From 75d1683b38e65855eb769f38cb06ca31cefaa606 Mon Sep 17 00:00:00 2001
From: Jean-Marie Mineau <jean-marie.mineau@protonmail.com>
Date: Sun, 3 Oct 2021 18:02:30 +0200
Subject: [PATCH] remember the sync token to avoid reloading the whole history

---
 .gitignore               |  3 +++
 requirements.txt         |  1 +
 setup.cfg                |  3 ++-
 src/matrix_bot/client.py | 46 ++++++++++++++++++++++++++++++++++------
 4 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/.gitignore b/.gitignore
index 29dba5a..e4a7426 100644
--- a/.gitignore
+++ b/.gitignore
@@ -137,3 +137,6 @@ dmypy.json
 
 # Cython debug symbols
 cython_debug/
+
+# Project specific files:
+.sync_token
diff --git a/requirements.txt b/requirements.txt
index 468ba73..111d322 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
 matrix-nio==0.18.7
+aiopath==0.5.12
diff --git a/setup.cfg b/setup.cfg
index a52660f..2b02687 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -11,7 +11,8 @@ packages = matrix_bot
 python_requires = >=3.9.2
 package_dir = =src
 install_requires = 
-		matrix-nio>=0.18.7
+	matrix-nio>=0.18.7
+	aiopath>=0.5.12
 
 [options.extras_require]
 testing = 
diff --git a/src/matrix_bot/client.py b/src/matrix_bot/client.py
index 693802b..ae7bc77 100644
--- a/src/matrix_bot/client.py
+++ b/src/matrix_bot/client.py
@@ -5,6 +5,7 @@ Connect to the matrix server and handle interactions with the server.
 
 import asyncio
 import nio
+from aiopath import AsyncPath
 from typing import (
     Optional,
     NoReturn,
@@ -32,6 +33,9 @@ class Client(Aobject):
     __client: nio.AsyncClient
     __rooms_by_aliases: dict[RoomAlias, Room]
     __rooms_by_id: dict[RoomId, Room]
+    __sync_token_file: AsyncPath
+    __sync_token:Optional[str]
+    __sync_token_queue:asyncio.Queue[str]
     allowed_rooms: Optional[dict[RoomId, Room]]
 
     async def __init__(
@@ -39,7 +43,8 @@ class Client(Aobject):
         username: str,
         homeserver: str,
         password: str,
-        allowed_rooms_names: Optional[list[Union[RoomAlias, RoomId]]]=None
+        allowed_rooms_names: Optional[list[Union[RoomAlias, RoomId]]]=None,
+        sync_token_file:str="./.sync_token",
     ):
         """
             Initialize the Client.
@@ -49,6 +54,9 @@ class Client(Aobject):
             allowed_rooms: the list of the rooms where the bot is allowed to connect
                 (given by room id (expl: '!xxx:matrix.org') of room alias (expl:
                 '#xxx:matrix.org'))
+            sync_token_file: the file where is stored the last sync token received from
+                the sync responses. This token avoid reloadind all the history of the
+                bot each time we start it.
         """
         self.__client = nio.AsyncClient(
             homeserver,
@@ -56,6 +64,13 @@ class Client(Aobject):
         )
         self.__rooms_by_aliases = {}
         self.__rooms_by_id = {}
+        self.__sync_token_file = AsyncPath(sync_token_file)
+        if (await self.__sync_token_file.is_file()):
+            async with self.__sync_token_file.open() as file:
+                self.__sync_token = (await file.read()).strip()
+        else:
+            self.__sync_token = None
+        self.__sync_token_queue = asyncio.Queue()
         resp = await self.__client.login(password)
         if isinstance(resp, nio.responses.LoginError):
             raise RuntimeError(f"Fail to connect: {resp.message}")
@@ -109,29 +124,46 @@ class Client(Aobject):
             self.__rooms_by_aliases[room_name] = room
             return room
 
-    async def sync(
+    async def __save_sync_tocken(self)->NoReturn:
+        """
+            Save the sync token.
+        """
+        while True:
+            token = await self.__sync_token_queue.get()
+            async with self.__sync_token_file.open(mode='w') as file:
+                await file.write(token)
+            self.__sync_token_queue.task_done()
+
+    async def __sync(
         self,
-        sync_delta:int=30
+        sync_timeout:int=30
     )->NoReturn:
         """
             Sync with the server every sync_delta seconds.
-            sync_delta: the time in sec between each sync.
+            sync_timeout: the max time in sec between each sync.
         """
         while True:
-            sync_resp = await self.__client.sync(sync_delta*1000)
+            sync_resp = await self.__client.sync(
+                sync_delta*1000,
+                since=self.__sync_token
+            )
             if isinstance(sync_resp, nio.responses.SyncError):
                 print(f"Error while syncronizing: {sync_resp.message}") # TODO: use proper logging
                 continue
+            self.__sync_token = sync_resp.next_batch
+            await self.__sync_token_queue.put(self.__sync_token)
 
     async def run(
         self,
-        sync_delta:int=30
+        sync_timeout:int=30
     )->NoReturn:
         """
             Run the bot: sync with the server and execute callbacks.
+            sync_timeout: the max time in sec between each sync.
         """
         await asyncio.gather(
-            self.sync(sync_delta=sync_delta)
+            self.__sync(sync_delta=sync_delta),
+            self.__save_sync_tocken()
         )