import logging
from subprocess import check_output, TimeoutExpired, CalledProcessError
from json import dumps
from sys import exit as sysexit, stdout
from time import sleep
from os import path

import paho.mqtt.client as mqtt
import paho.mqtt.enums as mqtt_enums

# Logger options
LOGFILE = '/mnt/logs/UPSmon.log'
if not path.exists("/mnt/logs"):
    LOGFILE = '/tmp/UPSmon.log'

#CONSOLE_DEBUG = logging.DEBUG
CONSOLE_DEBUG = logging.INFO
#FILE_DEBUG = logging.ERROR
#FILE_DEBUG = logging.WARNING
FILE_DEBUG = logging.INFO
#FILE_DEBUG = logging.DEBUG

LOG_FORMAT = ('%(asctime)s| %(levelname)-7s|%(funcName)-10s|%(lineno)-3d: %(message)-50s')
LOG_TIME_FORMAT = ('%m-%d %H:%M:%S')
LOGGER: logging.Logger

# UPSmon Config
CMD: list[str] = ['apcaccess', '-u']
T_LONG: float = 15.0
T_SHORT: float = 5.0
EXPORT_KEYS: list[str] = [
    'UPSNAME', 'STATUS', 'LINEV', 'LOADPCT', 'BCHARGE', 'TIMELEFT', 'ITEMP', 'BATTV', 'LINEFREQ'
]

def clean_data(v: str) -> float | str:
    if v.isalpha():
        return v
    return float(v)

def main() -> int:
    i: int = 0
    client: mqtt.Client = mqtt.Client(callback_api_version=mqtt_enums.CallbackAPIVersion.VERSION2)
    
    while client.connect(host='10.0.2.249', port=1883) != mqtt_enums.MQTTErrorCode.MQTT_ERR_SUCCESS:
        LOGGER.warning("MQTT Client retry connect")
        sleep(10.0)

    LOGGER.info("MQTT Client connected")
    client.loop_start()
    sleep(1.0)

    while client.is_connected():
        try:
            rv: bytes = check_output(CMD, timeout=2.0)
            data_raw: list[list[str]] = [
                l.split(':', 1) for l in rv.decode(encoding='ascii').splitlines()
            ]
            data = {
                k.strip().lower():clean_data(v.strip()) for k,v in data_raw if k.strip() in EXPORT_KEYS
            }
            LOGGER.debug(f"[{i}] {dumps(data, indent=2)}")
            
            tag: str = str(data.pop('upsname'))
            client.publish(topic='monitoring/ups/status',
                            payload=dumps(
                                obj=(data, {"upsname":tag})
                           ))
            
            sleep(T_LONG if data.get("status", "ONLINE") == "ONLINE" else T_SHORT)
            i += 1
        except KeyboardInterrupt:
            LOGGER.warning("Stopping...")
            client.loop_stop()
            client.disconnect()
            return 0
        except FileNotFoundError as f:
            LOGGER.error(f"{CMD} executable not found: {f}")
            return f.errno if f.errno else -1
        except CalledProcessError as e:
            LOGGER.error(f"{CMD} failed with: {e}")
            return e.returncode
        except TimeoutExpired as t:
            LOGGER.warning(f"{CMD} timed out: {t}")
            return int(t.timeout)
        except Exception as ee: # default case catch all
            LOGGER.error(f"Unexpected Exception: {ee}")
            return -3
        
    LOGGER.warning("MQTT Client Disconnected")
    return 1


if __name__ == "__main__":
    # Enabling Logger
    LOGGER = logging.getLogger(__name__)
    LOGGER.setLevel(logging.DEBUG)
    LOGGER.propagate = False
    formatter = logging.Formatter(LOG_FORMAT,LOG_TIME_FORMAT)

    # File logging
    fh = logging.FileHandler(LOGFILE)
    fh.setLevel(FILE_DEBUG)
    fh.setFormatter(formatter)
    LOGGER.addHandler(fh)

    # Console logging
    cl = logging.StreamHandler(stdout)
    cl.setLevel(CONSOLE_DEBUG)
    cl.setFormatter(formatter)
    LOGGER.addHandler(cl)

    LOGGER.warning("UPSmon started")

    while main() != 0:
        LOGGER.warning("Restarting...")
        sleep(30.0)
    sysexit(0)