from contextlib import contextmanager
from datetime import datetime
import locale
import os
import re
import shlex
import threading
from subprocess import Popen, PIPE


LOCALE_LOCK = threading.Lock()

@contextmanager
def setlocale(name):
    with LOCALE_LOCK:
        saved = locale.setlocale(locale.LC_ALL)
        try:
            yield locale.setlocale(locale.LC_ALL, name)
        finally:
            locale.setlocale(locale.LC_ALL, saved)


class RtcDevice():
    name = ""
    devStatus = {
        "active": False,
        "date": 0
    }
    modes = []
    utc = False

    def __init__(self, name = ""):
        self.name = name

        self.modes()
        self.status()

    def modes(self):
        cmd = "rtcwake --list-modes -d " + self.name
        process = Popen(shlex.split(cmd), stdout=PIPE)
        (output, err) = process.communicate()
        exit_code = process.wait()

        output = output.decode()

        self.modes = output.split()

    def status(self):
        cmd = "rtcwake -m show -d " + self.name
        process = Popen(shlex.split(cmd), stdout=PIPE)
        (output, err) = process.communicate()
        exit_code = process.wait()

        self.formatStatus(str(output))

    def formatStatus(self, message):
        re1='.*?'	# Non-greedy match on filler
        re2='(?:[a-z][a-z]+)'	# Uninteresting: word
        re3='.*?'	# Non-greedy match on filler
        re4='((?:[a-z][a-z]+))'	# Word 1
        re5='.*?'	# Non-greedy match on filler
        re6='((?:Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sep(?:tember)?|Sept|Oct(?:ober)?|Nov(?:ember)?|Dec(?:ember)?))'	# Month 1
        re7='.*?'	# Non-greedy match on filler
        re8='((?:(?:[0-2]?\\d{1})|(?:[3][01]{1})))(?![\\d])'	# Day 1
        re9='.*?'	# Non-greedy match on filler
        re10='((?:(?:[0-1][0-9])|(?:[2][0-3])|(?:[0-9])):(?:[0-5][0-9])(?::[0-5][0-9])?(?:\\s?(?:am|AM|pm|PM))?)'	# HourMinuteSec 1
        re11='.*?'	# Non-greedy match on filler
        re12='((?:(?:[1]{1}\\d{1}\\d{1}\\d{1})|(?:[2]{1}\\d{3})))(?![\\d])'	# Year 1

        rg = re.compile(re1+re2+re3+re4,re.IGNORECASE|re.DOTALL)
        m = rg.search(message)
        if m:
            active = m.group(1)
            if active == "on":
                self.devStatus["active"] = True
            else:
                self.devStatus["active"] = False

            if self.devStatus["active"]:
                rgx = re.compile(re1+re2+re3+re4+re5+re6+re7+re8+re9+re10+re11+re12,re.IGNORECASE|re.DOTALL)
                mx = rgx.search(message)
                if mx:
                    month = mx.group(2)
                    day = mx.group(3)
                    if len(day) == 1:
                        day = "0" + day
                    time = mx.group(4)
                    year = mx.group(5)
                    with setlocale('C'):
                        self.devStatus["date"] = datetime.strptime(year + " " + month + " " + day + " " + time, "%Y %b %d %H:%M:%S")

def getDevices():
    mainDir = "/sys/class/rtc"
    if os.path.isdir(mainDir):
        devices = [ name for name in os.listdir(mainDir) if os.path.isdir(os.path.join(mainDir, name)) ]

        if len(devices) > 0:
            return devices

    return False