import sys

from django.contrib import messages
from django.db import transaction
from django.utils.translation import ngettext, gettext_lazy as _

from orchestra.admin.decorators import action_with_confirmation

from .forms import ChangeReasonForm
from .helpers import markdown_formated_changes
from .models import Queue, Ticket


def change_ticket_state_factory(action, verbose_name, final_state):
    context = {
        'action': action,
        'form': ChangeReasonForm()
    }
    @transaction.atomic
    @action_with_confirmation(action_name=action, extra_context=context)
    def change_ticket_state(modeladmin, request, queryset, action=action, final_state=final_state):
        form = ChangeReasonForm(request.POST)
        if form.is_valid():
            reason = form.cleaned_data['reason']
            for ticket in queryset:
                if ticket.state != final_state:
                    changes = {
                        'state': (ticket.state, final_state)
                    }
                    is_read = ticket.is_read_by(request.user)
                    getattr(ticket, action)()
                    msg = _("Marked as %s") % final_state.lower()
                    modeladmin.log_change(request, ticket, msg)
                    content = markdown_formated_changes(changes)
                    content += reason
                    ticket.messages.create(content=content, author=request.user)
                    if is_read and not ticket.is_read_by(request.user):
                        ticket.mark_as_read_by(request.user)
            context = {
                'count': queryset.count(),
                'state': final_state.lower()
            }
            msg = _("%(count)s selected tickets are now %(state)s.") % context
            modeladmin.message_user(request, msg)
        else:
            context['form'] = form
            # action_with_confirmation must display form validation errors
            return True
    change_ticket_state.url_name = action
    change_ticket_state.tool_description = verbose_name
    change_ticket_state.short_description = _('%s selected tickets') % verbose_name
    change_ticket_state.help_text = _('Mark ticket as %s.') % final_state.lower()
    change_ticket_state.__name__ = action
    return change_ticket_state


action_map = {
    Ticket.RESOLVED: ('resolve', _("Resolve")),
    Ticket.REJECTED: ('reject', _("Reject")),
    Ticket.CLOSED: ('close', _("Close")),
}


thismodule = sys.modules[__name__]
for state, names in action_map.items():
    name, verbose_name = names
    action = change_ticket_state_factory(name, verbose_name, state)
    setattr(thismodule, '%s_tickets' % name, action)


@transaction.atomic
def take_tickets(modeladmin, request, queryset):
    for ticket in queryset:
        if ticket.owner != request.user:
            changes = {
                'owner': (ticket.owner, request.user)
            }
            is_read = ticket.is_read_by(request.user)
            ticket.take(request.user)
            modeladmin.log_change(request, ticket, _("Taken"))
            content = markdown_formated_changes(changes)
            ticket.messages.create(content=content, author=request.user)
            if is_read and not ticket.is_read_by(request.user):
                ticket.mark_as_read_by(request.user)
            modeladmin.log_change(request, ticket, 'Taken')
    context = {
        'count': queryset.count(),
        'user': request.user
    }
    msg = _("%(count)s selected tickets are now owned by %(user)s.") % context
    modeladmin.message_user(request, msg)
take_tickets.url_name = 'take'
take_tickets.tool_description = _("Take")
take_tickets.short_description = _("Take selected tickets")
take_tickets.help_text = _("Make yourself owner of the ticket.")


@transaction.atomic
def mark_as_unread(modeladmin, request, queryset):
    """ Mark a tickets as unread """
    for ticket in queryset:
        ticket.mark_as_unread_by(request.user)
        modeladmin.log_change(request, ticket, 'Marked as unread')
    num = len(queryset)
    msg = ngettext(
        _("Selected ticket has been marked as unread."),
        _("%i selected tickets have been marked as unread.") % num,
        num)
    modeladmin.message_user(request, msg)


@transaction.atomic
def mark_as_read(modeladmin, request, queryset):
    """ Mark a tickets as unread """
    for ticket in queryset:
        ticket.mark_as_read_by(request.user)
        modeladmin.log_change(request, ticket, 'Marked as read')
    num = len(queryset)
    msg = ngettext(
        _("Selected ticket has been marked as read."),
        _("%i selected tickets have been marked as read.") % num,
        num)
    modeladmin.message_user(request, msg)


@transaction.atomic
def set_default_queue(modeladmin, request, queryset):
    """ Set a queue as default issues queue """
    if queryset.count() != 1:
        messages.warning(request, _("Please, select only one queue."))
        return
    Queue.objects.filter(default=True).update(default=False)
    queue = queryset.get()
    queue.default = True
    queue.save(update_fields=['default'])
    modeladmin.log_change(request, queue, _("Chosen as default."))
    messages.info(request, _("Chosen '%s' as default queue.") % queue)