"""
dealing with the fault counters and available/abuse/abuse_blocked flags
"""

import traceback

from django.core.management.base import BaseCommand
from django.core.mail import send_mail
from django.db import transaction
from django.utils.translation import ugettext_lazy as _

from nsupdate.main.models import Host
from nsupdate.utils.mail import translate_for_user, send_mail_to_user

ABUSE_MSG = _("""\
Your host: %(fqdn)s (comment: %(comment)s)

Issue: The abuse flag for your host was set.

Explanation:
The abuse flag usually gets set if your update client sends way too many
updates although your IP address did not change.

Your update client sent %(faults_count)d faulty updates since we last checked.
We have reset the faults counter to 0 now, but we are rejecting updates
for this host until you resolve the issue.

Resolution:
You can easily do this on your own:
1. fix or replace the update client on this host - it must not send
   updates if the IP did not change
2. visit the service web interface and remove the abuse flag for this host

Notes:
- this is usually caused by a misbehaving / faulty update client
  (on your PC / server or router / firewall)
- the dyndns2 standard explicitly states that frequently sending
  nochg updates is considered abuse of the service
- you are using way more resources on the service than really needed
- for Linux and similar OSes, you can use the ddclient software - we
  give copy&paste-ready configuration help for it on our web UI
- if you need something else, use anything that can be considered
  a valid, well-behaved dyndns2-compatible update client
- if you already used such a software and you ran into this problem,
  complain to whoever wrote it about it sending nochg updates
""")


class Command(BaseCommand):
    help = 'deal with the faults counters'

    def add_arguments(self, parser):
        parser.add_argument('--show-server',
                            action='store_true',
                            dest='show_server',
                            default=False,
                            help='show server fault counters')
        parser.add_argument('--show-client',
                            action='store_true',
                            dest='show_client',
                            default=False,
                            help='show client fault counters')
        parser.add_argument('--reset-server',
                            action='store_true',
                            dest='reset_server',
                            default=False,
                            help='reset the server fault counters of all hosts')
        parser.add_argument('--reset-client',
                            action='store_true',
                            dest='reset_client',
                            default=False,
                            help='reset the client fault counters of all hosts')
        parser.add_argument('--reset-abuse',
                            action='store_true',
                            dest='reset_abuse',
                            default=False,
                            help='reset the abuse flag (to False) of all hosts')
        parser.add_argument('--reset-abuse-blocked',
                            action='store_true',
                            dest='reset_abuse_blocked',
                            default=False,
                            help='reset the abuse_blocked flag (to False) of all hosts')
        parser.add_argument('--reset-available',
                            action='store_true',
                            dest='reset_available',
                            default=False,
                            help='reset the available flag (to True) of all hosts')
        parser.add_argument('--flag-abuse',
                            action='store',
                            dest='flag_abuse',
                            default=None,
                            type=int,
                            help='if client faults N then set abuse flag and reset client faults')
        parser.add_argument('--notify-user',
                            action='store_true',
                            dest='notify_user',
                            default=False,
                            help='notify the user by email when host gets flagged for abuse')

    def handle(self, *args, **options):
        show_client = options['show_client']
        show_server = options['show_server']
        reset_client = options['reset_client']
        reset_server = options['reset_server']
        reset_available = options['reset_available']
        reset_abuse = options['reset_abuse']
        reset_abuse_blocked = options['reset_abuse_blocked']
        flag_abuse = options['flag_abuse']
        notify_user = options['notify_user']
        for h in Host.objects.all():
            try:
                with transaction.atomic():
                    if show_client or show_server:
                        output = u""
                        if show_client:
                            output += u"%-6d " % h.client_faults
                        if show_server:
                            output += u"%-6d " % h.server_faults
                        output += u"%s %s\n" % (h.created_by.username, h.get_fqdn(),)
                        self.stdout.write(output)
                    if (flag_abuse is not None or reset_client or reset_server or
                            reset_available or reset_abuse or reset_abuse_blocked):
                        if flag_abuse is not None:
                            if h.client_faults > flag_abuse:
                                h.abuse = True
                                faults_count = h.client_faults
                                h.client_faults = 0
                                fqdn = h.get_fqdn()
                                comment = h.comment
                                creator = h.created_by
                                self.stdout.write(
                                    "setting abuse flag for host %s (created by %s, client faults: %d)\n" % (
                                        fqdn, creator, faults_count))
                                if notify_user:
                                    subject, msg = translate_for_user(
                                        creator,
                                        _("issue with your host %(fqdn)s"),
                                        ABUSE_MSG
                                    )
                                    subject = subject % dict(fqdn=fqdn)
                                    msg = msg % dict(fqdn=fqdn, comment=comment, faults_count=faults_count)
                                    send_mail_to_user(creator, subject, msg)
                        if reset_client:
                            h.client_faults = 0
                        if reset_server:
                            h.server_faults = 0
                        if reset_available:
                            h.available = True
                        if reset_abuse:
                            h.abuse = False
                        if reset_abuse_blocked:
                            h.abuse_blocked = False
                        h.save()
            except Exception:
                try:
                    msg = u"The following Exception occurred when processing host %s!\n" % (h.get_fqdn(),)
                    self.stderr.write(msg)
                except Exception:
                    pass
                traceback.print_exc()