Change username of other users

database/database.go

@@ -77,6 +77,15 @@ func UserByUsername(username string) (*User, error) {
 	return user, nil
 }
 
+func ChangeUsername(userId int, newUsername string) error {
+	user, err := UserById(userId)
+	if err != nil {
+		return err
+	}
+	user.Username = newUsername
+	return db.Save(user).Error
+}
+
 // UserById get a user
 func UserById(userId int) (*User, error) {
 	var user *User

server/admin.go

@@ -13,6 +13,11 @@ import (
 	"time"
 )
 
+type UpdateUsername struct {
+	Id       int    `json:"id"`
+	Username string `json:"username"`
+}
+
 func AddUser(w http.ResponseWriter, r *http.Request) {
 	body, err := io.ReadAll(r.Body)
 	if err != nil {
@@ -176,3 +181,40 @@ func ChangeUserPassword(w http.ResponseWriter, r *http.Request) {
 	}
 	ok(payload, w, r)
 }
+
+func ChangeUsername(w http.ResponseWriter, r *http.Request) {
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		internalServerError(w, r)
+		log.Println(err)
+		return
+	}
+	newUserInfo := new(UpdateUsername)
+	err = json.Unmarshal(body, newUserInfo)
+	if err != nil {
+		internalServerError(w, r)
+		log.Println(err)
+		return
+	}
+	if len(newUserInfo.Username) < 3 {
+		badRequest("username need at least 3 characters", w, r)
+		return
+	}
+	_, err = database.UserByUsername(newUserInfo.Username)
+	if err == nil {
+		badRequest("username already exist", w, r)
+		return
+	}
+	err = database.ChangeUsername(newUserInfo.Id, newUserInfo.Username)
+	if err != nil {
+		internalServerError(w, r)
+		log.Println(err)
+		return
+	}
+	payload := &successMessage{
+		Message:   "Username changed",
+		Timestamp: time.Now(),
+		Status:    200,
+	}
+	ok(payload, w, r)
+}

server/server.go

@@ -39,6 +39,7 @@ func Serve() {
 			r.Route("/admin", func(adminRouter chi.Router) {
 				adminRouter.Use(adminMiddleware)
 				adminRouter.Post("/user", AddUser)
+				adminRouter.Post("/user/username", ChangeUsername)
 				adminRouter.Post("/user/passwd/{id}", ChangeUserPassword)
 				adminRouter.Delete("/user/{id}", RemoveUser)
 				adminRouter.Get("/user/{id}", User)