Add bot outgoing 2s throttle

app/bot.py

@@ -12,6 +12,7 @@ the security implications.
 
 import asyncio
 import logging
+import time
 from concurrent.futures import ThreadPoolExecutor
 from typing import Any
 
@@ -28,6 +29,14 @@ _bot_executor = ThreadPoolExecutor(max_workers=3, thread_name_prefix="bot_")
 # Timeout for bot code execution (seconds)
 BOT_EXECUTION_TIMEOUT = 10
 
+# Minimum spacing between bot message sends (seconds)
+# This ensures repeaters have time to return to listening mode
+BOT_MESSAGE_SPACING = 2.0
+
+# Global state for rate limiting bot sends
+_bot_send_lock = asyncio.Lock()
+_last_bot_send_time: float = 0.0
+
 
 def execute_bot_code(
     code: str,
@@ -124,35 +133,57 @@ async def process_bot_response(
     For DMs, sends a direct message back to the sender.
     For channel messages, sends to the same channel.
 
+    Bot messages are rate-limited to ensure at least BOT_MESSAGE_SPACING seconds
+    between sends, giving repeaters time to return to listening mode.
+
     Args:
         response: The response text to send
         is_dm: Whether the original message was a DM
         sender_key: Public key of the original sender (for DM replies)
         channel_key: Channel key for channel message replies
     """
+    global _last_bot_send_time
+
     from app.models import SendChannelMessageRequest, SendDirectMessageRequest
     from app.routers.messages import send_channel_message, send_direct_message
     from app.websocket import broadcast_event
 
-    try:
-        if is_dm:
-            logger.info("Bot sending DM reply to %s", sender_key[:12])
-            request = SendDirectMessageRequest(destination=sender_key, text=response)
-            message = await send_direct_message(request)
-            # Broadcast to WebSocket (endpoint returns to HTTP caller, bot needs explicit broadcast)
-            broadcast_event("message", message.model_dump())
-        elif channel_key:
-            logger.info("Bot sending channel reply to %s", channel_key[:8])
-            request = SendChannelMessageRequest(channel_key=channel_key, text=response)
-            message = await send_channel_message(request)
-            # Broadcast to WebSocket
-            broadcast_event("message", message.model_dump())
-        else:
-            logger.warning("Cannot send bot response: no destination")
-    except HTTPException as e:
-        logger.error("Bot failed to send response: %s", e.detail)
-    except Exception as e:
-        logger.error("Bot failed to send response: %s", e)
+    # Serialize bot sends and enforce minimum spacing
+    async with _bot_send_lock:
+        # Calculate how long since last bot send
+        now = time.monotonic()
+        time_since_last = now - _last_bot_send_time
+
+        if _last_bot_send_time > 0 and time_since_last < BOT_MESSAGE_SPACING:
+            wait_time = BOT_MESSAGE_SPACING - time_since_last
+            logger.debug("Rate limiting bot send, waiting %.2fs", wait_time)
+            await asyncio.sleep(wait_time)
+
+        try:
+            if is_dm:
+                logger.info("Bot sending DM reply to %s", sender_key[:12])
+                request = SendDirectMessageRequest(destination=sender_key, text=response)
+                message = await send_direct_message(request)
+                # Broadcast to WebSocket (endpoint returns to HTTP caller, bot needs explicit broadcast)
+                broadcast_event("message", message.model_dump())
+            elif channel_key:
+                logger.info("Bot sending channel reply to %s", channel_key[:8])
+                request = SendChannelMessageRequest(channel_key=channel_key, text=response)
+                message = await send_channel_message(request)
+                # Broadcast to WebSocket
+                broadcast_event("message", message.model_dump())
+            else:
+                logger.warning("Cannot send bot response: no destination")
+                return  # Don't update timestamp if we didn't send
+        except HTTPException as e:
+            logger.error("Bot failed to send response: %s", e.detail)
+            return  # Don't update timestamp on failure
+        except Exception as e:
+            logger.error("Bot failed to send response: %s", e)
+            return  # Don't update timestamp on failure
+
+        # Update last send time after successful send
+        _last_bot_send_time = time.monotonic()
 
 
 async def run_bot_for_message(

tests/test_bot.py

@@ -1,12 +1,16 @@
 """Tests for the bot execution module."""
 
+import asyncio
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
+import app.bot as bot_module
 from app.bot import (
+    BOT_MESSAGE_SPACING,
     _bot_semaphore,
     execute_bot_code,
+    process_bot_response,
     run_bot_for_message,
 )
 
@@ -381,3 +385,226 @@ class TestBotCodeValidation:
         # Should not raise
         validate_bot_code("")
         validate_bot_code("   ")
+
+
+class TestBotMessageRateLimiting:
+    """Test bot message rate limiting for repeater compatibility."""
+
+    @pytest.fixture(autouse=True)
+    def reset_rate_limit_state(self):
+        """Reset rate limiting state between tests."""
+        bot_module._last_bot_send_time = 0.0
+        yield
+        bot_module._last_bot_send_time = 0.0
+
+    @pytest.mark.asyncio
+    async def test_first_send_does_not_wait(self):
+        """First bot send should not wait (no previous send)."""
+        with (
+            patch("app.bot.time.monotonic", return_value=100.0),
+            patch("app.bot.asyncio.sleep", new_callable=AsyncMock) as mock_sleep,
+            patch("app.routers.messages.send_direct_message", new_callable=AsyncMock) as mock_send,
+            patch("app.websocket.broadcast_event"),
+        ):
+            mock_message = MagicMock()
+            mock_message.model_dump.return_value = {}
+            mock_send.return_value = mock_message
+
+            await process_bot_response(
+                response="Hello!",
+                is_dm=True,
+                sender_key="abc123def456" * 4,  # 64 chars
+                channel_key=None,
+            )
+
+            # Should not have slept (first send, _last_bot_send_time was 0)
+            mock_sleep.assert_not_called()
+            mock_send.assert_called_once()
+
+    @pytest.mark.asyncio
+    async def test_rapid_second_send_waits(self):
+        """Second send within spacing window should wait."""
+        # Previous send was at 100.0, current time is 100.5 (0.5 seconds later)
+        # So we need to wait 1.5 more seconds to reach 2.0 second spacing
+        bot_module._last_bot_send_time = 100.0
+
+        with (
+            patch("app.bot.time.monotonic", return_value=100.5),
+            patch("app.bot.asyncio.sleep", new_callable=AsyncMock) as mock_sleep,
+            patch("app.routers.messages.send_direct_message", new_callable=AsyncMock) as mock_send,
+            patch("app.websocket.broadcast_event"),
+        ):
+            mock_message = MagicMock()
+            mock_message.model_dump.return_value = {}
+            mock_send.return_value = mock_message
+
+            await process_bot_response(
+                response="Hello again!",
+                is_dm=True,
+                sender_key="abc123def456" * 4,
+                channel_key=None,
+            )
+
+            # Should have waited 1.5 seconds (2.0 - 0.5 elapsed)
+            mock_sleep.assert_called_once()
+            wait_time = mock_sleep.call_args[0][0]
+            assert abs(wait_time - 1.5) < 0.01
+
+    @pytest.mark.asyncio
+    async def test_send_after_spacing_does_not_wait(self):
+        """Send after spacing window should not wait."""
+        # Simulate a previous send 3 seconds ago (> BOT_MESSAGE_SPACING)
+        bot_module._last_bot_send_time = 97.0
+
+        with (
+            patch("app.bot.time.monotonic", return_value=100.0),
+            patch("app.bot.asyncio.sleep", new_callable=AsyncMock) as mock_sleep,
+            patch("app.routers.messages.send_direct_message", new_callable=AsyncMock) as mock_send,
+            patch("app.websocket.broadcast_event"),
+        ):
+            mock_message = MagicMock()
+            mock_message.model_dump.return_value = {}
+            mock_send.return_value = mock_message
+
+            await process_bot_response(
+                response="Hello!",
+                is_dm=True,
+                sender_key="abc123def456" * 4,
+                channel_key=None,
+            )
+
+            # Should not have slept (3 seconds > 2 second spacing)
+            mock_sleep.assert_not_called()
+
+    @pytest.mark.asyncio
+    async def test_timestamp_updated_after_successful_send(self):
+        """Last send timestamp should be updated after successful send."""
+        with (
+            patch("app.bot.time.monotonic", return_value=150.0),
+            patch("app.routers.messages.send_direct_message", new_callable=AsyncMock) as mock_send,
+            patch("app.websocket.broadcast_event"),
+        ):
+            mock_message = MagicMock()
+            mock_message.model_dump.return_value = {}
+            mock_send.return_value = mock_message
+
+            await process_bot_response(
+                response="Hello!",
+                is_dm=True,
+                sender_key="abc123def456" * 4,
+                channel_key=None,
+            )
+
+            assert bot_module._last_bot_send_time == 150.0
+
+    @pytest.mark.asyncio
+    async def test_timestamp_not_updated_on_failure(self):
+        """Last send timestamp should NOT be updated if send fails."""
+        from fastapi import HTTPException
+
+        bot_module._last_bot_send_time = 50.0  # Previous timestamp
+
+        with (
+            patch("app.bot.time.monotonic", return_value=100.0),
+            patch(
+                "app.routers.messages.send_direct_message",
+                new_callable=AsyncMock,
+                side_effect=HTTPException(status_code=500, detail="Send failed"),
+            ),
+        ):
+            await process_bot_response(
+                response="Hello!",
+                is_dm=True,
+                sender_key="abc123def456" * 4,
+                channel_key=None,
+            )
+
+            # Timestamp should remain unchanged
+            assert bot_module._last_bot_send_time == 50.0
+
+    @pytest.mark.asyncio
+    async def test_timestamp_not_updated_on_no_destination(self):
+        """Last send timestamp should NOT be updated if no destination."""
+        bot_module._last_bot_send_time = 50.0
+
+        with patch("app.bot.time.monotonic", return_value=100.0):
+            await process_bot_response(
+                response="Hello!",
+                is_dm=False,  # Not a DM
+                sender_key="",
+                channel_key=None,  # No channel either
+            )
+
+            # Timestamp should remain unchanged
+            assert bot_module._last_bot_send_time == 50.0
+
+    @pytest.mark.asyncio
+    async def test_concurrent_sends_are_serialized(self):
+        """Multiple concurrent sends should be serialized by the lock."""
+        send_order = []
+        send_times = []
+
+        async def mock_send(*args, **kwargs):
+            send_order.append(len(send_order))
+            send_times.append(bot_module.time.monotonic())
+            mock_message = MagicMock()
+            mock_message.model_dump.return_value = {}
+            return mock_message
+
+        # Use a real monotonic-like counter for this test
+        time_counter = [100.0]
+
+        def mock_monotonic():
+            return time_counter[0]
+
+        async def mock_sleep(duration):
+            time_counter[0] += duration
+
+        with (
+            patch("app.bot.time.monotonic", side_effect=mock_monotonic),
+            patch("app.bot.asyncio.sleep", side_effect=mock_sleep),
+            patch("app.routers.messages.send_direct_message", side_effect=mock_send),
+            patch("app.websocket.broadcast_event"),
+        ):
+            # Launch 3 concurrent sends
+            await asyncio.gather(
+                process_bot_response("Msg 1", True, "a" * 64, None),
+                process_bot_response("Msg 2", True, "b" * 64, None),
+                process_bot_response("Msg 3", True, "c" * 64, None),
+            )
+
+            # All 3 should have sent
+            assert len(send_order) == 3
+
+            # Each send should be at least BOT_MESSAGE_SPACING apart
+            # First send at 100, second at 102, third at 104
+            assert send_times[1] >= send_times[0] + BOT_MESSAGE_SPACING - 0.01
+            assert send_times[2] >= send_times[1] + BOT_MESSAGE_SPACING - 0.01
+
+    @pytest.mark.asyncio
+    async def test_channel_message_rate_limited(self):
+        """Channel message sends should also be rate limited."""
+        bot_module._last_bot_send_time = 99.0  # 1 second ago
+
+        with (
+            patch("app.bot.time.monotonic", return_value=100.0),
+            patch("app.bot.asyncio.sleep", new_callable=AsyncMock) as mock_sleep,
+            patch("app.routers.messages.send_channel_message", new_callable=AsyncMock) as mock_send,
+            patch("app.websocket.broadcast_event"),
+        ):
+            mock_message = MagicMock()
+            mock_message.model_dump.return_value = {}
+            mock_send.return_value = mock_message
+
+            await process_bot_response(
+                response="Channel hello!",
+                is_dm=False,
+                sender_key="",
+                channel_key="AABBCCDD" * 4,
+            )
+
+            # Should have waited 1 second (2.0 - 1.0 elapsed)
+            mock_sleep.assert_called_once()
+            wait_time = mock_sleep.call_args[0][0]
+            assert abs(wait_time - 1.0) < 0.01
+            mock_send.assert_called_once()