ChatManager to manage sending/receiving of chat messages (#143)

Co-authored-by: Théo Monnom <[email protected]>

Author: davidzhao

.github/workflows/tests.yml

@@ -17,9 +17,11 @@ jobs:
       - uses: actions/checkout@v3
         with:
           submodules: true
+          lfs: true
 
       - uses: actions/setup-python@v4
       - name: Run tests
         run: |
+          python3 ./livekit-rtc/rust-sdks/download_ffi.py --output livekit-rtc/livekit/rtc/resources
           pip3 install pytest ./livekit-protocol ./livekit-api ./livekit-rtc
-          pytest . --ignore=livekit-rtc/rust-sks
+          pytest . --ignore=livekit-rtc/rust-sdks

livekit-rtc/livekit/rtc/__init__.py

@@ -72,6 +72,7 @@
 )
 from .video_source import VideoSource
 from .video_stream import VideoStream
+from .chat import ChatManager, ChatMessage
 
 from .version import __version__
 
@@ -134,5 +135,7 @@
     "VideoFrameBuffer",
     "VideoSource",
     "VideoStream",
+    "ChatManager",
+    "ChatMessage",
     "__version__",
 ]

livekit-rtc/livekit/rtc/_utils.py

@@ -1,7 +1,22 @@
+# Copyright 2023 LiveKit, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import asyncio
 import logging
 from collections import deque
 import ctypes
+import random
 from typing import Callable, Generic, List, TypeVar
 
 logger = logging.getLogger("livekit")
@@ -101,3 +116,17 @@ async def join(self) -> None:
             subs = self._subscribers.copy()
             for queue in subs:
                 await queue.join()
+
+
+_base62_characters = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+
+def generate_random_base62(length=12):
+    """
+    Generate a random base62 encoded string of a specified length.
+
+    :param length: The desired length of the base62 encoded string.
+    :return: A base62 encoded string.
+    """
+    global _base62_characters
+    return "".join(random.choice(_base62_characters) for _ in range(length))

livekit-rtc/livekit/rtc/chat.py

@@ -0,0 +1,138 @@
+# Copyright 2023 LiveKit, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from dataclasses import dataclass, field
+from datetime import datetime
+import json
+import logging
+from typing import Any, Callable, Dict, Literal, Optional
+
+from .room import Room, Participant, DataPacket
+from ._event_emitter import EventEmitter
+from ._proto.room_pb2 import DataPacketKind
+from ._utils import generate_random_base62
+
+_CHAT_TOPIC = "lk-chat-topic"
+_CHAT_UPDATE_TOPIC = "lk-chat-update-topic"
+
+EventTypes = Literal["message_received",]
+
+
+class ChatManager(EventEmitter[EventTypes]):
+    """A utility class that sends and receives chat messages in the active session.
+
+    It implements LiveKit Chat Protocol, and serializes data to/from JSON data packets.
+    """
+
+    def __init__(self, room: Room):
+        super().__init__()
+        self._lp = room.local_participant
+        self._room = room
+
+        room.on("data_received", self._on_data_received)
+
+    def close(self):
+        self._room.off("data_received", self._on_data_received)
+
+    async def send_message(self, message: str) -> "ChatMessage":
+        """Send a chat message to the end user using LiveKit Chat Protocol.
+
+        Args:
+            message (str): the message to send
+
+        Returns:
+            ChatMessage: the message that was sent
+        """
+        msg = ChatMessage(
+            message=message,
+            is_local=True,
+            participant=self._lp,
+        )
+        await self._lp.publish_data(
+            payload=json.dumps(msg.asjsondict()),
+            kind=DataPacketKind.KIND_RELIABLE,
+            topic=_CHAT_TOPIC,
+        )
+        return msg
+
+    async def update_message(self, message: "ChatMessage"):
+        """Update a chat message that was previously sent.
+
+        If message.deleted is set to True, we'll signal to remote participants that the message
+        should be deleted.
+        """
+        await self._lp.publish_data(
+            payload=json.dumps(message.asjsondict()),
+            kind=DataPacketKind.KIND_RELIABLE,
+            topic=_CHAT_UPDATE_TOPIC,
+        )
+
+    def on_message(self, callback: Callable[["ChatMessage"], None]):
+        """Register a callback to be called when a chat message is received from the end user."""
+        self._callback = callback
+
+    def _on_data_received(self, dp: DataPacket):
+        # handle both new and updates the same way, as long as the ID is in there
+        # the user can decide how to replace the previous message
+        if dp.topic == _CHAT_TOPIC or dp.topic == _CHAT_UPDATE_TOPIC:
+            try:
+                parsed = json.loads(dp.data)
+                msg = ChatMessage.from_jsondict(parsed)
+                if dp.participant:
+                    msg.participant = dp.participant
+                self.emit("message_received", msg)
+            except Exception as e:
+                logging.warning("failed to parse chat message: %s", e, exc_info=e)
+
+
+@dataclass
+class ChatMessage:
+    message: Optional[str] = None
+    id: str = field(default_factory=generate_random_base62)
+    timestamp: datetime = field(default_factory=datetime.now)
+    deleted: bool = field(default=False)
+
+    # These fields are not part of the wire protocol. They are here to provide
+    # context for the application.
+    participant: Optional[Participant] = None
+    is_local: bool = field(default=False)
+
+    @classmethod
+    def from_jsondict(cls, d: Dict[str, Any]) -> "ChatMessage":
+        # older version of the protocol didn't contain a message ID, so we'll create one
+        id = d.get("id") or generate_random_base62()
+        timestamp = datetime.now()
+        if d.get("timestamp"):
+            timestamp = datetime.fromtimestamp(d.get("timestamp", 0) / 1000.0)
+        msg = cls(
+            id=id,
+            timestamp=timestamp,
+        )
+        msg.update_from_jsondict(d)
+        return msg
+
+    def update_from_jsondict(self, d: Dict[str, Any]) -> None:
+        self.message = d.get("message")
+        self.deleted = d.get("deleted", False)
+
+    def asjsondict(self):
+        """Returns a JSON serializable dictionary representation of the message."""
+        d = {
+            "id": self.id,
+            "message": self.message,
+            "timestamp": int(self.timestamp.timestamp() * 1000),
+        }
+        if self.deleted:
+            d["deleted"] = True
+        return d

livekit-rtc/tests/test_chat.py

@@ -0,0 +1,32 @@
+from datetime import datetime
+import json
+
+from livekit.rtc import ChatMessage
+
+
+def test_message_basics():
+    msg = ChatMessage()
+    assert msg.id is not None, "message id should be set"
+    assert msg.timestamp is not None, "timestamp should be set"
+    assert msg.timestamp.day == datetime.now().day, "timestamp should be today"
+    assert len(msg.id) > 5, "message id should be long enough"
+
+
+def test_message_serialization():
+    msg = ChatMessage(
+        message="hello",
+    )
+    data = msg.asjsondict()
+    msg2 = ChatMessage.from_jsondict(json.loads(json.dumps(data)))
+    assert msg2.message == msg.message, "message should be the same"
+    assert msg2.id == msg.id, "id should be the same"
+    assert int(msg2.timestamp.timestamp() / 1000) == int(
+        msg.timestamp.timestamp() / 1000
+    ), "timestamp should be the same"
+    assert not msg2.deleted, "not deleted"
+
+    # deletion is handled
+    msg.deleted = True
+    data = msg.asjsondict()
+    msg2 = ChatMessage.from_jsondict(json.loads(json.dumps(data)))
+    assert msg2.deleted, "should be deleted"