import os
from collections import defaultdict

from django.db import models
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from rest_framework.exceptions import ValidationError
from simple_history.utils import bulk_create_with_history

from assets.models import Host
from common.db.models import JMSBaseModel
from common.utils import random_string

__all__ = ['AppletHost', 'AppletHostDeployment']


class AppletHost(Host):
    deploy_options = models.JSONField(default=dict, verbose_name=_('Deploy options'))
    inited = models.BooleanField(default=False, verbose_name=_('Inited'))
    date_inited = models.DateTimeField(null=True, blank=True, verbose_name=_('Date inited'))
    date_synced = models.DateTimeField(null=True, blank=True, verbose_name=_('Date synced'))
    terminal = models.OneToOneField(
        'terminal.Terminal', on_delete=models.PROTECT, null=True, blank=True,
        related_name='applet_host', verbose_name=_('Terminal')
    )
    applets = models.ManyToManyField(
        'Applet', verbose_name=_('Applet'),
        through='AppletPublication', through_fields=('host', 'applet'),
    )
    LOCKING_ORG = '00000000-0000-0000-0000-000000000004'

    def __str__(self):
        return self.name

    @property
    def load(self):
        if not self.terminal:
            return 'offline'
        return self.terminal.load

    def check_terminal_binding(self, request):
        request_terminal = getattr(request.user, 'terminal', None)
        if not request_terminal:
            raise ValidationError('Request user has no terminal')

        self.date_synced = timezone.now()
        if self.terminal == request_terminal:
            self.save(update_fields=['date_synced'])
        else:
            self.terminal = request_terminal
            self.save(update_fields=['terminal', 'date_synced'])

    def check_applets_state(self, applets_value_list):
        applets = self.applets.all()
        name_version_mapper = {
            value['name']: value['version']
            for value in applets_value_list
        }

        status_applets = defaultdict(list)
        for applet in applets:
            if applet.name not in name_version_mapper:
                status_applets['unpublished'].append(applet)
            elif applet.version != name_version_mapper[applet.name]:
                status_applets['not_match'].append(applet)
            else:
                status_applets['published'].append(applet)

        for status, applets in status_applets.items():
            self.publications.filter(applet__in=applets) \
                .exclude(status=status) \
                .update(status=status)

    @staticmethod
    def random_username():
        return 'jms_' + random_string(8)

    @staticmethod
    def random_password():
        return random_string(16, special_char=True)

    def generate_accounts(self):
        amount = int(os.getenv('TERMINAL_ACCOUNTS_AMOUNT', 100))
        now_count = self.accounts.filter(privileged=False).count()
        need = amount - now_count

        accounts = []
        account_model = self.accounts.model
        for i in range(need):
            username = self.random_username()
            password = self.random_password()
            account = account_model(
                username=username, secret=password, name=username,
                asset_id=self.id, secret_type='password', version=1,
                org_id=self.LOCKING_ORG, is_active=False,
            )
            accounts.append(account)
        bulk_create_with_history(accounts, account_model, batch_size=20)


class AppletHostDeployment(JMSBaseModel):
    host = models.ForeignKey('AppletHost', on_delete=models.CASCADE, verbose_name=_('Hosting'))
    initial = models.BooleanField(default=False, verbose_name=_('Initial'))
    status = models.CharField(max_length=16, default='', verbose_name=_('Status'))
    date_start = models.DateTimeField(null=True, verbose_name=_('Date start'), db_index=True)
    date_finished = models.DateTimeField(null=True, verbose_name=_("Date finished"))
    comment = models.TextField(default='', blank=True, verbose_name=_('Comment'))
    task = models.UUIDField(null=True, verbose_name=_('Task'))

    class Meta:
        ordering = ('-date_start',)

    def start(self, **kwargs):
        from ...automations.deploy_applet_host import DeployAppletHostManager
        manager = DeployAppletHostManager(self)
        manager.run(**kwargs)

    def install_applet(self, applet_id, **kwargs):
        from ...automations.deploy_applet_host import DeployAppletHostManager
        from .applet import Applet
        if applet_id:
            applet = Applet.objects.get(id=applet_id)
        else:
            applet = None
        manager = DeployAppletHostManager(self, applet=applet)
        manager.install_applet(**kwargs)

    def save_task(self, task):
        self.task = task
        self.save(update_fields=['task'])