Create admin settings and moved signup disable setting there

internal/models/admin_setting.go

@@ -0,0 +1,56 @@
+package models
+
+import (
+	"errors"
+	"github.com/mattn/go-sqlite3"
+	"gorm.io/gorm/clause"
+)
+
+type AdminSetting struct {
+	Key   string `gorm:"uniqueIndex"`
+	Value string
+}
+
+const (
+	SettingDisableSignup = "disable-signup"
+)
+
+func GetSetting(key string) (string, error) {
+	var setting AdminSetting
+	err := db.Where("key = ?", key).First(&setting).Error
+	return setting.Value, err
+}
+
+func UpdateSetting(key string, value string) error {
+	return db.Clauses(clause.OnConflict{
+		Columns:   []clause.Column{{Name: "key"}}, // key colume
+		DoUpdates: clause.AssignmentColumns([]string{"value"}),
+	}).Create(&AdminSetting{
+		Key:   key,
+		Value: value,
+	}).Error
+}
+
+func setSetting(key string, value string) error {
+	return db.Create(&AdminSetting{Key: key, Value: value}).Error
+}
+
+func initAdminSettings(settings map[string]string) error {
+	for key, value := range settings {
+		if err := setSetting(key, value); err != nil {
+			if !isUniqueConstraintViolation(err) {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func isUniqueConstraintViolation(err error) bool {
+	var sqliteErr sqlite3.Error
+	if errors.As(err, &sqliteErr) && sqliteErr.ExtendedCode == sqlite3.ErrConstraintUnique {
+		return true
+	}
+	return false
+}