Implement user login with password hash verification and username lookup

internal/services/userService.go

@@ -15,4 +15,10 @@ func NewUserService(db *gorm.DB) *UserService {
 
 func (us *UserService) CreateUser(user models.ComUser) int {
 	return int(us.db.Create(&user).RowsAffected)
+}
+
+func (us *UserService) GetUserByUsername(username string) models.ComUser {
+	var user models.ComUser
+	us.db.Where("username = ?", username).First(&user)
+	return user
 }