feat: enhance logging in OAuth flow with additional cookie and request details

Author: sergot

backend/handlers/oauth.go

@@ -54,6 +54,10 @@ func (h *OAuthHandler) Login(c echo.Context) error {
 	slog.Info("OAuth state cookie set",
 		"provider", provider,
 		"state", state,
+		"redirect_url", redirectURL,
+		"cookie_path", cookie.Path,
+		"cookie_secure", cookie.Secure,
+		"cookie_samesite", cookie.SameSite,
 	)
 
 	return c.String(http.StatusOK, redirectURL)
@@ -72,11 +76,23 @@ func (h *OAuthHandler) Callback(c echo.Context) error {
 		cookieState = cookie.Value
 	}
 
+	// Debug: log all cookies and headers
+	allCookies := c.Cookies()
+	cookieNames := make([]string, len(allCookies))
+	for i, ck := range allCookies {
+		cookieNames[i] = ck.Name
+	}
+
 	slog.Info("OAuth callback received",
 		"provider", provider,
 		"state_from_query", state,
 		"state_from_cookie", cookieState,
 		"cookie_found", err == nil,
+		"cookie_error", err,
+		"all_cookies", cookieNames,
+		"request_host", c.Request().Host,
+		"request_scheme", c.Scheme(),
+		"referer", c.Request().Header.Get("Referer"),
 	)
 
 	// Clear the state cookie