'''
    Auto-updater
'''
from distutils.version import StrictVersion
import os
from subprocess import Popen
import sys
import tempfile

import requests

VERSIONFILE_URL = "http://codebox/lab/ModelePython/raw/VERSION"
SETUPFILE_URL = "http://codebox/lab/ModelePython/raw/setup-hello_world.exe"

CURDIR = os.path.dirname(__file__)

class UpdateNeeded(Exception):
    pass

class Unavailable(requests.exceptions.RequestException):
    pass

def autoupdate():
    try:
        if update_needed():
            update()
    except Unavailable:
        pass

def update_needed():
    # Available version
    try:
        raw = requests.get(VERSIONFILE_URL).text
        available_version = StrictVersion(raw)
    except (ValueError, requests.exceptions.RequestException):
        raise Unavailable()

    # Installed version
    with open(os.path.join(CURDIR, "VERSION")) as f:
        installed_version = f.read()

    return available_version > installed_version

def update():
    with tempfile.TemporaryDirectory() as tmpdir:

        # Download the setup.exe
        response = requests.get(SETUPFILE_URL, stream=True)

        with open("setup.exe", "wb") as handle:
            for data in response.iter_content():
                handle.write(data)

        # Run the installer and restart the start command
        args = "/SILENT && {}".format(tmpdir / "setup.exe", " ".join(sys.argv[:]))

        Popen([os.path.join(tmpdir, "setup.exe"), args], shell=True)

    # An UpdateNeeded exception is raised so the script exit before being restarted by subprocess
    raise UpdateNeeded()