feat(watcher,api,frontend): archive who writes to watched bots over mtproto

backend/src/watcher/runner.py

@@ -0,0 +1,72 @@
+import asyncio
+import contextlib
+import signal
+
+import asyncpg
+import uvloop
+
+from dependencies.container import container
+from utils.env import env
+from utils.logging import logger, setup_logging
+from utils.read.bots import BOTS_CHANGED_CHANNEL
+from watcher.registry import BotRegistry
+
+setup_logging()
+
+RETRY_INTERVAL = 300
+
+
+async def _retry_loop(registry: BotRegistry) -> None:
+    while True:
+        await asyncio.sleep(RETRY_INTERVAL)
+        with contextlib.suppress(Exception):
+            await registry.sync()
+
+
+async def _listen_changes(
+    registry: BotRegistry, tasks: set[asyncio.Task]
+) -> asyncpg.Connection:
+    def on_change(
+        _conn: asyncpg.Connection, _pid: int, _channel: str, _payload: str
+    ) -> None:
+        task = asyncio.create_task(registry.sync())
+        tasks.add(task)
+        task.add_done_callback(tasks.discard)
+
+    conn = await asyncpg.connect(dsn=env.db.connection_url)
+    await conn.add_listener(BOTS_CHANGED_CHANNEL, on_change)
+    return conn
+
+
+async def runner() -> None:
+    pool = await container.get(asyncpg.Pool)
+    registry = BotRegistry(pool)
+    tasks: set[asyncio.Task] = set()
+    listen_conn: asyncpg.Connection | None = None
+    stop = asyncio.Event()
+    asyncio.get_running_loop().add_signal_handler(signal.SIGTERM, stop.set)
+    retry = asyncio.create_task(_retry_loop(registry))
+    try:
+        await registry.sync()
+        if not registry.running:
+            logger.warning("[yellow]No bots yet. Add a bot token in the web UI.[/]")
+        listen_conn = await _listen_changes(registry, tasks)
+        logger.info("[green]Bot watcher running.[/]")
+        await stop.wait()
+    finally:
+        retry.cancel()
+        with contextlib.suppress(asyncio.CancelledError):
+            await retry
+        if listen_conn is not None:
+            with contextlib.suppress(Exception):
+                await listen_conn.close()
+        await registry.close()
+        await container.close()
+
+
+def main() -> None:
+    uvloop.install()
+    logger.info("Starting bot watcher...")
+    with contextlib.suppress(KeyboardInterrupt):
+        asyncio.run(runner())
+    logger.info("[red]Bot watcher stopped.[/]")