From a1c5827641f4c679b82d0541f729f86b657332d5 Mon Sep 17 00:00:00 2001
From: Maximilian Friedersdorff <max@gwairfelin.com>
Date: Wed, 10 Dec 2025 20:56:17 +0000
Subject: [PATCH] Refactor forgejo user interaction

---
 internal/auth/oauth.go         | 26 ++++++++++++++------------
 internal/middleware/session.go | 17 ++---------------
 2 files changed, 16 insertions(+), 27 deletions(-)

diff --git a/internal/auth/oauth.go b/internal/auth/oauth.go
index a746c48..6455a12 100644
--- a/internal/auth/oauth.go
+++ b/internal/auth/oauth.go
@@ -6,17 +6,12 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"log"
 	"net/http"
 
 	"forgejo.gwairfelin.com/max/gonotes/internal/conf"
 	"golang.org/x/oauth2"
 )
 
-type userInfo struct {
-	preferred_username string
-}
-
 func GenerateStateOAUTHCookie(w http.ResponseWriter, prefix string) string {
 
 	b := make([]byte, 16)
@@ -31,23 +26,23 @@ func GenerateStateOAUTHCookie(w http.ResponseWriter, prefix string) string {
 	return state
 }
 
-func GetUserData(code string, oauth *oauth2.Config) (map[string]any, error) {
+func GetUserFromForgejo(code string, oauth *oauth2.Config) (string, error) {
 	// Use code to get token and get user info from Google.
 
 	token, err := oauth.Exchange(context.Background(), code)
 	if err != nil {
-		return nil, fmt.Errorf("code exchange wrong: %s", err.Error())
+		return "", fmt.Errorf("code exchange wrong: %s", err.Error())
 	}
 
 	request, err := http.NewRequest("GET", conf.Conf.OIDC.UserinfoURL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to init http client for userinfo: %s", err.Error())
+		return "", fmt.Errorf("failed to init http client for userinfo: %s", err.Error())
 	}
 	request.Header.Set("Authorization", fmt.Sprintf("token %s", token.AccessToken))
 	response, err := http.DefaultClient.Do(request)
 
 	if err != nil {
-		return nil, fmt.Errorf("failed getting user info: %s", err.Error())
+		return "", fmt.Errorf("failed getting user info: %s", err.Error())
 	}
 	defer response.Body.Close()
 
@@ -55,10 +50,17 @@ func GetUserData(code string, oauth *oauth2.Config) (map[string]any, error) {
 
 	err = json.NewDecoder(response.Body).Decode(&uInf)
 	if err != nil {
-		return nil, fmt.Errorf("failed to parse response as json: %s", err.Error())
+		return "", fmt.Errorf("failed to parse response as json: %s", err.Error())
 	}
 
-	log.Printf("Contents of user data response %s", uInf)
+	username, ok := uInf["preferred_username"]
+	if !ok {
+		return "", fmt.Errorf("no username in response: %s", err.Error())
+	}
+	userStr, ok := username.(string)
+	if !ok {
+		return "", fmt.Errorf("username not a string: %s", err.Error())
+	}
 
-	return uInf, nil
+	return userStr, nil
 }
diff --git a/internal/middleware/session.go b/internal/middleware/session.go
index bea2354..a3af9fc 100644
--- a/internal/middleware/session.go
+++ b/internal/middleware/session.go
@@ -97,27 +97,14 @@ func (s *SessionStore) CallbackViewOAUTH(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	data, err := auth.GetUserData(r.FormValue("code"), s.oauth)
+	username, err := auth.GetUserFromForgejo(r.FormValue("code"), s.oauth)
 	if err != nil {
 		log.Println(err.Error())
 		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
 		return
 	}
 
-	username, ok := data["preferred_username"]
-	if !ok {
-		log.Println("No username in auth response")
-		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
-		return
-	}
-	userStr, ok := username.(string)
-	if !ok {
-		log.Println("Username not interpretable as string")
-		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
-		return
-	}
-
-	s.Login(userStr, w)
+	s.Login(username, w)
 	http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
 }