#!/usr/bin/env python
import glob
import logging
import re
import sys
from time import sleep

import yaml
from simple_pid import PID

SYSFS_HWMON_BASE = "/sys/class/hwmon/"


class ThermalZone:
    def __init__(self, config, hwmon_map) -> None:
        self.fans = config["fan"]
        self.temp_source = config["source"]
        self.pid = PID(config["pid"]["p"], config["pid"]["i"], config["pid"]["d"], setpoint=0)
        self.pid.output_limits = (0, 255)
        self.factor = 1 / config["factor"]
        self.name = config["name"]
        self.target = config["target"]
        self.hwname = config["hwmon"]
        self.hwmap = hwmon_map
        self.alias_replace = re.compile('|'.join(self.hwmap.keys()))
        self.setup_pwm()

        logging.getLogger("pyfan").info(
            "[{zone}] Source={source} Fans={fans} Factor={factor} PID={pid}".format(zone=self.name,
                                                                                    source=self.temp_source,
                                                                                    fans=self.fans,
                                                                                    factor=self.factor,
                                                                                    pid=(
                                                                                        self.pid.Kp, self.pid.Ki,
                                                                                        self.pid.Kd)))

    def eval(self):
        diff = self.target - self.get_temp()
        val = self.pid(diff)

        try:
            for target_fan in self.fans:
                if type(target_fan) is dict:
                    self.write_sysfs(list(target_fan.keys())[0], min(int(val), list(target_fan.values())[0]))
                else:
                    self.write_sysfs(target_fan, int(val))
        except OSError as err:
            logging.getLogger("pyfan").warning(
                "[%s] Failed to set pwm, trying to reset it. (%s)" % (self.name, err.strerror))
            self.setup_pwm(1)

        p, i, d = self.pid.components

        logging.getLogger("pyfan").debug(
            "[{name}] {val}% ({diff}C/{temp}C) ({p}|{i}|{d})".format(name=self.name, val=int(val / 255 * 100),
                                                                     diff=diff,
                                                                     temp=self.get_temp(), p=int(p), i=int(i),
                                                                     d=int(d)))

    def get_temp(self):
        return float(self.read_sysfs(self.temp_source)) * self.factor

    def restore(self):
        self.setup_pwm(2)

    def setup_pwm(self, value=1):
        for target_fan in self.fans:
            try:
                if type(target_fan) is dict:
                    self.set_pwm_mode(list(target_fan.keys())[0], value)
                else:
                    self.set_pwm_mode(target_fan, value)
            except FileNotFoundError as err:
                logging.getLogger("pyfan").warning("[%s] pwm not found. Not ready yet or wrong path? (%s)" % (self.name,
                                                                                                              err.strerror))

    def replace_alias(self, path):
        replaced = self.alias_replace.sub(lambda x: self.hwmap[x.group()], path)
        logging.getLogger("pyfan").debug("[ALIAS] %s -> %s" % (path, replaced))
        return replaced

    def build_pwm_path(self, specific):
        return self.replace_alias(SYSFS_HWMON_BASE + specific)

    def write_sysfs(self, path, value):
        with open(self.build_pwm_path(path), 'w') as sysfs_f:
            sysfs_f.write(str(value))

    def read_sysfs(self, path):
        with open(self.build_pwm_path(path)) as sysfs_f:
            return sysfs_f.readline()

    def set_pwm_mode(self, path, value=1):
        self.write_sysfs(path + "_enable", value)


class PyFan:
    def __init__(self, config="/etc/pyfan") -> None:
        self.config = self.__load_config(config)
        logging.basicConfig(level=logging.getLevelName(self.config["loglevel"]))
        self.zones = []
        self.hwmon_map = {}
        self.gen_hwmon_map()

        for zone in self.config["thermalzones"]:
            self.zones.append(ThermalZone(zone, self.hwmon_map))

        logging.getLogger("pyfan").info("Finished creating %d thermal zones." % len(self.zones))

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        for zone in self.zones:
            zone.restore()

    def eval(self):
        for zone in self.zones:
            zone.eval()

    @staticmethod
    def __load_config(path):
        with open(path) as cfg_file:
            return yaml.safe_load(cfg_file)

    def gen_hwmon_map(self):
        names = glob.glob(SYSFS_HWMON_BASE + "hwmon*/name")

        for name in names:
            hwmon = name.split("/")[-2]
            with open(name) as file:
                hwname = file.read().strip()
            self.hwmon_map[hwname] = hwmon


if __name__ == "__main__":
    with PyFan() as pyfan:
        while True:
            try:
                pyfan.eval()
                sleep(1)
            except KeyboardInterrupt:
                sys.exit(0)