#!/usr/bin/python3
#
#

from django.db import models
from django.utils.timezone import now
from django.utils.translation import gettext as _

# Okay, going to illustrate my thinking here:
# A ##Context## is a set of servers that operate together as 
# authoritative for a group of zones.

# (I was going to call it a Network, but then I found out 
# about https://doc.powerdns.com/authoritative/views.html )

# All ##Servers## within a Context are presumed to be
# using the same database and be otherwise interchangeable,
# Although given the limitations of some backends they can 
# be set to read-only.

class PDNSContext(models.Model):
    name = models.CharField(verbose_name=_('Name'),
        max_length=20,
        unique=True,
        primary_key=True,
    )

    description = models.TextField(verbose_name=_('Description'),
        blank=True, 
        null=True,
    )

    def __str__(self):
        return self.name

    def total_servers(self):
        return self.servers.all().count()
    
    def online_servers(self):
        return self.servers.filter(online=True).count()
    
    def offline_servers(self):
        return self.servers.filter(online=False).count()
        
    def status(self): 
        return _('Context %(name)s: %(total)d total, %(online)d online, %(offline)d offline.') % {
            'name': self.name,
            'total': self.total_servers(),
            'online': self.online_servers(),
            'offline': self.offline_servers()}


class PDNSServer(models.Model):
    name = models.CharField(verbose_name=_('Name'),
        max_length=40,
        unique=True,
        primary_key=True,
    )

    server_uri = models.URLField(verbose_name=_('Server URL'),
        help_text='Prefer IP addresses; use FQDN at your own risk.',
        max_length=80,
        blank=False,
        null=False
    )

    context=models.ForeignKey(PDNSContext, 
        verbose_name=_('Context'),
        on_delete=models.PROTECT, 
        related_name='servers'
    )

    online = models.BooleanField(verbose_name=_('Online status'),
        editable=False,
        default=False
    )

    last_checked = models.DateTimeField(verbose_name=_('Last checked'),
        editable=False,
        null=True
    )

    last_seen = models.DateTimeField(verbose_name=_('Last seen online'),
        editable=False,
        null=True
    )

    def __str__(self):
        selfstr= _("%(name)s (%(context)s): %(url)s") % { 'name': self.name, 
            'context': self.context.name, 
            'url': self.server_uri}
        return selfstr

    def status(self):
        status = _('Online') if self.online else _('Offline')
        return _('%(status)s since %(time)s') % {
            'status': status,
            'time': self.last_checked
        }