import datetime

from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils import timezone

from common.mixins import CommonModelMixin
from orgs.mixins.models import OrgModelMixin
from .session import Session


__all__ = ['SessionSharing', 'SessionJoinRecord']


class SessionSharing(CommonModelMixin, OrgModelMixin):
    session = models.ForeignKey(
        'terminal.Session', on_delete=models.CASCADE, verbose_name=_('Session')
    )
    # creator / created_by
    creator = models.ForeignKey(
        'users.User', on_delete=models.CASCADE, blank=True, null=True,
        verbose_name=_('Creator')
    )
    verify_code = models.CharField(max_length=16, verbose_name=_('Verify code'))
    is_active = models.BooleanField(
        default=True, verbose_name=_('Active'), db_index=True
    )
    expired_time = models.IntegerField(
        default=0, verbose_name=_('Expired time (min)'), db_index=True
    )

    class Meta:
        ordering = ('-date_created', )
        verbose_name = _('Session sharing')
        permissions = [
            ('add_supersessionsharing', _("Can add super session sharing"))
        ]

    def __str__(self):
        return 'Creator: {}'.format(self.creator)

    @property
    def date_expired(self):
        return self.date_created + datetime.timedelta(minutes=self.expired_time)

    @property
    def is_expired(self):
        if timezone.now() > self.date_expired:
            return False
        return True

    def can_join(self):
        if not self.is_active:
            return False, _('Link not active')
        if not self.is_expired:
            return False, _('Link expired')
        return True, ''


class SessionJoinRecord(CommonModelMixin, OrgModelMixin):
    LOGIN_FROM = Session.LOGIN_FROM

    session = models.ForeignKey(
        'terminal.Session', on_delete=models.CASCADE, verbose_name=_('Session')
    )
    verify_code = models.CharField(max_length=16, verbose_name=_('Verify code'))
    sharing = models.ForeignKey(
        SessionSharing, on_delete=models.CASCADE,
        verbose_name=_('Session sharing')
    )
    joiner = models.ForeignKey(
        'users.User', on_delete=models.CASCADE, blank=True, null=True,
        verbose_name=_('Joiner')
    )
    date_joined = models.DateTimeField(
        auto_now_add=True, verbose_name=_("Date joined"), db_index=True,
    )
    date_left = models.DateTimeField(
        verbose_name=_("Date left"), null=True, db_index=True
    )
    remote_addr = models.CharField(
        max_length=128, verbose_name=_("Remote addr"), blank=True, null=True,
        db_index=True
    )
    login_from = models.CharField(
        max_length=2, choices=LOGIN_FROM.choices, default="WT",
        verbose_name=_("Login from")
    )
    is_success = models.BooleanField(
        default=True, db_index=True, verbose_name=_('Success')
    )
    reason = models.CharField(
        max_length=1024, default='-', blank=True, null=True,
        verbose_name=_('Reason')
    )
    is_finished = models.BooleanField(
        default=False, db_index=True, verbose_name=_('Finished')
    )

    class Meta:
        ordering = ('-date_joined', )
        verbose_name = _("Session join record")

    def __str__(self):
        return 'Joiner: {}'.format(self.joiner)

    @property
    def joiner_display(self):
        return str(self.joiner)

    def can_join(self):
        # sharing
        sharing_can_join, reason = self.sharing.can_join()
        if not sharing_can_join:
            return False, reason
        # self
        if self.verify_code != self.sharing.verify_code:
            return False, _('Invalid verification code')
        return True, ''

    def join_failed(self, reason):
        self.is_success = False
        self.reason = reason[:1024]
        self.save()

    def finished(self):
        if self.is_finished:
            return
        self.date_left = timezone.now()
        self.is_finished = True
        self.save()