meshtastic-matrix-relay/main.py

"""
This script connects a Meshtastic mesh network to Matrix chat rooms by relaying messages between them.
It uses Meshtastic-python and Matrix nio client library to interface with the radio and the Matrix server respectively.
"""
import asyncio
import time
import logging
import re
import sqlite3
import yaml
import meshtastic.tcp_interface
import meshtastic.serial_interface
from nio import AsyncClient, AsyncClientConfig, MatrixRoom, RoomMessageText, RoomAliasEvent
from pubsub import pub
from yaml.loader import SafeLoader
from typing import List

bot_start_time = int(time.time() * 1000) # Timestamp when the bot starts, used to filter out old messages

logging.basicConfig()
logger = logging.getLogger(name="meshtastic.matrix.relay")

# Load configuration
with open("config.yaml", "r") as f:
    relay_config = yaml.load(f, Loader=SafeLoader)

logger.setLevel(getattr(logging, relay_config["logging"]["level"].upper()))

# Initialize SQLite database
def initialize_database():
    with sqlite3.connect("meshtastic.sqlite") as conn:
        cursor = conn.cursor()
        cursor.execute(
            "CREATE TABLE IF NOT EXISTS longnames (meshtastic_id TEXT PRIMARY KEY, longname TEXT)"
        )
        conn.commit()


# Get the longname for a given Meshtastic ID
def get_longname(meshtastic_id):
    with sqlite3.connect("meshtastic.sqlite") as conn:
        cursor = conn.cursor()
        cursor.execute(
            "SELECT longname FROM longnames WHERE meshtastic_id=?", (meshtastic_id,)
        )
        result = cursor.fetchone()
    return result[0] if result else None


def save_longname(meshtastic_id, longname):
    with sqlite3.connect("meshtastic.sqlite") as conn:
        cursor = conn.cursor()
        cursor.execute(
            "INSERT OR REPLACE INTO longnames (meshtastic_id, longname) VALUES (?, ?)",
            (meshtastic_id, longname),
        )
        conn.commit()


def update_longnames():
    if meshtastic_interface.nodes:
        for node in meshtastic_interface.nodes.values():
            user = node.get("user")
            if user:
                meshtastic_id = user["id"]
                longname = user.get("longName", "N/A")
                save_longname(meshtastic_id, longname)


async def join_matrix_room(matrix_client, room_id_or_alias: str) -> None:
    """Join a Matrix room by its ID or alias."""
    try:
        if room_id_or_alias.startswith("#"):
            response = await matrix_client.resolve_room_alias(room_id_or_alias)
            if not response.room_id:
                logger.error(f"Failed to resolve room alias '{room_id_or_alias}': {response.message}")
                return
            room_id = response.room_id
        else:
            room_id = room_id_or_alias

        if room_id not in matrix_client.rooms:
            response = await matrix_client.join(room_id)
            if response and hasattr(response, 'room_id'):
                logger.info(f"Joined room '{room_id_or_alias}' successfully")
            else:
                logger.error(f"Failed to join room '{room_id_or_alias}': {response.message}")
        else:
            logger.debug(f"Bot is already in room '{room_id_or_alias}'")
    except Exception as e:
        logger.error(f"Error joining room '{room_id_or_alias}': {e}")

# Initialize Meshtastic interface
connection_type = relay_config["meshtastic"]["connection_type"]
if connection_type == "serial":
    serial_port = relay_config["meshtastic"]["serial_port"]
    logger.info(f"Connecting to radio using serial port {serial_port} ...")
    meshtastic_interface = meshtastic.serial_interface.SerialInterface(serial_port)
else:
    target_host = relay_config["meshtastic"]["host"]
    logger.info(f"Connecting to radio at {target_host} ...")
    meshtastic_interface = meshtastic.tcp_interface.TCPInterface(hostname=target_host)

matrix_client = None

# Matrix configuration
matrix_homeserver = relay_config["matrix"]["homeserver"]
matrix_access_token = relay_config["matrix"]["access_token"]
bot_user_id = relay_config["matrix"]["bot_user_id"]
matrix_rooms: List[dict] = relay_config["matrix_rooms"]

# Send message to the Matrix room
async def matrix_relay(matrix_client, room_id, message, longname, meshnet_name):
    try:
        content = {
            "msgtype": "m.text",
            "body": message,
            "meshtastic_longname": longname,
            "meshtastic_meshnet": meshnet_name,
        }
        await asyncio.wait_for(
            matrix_client.room_send(
                room_id=room_id,
                message_type="m.room.message",
                content=content,
            ),
            timeout=0.5,
        )
        logger.info(f"Sent inbound radio message to matrix room: {room_id}")

    except asyncio.TimeoutError:
        logger.error(f"Timed out while waiting for Matrix response")
    except Exception as e:
        logger.error(f"Error sending radio message to matrix room {room_id}: {e}")


# Callback for new messages from Meshtastic
def on_meshtastic_message(packet, loop=None):
    sender = packet["fromId"]

    if "text" in packet["decoded"] and packet["decoded"]["text"]:
        text = packet["decoded"]["text"]

        if "channel" in packet:
            channel = packet["channel"]
        else:
            if packet["decoded"]["portnum"] == "TEXT_MESSAGE_APP":
                channel = 0
            else:
                logger.debug(f"Unknown packet")
                return

        # Check if the channel is mapped to a Matrix room in the configuration
        channel_mapped = False
        for room in matrix_rooms:
            if room["meshtastic_channel"] == channel:
                channel_mapped = True
                break

        if not channel_mapped:
            logger.debug(f"Skipping message from unmapped channel {channel}")
            return

        logger.info(f"Processing inbound radio message from {sender} on channel {channel}")

        longname = get_longname(sender) or sender
        meshnet_name = relay_config["meshtastic"]["meshnet_name"]

        formatted_message = f"[{longname}/{meshnet_name}]: {text}"
        logger.info(f"Relaying Meshtastic message from {longname} to Matrix: {formatted_message}")

        for room in matrix_rooms:
            if room["meshtastic_channel"] == channel:
                asyncio.run_coroutine_threadsafe(
                    matrix_relay(matrix_client, room["id"], formatted_message, longname, meshnet_name),
                    loop=loop,
                )
    else:
        portnum = packet["decoded"]["portnum"]
        if portnum == "TELEMETRY_APP":
            logger.debug("Ignoring Telemetry packet")
        elif portnum == "POSITION_APP":
            logger.debug("Ignoring Position packet")
        elif portnum == "ADMIN_APP":
            logger.debug("Ignoring Admin packet")
        else:
            logger.debug(f"Ignoring Unknown packet")



def truncate_message(text, max_bytes=234):  #234 is the maximum that we can run without an error. Trying it for awhile, otherwise lower this to 230 or less.
    """
    Truncate the given text to fit within the specified byte size.

    :param text: The text to truncate.
    :param max_bytes: The maximum allowed byte size for the truncated text.
    :return: The truncated text.
    """
    truncated_text = text.encode('utf-8')[:max_bytes].decode('utf-8', 'ignore')
    return truncated_text



# Callback for new messages in Matrix room
async def on_room_message(room: MatrixRoom, event: RoomMessageText) -> None:
    
    full_display_name = "Unknown user"
    if event.sender != bot_user_id:
        message_timestamp = event.server_timestamp

        if message_timestamp > bot_start_time:
            text = event.body.strip()
            
            # Remove unnecessary part of the message content
            split_content = text.split("]: ", 1)
            if len(split_content) > 1:
                text = split_content[1]

            logger.info(f"Processing matrix message from {event.sender}: {text}")

            longname = event.source['content'].get("meshtastic_longname")
            meshnet_name = event.source['content'].get("meshtastic_meshnet")
            local_meshnet_name = relay_config["meshtastic"]["meshnet_name"]

            if longname and meshnet_name:
                if meshnet_name != local_meshnet_name:
                    short_longname = longname[:3]
                    short_meshnet_name = meshnet_name[:4]
                    text = f"{short_longname}/{short_meshnet_name}: {text}"
                else:
                    logger.info("Ignoring message from the same meshnet.")
                    return
            else:
                display_name_response = await matrix_client.get_displayname(event.sender)
                full_display_name = display_name_response.displayname or event.sender
                short_display_name = full_display_name[:5]

                text = f"{short_display_name}[M]: {text}"

            text = truncate_message(text)

            # Find the corresponding room configuration
            room_config = None
            for config in matrix_rooms:
                if config["id"] == room.room_id:
                    room_config = config
                    break

            if room_config:
                meshtastic_channel = room_config["meshtastic_channel"]

                if relay_config["meshtastic"]["broadcast_enabled"]:
                    logger.info(f"Sending radio message from {full_display_name} to radio broadcast")
                    meshtastic_interface.sendText(
                        text=text, channelIndex=meshtastic_channel
                    )
                else:
                    logger.debug(f"Broadcast not supported: Message from {full_display_name} dropped.")



async def main():
    global matrix_client

    # Initialize the SQLite database
    initialize_database()

    config = AsyncClientConfig(encryption_enabled=False)
    matrix_client = AsyncClient(matrix_homeserver, bot_user_id, config=config)
    matrix_client.access_token = matrix_access_token

    logger.info("Connecting to Matrix server...")
    try:
        login_response = await matrix_client.login(matrix_access_token)
        logger.info(f"Login response: {login_response}")
    except Exception as e:
        logger.error(f"Error connecting to Matrix server: {e}")
        return
    
    # Join the rooms specified in the config.yaml
    for room in matrix_rooms:
        await join_matrix_room(matrix_client, room["id"])

    # Register the Meshtastic message callback
    logger.info(f"Listening for inbound radio messages ...")
    pub.subscribe(
        on_meshtastic_message, "meshtastic.receive", loop=asyncio.get_event_loop()
    )

    # Register the message callback
    logger.info(f"Listening for inbound matrix messages ...")
    matrix_client.add_event_callback(on_room_message, RoomMessageText)

    # Start the Matrix client
    while True:
        try:
            # Update longnames
            update_longnames()

            logger.info("Syncing with Matrix server...")
            await matrix_client.sync_forever(timeout=30000)
            logger.info("Sync completed.")
        except Exception as e:
            logger.error(f"Error syncing with Matrix server: {e}")

        await asyncio.sleep(60)  # Update longnames every 60 seconds

asyncio.run(main())