#!/usr/bin/env python3
import argparse
import asyncio
import logging
import os
import sys

from pyA20.gpio import gpio
from pyA20.gpio import port

logger = logging.getLogger(__name__)
bus = None
lock = asyncio.Lock()

PIN = port.PA10
OFF = 1
ON = 0


async def relay_set(value):
    async with lock:
        gpio.output(PIN, value)


async def relay_get():
    async with lock:
        return int(gpio.input(PIN)) == ON


async def handle_client(reader, writer):
    request = None
    while request != 'quit':
        try:
            request = await reader.read(255)
            if request == b'\x04':
                break
            request = request.decode('utf-8').strip()
        except Exception:
            break

        data = 'unknown'
        if request == 'on':
            await relay_set(ON)
            logger.info('set on')
            data = 'ok'

        elif request == 'off':
            await relay_set(OFF)
            logger.info('set off')
            data = 'ok'

        elif request == 'get':
            status = await relay_get()
            data = 'on' if status is True else 'off'

        writer.write((data + '\r\n').encode('utf-8'))
        try:
            await writer.drain()
        except ConnectionError:
            break

    try:
        writer.close()
    except ConnectionError:
        pass


async def run_server(host, port):
    server = await asyncio.start_server(handle_client, host, port)
    async with server:
        logger.info('Server started.')
        await server.serve_forever()


if __name__ == '__main__':
    if not os.getegid() == 0:
        sys.exit('Must be run as root.')

    parser = argparse.ArgumentParser()
    parser.add_argument('--host', type=str, default='127.0.0.1')
    parser.add_argument('--port', type=int, default=8307)

    args = parser.parse_args()
    logging.basicConfig(level=logging.INFO)

    gpio.init()
    gpio.setcfg(PIN, gpio.OUTPUT)

    try:
        asyncio.run(run_server(args.host, args.port))
    except KeyboardInterrupt:
        logging.info('Exiting...')