# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2018 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# https://cloudlinux.com/docs/LICENCE.TXT
#
import logging
import os
import re
import subprocess
import time

from clcommon.lib.cledition import CLEditionDetectionError

from lve_utils import PKG_VERSION

PKG_VERSION_TINY = re.sub(r'\.el\w(h?)\.', '.elX.', PKG_VERSION)

# https://cl.sentry.cloudlinux.com/settings/cloudlinux_os/projects/userland
SENTRY_DSN = 'https://9713d1296f804031b058b8f2d789d7ac:' \
             '8ddacae32d8246cf8b25cf826bf3fc0a@cl.sentry.cloudlinux.com/12'
LAST_KNOWN_EDITION_CACHE_PATH = '/var/lve/.edition.previous'
SYSTEMID_FILE_PATH = '/etc/sysconfig/rhn/systemid'

# how much time should past after registration
# before we assume that server is "old"
_SECONDS_IN_DAY = 24 * 60 * 60
SYSTEMID_NEW_TIME = 3 * _SECONDS_IN_DAY


def _reconfigure_server(current_edition, is_pre_check):
    """
    Run reconfiguration script
    """
    subprocess.run([
        '/usr/sbin/cloudlinux-customizer',
        'preconfigure' if is_pre_check else 'reconfigure',
        '-t', current_edition], check=True,
        text=True, stderr=subprocess.STDOUT
    )


# _on_* handlers below are different for the future additional actions
# that will be added with edition switch support

def _on_edition_changed(previous_edition, current_edition, is_pre_check):
    """
    Called when saved edition does not match current one.
    """
    _reconfigure_server(current_edition, is_pre_check)


def _on_server_newly_registered(current_edition, is_pre_check):
    """
    Called when saved server id detected as one registered recently
    """
    _reconfigure_server(current_edition, is_pre_check)


def _get_registration_time():
    """
    Assume that last registration time is
    the date of systemid modification.
    """
    try:
        return os.path.getmtime(SYSTEMID_FILE_PATH)
    except FileNotFoundError:
        return None


def _get_last_check_time():
    """
    Assume that last check time is equal
    to the date of last cache modification.
    """
    try:
        return os.path.getmtime(LAST_KNOWN_EDITION_CACHE_PATH)
    except FileNotFoundError:
        return None


def check(new_edition: str, is_pre_check=False):
    """
    Compares current edition with latest saved in file and
    @param new_edition:
        provides information about new edition that server is using
        Depending on is_pre_check this edition can either be already applied
        or just planning to be installed
    @param is_pre_check:
        True means that current check is executed BEFORE
        new jwt is actually saved in jwt.token file

        False means that registration is complete and jwt.token file
        was updated with new edition token
    """
    try:
        with open(LAST_KNOWN_EDITION_CACHE_PATH, encoding='utf-8') as f:
            last_edition = f.read()
    except FileNotFoundError:
        last_edition = None

    registration_time = _get_registration_time()
    is_edition_changed = last_edition and last_edition != new_edition

    # system_id file exists and it is younger than 3d
    is_registration_fresh = \
        registration_time is not None \
        and registration_time >= (time.time() - SYSTEMID_NEW_TIME)

    last_check_time = _get_last_check_time()

    # edition cache file does not exist yet
    # or system_id exists but edition cache was modified before registration
    # and edition (RE-REGISTRATION CASE) is changing
    is_last_check_before_registration = \
        (last_check_time is None) or (
                registration_time is not None
                and last_check_time < registration_time and is_edition_changed)

    logging.info('Checking edition registration data: registration time=%s, last edition=%s, new edition=%s',
                 str(registration_time),
                 str(last_edition),
                 str(new_edition))

    if is_last_check_before_registration and is_registration_fresh:
        logging.info('New server registration detected, last check time=%s, registration time=%s',
                     str(last_check_time),
                     str(registration_time))
        _on_server_newly_registered(new_edition, is_pre_check)
    elif is_edition_changed:
        logging.info('Edition change detected, last edition=%s, new edition=%s',
                     str(last_edition),
                     str(new_edition))
        _on_edition_changed(last_edition, new_edition, is_pre_check)
    else:
        logging.info('Nothing to do, requested edition=%s already configured', str(new_edition))

    # keep old edition in file until post hook executes
    if not is_pre_check:
        logging.info('Saving new edition="%s"', str(new_edition))
        save_edition(edition=new_edition)


def save_edition(edition):
    """
    Stores current edition value in cache file
    """
    try:
        with open(LAST_KNOWN_EDITION_CACHE_PATH, 'w', encoding='utf-8') as f:
            f.write(edition)
    except CLEditionDetectionError as e:
        logging.warning('Unable to detect current edition, error=%s', e)