import os
DEBUG = os.environ.get('DEBUG')

import logging
logging.basicConfig(
    format='[%(asctime)s] %(levelname)s %(module)s/%(funcName)s - %(message)s',
    level=logging.DEBUG if DEBUG else logging.INFO)

import json
from telethon import TelegramClient, events
from asyncio_mqtt import Client

import settings


STORAGE_FILE = 'data/data.json'
storage = dict(nodes={})
def save_data():
    with open(STORAGE_FILE, 'w') as f:
        json.dump(storage, f, sort_keys=True, indent=4)
try:
    storage = json.load(open(STORAGE_FILE))
except FileNotFoundError:
    save_data()


bot = TelegramClient('data/bot', settings.API_ID, settings.API_HASH).start(bot_token=settings.API_TOKEN)

def int_to_mesh_id(num):
    # converts signed 32-bit ints to unsigned hex meshtastic IDs
    # example: -697240346 to !d670f4e6

    hex_str = hex(num & 0xFFFFFFFF)
    return '!' + hex_str[2:].zfill(8)

async def process_text(data):
    msg_to = data.get('to', None)

    if msg_to not in [-1, 4294967295]:
        logging.debug('Message not for channel: %s', str(data))
        return

    try:
        msg_text = data['payload']['text']
        sender = data['from']
    except (KeyError, TypeError):
        logging.info('Invalid payload: %s', str(data))
        return

    sender_id = int_to_mesh_id(sender)

    try:
        from_name = storage['nodes'][sender_id]['long_name']
    except (KeyError, TypeError):
        from_name = sender_id

    logging.info('Channel message from %s: %s', from_name, msg_text)

    msg = from_name + ': ' + msg_text
    await bot.send_message(settings.CHAT_ID, msg, link_preview=False)

async def process_info(data):
    try:
        node_id = data['payload']['id']
        long_name = data['payload']['longname']
        short_name = data['payload']['shortname']
    except (KeyError, TypeError):
        logging.info('Invalid payload: %s', str(data))
        return

    logging.info('Node %s info: %s (%s)', node_id, long_name, short_name)

    storage['nodes'][node_id] = dict(
        node_id=node_id,
        long_name=long_name,
        short_name=short_name,
    )
    save_data()


async def process_mqtt(message):
    try:
        text = message.payload.decode()
    except UnicodeDecodeError:
        logging.info('Problem decoding unicode: %s', message.payload)
        return

    topic = message.topic
    logging.debug('MQTT topic: %s, message: %s', topic, text)

    try:
        data = json.loads(text)
    except json.JSONDecodeError:
        logging.info('Problem decoding json: %s', text)
        return

    if type(data) != dict or 'id' not in data:
        logging.info('Not valid Meshtastic message: %s', text)
        return

    msg_type = data.get('type', '')

    if msg_type == 'text':
        await process_text(data)
    elif msg_type == 'nodeinfo':
        await process_info(data)
    else:
        logging.debug('Ignored message type %s: %s', msg_type, text)
        return

async def fetch_mqtt():
    async with Client('localhost') as client:
        async with client.filtered_messages('msh/+/+/json/#') as messages:
            await client.subscribe('msh/+/+/json/#')
            async for message in messages:
                await process_mqtt(message)

with bot:
    bot.loop.create_task(fetch_mqtt())
    bot.run_until_disconnected()