#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""
Module managing temperature in the shroombox.
"""

from os import getpid
import pigpio
from math import isnan
import logging
import time
from simple_pid import PID

__author__ = "Franek Łazarewicz-Muradyan"
__licence__ = "GPL"
__version__ = "0.0.1"
__status__ = "Proof of concept"

# **********************
# Hardware Settings
# **********************

# One wire temperature sensor settings
w1_sensor_id = '28-0517c1b121ff'
w1_sensor_f = f'/sys/devices/w1_bus_master1/{w1_sensor_id}/w1_slave'
# Heater settings
relay_pin = 5
mosfet_pin = 22

# **********************
# Software Settings
# **********************

timeformat = '%Y-%M-%d %H:%M:%S'
temperature_min = 20
temperature_max = 24
temperature_target = 20
read_retry = 3
logname = '/var/log/pipi/shroombox.log'
data_file = '/var/log/pipi/shroombox.csv'

# **********************
# PID Settings
# **********************
Kp = 1
Ki = 0.2
Kd = 0
sample_time = 10

# **********************
# Code
# **********************


logging.basicConfig(
    filename=logname,
    encoding='utf-8',
    filemode='a',
    format='%(asctime)s,%(msecs)d %(name)s%(levelname)s %(message)s', datefmt='%H:%M:%S',
    level=logging.DEBUG,
)
logging.info("Starting shroombox")
logger = logging.getLogger()


def read_temp(
        retry: int = 0,
) -> float:
    # If sensor is physically disconected, opening file will fail
    temperature = float('NaN')
    if retry > read_retry:
        return temperature
    with open(w1_sensor_f, 'r') as sensor:
        ok = sensor.readline()[-4:].strip('\n')
        if ok == 'YES':
            try:
                temperature = round(int(sensor.readline().split('=')[1])/1000, 1)
            except IndexError:  # TODO: What other exceptions?
                return temperature
        else:
            retry += 1
            read_temp(retry=retry)
    return temperature


def heater_on(
        temp: float,
        on: bool = False,
) -> bool:
    status = pio.read(relay_pin)
    timestamp = time.strftime(timeformat)
    # turning it off
    if not on:
        if status == 1:
            return False
        else:
            try:
                pio.write(relay_pin, 1)
                message = f"Turning off, temp: {temp}, {timestamp}"
                logger.info(message)
                return False
            except:  # TODO: documentation doesn't talk about exceptions on write
                return True
    # turning it on
    if on:
        if status == 0:
            return False
        else:
            try:
                pio.write(relay_pin, 0)
                message = f"Turning on, temp: {temp}, {timestamp}"
                logger.info(message)
                return False
            except:
                return True


def temp_control(
        current_temperature: float
) -> int:
    pid = PID(Kp, Ki, Kd, setpoint=temperature_target)
    pid.output_limits = (0, 255)
    pid.sample_time = sample_time
    return pid(current_temperature)


def main_alt():
    temp = read_temp_alt()
    timestamp = time.strftime(timeformat)
    print(temp)
    with open(data_file, 'a') as dat:
        dat.write(temp)
    frequency = temp_control(temp)
    try:
        pio.set_PWM_frequency(mosfet_pin, frequency)
    except (
        pio.PI_BAD_USER_GPIO,
        pio.PI_NOT_PERMITTED,
    ) as exc:
        logger.warning(f"Failed to set GPIO PWM frequency: {exc} {timestamp}")


def main():
    temp = read_temp()
    timestamp = time.strftime(timeformat)
    print(temp)
    if temp <= temperature_min:
        # if temp < temperature_min - 5:
        #     print(f"Heater doesn't work, battery empty?")
        #     logger.warning(f"Heater doesn't work, battery empty?")
        #     state = heater_on(temp, on=False)
        state = heater_on(temp, on=True)
        if state != 0:
            logger.warning(f"heater_on() method returned {state}, {timestamp}")
    elif temp >= temperature_max:
        state = heater_on(temp, on=False)
        if state != 0:
            logger.warning(f"heater_on() method returned {state} {timestamp}")
    elif isnan(temp):
        state = heater_on(temp, on=False)
        logging.warning(f"Cannot read temperature, check your connections! {timestamp}")


if __name__ == '__main__':
    with open('/run/shroombox.pid', 'w') as f:
        f.write(str(getpid()))
    while True:
        pio = pigpio.pi()
        main()
        time.sleep(30)