(interactions): Add interaction manager.

bot/meta/interactions/manager.py

@@ -0,0 +1,94 @@
+import asyncio
+from datetime import datetime, timedelta
+
+
+class InteractionManager:
+    def __init__(self, timeout=600, extend=None):
+        self.futures = []
+        self.self_futures = []
+
+        self.cleanup_function = self._cleanup
+        self.timeout_function = self._timeout
+        self.close_function = self._close
+
+        self.timeout = timeout
+        self.extend = extend or timeout
+        self.expires_at = None
+
+        self.cleaned_up = asyncio.Event()
+
+    async def _timeout_loop(self):
+        diff = self.expires_at - datetime.now()
+        while True:
+            try:
+                await asyncio.sleep(diff)
+            except asyncio.CancelledError:
+                break
+            diff = self.expires_at - datetime.now()
+            if diff <= 0:
+                asyncio.create_task(self.timeout())
+                break
+
+    def extend_timeout(self):
+        new_expiry = max(datetime.now() + timedelta(seconds=self.extend), self.expires_at)
+        self.expires_at = new_expiry
+
+    async def wait(self):
+        """
+        Wait until the manager is "done".
+        That is, until all the futures are done, or `closed` is set.
+        """
+        closed_task = asyncio.create_task(self.cleaned_up.wait())
+        futures_task = asyncio.create_task(asyncio.wait(self.futures))
+        await asyncio.wait((closed_task, futures_task), return_when=asyncio.FIRST_COMPLETED)
+
+    async def __aenter__(self):
+        if self.timeout is not None:
+            self.expires_at = datetime.now() + timedelta(seconds=self.timeout)
+            self.self_futures.append(asyncio.create_task(self._timeout_loop()))
+        return self
+
+    async def __aexit__(self, *args):
+        if not self.cleaned_up.is_set():
+            await self.cleanup(exiting=True)
+
+    async def _cleanup(self, manager, timeout=False, closing=False, exiting=False, **kwargs):
+        for future in self.futures:
+            future.cancel()
+        for future in self.self_futures:
+            future.cancel()
+        self.cleaned_up.set()
+
+    def on_cleanup(self, func):
+        self.cleanup_function = func
+        return func
+
+    async def cleanup(self, **kwargs):
+        await self.cleanup_function(self, **kwargs)
+
+    async def _timeout(self, manager, **kwargs):
+        await self.cleanup(timeout=True, **kwargs)
+
+    def on_timeout(self, func):
+        self.timeout_function = func
+        return func
+
+    async def timeout(self):
+        await self.timeout_function(self)
+
+    async def close(self, **kwargs):
+        """
+        Request closure of the manager.
+        """
+        await self.close_function(self, **kwargs)
+
+    def on_close(self, func):
+        self.close_function = func
+        return func
+
+    async def _close(self, manager, **kwargs):
+        await self.cleanup(closing=True, **kwargs)
+
+    def add_future(self, future):
+        self.futures.append(future)
+        return future