fix: Return a proper 401 respnose on auth fail

app/src/main/java/com/p_vacho/neat_calendar/api/AuthInterceptor.kt

@@ -38,45 +38,57 @@ class AuthInterceptor(
             return chain.proceed(originalRequest)
         }
 
-        // No point in continuing if our refresh token expired, make the user to re-login
-        if (tokenManager.refreshToken == null || tokenManager.isRefreshTokenExpired()) {
-            handleFail()
-        }
+        try {
 
-        refreshAccessTokenIfNeeded()
-
-        // Override the original request and add the access token, which should be
-        // available & non-expired after the above checks (though it's still possible
-        // that it was invalidated through other means, so we can still fail here).
-        val requestBuilder = originalRequest.newBuilder()
-        requestBuilder.addHeader("Authorization", "Bearer $tokenManager.accessToken")
-        val response = chain.proceed(requestBuilder.build())
-
-        // Handle authentication failure, if it occurs
-        if (response.code() == 401) {
-            // Clear the access token, as it didn't work anyways, we got 401 with it
-            tokenManager.clearAccessToken()
-
-            // This will definitely trigger a refresh now, as we cleared the access token
-            refreshAccessTokenIfNeeded()
-
-            // Retry the original request with the refreshed access token
-            val newBuilder = originalRequest.newBuilder()
-            newBuilder.addHeader("Authorization", "Bearer ${tokenManager.accessToken}")
-            val newResponse = chain.proceed(newBuilder.build())
-
-            // If this request also lead to a 401, something is very wrong, as the access token
-            // was in fact refreshed by now, which means our refresh token does work, but the
-            // access token it gave us wasn't valid.
-            if (newResponse.code() == 401) {
-                Log.e("API", "Got 403 from a freshly refreshed access token: $newResponse")
-                throw IllegalStateException("Got 403 from a freshly refreshed access token")
+            // No point in continuing if our refresh token expired, make the user to re-login
+            if (tokenManager.refreshToken == null || tokenManager.isRefreshTokenExpired()) {
+                handleFail()
             }
 
-            newResponse
-        }
+            refreshAccessTokenIfNeeded()
 
-        return response
+            // Override the original request and add the access token, which should be
+            // available & non-expired after the above checks (though it's still possible
+            // that it was invalidated through other means, so we can still fail here).
+            val requestBuilder = originalRequest.newBuilder()
+            requestBuilder.addHeader("Authorization", "Bearer $tokenManager.accessToken")
+            val response = chain.proceed(requestBuilder.build())
+
+            // Handle authentication failure, if it occurs
+            if (response.code() == 401) {
+                // Clear the access token, as it didn't work anyways, we got 401 with it
+                tokenManager.clearAccessToken()
+
+                // This will definitely trigger a refresh now, as we cleared the access token
+                refreshAccessTokenIfNeeded()
+
+                // Retry the original request with the refreshed access token
+                val newBuilder = originalRequest.newBuilder()
+                newBuilder.addHeader("Authorization", "Bearer ${tokenManager.accessToken}")
+                val newResponse = chain.proceed(newBuilder.build())
+
+                // If this request also lead to a 401, something is very wrong, as the access token
+                // was in fact refreshed by now, which means our refresh token does work, but the
+                // access token it gave us wasn't valid.
+                if (newResponse.code() == 401) {
+                    Log.e("API", "Got 403 from a freshly refreshed access token: $newResponse")
+                    throw IllegalStateException("Got 403 from a freshly refreshed access token")
+                }
+
+                return newResponse
+            }
+
+            return response
+        } catch (e: CancellationException) {
+            // Return an error response to gracefully end the request
+            return Response.Builder()
+                .request(chain.request())
+                .protocol(Protocol.HTTP_1_1)
+                .code(401)
+                .message("Session expired")
+                .body(ResponseBody.create(null, "Session expired"))
+                .build()
+        }
     }
 
     @Synchronized // Avoid simultaneous refresh attempts