django-helpdeskmig/helpdesk/views/staff.py

"""
django-helpdesk - A Django powered ticket tracker for small enterprise.

(c) Copyright 2008 Jutda. All Rights Reserved. See LICENSE for details.

views/staff.py - The bulk of the application - provides most business logic and
                 renders all staff-facing views.
"""
from __future__ import unicode_literals
from datetime import date, datetime, timedelta
import re

from django import VERSION as DJANGO_VERSION
from django.conf import settings
from django.contrib.auth import get_user_model
from django.urls import reverse
from django.core.exceptions import ValidationError, PermissionDenied
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
from django.db.models import Q
from django.http import HttpResponseRedirect, Http404, HttpResponse
from django.shortcuts import render, get_object_or_404
from django.utils.dates import MONTHS_3
from django.utils.translation import ugettext as _
from django.utils.html import escape
from django import forms
from django.utils import timezone

from django.utils import six

from helpdesk.forms import (
    TicketForm, UserSettingsForm, EmailIgnoreForm, EditTicketForm, TicketCCForm,
    TicketCCEmailForm, TicketCCUserForm, EditFollowUpForm, TicketDependencyForm
)
from helpdesk.decorators import staff_member_required, superuser_required
from helpdesk.lib import (
    send_templated_mail, apply_query, safe_template_context,
    process_attachments, queue_template_context,
)
from helpdesk.models import (
    Ticket, Queue, FollowUp, TicketChange, PreSetReply, Attachment, SavedSearch,
    IgnoreEmail, TicketCC, TicketDependency,
)
from helpdesk import settings as helpdesk_settings


User = get_user_model()


def _get_user_queues(user):
    """Return the list of Queues the user can access.

    :param user: The User (the class should have the has_perm method)
    :return: A Python list of Queues
    """
    all_queues = Queue.objects.all()
    limit_queues_by_user = \
        helpdesk_settings.HELPDESK_ENABLE_PER_QUEUE_STAFF_PERMISSION \
        and not user.is_superuser
    if limit_queues_by_user:
        id_list = [q.pk for q in all_queues if user.has_perm(q.permission_name)]
        return all_queues.filter(pk__in=id_list)
    else:
        return all_queues


def _has_access_to_queue(user, queue):
    """Check if a certain user can access a certain queue.

    :param user: The User (the class should have the has_perm method)
    :param queue: The django-helpdesk Queue instance
    :return: True if the user has permission (either by default or explicitly), false otherwise
    """
    if user.is_superuser or not helpdesk_settings.HELPDESK_ENABLE_PER_QUEUE_STAFF_PERMISSION:
        return True
    else:
        return user.has_perm(queue.permission_name)


def _is_my_ticket(user, ticket):
    """Check to see if the user has permission to access
    a ticket. If not then deny access."""
    if user.is_superuser or user.is_staff or user.id == ticket.assigned_to.id:
        return True
    else:
        return False


@staff_member_required
def dashboard(request):
    """
    A quick summary overview for users: A list of their own tickets, a table
    showing ticket counts by queue/status, and a list of unassigned tickets
    with options for them to 'Take' ownership of said tickets.
    """

    # user settings num tickets per page
    tickets_per_page = request.user.usersettings_helpdesk.settings.get('tickets_per_page') or 25

    # page vars for the three ticket tables
    user_tickets_page = request.GET.get('ut_page', 1)
    user_tickets_closed_resolved_page = request.GET.get('utcr_page', 1)
    all_tickets_reported_by_current_user_page = request.GET.get('atrbcu_page', 1)

    # open & reopened tickets, assigned to current user
    tickets = Ticket.objects.select_related('queue').filter(
        assigned_to=request.user,
    ).exclude(
        status__in=[Ticket.CLOSED_STATUS, Ticket.RESOLVED_STATUS],
    )

    # closed & resolved tickets, assigned to current user
    tickets_closed_resolved = Ticket.objects.select_related('queue').filter(
        assigned_to=request.user,
        status__in=[Ticket.CLOSED_STATUS, Ticket.RESOLVED_STATUS])

    user_queues = _get_user_queues(request.user)

    unassigned_tickets = Ticket.objects.select_related('queue').filter(
        assigned_to__isnull=True,
        queue__in=user_queues
    ).exclude(
        status=Ticket.CLOSED_STATUS,
    )

    # all tickets, reported by current user
    all_tickets_reported_by_current_user = ''
    email_current_user = request.user.email
    if email_current_user:
        all_tickets_reported_by_current_user = Ticket.objects.select_related('queue').filter(
            submitter_email=email_current_user,
        ).order_by('status')

    tickets_in_queues = Ticket.objects.filter(
        queue__in=user_queues,
    )
    basic_ticket_stats = calc_basic_ticket_stats(tickets_in_queues)

    # The following query builds a grid of queues & ticket statuses,
    # to be displayed to the user. EG:
    #          Open  Resolved
    # Queue 1    10     4
    # Queue 2     4    12

    queues = _get_user_queues(request.user).values_list('id', flat=True)

    from_clause = """FROM    helpdesk_ticket t,
                    helpdesk_queue q"""
    if queues:
        where_clause = """WHERE   q.id = t.queue_id AND
                        q.id IN (%s)""" % (",".join(("%d" % pk for pk in queues)))
    else:
        where_clause = """WHERE   q.id = t.queue_id"""

    # get user assigned tickets page
    paginator = Paginator(
        tickets, tickets_per_page)
    try:
        tickets = paginator.page(user_tickets_page)
    except PageNotAnInteger:
        tickets = paginator.page(1)
    except EmptyPage:
        tickets = paginator.page(
            paginator.num_pages)

    # get user completed tickets page
    paginator = Paginator(
        tickets_closed_resolved, tickets_per_page)
    try:
        tickets_closed_resolved = paginator.page(
            user_tickets_closed_resolved_page)
    except PageNotAnInteger:
        tickets_closed_resolved = paginator.page(1)
    except EmptyPage:
        tickets_closed_resolved = paginator.page(
            paginator.num_pages)

    # get user submitted tickets page
    paginator = Paginator(
        all_tickets_reported_by_current_user, tickets_per_page)
    try:
        all_tickets_reported_by_current_user = paginator.page(
            all_tickets_reported_by_current_user_page)
    except PageNotAnInteger:
        all_tickets_reported_by_current_user = paginator.page(1)
    except EmptyPage:
        all_tickets_reported_by_current_user = paginator.page(
            paginator.num_pages)

    return render(request, 'helpdesk/dashboard.html', {
        'user_tickets': tickets,
        'user_tickets_closed_resolved': tickets_closed_resolved,
        'unassigned_tickets': unassigned_tickets,
        'all_tickets_reported_by_current_user': all_tickets_reported_by_current_user,
        'basic_ticket_stats': basic_ticket_stats,
    })


@staff_member_required
def delete_ticket(request, ticket_id):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    if request.method == 'GET':
        return render(request, 'helpdesk/delete_ticket.html', {
            'ticket': ticket,
        })
    else:
        ticket.delete()
        return HttpResponseRedirect(reverse('helpdesk:home'))


@staff_member_required
def followup_edit(request, ticket_id, followup_id):
    """Edit followup options with an ability to change the ticket."""
    followup = get_object_or_404(FollowUp, id=followup_id)
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    if request.method == 'GET':
        form = EditFollowUpForm(initial={
            'title': escape(followup.title),
            'ticket': followup.ticket,
            'comment': escape(followup.comment),
            'public': followup.public,
            'new_status': followup.new_status,
        })

        ticketcc_string, show_subscribe = \
            return_ticketccstring_and_show_subscribe(request.user, ticket)

        return render(request, 'helpdesk/followup_edit.html', {
            'followup': followup,
            'ticket': ticket,
            'form': form,
            'ticketcc_string': ticketcc_string,
        })
    elif request.method == 'POST':
        form = EditFollowUpForm(request.POST)
        if form.is_valid():
            title = form.cleaned_data['title']
            _ticket = form.cleaned_data['ticket']
            comment = form.cleaned_data['comment']
            public = form.cleaned_data['public']
            new_status = form.cleaned_data['new_status']
            # will save previous date
            old_date = followup.date
            new_followup = FollowUp(title=title, date=old_date, ticket=_ticket, comment=comment, public=public, new_status=new_status, )
            # keep old user if one did exist before.
            if followup.user:
                new_followup.user = followup.user
            new_followup.save()
            # get list of old attachments & link them to new_followup
            attachments = Attachment.objects.filter(followup=followup)
            for attachment in attachments:
                attachment.followup = new_followup
                attachment.save()
            # delete old followup
            followup.delete()
        return HttpResponseRedirect(reverse('helpdesk:view', args=[ticket.id]))


@staff_member_required
def followup_delete(request, ticket_id, followup_id):
    """followup delete for superuser"""

    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not request.user.is_superuser:
        return HttpResponseRedirect(reverse('helpdesk:view', args=[ticket.id]))

    followup = get_object_or_404(FollowUp, id=followup_id)
    followup.delete()
    return HttpResponseRedirect(reverse('helpdesk:view', args=[ticket.id]))


@staff_member_required
def view_ticket(request, ticket_id):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    if 'take' in request.GET:
        # Allow the user to assign the ticket to themselves whilst viewing it.

        # Trick the update_ticket() view into thinking it's being called with
        # a valid POST.
        request.POST = {
            'owner': request.user.id,
            'public': 1,
            'title': ticket.title,
            'comment': ''
        }
        return update_ticket(request, ticket_id)

    if 'subscribe' in request.GET:
        # Allow the user to subscribe him/herself to the ticket whilst viewing it.
        ticket_cc, show_subscribe = \
            return_ticketccstring_and_show_subscribe(request.user, ticket)
        if show_subscribe:
            subscribe_staff_member_to_ticket(ticket, request.user)
            return HttpResponseRedirect(reverse('helpdesk:view', args=[ticket.id]))

    if 'close' in request.GET and ticket.status == Ticket.RESOLVED_STATUS:
        if not ticket.assigned_to:
            owner = 0
        else:
            owner = ticket.assigned_to.id

        # Trick the update_ticket() view into thinking it's being called with
        # a valid POST.
        request.POST = {
            'new_status': Ticket.CLOSED_STATUS,
            'public': 1,
            'owner': owner,
            'title': ticket.title,
            'comment': _('Accepted resolution and closed ticket'),
        }

        return update_ticket(request, ticket_id)

    if helpdesk_settings.HELPDESK_STAFF_ONLY_TICKET_OWNERS:
        users = User.objects.filter(is_active=True, is_staff=True).order_by(User.USERNAME_FIELD)
    else:
        users = User.objects.filter(is_active=True).order_by(User.USERNAME_FIELD)

    # TODO: shouldn't this template get a form to begin with?
    form = TicketForm(initial={'due_date': ticket.due_date})

    ticketcc_string, show_subscribe = \
        return_ticketccstring_and_show_subscribe(request.user, ticket)

    return render(request, 'helpdesk/ticket.html', {
        'ticket': ticket,
        'form': form,
        'active_users': users,
        'priorities': Ticket.PRIORITY_CHOICES,
        'preset_replies': PreSetReply.objects.filter(
            Q(queues=ticket.queue) | Q(queues__isnull=True)),
        'ticketcc_string': ticketcc_string,
        'SHOW_SUBSCRIBE': show_subscribe,
    })


def return_ticketccstring_and_show_subscribe(user, ticket):
    """used in view_ticket() and followup_edit()"""
    # create the ticketcc_string and check whether current user is already
    # subscribed
    username = user.get_username().upper()
    useremail = user.email.upper()
    strings_to_check = list()
    strings_to_check.append(username)
    strings_to_check.append(useremail)

    ticketcc_string = ''
    all_ticketcc = ticket.ticketcc_set.all()
    counter_all_ticketcc = len(all_ticketcc) - 1
    show_subscribe = True
    for i, ticketcc in enumerate(all_ticketcc):
        ticketcc_this_entry = str(ticketcc.display)
        ticketcc_string += ticketcc_this_entry
        if i < counter_all_ticketcc:
            ticketcc_string += ', '
        if strings_to_check.__contains__(ticketcc_this_entry.upper()):
            show_subscribe = False

    # check whether current user is a submitter or assigned to ticket
    assignedto_username = str(ticket.assigned_to).upper()
    strings_to_check = list()
    if ticket.submitter_email is not None:
        submitter_email = ticket.submitter_email.upper()
        strings_to_check.append(submitter_email)
    strings_to_check.append(assignedto_username)
    if strings_to_check.__contains__(username) or strings_to_check.__contains__(useremail):
        show_subscribe = False

    return ticketcc_string, show_subscribe


def subscribe_staff_member_to_ticket(ticket, user):
    """used in view_ticket() and update_ticket()"""
    ticketcc = TicketCC(
        ticket=ticket,
        user=user,
        can_view=True,
        can_update=True,
    )
    ticketcc.save()


def update_ticket(request, ticket_id, public=False):
    if not (public or (
            request.user.is_authenticated and
            request.user.is_active and (
                request.user.is_staff or
                helpdesk_settings.HELPDESK_ALLOW_NON_STAFF_TICKET_UPDATE))):
        return HttpResponseRedirect('%s?next=%s' %
                                    (reverse('helpdesk:login'), request.path))

    ticket = get_object_or_404(Ticket, id=ticket_id)

    date_re = re.compile(
        r'(?P<month>\d{1,2})/(?P<day>\d{1,2})/(?P<year>\d{4})$'
    )

    comment = request.POST.get('comment', '')
    new_status = int(request.POST.get('new_status', ticket.status))
    title = request.POST.get('title', '')
    public = request.POST.get('public', False)
    owner = int(request.POST.get('owner', -1))
    priority = int(request.POST.get('priority', ticket.priority))
    due_date_year = int(request.POST.get('due_date_year', 0))
    due_date_month = int(request.POST.get('due_date_month', 0))
    due_date_day = int(request.POST.get('due_date_day', 0))
    # NOTE: jQuery's default for dates is mm/dd/yy
    # very US-centric but for now that's the only format supported
    # until we clean up code to internationalize a little more
    due_date = request.POST.get('due_date', None) or None

    if due_date is not None:
        # based on Django code to parse dates:
        # https://docs.djangoproject.com/en/2.0/_modules/django/utils/dateparse/
        match = date_re.match(due_date)
        if match:
            kw = {k: int(v) for k, v in match.groupdict().items()}
            due_date = date(**kw)
    else:
        # old way, probably deprecated?
        if not (due_date_year and due_date_month and due_date_day):
            due_date = ticket.due_date
        else:
            # NOTE: must be an easier way to create a new date than doing it this way?
            if ticket.due_date:
                due_date = ticket.due_date
            else:
                due_date = timezone.now()
            due_date = due_date.replace(due_date_year, due_date_month, due_date_day)

    no_changes = all([
        not request.FILES,
        not comment,
        new_status == ticket.status,
        title == ticket.title,
        priority == int(ticket.priority),
        due_date == ticket.due_date,
        (owner == -1) or (not owner and not ticket.assigned_to) or
        (owner and User.objects.get(id=owner) == ticket.assigned_to),
    ])
    if no_changes:
        return return_to_ticket(request.user, helpdesk_settings, ticket)

    # We need to allow the 'ticket' and 'queue' contexts to be applied to the
    # comment.
    context = safe_template_context(ticket)

    from django.template import engines
    template_func = engines['django'].from_string
    # this prevents system from trying to render any template tags
    # broken into two stages to prevent changes from first replace being themselves
    # changed by the second replace due to conflicting syntax
    comment = comment.replace('{%', 'X-HELPDESK-COMMENT-VERBATIM').replace('%}', 'X-HELPDESK-COMMENT-ENDVERBATIM')
    comment = comment.replace('X-HELPDESK-COMMENT-VERBATIM', '{% verbatim %}{%').replace('X-HELPDESK-COMMENT-ENDVERBATIM', '%}{% endverbatim %}')
    # render the neutralized template
    comment = template_func(comment).render(context)

    if owner is -1 and ticket.assigned_to:
        owner = ticket.assigned_to.id

    f = FollowUp(ticket=ticket, date=timezone.now(), comment=comment)

    if request.user.is_staff or helpdesk_settings.HELPDESK_ALLOW_NON_STAFF_TICKET_UPDATE:
        f.user = request.user

    f.public = public

    reassigned = False

    old_owner = ticket.assigned_to
    if owner is not -1:
        if owner != 0 and ((ticket.assigned_to and owner != ticket.assigned_to.id) or not ticket.assigned_to):
            new_user = User.objects.get(id=owner)
            f.title = _('Assigned to %(username)s') % {
                'username': new_user.get_username(),
            }
            ticket.assigned_to = new_user
            reassigned = True
        # user changed owner to 'unassign'
        elif owner == 0 and ticket.assigned_to is not None:
            f.title = _('Unassigned')
            ticket.assigned_to = None

    old_status_str = ticket.get_status_display()
    old_status = ticket.status
    if new_status != ticket.status:
        ticket.status = new_status
        ticket.save()
        f.new_status = new_status
        ticket_status_changed = True
        if f.title:
            f.title += ' and %s' % ticket.get_status_display()
        else:
            f.title = '%s' % ticket.get_status_display()

    if not f.title:
        if f.comment:
            f.title = _('Comment')
        else:
            f.title = _('Updated')

    f.save()

    files = process_attachments(f, request.FILES.getlist('attachment'))

    if title and title != ticket.title:
        c = TicketChange(
            followup=f,
            field=_('Title'),
            old_value=ticket.title,
            new_value=title,
        )
        c.save()
        ticket.title = title

    if new_status != old_status:
        c = TicketChange(
            followup=f,
            field=_('Status'),
            old_value=old_status_str,
            new_value=ticket.get_status_display(),
        )
        c.save()

    if ticket.assigned_to != old_owner:
        c = TicketChange(
            followup=f,
            field=_('Owner'),
            old_value=old_owner,
            new_value=ticket.assigned_to,
        )
        c.save()

    if priority != ticket.priority:
        c = TicketChange(
            followup=f,
            field=_('Priority'),
            old_value=ticket.priority,
            new_value=priority,
        )
        c.save()
        ticket.priority = priority

    if due_date != ticket.due_date:
        c = TicketChange(
            followup=f,
            field=_('Due on'),
            old_value=ticket.due_date,
            new_value=due_date,
        )
        c.save()
        ticket.due_date = due_date

    if new_status in (Ticket.RESOLVED_STATUS, Ticket.CLOSED_STATUS):
        if new_status == Ticket.RESOLVED_STATUS or ticket.resolution is None:
            ticket.resolution = comment

    messages_sent_to = []

    # ticket might have changed above, so we re-instantiate context with the
    # (possibly) updated ticket.
    context = safe_template_context(ticket)
    context.update(
        resolution=ticket.resolution,
        comment=f.comment,
    )

    if public and (f.comment or (
        f.new_status in (Ticket.RESOLVED_STATUS,
                         Ticket.CLOSED_STATUS))):
        if f.new_status == Ticket.RESOLVED_STATUS:
            template = 'resolved_'
        elif f.new_status == Ticket.CLOSED_STATUS:
            template = 'closed_'
        else:
            template = 'updated_'

        template_suffix = 'submitter'

        if ticket.submitter_email:
            send_templated_mail(
                template + template_suffix,
                context,
                recipients=ticket.submitter_email,
                sender=ticket.queue.from_address,
                fail_silently=True,
                files=files,
            )
            messages_sent_to.append(ticket.submitter_email)

        template_suffix = 'cc'

        for cc in ticket.ticketcc_set.all():
            if cc.email_address not in messages_sent_to:
                send_templated_mail(
                    template + template_suffix,
                    context,
                    recipients=cc.email_address,
                    sender=ticket.queue.from_address,
                    fail_silently=True,
                    files=files,
                )
                messages_sent_to.append(cc.email_address)

    if ticket.assigned_to and \
            request.user != ticket.assigned_to and \
            ticket.assigned_to.email and \
            ticket.assigned_to.email not in messages_sent_to:
        # We only send e-mails to staff members if the ticket is updated by
        # another user. The actual template varies, depending on what has been
        # changed.
        if reassigned:
            template_staff = 'assigned_owner'
        elif f.new_status == Ticket.RESOLVED_STATUS:
            template_staff = 'resolved_owner'
        elif f.new_status == Ticket.CLOSED_STATUS:
            template_staff = 'closed_owner'
        else:
            template_staff = 'updated_owner'

        if (not reassigned or
                (reassigned and
                    ticket.assigned_to.usersettings_helpdesk.settings.get(
                        'email_on_ticket_assign', False))) or \
            (not reassigned and
                ticket.assigned_to.usersettings_helpdesk.settings.get(
                    'email_on_ticket_change', False)):
            send_templated_mail(
                template_staff,
                context,
                recipients=ticket.assigned_to.email,
                sender=ticket.queue.from_address,
                fail_silently=True,
                files=files,
            )
            messages_sent_to.append(ticket.assigned_to.email)

    if ticket.queue.updated_ticket_cc and ticket.queue.updated_ticket_cc not in messages_sent_to:
        if reassigned:
            template_cc = 'assigned_cc'
        elif f.new_status == Ticket.RESOLVED_STATUS:
            template_cc = 'resolved_cc'
        elif f.new_status == Ticket.CLOSED_STATUS:
            template_cc = 'closed_cc'
        else:
            template_cc = 'updated_cc'

        send_templated_mail(
            template_cc,
            context,
            recipients=ticket.queue.updated_ticket_cc,
            sender=ticket.queue.from_address,
            fail_silently=True,
            files=files,
        )

    ticket.save()

    # auto subscribe user if enabled
    if helpdesk_settings.HELPDESK_AUTO_SUBSCRIBE_ON_TICKET_RESPONSE and request.user.is_authenticated:
        ticketcc_string, SHOW_SUBSCRIBE = return_ticketccstring_and_show_subscribe(request.user, ticket)
        if SHOW_SUBSCRIBE:
            subscribe_staff_member_to_ticket(ticket, request.user)

    return return_to_ticket(request.user, helpdesk_settings, ticket)


def return_to_ticket(user, helpdesk_settings, ticket):
    """Helper function for update_ticket"""

    if user.is_staff or helpdesk_settings.HELPDESK_ALLOW_NON_STAFF_TICKET_UPDATE:
        return HttpResponseRedirect(ticket.get_absolute_url())
    else:
        return HttpResponseRedirect(ticket.ticket_url)


@staff_member_required
def mass_update(request):
    tickets = request.POST.getlist('ticket_id')
    action = request.POST.get('action', None)
    if not (tickets and action):
        return HttpResponseRedirect(reverse('helpdesk:list'))

    if action.startswith('assign_'):
        parts = action.split('_')
        user = User.objects.get(id=parts[1])
        action = 'assign'
    elif action == 'take':
        user = request.user
        action = 'assign'

    for t in Ticket.objects.filter(id__in=tickets):
        if not _has_access_to_queue(request.user, t.queue):
            continue

        if action == 'assign' and t.assigned_to != user:
            t.assigned_to = user
            t.save()
            f = FollowUp(ticket=t,
                         date=timezone.now(),
                         title=_('Assigned to %(username)s in bulk update' % {
                             'username': user.get_username()
                         }),
                         public=True,
                         user=request.user)
            f.save()
        elif action == 'unassign' and t.assigned_to is not None:
            t.assigned_to = None
            t.save()
            f = FollowUp(ticket=t,
                         date=timezone.now(),
                         title=_('Unassigned in bulk update'),
                         public=True,
                         user=request.user)
            f.save()
        elif action == 'close' and t.status != Ticket.CLOSED_STATUS:
            t.status = Ticket.CLOSED_STATUS
            t.save()
            f = FollowUp(ticket=t,
                         date=timezone.now(),
                         title=_('Closed in bulk update'),
                         public=False,
                         user=request.user,
                         new_status=Ticket.CLOSED_STATUS)
            f.save()
        elif action == 'close_public' and t.status != Ticket.CLOSED_STATUS:
            t.status = Ticket.CLOSED_STATUS
            t.save()
            f = FollowUp(ticket=t,
                         date=timezone.now(),
                         title=_('Closed in bulk update'),
                         public=True,
                         user=request.user,
                         new_status=Ticket.CLOSED_STATUS)
            f.save()
            # Send email to Submitter, Owner, Queue CC
            context = safe_template_context(t)
            context.update(resolution=t.resolution,
                           queue=queue_template_context(t.queue))

            messages_sent_to = []

            if t.submitter_email:
                send_templated_mail(
                    'closed_submitter',
                    context,
                    recipients=t.submitter_email,
                    sender=t.queue.from_address,
                    fail_silently=True,
                )
                messages_sent_to.append(t.submitter_email)

            for cc in t.ticketcc_set.all():
                if cc.email_address not in messages_sent_to:
                    send_templated_mail(
                        'closed_submitter',
                        context,
                        recipients=cc.email_address,
                        sender=t.queue.from_address,
                        fail_silently=True,
                    )
                    messages_sent_to.append(cc.email_address)

            if t.assigned_to and \
                    request.user != t.assigned_to and \
                    t.assigned_to.email and \
                    t.assigned_to.email not in messages_sent_to:
                send_templated_mail(
                    'closed_owner',
                    context,
                    recipients=t.assigned_to.email,
                    sender=t.queue.from_address,
                    fail_silently=True,
                )
                messages_sent_to.append(t.assigned_to.email)

            if t.queue.updated_ticket_cc and \
                    t.queue.updated_ticket_cc not in messages_sent_to:
                send_templated_mail(
                    'closed_cc',
                    context,
                    recipients=t.queue.updated_ticket_cc,
                    sender=t.queue.from_address,
                    fail_silently=True,
                )

        elif action == 'delete':
            t.delete()

    return HttpResponseRedirect(reverse('helpdesk:list'))


@staff_member_required
def ticket_list(request):
    context = {}

    user_queues = _get_user_queues(request.user)
    # Prefilter the allowed tickets
    base_tickets = Ticket.objects.filter(queue__in=user_queues)

    # Query_params will hold a dictionary of parameters relating to
    # a query, to be saved if needed:
    query_params = {
        'filtering': {},
        'sorting': None,
        'sortreverse': False,
        'keyword': None,
        'search_string': None,
    }

    from_saved_query = False

    # If the user is coming from the header/navigation search box, lets' first
    # look at their query to see if they have entered a valid ticket number. If
    # they have, just redirect to that ticket number. Otherwise, we treat it as
    # a keyword search.

    if request.GET.get('search_type', None) == 'header':
        query = request.GET.get('q')
        filter = None
        if query.find('-') > 0:
            try:
                queue, id = Ticket.queue_and_id_from_query(query)
                id = int(id)
            except ValueError:
                id = None

            if id:
                filter = {'queue__slug': queue, 'id': id}
        else:
            try:
                query = int(query)
            except ValueError:
                query = None

            if query:
                filter = {'id': int(query)}

        if filter:
            try:
                ticket = base_tickets.get(**filter)
                return HttpResponseRedirect(ticket.staff_url)
            except Ticket.DoesNotExist:
                # Go on to standard keyword searching
                pass

    saved_query = None
    if request.GET.get('saved_query', None):
        from_saved_query = True
        try:
            saved_query = SavedSearch.objects.get(pk=request.GET.get('saved_query'))
        except SavedSearch.DoesNotExist:
            return HttpResponseRedirect(reverse('helpdesk:list'))
        if not (saved_query.shared or saved_query.user == request.user):
            return HttpResponseRedirect(reverse('helpdesk:list'))

        import json
        from helpdesk.lib import b64decode
        try:
            if six.PY3:
                if DJANGO_VERSION[0] > 1:
                    # if Django >= 2.0
                    query_params = json.loads(b64decode(str(saved_query.query).lstrip("b\\'")).decode())
                else:
                    query_params = json.loads(b64decode(str(saved_query.query)).decode())
            else:
                query_params = json.loads(b64decode(str(saved_query.query)))
        except ValueError:
            # Query deserialization failed. (E.g. was a pickled query)
            return HttpResponseRedirect(reverse('helpdesk:list'))

    elif not ('queue' in request.GET or
              'assigned_to' in request.GET or
              'status' in request.GET or
              'q' in request.GET or
              'sort' in request.GET or
              'sortreverse' in request.GET):

        # Fall-back if no querying is being done, force the list to only
        # show open/reopened/resolved (not closed) cases sorted by creation
        # date.

        query_params = {
            'filtering': {'status__in': [1, 2, 3]},
            'sorting': 'created',
        }
    else:
        queues = request.GET.getlist('queue')
        if queues:
            try:
                queues = [int(q) for q in queues]
                query_params['filtering']['queue__id__in'] = queues
            except ValueError:
                pass

        owners = request.GET.getlist('assigned_to')
        if owners:
            try:
                owners = [int(u) for u in owners]
                query_params['filtering']['assigned_to__id__in'] = owners
            except ValueError:
                pass

        statuses = request.GET.getlist('status')
        if statuses:
            try:
                statuses = [int(s) for s in statuses]
                query_params['filtering']['status__in'] = statuses
            except ValueError:
                pass

        date_from = request.GET.get('date_from')
        if date_from:
            query_params['filtering']['created__gte'] = date_from

        date_to = request.GET.get('date_to')
        if date_to:
            query_params['filtering']['created__lte'] = date_to

        # KEYWORD SEARCHING
        q = request.GET.get('q', None)

        if q:
            context = dict(context, query=q)
            query_params['search_string'] = q

        # SORTING
        sort = request.GET.get('sort', None)
        if sort not in ('status', 'assigned_to', 'created', 'title', 'queue', 'priority'):
            sort = 'created'
        query_params['sorting'] = sort

        sortreverse = request.GET.get('sortreverse', None)
        query_params['sortreverse'] = sortreverse

    tickets = base_tickets.select_related()

    try:
        ticket_qs = apply_query(tickets, query_params)
    except ValidationError:
        # invalid parameters in query, return default query
        query_params = {
            'filtering': {'status__in': [1, 2, 3]},
            'sorting': 'created',
        }
        ticket_qs = apply_query(tickets, query_params)

    search_message = ''
    if 'query' in context and settings.DATABASES['default']['ENGINE'].endswith('sqlite'):
        search_message = _(
            '<p><strong>Note:</strong> Your keyword search is case sensitive '
            'because of your database. This means the search will <strong>not</strong> '
            'be accurate. By switching to a different database system you will gain '
            'better searching! For more information, read the '
            '<a href="http://docs.djangoproject.com/en/dev/ref/databases/#sqlite-string-matching">'
            'Django Documentation on string matching in SQLite</a>.')

    import json
    from helpdesk.lib import b64encode
    urlsafe_query = b64encode(json.dumps(query_params).encode('UTF-8'))

    user_saved_queries = SavedSearch.objects.filter(Q(user=request.user) | Q(shared__exact=True))

    return render(request, 'helpdesk/ticket_list.html', dict(
        context,
        tickets=ticket_qs,
        default_tickets_per_page=request.user.usersettings_helpdesk.settings.get('tickets_per_page') or 25,
        user_choices=User.objects.filter(is_active=True, is_staff=True),
        queue_choices=user_queues,
        status_choices=Ticket.STATUS_CHOICES,
        urlsafe_query=urlsafe_query,
        user_saved_queries=user_saved_queries,
        query_params=query_params,
        from_saved_query=from_saved_query,
        saved_query=saved_query,
        search_message=search_message,
    ))


@staff_member_required
def edit_ticket(request, ticket_id):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    if request.method == 'POST':
        form = EditTicketForm(request.POST, instance=ticket)
        if form.is_valid():
            ticket = form.save()
            return HttpResponseRedirect(ticket.get_absolute_url())
    else:
        form = EditTicketForm(instance=ticket)

    return render(request, 'helpdesk/edit_ticket.html', {'form': form})


@staff_member_required
def create_ticket(request):
    if helpdesk_settings.HELPDESK_STAFF_ONLY_TICKET_OWNERS:
        assignable_users = User.objects.filter(is_active=True, is_staff=True).order_by(User.USERNAME_FIELD)
    else:
        assignable_users = User.objects.filter(is_active=True).order_by(User.USERNAME_FIELD)

    if request.method == 'POST':
        form = TicketForm(request.POST, request.FILES)
        form.fields['queue'].choices = [('', '--------')] + [
            (q.id, q.title) for q in Queue.objects.all()]
        form.fields['assigned_to'].choices = [('', '--------')] + [
            (u.id, u.get_username()) for u in assignable_users]
        if form.is_valid():
            ticket = form.save(user=request.user)
            if _has_access_to_queue(request.user, ticket.queue):
                return HttpResponseRedirect(ticket.get_absolute_url())
            else:
                return HttpResponseRedirect(reverse('helpdesk:dashboard'))
    else:
        initial_data = {}
        if request.user.usersettings_helpdesk.settings.get('use_email_as_submitter', False) and request.user.email:
            initial_data['submitter_email'] = request.user.email
        if 'queue' in request.GET:
            initial_data['queue'] = request.GET['queue']

        form = TicketForm(initial=initial_data)
        form.fields['queue'].choices = [('', '--------')] + [
            (q.id, q.title) for q in Queue.objects.all()]
        form.fields['assigned_to'].choices = [('', '--------')] + [
            (u.id, u.get_username()) for u in assignable_users]
        if helpdesk_settings.HELPDESK_CREATE_TICKET_HIDE_ASSIGNED_TO:
            form.fields['assigned_to'].widget = forms.HiddenInput()

    return render(request, 'helpdesk/create_ticket.html', {'form': form})


@staff_member_required
def raw_details(request, type):
    # TODO: This currently only supports spewing out 'PreSetReply' objects,
    # in the future it needs to be expanded to include other items. All it
    # does is return a plain-text representation of an object.

    if type not in ('preset',):
        raise Http404

    if type == 'preset' and request.GET.get('id', False):
        try:
            preset = PreSetReply.objects.get(id=request.GET.get('id'))
            return HttpResponse(preset.body)
        except PreSetReply.DoesNotExist:
            raise Http404

    raise Http404


@staff_member_required
def hold_ticket(request, ticket_id, unhold=False):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    if unhold:
        ticket.on_hold = False
        title = _('Ticket taken off hold')
    else:
        ticket.on_hold = True
        title = _('Ticket placed on hold')

    f = FollowUp(
        ticket=ticket,
        user=request.user,
        title=title,
        date=timezone.now(),
        public=True,
    )
    f.save()

    ticket.save()

    return HttpResponseRedirect(ticket.get_absolute_url())


@staff_member_required
def unhold_ticket(request, ticket_id):
    return hold_ticket(request, ticket_id, unhold=True)


@staff_member_required
def rss_list(request):
    return render(request, 'helpdesk/rss_list.html', {'queues': Queue.objects.all()})


@staff_member_required
def report_index(request):
    number_tickets = Ticket.objects.all().count()
    saved_query = request.GET.get('saved_query', None)

    user_queues = _get_user_queues(request.user)
    Tickets = Ticket.objects.filter(queue__in=user_queues)
    basic_ticket_stats = calc_basic_ticket_stats(Tickets)

    # The following query builds a grid of queues & ticket statuses,
    # to be displayed to the user. EG:
    #          Open  Resolved
    # Queue 1    10     4
    # Queue 2     4    12
    Queues = user_queues if user_queues else Queue.objects.all()

    dash_tickets = []
    for queue in Queues:
        dash_ticket = {
            'queue': queue.id,
            'name': queue.title,
            'open': queue.ticket_set.filter(status__in=[1, 2]).count(),
            'resolved': queue.ticket_set.filter(status=3).count(),
            'closed': queue.ticket_set.filter(status=4).count(),
        }
        dash_tickets.append(dash_ticket)

    return render(request, 'helpdesk/report_index.html', {
        'number_tickets': number_tickets,
        'saved_query': saved_query,
        'basic_ticket_stats': basic_ticket_stats,
        'dash_tickets': dash_tickets,
    })


@staff_member_required
def run_report(request, report):
    if Ticket.objects.all().count() == 0 or report not in (
            'queuemonth', 'usermonth', 'queuestatus', 'queuepriority', 'userstatus',
            'userpriority', 'userqueue', 'daysuntilticketclosedbymonth'):
        return HttpResponseRedirect(reverse("helpdesk:report_index"))

    report_queryset = Ticket.objects.all().select_related().filter(
        queue__in=_get_user_queues(request.user)
    )

    from_saved_query = False
    saved_query = None

    if request.GET.get('saved_query', None):
        from_saved_query = True
        try:
            saved_query = SavedSearch.objects.get(pk=request.GET.get('saved_query'))
        except SavedSearch.DoesNotExist:
            return HttpResponseRedirect(reverse('helpdesk:report_index'))
        if not (saved_query.shared or saved_query.user == request.user):
            return HttpResponseRedirect(reverse('helpdesk:report_index'))

        import json
        from helpdesk.lib import b64decode
        try:
            if six.PY3:
                if DJANGO_VERSION[0] > 1:
                    # if Django >= 2.0
                    query_params = json.loads(b64decode(str(saved_query.query).lstrip("b\\'")).decode())
                else:
                    query_params = json.loads(b64decode(str(saved_query.query)).decode())
            else:
                query_params = json.loads(b64decode(str(saved_query.query)))
        except json.JSONDecodeError:
            return HttpResponseRedirect(reverse('helpdesk:report_index'))

        report_queryset = apply_query(report_queryset, query_params)

    from collections import defaultdict
    summarytable = defaultdict(int)
    # a second table for more complex queries
    summarytable2 = defaultdict(int)

    def month_name(m):
        MONTHS_3[m].title()

    first_ticket = Ticket.objects.all().order_by('created')[0]
    first_month = first_ticket.created.month
    first_year = first_ticket.created.year

    last_ticket = Ticket.objects.all().order_by('-created')[0]
    last_month = last_ticket.created.month
    last_year = last_ticket.created.year

    periods = []
    year, month = first_year, first_month
    working = True
    periods.append("%s-%s" % (year, month))

    while working:
        month += 1
        if month > 12:
            year += 1
            month = 1
        if (year > last_year) or (month > last_month and year >= last_year):
            working = False
        periods.append("%s-%s" % (year, month))

    if report == 'userpriority':
        title = _('User by Priority')
        col1heading = _('User')
        possible_options = [t[1].title() for t in Ticket.PRIORITY_CHOICES]
        charttype = 'bar'

    elif report == 'userqueue':
        title = _('User by Queue')
        col1heading = _('User')
        queue_options = _get_user_queues(request.user)
        possible_options = [q.title for q in queue_options]
        charttype = 'bar'

    elif report == 'userstatus':
        title = _('User by Status')
        col1heading = _('User')
        possible_options = [s[1].title() for s in Ticket.STATUS_CHOICES]
        charttype = 'bar'

    elif report == 'usermonth':
        title = _('User by Month')
        col1heading = _('User')
        possible_options = periods
        charttype = 'date'

    elif report == 'queuepriority':
        title = _('Queue by Priority')
        col1heading = _('Queue')
        possible_options = [t[1].title() for t in Ticket.PRIORITY_CHOICES]
        charttype = 'bar'

    elif report == 'queuestatus':
        title = _('Queue by Status')
        col1heading = _('Queue')
        possible_options = [s[1].title() for s in Ticket.STATUS_CHOICES]
        charttype = 'bar'

    elif report == 'queuemonth':
        title = _('Queue by Month')
        col1heading = _('Queue')
        possible_options = periods
        charttype = 'date'

    elif report == 'daysuntilticketclosedbymonth':
        title = _('Days until ticket closed by Month')
        col1heading = _('Queue')
        possible_options = periods
        charttype = 'date'

    metric3 = False
    for ticket in report_queryset:
        if report == 'userpriority':
            metric1 = u'%s' % ticket.get_assigned_to
            metric2 = u'%s' % ticket.get_priority_display()

        elif report == 'userqueue':
            metric1 = u'%s' % ticket.get_assigned_to
            metric2 = u'%s' % ticket.queue.title

        elif report == 'userstatus':
            metric1 = u'%s' % ticket.get_assigned_to
            metric2 = u'%s' % ticket.get_status_display()

        elif report == 'usermonth':
            metric1 = u'%s' % ticket.get_assigned_to
            metric2 = u'%s-%s' % (ticket.created.year, ticket.created.month)

        elif report == 'queuepriority':
            metric1 = u'%s' % ticket.queue.title
            metric2 = u'%s' % ticket.get_priority_display()

        elif report == 'queuestatus':
            metric1 = u'%s' % ticket.queue.title
            metric2 = u'%s' % ticket.get_status_display()

        elif report == 'queuemonth':
            metric1 = u'%s' % ticket.queue.title
            metric2 = u'%s-%s' % (ticket.created.year, ticket.created.month)

        elif report == 'daysuntilticketclosedbymonth':
            metric1 = u'%s' % ticket.queue.title
            metric2 = u'%s-%s' % (ticket.created.year, ticket.created.month)
            metric3 = ticket.modified - ticket.created
            metric3 = metric3.days

        summarytable[metric1, metric2] += 1
        if metric3:
            if report == 'daysuntilticketclosedbymonth':
                summarytable2[metric1, metric2] += metric3

    table = []

    if report == 'daysuntilticketclosedbymonth':
        for key in summarytable2.keys():
            summarytable[key] = summarytable2[key] / summarytable[key]

    header1 = sorted(set(list(i for i, _ in summarytable.keys())))

    column_headings = [col1heading] + possible_options

    # Pivot the data so that 'header1' fields are always first column
    # in the row, and 'possible_options' are always the 2nd - nth columns.
    for item in header1:
        data = []
        for hdr in possible_options:
            data.append(summarytable[item, hdr])
        table.append([item] + data)

    # Zip data and headers together in one list for Morris.js charts
    # will get a list like [(Header1, Data1), (Header2, Data2)...]
    seriesnum = 0
    morrisjs_data = []
    for label in column_headings[1:]:
        seriesnum += 1
        datadict = {"x": label}
        for n in range(0, len(table)):
            datadict[n] = table[n][seriesnum]
        morrisjs_data.append(datadict)

    series_names = []
    for series in table:
        series_names.append(series[0])

    return render(request, 'helpdesk/report_output.html', {
        'title': title,
        'charttype': charttype,
        'data': table,
        'headings': column_headings,
        'series_names': series_names,
        'morrisjs_data': morrisjs_data,
        'from_saved_query': from_saved_query,
        'saved_query': saved_query,
    })


@staff_member_required
def save_query(request):
    title = request.POST.get('title', None)
    shared = request.POST.get('shared', False)
    if shared == 'on':  # django only translates '1', 'true', 't' into True
        shared = True
    query_encoded = request.POST.get('query_encoded', None)

    if not title or not query_encoded:
        return HttpResponseRedirect(reverse('helpdesk:list'))

    query = SavedSearch(title=title, shared=shared, query=query_encoded, user=request.user)
    query.save()

    return HttpResponseRedirect('%s?saved_query=%s' % (reverse('helpdesk:list'), query.id))


@staff_member_required
def delete_saved_query(request, id):
    query = get_object_or_404(SavedSearch, id=id, user=request.user)

    if request.method == 'POST':
        query.delete()
        return HttpResponseRedirect(reverse('helpdesk:list'))
    else:
        return render(request, 'helpdesk/confirm_delete_saved_query.html', {'query': query})


@staff_member_required
def user_settings(request):
    s = request.user.usersettings_helpdesk
    if request.POST:
        form = UserSettingsForm(request.POST)
        if form.is_valid():
            s.settings = form.cleaned_data
            s.save()
    else:
        form = UserSettingsForm(s.settings)

    return render(request, 'helpdesk/user_settings.html', {'form': form})


@superuser_required
def email_ignore(request):
    return render(request, 'helpdesk/email_ignore_list.html', {
        'ignore_list': IgnoreEmail.objects.all(),
    })


@superuser_required
def email_ignore_add(request):
    if request.method == 'POST':
        form = EmailIgnoreForm(request.POST)
        if form.is_valid():
            form.save()
            return HttpResponseRedirect(reverse('helpdesk:email_ignore'))
    else:
        form = EmailIgnoreForm(request.GET)

    return render(request, 'helpdesk/email_ignore_add.html', {'form': form})


@superuser_required
def email_ignore_del(request, id):
    ignore = get_object_or_404(IgnoreEmail, id=id)
    if request.method == 'POST':
        ignore.delete()
        return HttpResponseRedirect(reverse('helpdesk:email_ignore'))
    else:
        return render(request, 'helpdesk/email_ignore_del.html', {'ignore': ignore})


@staff_member_required
def ticket_cc(request, ticket_id):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    copies_to = ticket.ticketcc_set.all()
    return render(request, 'helpdesk/ticket_cc_list.html', {
        'copies_to': copies_to,
        'ticket': ticket,
    })


@staff_member_required
def ticket_cc_add(request, ticket_id):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    if request.method == 'POST':
        form = TicketCCForm(request.POST)
        if form.is_valid():
            ticketcc = form.save(commit=False)
            ticketcc.ticket = ticket
            ticketcc.save()
            return HttpResponseRedirect(reverse('helpdesk:ticket_cc',
                                                kwargs={'ticket_id': ticket.id}))
    else:
        form_email = TicketCCEmailForm()
        form_user = TicketCCUserForm()
    return render(request, 'helpdesk/ticket_cc_add.html', {
        'ticket': ticket,
        'form_email': form_email,
        'form_user': form_user,
    })


@staff_member_required
def ticket_cc_del(request, ticket_id, cc_id):
    cc = get_object_or_404(TicketCC, ticket__id=ticket_id, id=cc_id)

    if request.method == 'POST':
        cc.delete()
        return HttpResponseRedirect(reverse('helpdesk:ticket_cc',
                                            kwargs={'ticket_id': cc.ticket.id}))
    return render(request, 'helpdesk/ticket_cc_del.html', {'cc': cc})


@staff_member_required
def ticket_dependency_add(request, ticket_id):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()
    if request.method == 'POST':
        form = TicketDependencyForm(request.POST)
        if form.is_valid():
            ticketdependency = form.save(commit=False)
            ticketdependency.ticket = ticket
            if ticketdependency.ticket != ticketdependency.depends_on:
                ticketdependency.save()
            return HttpResponseRedirect(reverse('helpdesk:view', args=[ticket.id]))
    else:
        form = TicketDependencyForm()
    return render(request, 'helpdesk/ticket_dependency_add.html', {
        'ticket': ticket,
        'form': form,
    })


@staff_member_required
def ticket_dependency_del(request, ticket_id, dependency_id):
    dependency = get_object_or_404(TicketDependency, ticket__id=ticket_id, id=dependency_id)
    if request.method == 'POST':
        dependency.delete()
        return HttpResponseRedirect(reverse('helpdesk:view', args=[ticket_id]))
    return render(request, 'helpdesk/ticket_dependency_del.html', {'dependency': dependency})


@staff_member_required
def attachment_del(request, ticket_id, attachment_id):
    ticket = get_object_or_404(Ticket, id=ticket_id)
    if not _has_access_to_queue(request.user, ticket.queue):
        raise PermissionDenied()
    if not _is_my_ticket(request.user, ticket):
        raise PermissionDenied()

    attachment = get_object_or_404(Attachment, id=attachment_id)
    if request.method == 'POST':
        attachment.delete()
        return HttpResponseRedirect(reverse('helpdesk:view', args=[ticket_id]))
    return render(request, 'helpdesk/ticket_attachment_del.html', {
        'attachment': attachment,
        'filename': attachment.filename,
    })


def calc_average_nbr_days_until_ticket_resolved(Tickets):
    nbr_closed_tickets = len(Tickets)
    days_per_ticket = 0
    days_each_ticket = list()

    for ticket in Tickets:
        time_ticket_open = ticket.modified - ticket.created
        days_this_ticket = time_ticket_open.days
        days_per_ticket += days_this_ticket
        days_each_ticket.append(days_this_ticket)

    if nbr_closed_tickets > 0:
        mean_per_ticket = days_per_ticket / nbr_closed_tickets
    else:
        mean_per_ticket = 0

    return mean_per_ticket


def calc_basic_ticket_stats(Tickets):
    # all not closed tickets (open, reopened, resolved,) - independent of user
    all_open_tickets = Tickets.exclude(status=Ticket.CLOSED_STATUS)
    today = datetime.today()

    date_30 = date_rel_to_today(today, 30)
    date_60 = date_rel_to_today(today, 60)
    date_30_str = date_30.strftime('%Y-%m-%d')
    date_60_str = date_60.strftime('%Y-%m-%d')

    # > 0 & <= 30
    ota_le_30 = all_open_tickets.filter(created__gte=date_30_str)
    N_ota_le_30 = len(ota_le_30)

    # >= 30 & <= 60
    ota_le_60_ge_30 = all_open_tickets.filter(created__gte=date_60_str, created__lte=date_30_str)
    N_ota_le_60_ge_30 = len(ota_le_60_ge_30)

    # >= 60
    ota_ge_60 = all_open_tickets.filter(created__lte=date_60_str)
    N_ota_ge_60 = len(ota_ge_60)

    # (O)pen (T)icket (S)tats
    ots = list()
    # label, number entries, color, sort_string
    ots.append(['Tickets < 30 days', N_ota_le_30, 'success',
                sort_string(date_30_str, ''), ])
    ots.append(['Tickets 30 - 60 days', N_ota_le_60_ge_30,
                'success' if N_ota_le_60_ge_30 == 0 else 'warning',
                sort_string(date_60_str, date_30_str), ])
    ots.append(['Tickets > 60 days', N_ota_ge_60,
                'success' if N_ota_ge_60 == 0 else 'danger',
                sort_string('', date_60_str), ])

    # all closed tickets - independent of user.
    all_closed_tickets = Tickets.filter(status=Ticket.CLOSED_STATUS)
    average_nbr_days_until_ticket_closed = \
        calc_average_nbr_days_until_ticket_resolved(all_closed_tickets)
    # all closed tickets that were opened in the last 60 days.
    all_closed_last_60_days = all_closed_tickets.filter(created__gte=date_60_str)
    average_nbr_days_until_ticket_closed_last_60_days = \
        calc_average_nbr_days_until_ticket_resolved(all_closed_last_60_days)

    # put together basic stats
    basic_ticket_stats = {
        'average_nbr_days_until_ticket_closed': average_nbr_days_until_ticket_closed,
        'average_nbr_days_until_ticket_closed_last_60_days':
            average_nbr_days_until_ticket_closed_last_60_days,
        'open_ticket_stats': ots,
    }

    return basic_ticket_stats


def get_color_for_nbr_days(nbr_days):
    if nbr_days < 5:
        color_string = 'green'
    elif nbr_days < 10:
        color_string = 'orange'
    else:  # more than 10 days
        color_string = 'red'

    return color_string


def days_since_created(today, ticket):
    return (today - ticket.created).days


def date_rel_to_today(today, offset):
    return today - timedelta(days=offset)


def sort_string(begin, end):
    return 'sort=created&date_from=%s&date_to=%s&status=%s&status=%s&status=%s' % (
        begin, end, Ticket.OPEN_STATUS, Ticket.REOPENED_STATUS, Ticket.RESOLVED_STATUS)