Add a bunch of stuff, mostly user and db related

model/user.go

@@ -1,5 +1,9 @@
 package model
 
+import (
+	"fmt"
+)
+
 type User struct {
 	ID       int
 	Name     string
@@ -7,3 +11,23 @@ type User struct {
 	Username string
 	Password string
 }
+
+func (u *User) IsValid() error {
+	if u.Name == "" {
+		return fmt.Errorf("name must not be empty")
+	}
+
+	if u.Mail == "" {
+		return fmt.Errorf("mail must not be empty")
+	}
+
+	if u.Username == "" {
+		return fmt.Errorf("username must not be empty")
+	}
+
+	if u.Password == "" {
+		return fmt.Errorf("password must not be empty")
+	}
+
+	return nil
+}

model/utils.go

@@ -0,0 +1,9 @@
+package model
+
+import (
+	"github.com/google/uuid"
+)
+
+func NewID() string {
+	return uuid.New().String()
+}