#!/usr/bin/python3

import smbus
import RPi.GPIO as GPIO
import os
import time
from threading import Thread

rev = GPIO.RPI_REVISION
if rev == 2 or rev == 3:
  bus = smbus.SMBus(1)
else:
  bus = smbus.SMBus(0)
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
shutdown_pin = 4
GPIO.setup(shutdown_pin, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

def shutdown_check():
  while True:
    pulsetime = 1
    GPIO.wait_for_edge(shutdown_pin, GPIO.RISING)
    time.sleep(0.01)
    while GPIO.input(shutdown_pin) == GPIO.HIGH:
      time.sleep(0.01)
      pulsetime += 1
    if pulsetime >= 2 and pulsetime <= 3:
      os.system("reboot")
    elif pulsetime >= 4 and pulsetime <= 5:
      os.system("poweroff")

def get_fanspeed(tempval, configlist):
  for curconfig in configlist:
    curpair = curconfig.split("=")
    tempcfg = float(curpair[0])
    fancfg = int(float(curpair[1]))
    if tempval >= tempcfg:
      if fancfg < 1:
        return 0
      elif fancfg < 25:
        return 25
      return fancfg
  return 0

def load_config(fname):
  newconfig = []
  try:
    with open(fname, "r") as fp:
      for curline in fp:
        if not curline:
          continue
        tmpline = curline.strip()
        if not tmpline:
          continue
        if tmpline[0] == "#":
          continue
        tmppair = tmpline.split("=")
        if len(tmppair) != 2:
          continue
        tempval = 0
        fanval = 0
        try:
          tempval = float(tmppair[0])
          if tempval < 0 or tempval > 100:
            continue
        except:
          continue
        try:
          fanval = int(float(tmppair[1]))
          if fanval < 0 or fanval > 100:
            continue
        except:
          continue
        newconfig.append("{:5.1f}={}".format(tempval, fanval))
    if len(newconfig) > 0:
      newconfig.sort(reverse=True)
  except:
    return []
  return newconfig

def temp_check():
  fanconfig = ["70=100", "65=75", "50=50", "55=25"]
  tmpconfig = load_config("/etc/argon-one.conf")
  if len(tmpconfig) > 0:
      fanconfig = tmpconfig
  address = 0x1A
  prevblock = 0
  while True:
    try:
      tempfp = open("/sys/class/thermal/thermal_zone0/temp", "r")
      temp = tempfp.readline()
      tempfp.close()
      val = float(int(temp) / 1000)
    except IOError:
      val = 0
    block = get_fanspeed(val, fanconfig)
    if block < prevblock:
      time.sleep(30)
    prevblock = block
    try:
      if block > 0:
        bus.write_byte(address, 100)
        time.sleep(1)
        bus.write_byte(address, block)
    except IOError:
      temp = ""
    time.sleep(30)

try:
  t1 = Thread(target=shutdown_check)
  t2 = Thread(target=temp_check)
  t1.start()
  t2.start()
except:
  t1.stop()
  t2.stop()
  GPIO.cleanup()