import os
import sys
import time
import string
import serial
import logging
import signal
import json

# Get environment variables
env = dict(os.environ)
LOGGER: logging.Logger

class Runner:
    running: bool = True
    def __init__(self):
        signal.signal(signal.SIGINT, self.stop)
        signal.signal(signal.SIGTERM, self.stop)

    def stop(self, _): 
        self.running = False

def send(port: serial.Serial, d: str):
    port.write((d+'\r').encode('ascii'))
    port.flush()

def receive(port: serial.Serial, d: str) -> str:
    r = port.read_until(b'\r').decode('ascii').rstrip()
    LOGGER.debug(f"{d} : {r}")
    return r

def bruteforceCommands(port: serial.Serial):
    # T and S cause unwanted shutdown
    letters = string.ascii_uppercase.replace('T','').replace('S','') 
    LOGGER.debug(f"Test commands: {letters}")
    for c in letters:
        send(port, c)
        receive(port, c)
        for n in range(10):
            d = c+f"{n:1d}"
            send(port, d)
            receive(port, d)
        for n in range(100):
            d = c+f"{n:02d}"
            send(port, d)
            receive(port, d)

def main():
    INTERVAL = int(env['INTERVAL'])
    run = Runner.running
    port = serial.Serial(port=env['PORT'], baudrate=int(env['BAUD']), bytesize=8, parity='N', stopbits=1)
    while run:
        try:
            send(port, "Q1")
            data = receive(port, "Q1").lstrip('(').split()
            if len(data) < 8:
                LOGGER.error(f"Incomplete data: {data}")
                continue
            values = {
                'inV': float(data[0]),
                'outV': float(data[2]),
                'loadPercent': float(data[3]),
                'lineFreq': float(data[4]),
                'timeLeft': float(data[5]),
                'onBatt': True if str(data[7]).startswith('1') else False,
                'onLine': True if str(data[7]).endswith('1') else False,
            }
            LOGGER.debug(f"UPS Status: \n{json.dumps(values, indent=2)}")
            time.sleep(INTERVAL)
        except KeyboardInterrupt:
            run = False
        except Exception as e:
            print(f"Unexpected exception: [{e}]")
            return 1
    port.close()


if __name__ == "__main__":
    # Logger Constants 
    LOG_FORMAT = '%(asctime)s| %(levelname)-7s|%(funcName)-10s|%(lineno)-3d: %(message)-50s'

    # Enabling Logger 
    LOGGER = logging.getLogger(__name__)
    LOGGER.setLevel(logging.DEBUG)
    LOGGER.propagate = False
    formatter = logging.Formatter(LOG_FORMAT, None)
    levels = logging.getLevelNamesMapping()

    # File logging 
    log_name = os.path.abspath(env['LOG_FILE'])
    fh = logging.FileHandler(log_name)
    fh.setLevel(levels[env['LOG_FILE_LVL']])
    fh.setFormatter(formatter)
    LOGGER.addHandler(fh)

    # Console logging 
    cl = logging.StreamHandler(sys.stdout)
    cl.setLevel(levels[env['LOG_CLI_LVL']])
    cl.setFormatter(formatter)
    LOGGER.addHandler(cl)

    LOGGER.warning(f"UPSmon started on: {time.asctime()}")
    
    while main():
        LOGGER.error("Main thread exited unexpectedly")
        time.sleep(15)
    sys.exit(0)