fix: reset destroys app (#319)

Co-authored-by: cachho <admin@ch-webdev.com>

embedchain/embedchain.py

@@ -372,13 +372,21 @@ class EmbedChain:
     def reset(self):
         """
         Resets the database. Deletes all embeddings irreversibly.
-        `App` has to be reinitialized after using this method.
+        `App` does not have to be reinitialized after using this method.
         """
         # Send anonymous telemetry
         thread_telemetry = threading.Thread(target=self._send_telemetry_event, args=("reset",))
         thread_telemetry.start()
-
+      
+        collection_name = self.collection.name
         self.db.reset()
+        self.collection = self.config.db._get_or_create_collection(collection_name)
+        # Todo: Automatically recreating a collection with the same name cannot be the best way to handle a reset.
+        # A downside of this implementation is, if you have two instances,
+        # the other instance will not get the updated `self.collection` attribute.
+        # A better way would be to create the collection if it is called again after being reset.
+        # That means, checking if collection exists in the db-consuming methods, and creating it if it doesn't.
+        # That's an extra steps for all uses, just to satisfy a niche use case in a niche method. For now, this will do.
 
     @retry(stop=stop_after_attempt(3), wait=wait_fixed(1))
     def _send_telemetry_event(self, method: str, extra_metadata: Optional[dict] = None):
@@ -397,4 +405,4 @@ class EmbedChain:
                 metadata.update(extra_metadata)
 
             response = requests.post(url, json={"metadata": metadata})
-            response.raise_for_status()
+            response.raise_for_status()