pandora/server/bumble_experimental/asha.py

# Copyright 2022 Google LLC
#
# 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
#
#     https://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 grpc
import logging
import struct

from bumble.core import AdvertisingData
from bumble.device import Connection, Connection as BumbleConnection, Device
from bumble.gatt import (
    GATT_ASHA_AUDIO_CONTROL_POINT_CHARACTERISTIC,
    GATT_ASHA_AUDIO_STATUS_CHARACTERISTIC,
    GATT_ASHA_LE_PSM_OUT_CHARACTERISTIC,
    GATT_ASHA_READ_ONLY_PROPERTIES_CHARACTERISTIC,
    GATT_ASHA_SERVICE,
    GATT_ASHA_VOLUME_CHARACTERISTIC,
    Characteristic,
    CharacteristicValue,
    TemplateService,
)
from bumble.l2cap import Channel
from bumble.pandora import utils
from bumble.utils import AsyncRunner
from google.protobuf.empty_pb2 import Empty  # pytype: disable=pyi-error
from pandora_experimental.asha_grpc_aio import AshaServicer
from pandora_experimental.asha_pb2 import CaptureAudioRequest, CaptureAudioResponse, RegisterRequest
from typing import AsyncGenerator, List, Optional


class AshaGattService(TemplateService):
    # TODO: update bumble and remove this when complete
    UUID = GATT_ASHA_SERVICE
    OPCODE_START = 1
    OPCODE_STOP = 2
    OPCODE_STATUS = 3
    PROTOCOL_VERSION = 0x01
    RESERVED_FOR_FUTURE_USE = [00, 00]
    FEATURE_MAP = [0x01]  # [LE CoC audio output streaming supported]
    SUPPORTED_CODEC_ID = [0x02, 0x01]  # Codec IDs [G.722 at 16 kHz]
    RENDER_DELAY = [00, 00]

    def __init__(self, capability: int, hisyncid: List[int], device: Device, psm: int = 0) -> None:
        self.hisyncid = hisyncid
        self.capability = capability  # Device Capabilities [Left, Monaural]
        self.device = device
        self.audio_out_data = b""
        self.psm: int = psm  # a non-zero psm is mainly for testing purpose

        logger = logging.getLogger(__name__)

        # Handler for volume control
        def on_volume_write(connection: Connection, value: bytes) -> None:
            logger.info(f"--- VOLUME Write:{value[0]}")
            self.emit("volume", connection, value[0])

        # Handler for audio control commands
        def on_audio_control_point_write(connection: Connection, value: bytes) -> None:
            logger.info(f"type {type(value)}")
            logger.info(f"--- AUDIO CONTROL POINT Write:{value.hex()}")
            opcode = value[0]
            if opcode == AshaGattService.OPCODE_START:
                # Start
                audio_type = ("Unknown", "Ringtone", "Phone Call", "Media")[value[2]]
                logger.info(
                    f"### START: codec={value[1]}, "
                    f"audio_type={audio_type}, "
                    f"volume={value[3]}, "
                    f"otherstate={value[4]}"
                )
                self.emit(
                    "start",
                    connection,
                    {
                        "codec": value[1],
                        "audiotype": value[2],
                        "volume": value[3],
                        "otherstate": value[4],
                    },
                )
            elif opcode == AshaGattService.OPCODE_STOP:
                logger.info("### STOP")
                self.emit("stop", connection)
            elif opcode == AshaGattService.OPCODE_STATUS:
                logger.info(f"### STATUS: connected={value[1]}")

            # OPCODE_STATUS does not need audio status point update
            if opcode != AshaGattService.OPCODE_STATUS:
                AsyncRunner.spawn(device.notify_subscribers(self.audio_status_characteristic, force=True))  # type: ignore[no-untyped-call]

        def on_read_only_properties_read(connection: Connection) -> bytes:
            value = (
                bytes(
                    [
                        AshaGattService.PROTOCOL_VERSION,  # Version
                        self.capability,
                    ]
                )
                + bytes(self.hisyncid)
                + bytes(AshaGattService.FEATURE_MAP)
                + bytes(AshaGattService.RENDER_DELAY)
                + bytes(AshaGattService.RESERVED_FOR_FUTURE_USE)
                + bytes(AshaGattService.SUPPORTED_CODEC_ID)
            )
            self.emit("read_only_properties", connection, value)
            return value

        def on_le_psm_out_read(connection: Connection) -> bytes:
            self.emit("le_psm_out", connection, self.psm)
            return struct.pack("<H", self.psm)

        self.read_only_properties_characteristic = Characteristic(
            GATT_ASHA_READ_ONLY_PROPERTIES_CHARACTERISTIC,
            Characteristic.READ,
            Characteristic.READABLE,
            CharacteristicValue(read=on_read_only_properties_read),  # type: ignore[no-untyped-call]
        )

        self.audio_control_point_characteristic = Characteristic(
            GATT_ASHA_AUDIO_CONTROL_POINT_CHARACTERISTIC,
            Characteristic.WRITE | Characteristic.WRITE_WITHOUT_RESPONSE,
            Characteristic.WRITEABLE,
            CharacteristicValue(write=on_audio_control_point_write),  # type: ignore[no-untyped-call]
        )
        self.audio_status_characteristic = Characteristic(
            GATT_ASHA_AUDIO_STATUS_CHARACTERISTIC,
            Characteristic.READ | Characteristic.NOTIFY,
            Characteristic.READABLE,
            bytes([0]),
        )
        self.volume_characteristic = Characteristic(
            GATT_ASHA_VOLUME_CHARACTERISTIC,
            Characteristic.WRITE_WITHOUT_RESPONSE,
            Characteristic.WRITEABLE,
            CharacteristicValue(write=on_volume_write),  # type: ignore[no-untyped-call]
        )

        # Register an L2CAP CoC server
        def on_coc(channel: Channel) -> None:
            def on_data(data: bytes) -> None:
                logging.debug(f"data received:{data.hex()}")

                self.emit("data", channel.connection, data)
                self.audio_out_data += data

            channel.sink = on_data  # type: ignore[no-untyped-call]

        # let the server find a free PSM
        self.psm = self.device.register_l2cap_channel_server(self.psm, on_coc, 8)  # type: ignore[no-untyped-call]
        self.le_psm_out_characteristic = Characteristic(
            GATT_ASHA_LE_PSM_OUT_CHARACTERISTIC,
            Characteristic.READ,
            Characteristic.READABLE,
            CharacteristicValue(read=on_le_psm_out_read),  # type: ignore[no-untyped-call]
        )

        characteristics = [
            self.read_only_properties_characteristic,
            self.audio_control_point_characteristic,
            self.audio_status_characteristic,
            self.volume_characteristic,
            self.le_psm_out_characteristic,
        ]

        super().__init__(characteristics)  # type: ignore[no-untyped-call]

    def get_advertising_data(self) -> bytes:
        # Advertisement only uses 4 least significant bytes of the HiSyncId.
        return bytes(
            AdvertisingData(
                [
                    (
                        AdvertisingData.SERVICE_DATA_16_BIT_UUID,
                        bytes(GATT_ASHA_SERVICE)
                        + bytes(
                            [
                                AshaGattService.PROTOCOL_VERSION,
                                self.capability,
                            ]
                        )
                        + bytes(self.hisyncid[:4]),
                    ),
                ]
            )
        )


class AshaService(AshaServicer):
    device: Device
    asha_service: Optional[AshaGattService]

    def __init__(self, device: Device) -> None:
        self.log = utils.BumbleServerLoggerAdapter(logging.getLogger(), {"service_name": "Asha", "device": device})
        self.device = device
        self.asha_service = None

    @utils.rpc
    async def Register(self, request: RegisterRequest, context: grpc.ServicerContext) -> Empty:
        logging.info("Register")
        # asha service from bumble profile
        self.asha_service = AshaGattService(request.capability, request.hisyncid, self.device)
        self.device.add_service(self.asha_service)  # type: ignore[no-untyped-call]
        return Empty()

    @utils.rpc
    async def CaptureAudio(
        self, request: CaptureAudioRequest, context: grpc.ServicerContext
    ) -> AsyncGenerator[CaptureAudioResponse, None]:
        connection_handle = int.from_bytes(request.connection.cookie.value, "big")
        logging.info(f"CaptureAudioData connection_handle:{connection_handle}")

        if not (connection := self.device.lookup_connection(connection_handle)):
            raise RuntimeError(f"Unknown connection for connection_handle:{connection_handle}")

        queue: asyncio.Queue[bytes] = asyncio.Queue()

        def on_data(asha_connection: BumbleConnection, data: bytes) -> None:
            if asha_connection == connection:
                queue.put_nowait(data)

        self.asha_service.on("data", on_data)  # type: ignore

        try:
            while data := await queue.get():
                yield CaptureAudioResponse(data=data)
        finally:
            self.asha_service.remove_listener("data", on_data)  # type: ignore