# Copyright 2014 Budapest University of Technology and Economics (BME IK)
#
# This file is part of CIRCLE Cloud.
#
# CIRCLE is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# CIRCLE is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along
# with CIRCLE.  If not, see <http://www.gnu.org/licenses/>.

from manager.mancelery import celery
from vm.tasks.agent_tasks import (restart_networking, change_password,
                                  set_time, set_hostname, start_access_server,
                                  cleanup, update)
import time
from base64 import encodestring
from StringIO import StringIO
from tarfile import TarFile, TarInfo
from django.conf import settings
from django.utils import timezone
from celery.result import TimeoutError
from monitor.client import Client


def send_init_commands(instance, act, vm):
    queue = instance.get_remote_queue_name("agent")

    with act.sub_activity('cleanup'):
        cleanup.apply_async(queue=queue, args=(vm, ))
    with act.sub_activity('restart_networking'):
        restart_networking.apply_async(queue=queue, args=(vm, ))
    with act.sub_activity('change_password'):
        change_password.apply_async(queue=queue, args=(vm, instance.pw))
    with act.sub_activity('set_time'):
        set_time.apply_async(queue=queue, args=(vm, time.time()))
    with act.sub_activity('set_hostname'):
        set_hostname.apply_async(
            queue=queue, args=(vm, instance.primary_host.hostname))


def create_agent_tar():
    def exclude(tarinfo):
        if tarinfo.name.startswith('./.git'):
            return None
        else:
            return tarinfo

    f = StringIO()

    with TarFile.open(fileobj=f, mode='w|gz') as tar:
        tar.add(settings.AGENT_DIR, arcname='.', filter=exclude)

        version_fileobj = StringIO(settings.AGENT_VERSION)
        version_info = TarInfo(name='version.txt')
        version_info.size = len(version_fileobj.buf)
        tar.addfile(version_info, version_fileobj)

    return encodestring(f.getvalue()).replace('\n', '')


@celery.task
def agent_started(vm, version=None):
    from vm.models import Instance, instance_activity, InstanceActivity
    instance = Instance.objects.get(id=int(vm.split('-')[-1]))
    queue = instance.get_remote_queue_name("agent")
    initialized = InstanceActivity.objects.filter(
        instance=instance, activity_code='vm.Instance.agent.cleanup').exists()

    with instance_activity(code_suffix='agent', instance=instance) as act:
        with act.sub_activity('starting'):
            pass

        if version and version != settings.AGENT_VERSION:
            try:
                with act.sub_activity('update'):
                    update.apply_async(
                        queue=queue,
                        args=(vm, create_agent_tar())).get(timeout=10)
                    return
            except TimeoutError:
                pass

        if not initialized:
            measure_boot_time(instance)
            send_init_commands(instance, act, vm)

        with act.sub_activity('start_access_server'):
            start_access_server.apply_async(queue=queue, args=(vm, ))


def measure_boot_time(instance):
    if not instance.template:
        return

    from vm.models import InstanceActivity
    deploy_time = InstanceActivity.objects.filter(
        instance=instance, activity_code="vm.Instance.deploy"
    ).latest("finished").finished

    total_boot_time = (timezone.now() - deploy_time).total_seconds()

    Client().send([
        "template.%(pk)d.boot_time %(val)f %(time)s" % {
            'pk': instance.template.pk,
            'val': total_boot_time,
            'time': time.time(),
        }
    ])


@celery.task
def agent_stopped(vm):
    from vm.models import Instance, InstanceActivity
    instance = Instance.objects.get(id=int(vm.split('-')[-1]))
    qs = InstanceActivity.objects.filter(instance=instance,
                                         activity_code='vm.Instance.agent')
    act = qs.latest('id')
    with act.sub_activity('stopping'):
        pass