Restructured code, moved all modules into internal

For now all modules are considered internal. This might change later

internal/backends/auth.go

@@ -0,0 +1,54 @@
+/*
+Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
+
+This file is part of Scotty.
+
+Scotty is free software: you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later version.
+
+Scotty is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+Scotty. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package backends
+
+import (
+	"net/url"
+	"strings"
+
+	"github.com/spf13/viper"
+	"go.uploadedlobster.com/scotty/internal/models"
+	"go.uploadedlobster.com/scotty/internal/storage"
+)
+
+func BuildRedirectURL(config *viper.Viper, backend string) (*url.URL, error) {
+	callbackHost, _ := strings.CutSuffix(config.GetString("oauth-host"), "/")
+	if callbackHost == "" {
+		callbackHost = "127.0.0.1:2369"
+	}
+	callbackPath := "/callback/" + backend
+	return url.Parse("http://" + callbackHost + callbackPath)
+}
+
+func Authenticate(service string, backend models.Backend, db storage.Database, config *viper.Viper) (bool, error) {
+	authenticator, auth := backend.(models.OAuth2Authenticator)
+	if auth {
+		redirectURL, err := BuildRedirectURL(config, backend.Name())
+		if err != nil {
+			return auth, err
+		}
+		token, err := db.GetOAuth2Token(service)
+		if err != nil {
+			return auth, err
+		}
+		conf := authenticator.OAuth2Strategy(redirectURL).Config()
+		tokenSource := NewDatabaseTokenSource(db, service, &conf, token)
+		authenticator.OAuth2Setup(tokenSource)
+	}
+	return auth, nil
+}