From d84614402319b125b420f874bbff5d5659662847 Mon Sep 17 00:00:00 2001
From: Jerry Johns <johnsj@google.com>
Date: Wed, 22 Jun 2022 11:32:46 -0700
Subject: [PATCH] Add a new callback on the `SubscriptionTransaction` object to
 permit (#19833)

registering for resubscription notifications.
---
 .../python/chip/clusters/Attribute.py         | 21 ++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/controller/python/chip/clusters/Attribute.py b/src/controller/python/chip/clusters/Attribute.py
index 5c5ba9e4025bdd..a11d324d5890a4 100644
--- a/src/controller/python/chip/clusters/Attribute.py
+++ b/src/controller/python/chip/clusters/Attribute.py
@@ -466,6 +466,7 @@ def UpdateCachedData(self):
 
 class SubscriptionTransaction:
     def __init__(self, transaction: 'AsyncReadTransaction', subscriptionId, devCtrl):
+        self._onResubscriptionAttemptedCb = DefaultResubscriptionAttemptedCallback
         self._onAttributeChangeCb = DefaultAttributeChangeCallback
         self._onEventChangeCb = DefaultEventChangeCallback
         self._onErrorCb = DefaultErrorCallback
@@ -492,6 +493,15 @@ def GetAttribute(self, path: TypedAttributePath) -> Any:
     def GetEvents(self):
         return self._readTransaction.GetAllEventValues()
 
+    def SetResubscriptionAttemptedCallback(self, callback: Callable[[SubscriptionTransaction, int, int], None]):
+        '''
+        Sets the callback function that gets invoked anytime a re-subscription is attempted. The callback is expected
+        to have the following signature:
+            def Callback(transaction: SubscriptionTransaction, errorEncountered: int, nextResubscribeIntervalMsec: int)
+        '''
+        if callback is not None:
+            self._onResubscriptionAttemptedCb = callback
+
     def SetAttributeUpdateCallback(self, callback: Callable[[TypedAttributePath, SubscriptionTransaction], None]):
         '''
         Sets the callback function for the attribute value change event, accepts a Callable accepts an attribute path and the cached data.
@@ -540,6 +550,10 @@ def __repr__(self):
         return f'<Subscription (Id={self._subscriptionId})>'
 
 
+def DefaultResubscriptionAttemptedCallback(transaction: SubscriptionTransaction, terminationError, nextResubscribeIntervalMsec):
+    print(f"Previous subscription failed with Error: {terminationError} - re-subscribing in {nextResubscribeIntervalMsec}ms...")
+
+
 def DefaultAttributeChangeCallback(path: TypedAttributePath, transaction: SubscriptionTransaction):
     data = transaction.GetAttribute(path)
     value = {
@@ -682,8 +696,9 @@ def handleSubscriptionEstablished(self, subscriptionId):
         self._event_loop.call_soon_threadsafe(
             self._handleSubscriptionEstablished, subscriptionId)
 
-    def handleResubscriptionAttempted(self, terminationCause, nextResubscribeIntervalMsec):
-        print("would resubscribe with error " + str(terminationCause) + " in " + str(nextResubscribeIntervalMsec))
+    def handleResubscriptionAttempted(self, terminationCause: int, nextResubscribeIntervalMsec: int):
+        self._event_loop.call_soon_threadsafe(
+            self._subscription_handler._onResubscriptionAttemptedCb, self._subscription_handler, terminationCause, nextResubscribeIntervalMsec)
 
     def _handleReportBegin(self):
         pass
@@ -810,7 +825,7 @@ def _OnSubscriptionEstablishedCallback(closure, subscriptionId):
 
 
 @_OnResubscriptionAttemptedCallbackFunct
-def _OnResubscriptionAttemptedCallback(closure, terminationCause, nextResubscribeIntervalMsec):
+def _OnResubscriptionAttemptedCallback(closure, terminationCause: int, nextResubscribeIntervalMsec: int):
     closure.handleResubscriptionAttempted(terminationCause, nextResubscribeIntervalMsec)