From 8eed8382cb7d9c9d859649fa94b4e4d311262973 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Mon, 26 Feb 2024 15:30:57 +0200
Subject: [PATCH] Add proper error codes in google login provisioning API

---
 provisioning.go | 52 ++++++++++++++++++++++++++++++++++++++-----------
 user.go         |  3 ++-
 2 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/provisioning.go b/provisioning.go
index c608d74..85c1c62 100644
--- a/provisioning.go
+++ b/provisioning.go
@@ -33,6 +33,7 @@ import (
 	"maunium.net/go/mautrix/bridge/status"
 	"maunium.net/go/mautrix/id"
 
+	"go.mau.fi/mautrix-gmessages/libgm"
 	"go.mau.fi/mautrix-gmessages/libgm/gmproto"
 )
 
@@ -340,11 +341,18 @@ func (prov *ProvisioningAPI) GoogleLoginStart(w http.ResponseWriter, r *http.Req
 	emoji, err := user.AsyncLoginGoogleStart(req.Cookies)
 	if err != nil {
 		log.Err(err).Msg("Failed to start login")
-		// TODO proper error codes
-		jsonResponse(w, http.StatusInternalServerError, Error{
-			Error:   "Failed to start login",
-			ErrCode: "start login fail",
-		})
+		switch {
+		case errors.Is(err, libgm.ErrNoDevicesFound):
+			jsonResponse(w, http.StatusBadRequest, Error{
+				Error:   err.Error(),
+				ErrCode: "no-devices-found",
+			})
+		default:
+			jsonResponse(w, http.StatusInternalServerError, Error{
+				Error:   "Failed to start login",
+				ErrCode: "unknown",
+			})
+		}
 		return
 	}
 	jsonResponse(w, http.StatusOK, &RespGoogleLoginStart{Status: "emoji", Emoji: emoji})
@@ -358,12 +366,34 @@ func (prov *ProvisioningAPI) GoogleLoginWait(w http.ResponseWriter, r *http.Requ
 
 	err := user.AsyncLoginGoogleWait()
 	if err != nil {
-		log.Err(err).Msg("Failed to start login")
-		// TODO proper error codes
-		jsonResponse(w, http.StatusInternalServerError, Error{
-			Error:   "Failed to finish login",
-			ErrCode: "finish login fail",
-		})
+		log.Err(err).Msg("Failed to wait for google login")
+		switch {
+		case errors.Is(err, ErrNoLoginInProgress):
+			jsonResponse(w, http.StatusBadRequest, Error{
+				Error:   "No login in progress",
+				ErrCode: "login-not-in-progress",
+			})
+		case errors.Is(err, libgm.ErrIncorrectEmoji):
+			jsonResponse(w, http.StatusBadRequest, Error{
+				Error:   err.Error(),
+				ErrCode: "incorrect-emoji",
+			})
+		case errors.Is(err, libgm.ErrPairingCancelled):
+			jsonResponse(w, http.StatusBadRequest, Error{
+				Error:   err.Error(),
+				ErrCode: "pairing-cancelled",
+			})
+		case errors.Is(err, libgm.ErrPairingTimeout):
+			jsonResponse(w, http.StatusBadRequest, Error{
+				Error:   err.Error(),
+				ErrCode: "timeout",
+			})
+		default:
+			jsonResponse(w, http.StatusInternalServerError, Error{
+				Error:   "Failed to finish login",
+				ErrCode: "unknown",
+			})
+		}
 		return
 	}
 	jsonResponse(w, http.StatusOK, LoginResponse{Status: "success"})
diff --git a/user.go b/user.go
index 1505443..4080f7b 100644
--- a/user.go
+++ b/user.go
@@ -377,6 +377,7 @@ func (user *User) SetManagementRoom(roomID id.RoomID) {
 
 var ErrAlreadyLoggedIn = errors.New("already logged in")
 var ErrLoginInProgress = errors.New("login already in progress")
+var ErrNoLoginInProgress = errors.New("no login in progress")
 var ErrLoginTimeout = errors.New("login timed out")
 
 func (user *User) createClient(sess *libgm.AuthData) {
@@ -507,7 +508,7 @@ func (user *User) AsyncLoginGoogleStart(cookies map[string]string) (outEmoji str
 func (user *User) AsyncLoginGoogleWait() error {
 	ch := user.googleAsyncPairErrChan.Swap(nil)
 	if ch == nil {
-		return fmt.Errorf("no login in progress")
+		return ErrNoLoginInProgress
 	}
 	return <-*ch
 }