# combo - content management system
# Copyright (C) 2014-2017  Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import json

from django.conf import settings
from django.contrib.contenttypes.models import ContentType
from django.core.exceptions import PermissionDenied
from django.core.urlresolvers import reverse
from django.db.models import Max, Min
from django.http import Http404, HttpResponse, HttpResponseRedirect
from django.utils.encoding import force_text
from django.views.decorators.csrf import csrf_exempt
from django.views.generic import View

from combo.data.models import CellBase, ConfigJsonCell
from combo.data.library import get_cell_class
from combo.public.views import render_cell

from .models import DashboardCell, Tile
from .templatetags.dashboard import get_cell_data


def dashboard_success(request, dashboard, cell_data):
    dashboard_url = dashboard.page.get_online_url()

    if request.is_ajax():
        return HttpResponse(
                json.dumps({
                    'err': 0,
                    'url': request.build_absolute_uri(dashboard_url),
                    'cell_data': cell_data}),
                content_type='application/json')

    return HttpResponseRedirect(dashboard_url)


class DashboardAddTileView(View):
    def get(self, request, *args, **kwargs):
        if not request.user.is_authenticated():
            raise PermissionDenied()

        dashboard = DashboardCell.objects.all()[0]
        cell = CellBase.get_cell(kwargs['cell_reference'])
        if not cell.page.is_visible(request.user):
            raise PermissionDenied()
        if not cell.is_visible(request.user):
            raise PermissionDenied()
        cell.pk = None
        cell.page = dashboard.page
        cell.placeholder = '_dashboard'
        cell.save()

        tile = Tile(dashboard=dashboard,
                cell=cell,
                user=request.user,
                order=0)
        if settings.COMBO_DASHBOARD_NEW_TILE_POSITION == 'first':
            order = Tile.objects.filter(dashboard=dashboard, user=request.user).aggregate(Min('order')).get('order__min')
            tile.order = order - 1 if order is not None else 0
        elif settings.COMBO_DASHBOARD_NEW_TILE_POSITION == 'last':
            order = Tile.objects.filter(dashboard=dashboard, user=request.user).aggregate(Max('order')).get('order_max')
            tile.order = order + 1 if order is not None else 0
        tile.save()

        cell_data = get_cell_data(cell)
        cell_data['remove_url'] = reverse(
                'combo-dashboard-remove-tile',
                kwargs={'cell_reference': cell.get_reference()})

        return dashboard_success(request, dashboard, cell_data)

dashboard_add_tile = DashboardAddTileView.as_view()


class DashboardRemoveTileView(View):
    def get(self, request, *args, **kwargs):
        cell = CellBase.get_cell(kwargs['cell_reference'])
        try:
            tile = Tile.get_by_cell(cell)
        except Tile.DoesNotExist:
            raise Http404()
        if tile.user != request.user:
            raise PermissionDenied()
        dashboard = tile.dashboard
        cell_data = get_cell_data(cell)
        tile.delete()

        # do not remove cell so it can directly be added back
        cell_data['add_url'] = reverse(
                'combo-dashboard-add-tile',
                kwargs={'cell_reference': cell.get_reference()})

        return dashboard_success(request, dashboard, cell_data)

dashboard_remove_tile = DashboardRemoveTileView.as_view()


@csrf_exempt
def dashboard_auto_tile(request, *args, **kwargs):
    dashboard = DashboardCell.objects.all()[0]
    cell = ConfigJsonCell(key=kwargs.get('key'), order=1,
            page_id=dashboard.page_id, placeholder='_auto_tile')

    # only keep parameters that are actually defined for this cell type.
    cell_form_keys = [x['varname'] for x in settings.JSON_CELL_TYPES[cell.key].get('form') or {}]
    cell.parameters = {}
    request_body = json.loads(force_text(request.body))
    for key in cell_form_keys:
        cell.parameters[key] = request_body.get(key)

    # save cell so it can be reused later, for example to be added to
    # dashboard, or to be used as reference in another page, etc.
    cell.save()

    response = render_cell(request, cell=cell)
    response['x-add-to-dashboard-url'] = reverse(
                'combo-dashboard-add-tile',
                kwargs={'cell_reference': cell.get_reference()})
    return response


def dashboard_reorder_tiles(request, *args, **kwargs):
    dashboard = DashboardCell.objects.all()[0]
    new_order = request.GET['order'].split(',')
    tiles = dict((str(x.id), x) for x in Tile.objects.filter(id__in=new_order))
    for i, tile_id in enumerate(new_order):
        tile = tiles.get(tile_id)
        if tile.user != request.user:
            raise PermissionDenied()
        if tile:
            tile.order = i
    for tile in tiles.values():
        tile.save()
    return HttpResponse(status=204)