error) {
	enabled, err := strconv.ParseBool(key)
	if err != nil {
		return false, ErrGetBool(key, err)
	}

	return enabled, nil
}

func StrConcat(s ...string) string {
	var buf strings.Builder

	for _, str := range s {
		buf.WriteString(str)
	}
	return buf.String()
}

func Marshal(obj interface{}) (string, error) {
	result, err := json.Marshal(obj)
	if err != nil {
		return " ", ErrMarshal(err)
	}
	return string(result), nil
}

func Filepath() string {
	_, fn, line, _ := runtime.Caller(0)

	return fmt.Sprintf("file: %s, line: %d", fn, line)
}

func DownloadFile(filepath string, url string) error {
	// Get the data
	resp, err := http.Get(url)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		return fmt.Errorf("failed to get the file %d status code for %s file", resp.StatusCode, url)
	}

	// Create the file
	out, err := os.Create(filepath)
	if err != nil {
		return err
	}
	defer out.Close()

	// Write the body to file
	_, err = io.Copy(out, resp.Body)
	return err
}

// GetHome returns the home path
func GetHome() string {
	usr, _ := user.Current()
	return usr.HomeDir
}

// CreateFile creates a file with the given content on the given location with
// the given filename
func CreateFile(contents []byte, filename string, location string) error {
	// Create file in -rw-r--r-- mode
	fd, err := os.OpenFile(filepath.Join(location, filename), os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		return err
	}

	if _, err = fd.Write(contents); err != nil {
		fd.Close()
		return err
	}

	if err = fd.Close(); err != nil {
		return err
	}

	return nil
}

// ReadFileSource supports "http", "https" and "file" protocols.
// it takes in the location as a uri and returns the contents of
// file as a string.
func ReadFileSource(uri string) (string, error) {
	if strings.HasPrefix(uri, "http") {
		return ReadRemoteFile(uri)
	}
	if strings.HasPrefix(uri, "file") {
		return ReadLocalFile(uri)
	}

	return "", ErrInvalidProtocol
}

// ReadRemoteFile takes in the location of a remote file
// in the format 'http://location/of/file' or 'https://location/file'
// and returns the content of the file if the location is valid and
// no error occurs
func ReadRemoteFile(url string) (string, error) {
	response, err := http.Get(url)
	if err != nil {
		return " ", err
	}
	if response.StatusCode == http.StatusNotFound {
		return " ", ErrRemoteFileNotFound(url)
	}

	defer response.Body.Close()

	buf := new(bytes.Buffer)
	_, err = io.Copy(buf, response.Body)
	if err != nil {
		return " ", ErrReadingRemoteFile(err)
	}

	return buf.String(), nil
}

// ReadLocalFile takes in the location of a local file
// in the format `file://location/of/file` and returns
// the content of the file if the path is valid and no
// error occurs
func ReadLocalFile(location string) (string, error) {
	// remove the protocol prefix
	location = strings.TrimPrefix(location, "file://")

	// Need to support variable file locations hence
	// #nosec
	data, err := os.ReadFile(location)
	if err != nil {
		return "", ErrReadingLocalFile(err)
	}

	return string(data), nil
}

// Gets the latest stable release tags from github for a given org name and repo name(in that org) in sorted order
func GetLatestReleaseTagsSorted(org string, repo string) ([]string, error) {
	var url string = "https://github.com/" + org + "/" + repo + "/releases"
	resp, err := http.Get(url)
	if err != nil {
		return nil, ErrGettingLatestReleaseTag(err)
	}
	defer safeClose(resp.Body)

	if resp.StatusCode != http.StatusOK {
		return nil, ErrGettingLatestReleaseTag(err)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, ErrGettingLatestReleaseTag(err)
	}
	re := regexp.MustCompile("/releases/tag/(.*?)\"")
	releases := re.FindAllString(string(body), -1)
	if len(releases) == 0 {
		return nil, ErrGettingLatestReleaseTag(errors.New("no release found in this repository"))
	}
	var versions []string
	for _, rel := range releases {
		latest := strings.ReplaceAll(rel, "/releases/tag/", "")
		latest = strings.ReplaceAll(latest, "\"", "")
		versions = append(versions, latest)
	}
	versions = SortDottedStringsByDigits(versions)
	return versions, nil
}

// SafeClose is a helper function help to close the io
func safeClose(co io.Closer) {
	if cerr := co.Close(); cerr != nil {
		log.Error(cerr)
	}
}

func Contains[G []K, K comparable](slice G, ele K) bool {
	for _, item := range slice {
		if item == ele {
			return true
		}
	}
	return false
}

func Cast[K any](val interface{}) (K, error) {
	var assertedValue K
	if IsInterfaceNil(val) {
		return assertedValue, ErrTypeCast(fmt.Errorf("nil interface cannot be type casted"))
	}
	var ok bool
	assertedValue, ok = val.(K)
	if !ok {
		return assertedValue, ErrTypeCast(fmt.Errorf("the underlying type of the interface is %s", reflect.TypeOf(val).Name()))
	}
	return assertedValue, nil
}

func MarshalAndUnmarshal[fromType any, toType any](val fromType) (unmarshalledvalue toType, err error) {
	data, err := Marshal(val)
	if err != nil {
		return
	}

	err = Unmarshal(data, &unmarshalledvalue)
	if err != nil {
		return
	}
	return
}

func IsClosed[K any](ch chan K) bool {
	select {
	case <-ch:
		return true
	default:
		return false
	}
}

// WriteToFile writes the given content to the given file path
func WriteToFile(path string, content string) error {
	file, err := os.Create(path)
	if err != nil {
		return ErrCreateFile(err, path)
	}

	_, err = file.WriteString(content)
	if err != nil {
		return ErrWriteFile(err, path)
	}
	// Close the file to save the changes.
	err = file.Close()
	if err != nil {
		return ErrWriteFile(err, path)
	}
	return nil
}

// FormatName formats the given string to by replacing " " with "-"
func FormatName(input string) string {
	formatedName := strings.ReplaceAll(input, " ", "-")
	formatedName = strings.ToLower(formatedName)
	return formatedName
}

func GetRandomAlphabetsOfDigit(length int) (s string) {
	charSet := "abcdedfghijklmnopqrstuvwxyz"
	for i := 0; i < length; i++ {
		random := mathrand.Intn(len(charSet))
		randomChar := charSet[random]
		s += string(randomChar)
	}
	return
}

// combineErrors merges a slice of error
// into one error separated by the given separator
func CombineErrors(errs []error, sep string) error {
	if len(errs) == 0 {
		return nil
	}

	var errString []string
	for _, err := range errs {
		errString = append(errString, err.Error())
	}

	return errors.New(strings.Join(errString, sep))
}

func MergeMaps(mergeInto, toMerge map[string]interface{}) map[string]interface{} {
	if mergeInto == nil {
		mergeInto = make(map[string]interface{})
	}
	for k, v := range toMerge {
		mergeInto[k] = v
	}
	return mergeInto
}

func WriteJSONToFile[K any](outputPath string, data K) error {
	byt, err := json.MarshalIndent(data, " ", " ")
	if err != nil {
		return ErrMarshal(err)
	}

	file, err := os.Create(outputPath)
	if err != nil {
		return ErrCreateFile(err, outputPath)
	}

	_, err = file.Write(byt)
	if err != nil {
		return ErrWriteFile(err, outputPath)
	}
	return nil
}

func CreateDirectory(path string) error {
	err := os.MkdirAll(path, 0755)
	if err != nil {
		err = ErrCreateDir(err, path)

		return err
	}
	return nil
}

func ReplaceSpacesAndConvertToLowercase(s string) string {
	return strings.ToLower(strings.ReplaceAll(s, " ", ""))
}

func ExtractDomainFromURL(location string) string {
	parsedURL, err := url.Parse(location)
	// If unable to extract domain return the location as is.
	if err != nil {
		return location
	}
	return regexp.MustCompile(`(([a-zA-Z0-9]+\.)([a-zA-Z0-9]+))$`).FindString(parsedURL.Hostname())
}

func IsInterfaceNil(val interface{}) bool {
	if val == nil {
		return true
	}
	switch reflect.TypeOf(val).Kind() {
	case reflect.Ptr, reflect.Map, reflect.Array, reflect.Chan, reflect.Slice:
		return reflect.ValueOf(val).IsNil()
	}
	return false

}

func IsSchemaEmpty(schema string) (valid bool) {
	if schema == "" {
		return
	}
	m := make(map[string]interface{})
	_ = json.Unmarshal([]byte(schema), &m)
	if m["properties"] == nil {
		return
	}
	valid = true
	return
}