Refactor main.go to handle new tag and field names

The changes include the renaming of variable 'newName' to 'jsonName' improving overall clarity, and a significant refactoring of the field tag handling logic. New logic is introduced to handle 'protobuf' tags and improve handling of 'json' tags, while also preventing duplicate tags. This refactor enhances code maintainability and readability.

protoc-go-inject-tags/main.go

@@ -34,6 +34,7 @@ func init() {
 	flag.StringVar(&ignore, "ignore", "", "ignore fields for struct eg: form:file,json:file")
 	fset = token.NewFileSet()
 }
+
 func main() {
 	flag.Parse()
 
@@ -131,39 +132,51 @@ func handleTags(fields *ast.FieldList) {
 			continue
 		}
 
-		var newName string
+		var jsonName string
 		for _, name := range field.Names {
-			newName = strings.ToLower(strings.Join(camelcase.Split(name.Name), "_"))
+			jsonName = strings.ToLower(strings.Join(camelcase.Split(name.Name), "_"))
 		}
-
 		tv := strings.ReplaceAll(field.Tag.Value, "`", "")
 		tagList := strings.Split(tv, " ")
-		fieldTags := make(map[string]*fieldTag, 0)
+		fieldTags := make(map[string]*fieldTag)
 		var sortTags []string
+
 		for _, t := range tagList {
 			tf := strings.Split(t, ":")
 			if len(tf) != 2 {
 				continue
 			}
-			fieldTags[tf[0]] = &fieldTag{
-				tagName:  strings.TrimSpace(tf[0]),
-				tagValue: strings.Replace(tf[1], "\"", "", -1),
+			tagName := strings.TrimSpace(tf[0])
+			tagValue := strings.Replace(tf[1], "\"", "", -1)
+			fieldTags[tagName] = &fieldTag{
+				tagName:  tagName,
+				tagValue: tagValue,
+			}
+			sortTags = append(sortTags, tagName)
+
+			if tagName == "protobuf" {
+				if jsonIndex := strings.Index(tagValue, "json="); jsonIndex != -1 {
+					jsonValue := tagValue[jsonIndex+5:]
+					jsonValue = strings.Split(jsonValue, ",")[0]
+					jsonName = jsonValue
+				}
 			}
-			sortTags = append(sortTags, tf[0])
 		}
 
 		for _, tag := range tagsValue {
-			if _, ok := fieldTags[tag]; ok {
-				continue
-			}
-
-			fieldTags[tag] = &fieldTag{tagName: tag, tagValue: fmt.Sprintf("%s,omitempty", newName)}
+			fieldTags[tag] = &fieldTag{tagName: tag, tagValue: fmt.Sprintf("%s,omitempty", jsonName)}
 			sortTags = append(sortTags, tag)
 		}
 
+		fieldTags["json"] = &fieldTag{tagName: "json", tagValue: fmt.Sprintf("%s,omitempty", jsonName)}
+
 		var newTags string
+		seenTags := make(map[string]bool)
 		for _, tag := range sortTags {
-			newTags += fmt.Sprintf("%s:\"%s\" ", fieldTags[tag].tagName, fieldTags[tag].tagValue)
+			if !seenTags[tag] {
+				newTags += fmt.Sprintf("%s:\"%s\" ", fieldTags[tag].tagName, fieldTags[tag].tagValue)
+				seenTags[tag] = true
+			}
 		}
 
 		for _, v := range ignoreFields {
@@ -172,6 +185,6 @@ func handleTags(fields *ast.FieldList) {
 			}
 		}
 
-		field.Tag.Value = fmt.Sprintf("`%s`", newTags)
+		field.Tag.Value = fmt.Sprintf("`%s`", strings.TrimSpace(newTags))
 	}
 }