fix: Modify getURL method to correctly support special characters

fixes https://github.com/rhnvrm/simples3/issues/7

simples3.go

@@ -7,6 +7,7 @@ import (
 	"bytes"
 	"crypto/hmac"
 	"crypto/sha256"
+	"encoding/hex"
 	"encoding/json"
 	"encoding/xml"
 	"errors"
@@ -15,8 +16,10 @@ import (
 	"io/ioutil"
 	"mime/multipart"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
+	"unicode/utf8"
 )
 
 const (
@@ -159,17 +162,23 @@ func (s3 *S3) getClient() *http.Client {
 	return s3.Client
 }
 
-func (s3 *S3) getURL(bucket string, args ...string) (uri string) {
+// getURL constructs a URL for a given path, with multiple optional
+// arguments as individual subfolders, based on the endpoint
+// specified in s3 struct.
+func (s3 *S3) getURL(path string, args ...string) (uri string) {
+	if len(args) > 0 {
+		path += "/" + strings.Join(args, "/")
+	}
+	// need to encode special characters in the path part of the URL
+	encodedPath := encodePath(path)
+
 	if len(s3.Endpoint) > 0 {
-		uri = s3.Endpoint + "/" + bucket
+		uri = s3.Endpoint + "/" + encodedPath
 	} else {
-		uri = fmt.Sprintf(s3.URIFormat, s3.Region, bucket)
+		uri = fmt.Sprintf(s3.URIFormat, s3.Region, encodedPath)
 	}
 
-	if len(args) > 0 {
-		uri = uri + "/" + strings.Join(args, "/")
-	}
-	return
+	return uri
 }
 
 // SetEndpoint can be used to the set a custom endpoint for
@@ -391,3 +400,45 @@ func (s3 *S3) FileDelete(u DeleteInput) error {
 
 	return nil
 }
+
+// if object matches reserved string, no need to encode them
+var reservedObjectNames = regexp.MustCompile("^[a-zA-Z0-9-_.~/]+$")
+
+// encodePath encode the strings from UTF-8 byte representations to HTML hex escape sequences
+//
+// This is necessary since regular url.Parse() and url.Encode() functions do not support UTF-8
+// non english characters cannot be parsed due to the nature in which url.Encode() is written
+//
+// This function on the other hand is a direct replacement for url.Encode() technique to support
+// pretty much every UTF-8 character.
+// adapted from https://github.com/minio/minio-go/blob/fe1f3855b146c1b6ce4199740d317e44cf9e85c2/pkg/s3utils/utils.go#L285
+func encodePath(pathName string) string {
+	if reservedObjectNames.MatchString(pathName) {
+		return pathName
+	}
+	var encodedPathname strings.Builder
+	for _, s := range pathName {
+		if 'A' <= s && s <= 'Z' || 'a' <= s && s <= 'z' || '0' <= s && s <= '9' { // §2.3 Unreserved characters (mark)
+			encodedPathname.WriteRune(s)
+			continue
+		}
+		switch s {
+		case '-', '_', '.', '~', '/': // §2.3 Unreserved characters (mark)
+			encodedPathname.WriteRune(s)
+			continue
+		default:
+			len := utf8.RuneLen(s)
+			if len < 0 {
+				// if utf8 cannot convert, return the same string as is
+				return pathName
+			}
+			u := make([]byte, len)
+			utf8.EncodeRune(u, s)
+			for _, r := range u {
+				hex := hex.EncodeToString([]byte{r})
+				encodedPathname.WriteString("%" + strings.ToUpper(hex))
+			}
+		}
+	}
+	return encodedPathname.String()
+}