combo/combo/apps/maps/models.py

# combo - content management system
# Copyright (C) 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/>.


from django.db import models
from django.utils.text import slugify
from django.utils.translation import ugettext_lazy as _
from django.core.urlresolvers import reverse_lazy
from django import forms
from django import template
from django.conf import settings
from django.core.exceptions import PermissionDenied

from combo.data.models import CellBase
from combo.data.library import register_cell_class
from combo.utils import requests


ICONS = [
    ('home', _('Home')),
    ('building', _('Building')),
    ('hospital', _('Hospital')),
    ('ambulance', _('Ambulance')),
    ('taxi', _('Taxi')),
    ('subway', _('Subway')),
    ('wheelchair', _('Wheelchair')),
    ('bicycle', _('Bicycle')),
    ('car', _('Car')),
    ('train', _('Train')),
    ('bus', _('Bus')),
    ('motorcycle', _('Motorcycle')),
    ('truck', _('Truck')),
]

ZOOM_LEVELS = [ ('0', _('Whole world')),
                ('9', _('Wide area')),
                ('11', _('Area')),
                ('13', _('Town')),
                ('16', _('Small road')),
                ('19', _('Ant')),]


class MapLayer(models.Model):
    label = models.CharField(_('Label'), max_length=128)
    slug = models.SlugField(_('Slug'))
    geojson_url = models.URLField(_('Geojson URL'), max_length=1024)
    marker_colour = models.CharField(_('Marker colour'), max_length=7, default='#0000FF')
    icon = models.CharField(_('Marker icon'), max_length=32, blank=True, null=True,
                            choices=ICONS)
    icon_colour = models.CharField(_('Icon colour'), max_length=7, default='#FFFFFF')

    def save(self, *args, **kwargs):
        if not self.slug:
            base_slug = slugify(self.label)
            slug = base_slug
            i = 1
            while True:
                try:
                    MapLayer.objects.get(slug=slug)
                except self.DoesNotExist:
                    break
                slug = '%s-%s' % (base_slug, i)
                i += 1
            self.slug = slug
        super(MapLayer, self).save(*args, **kwargs)

    def __unicode__(self):
        return self.label

    def get_geojson(self, request):
        response = requests.get(self.geojson_url,
                            remote_service='auto',
                            user=request.user,
                            headers={'accept': 'application/json'})
        if not response.ok:
            return []
        data = response.json()
        if 'features' in data:
            features = data['features']
        else:
            features = data
        for feature in features:
            feature['properties']['colour'] = self.marker_colour
            feature['properties']['icon_colour'] = self.icon_colour
            feature['properties']['label'] = self.label
            feature['properties']['icon'] = self.icon
        return features


@register_cell_class
class Map(CellBase):
    title = models.CharField(_('Title'), max_length=150, blank=True)
    initial_zoom = models.CharField(_('Initial zoom level'), max_length=2,
                                    choices=ZOOM_LEVELS, default='13')
    min_zoom = models.CharField(_('Minimal zoom level'), max_length=2,
                                   choices=ZOOM_LEVELS, default='0')
    max_zoom = models.CharField(_('Maximal zoom level'), max_length=2,
                                choices=ZOOM_LEVELS, default=19)
    layers = models.ManyToManyField(MapLayer, verbose_name=_('Layers'), blank=True)

    template_name = 'maps/map_cell.html'

    class Meta:
        verbose_name = _('Map')

    class Media:
        js = ('xstatic/leaflet.js', 'js/combo.map.js')
        css = {'all': ('xstatic/leaflet.css', 'css/combo.map.css')}

    def get_default_position(self):
        return settings.COMBO_MAP_DEFAULT_POSITION

    def get_default_form_class(self):
        fields = ('title', 'initial_zoom', 'min_zoom',
                  'max_zoom', 'layers')
        widgets = {'layers': forms.widgets.CheckboxSelectMultiple}
        return forms.models.modelform_factory(self.__class__, fields=fields,
                                             widgets=widgets)

    def get_geojson(self, request):
        geojson = {'type': 'FeatureCollection', 'features': []}
        for layer in self.layers.all():
            geojson['features'] += layer.get_geojson(request)
        return geojson

    @classmethod
    def is_enabled(cls):
        return MapLayer.objects.count() > 0

    def get_cell_extra_context(self, context):
        ctx = super(Map, self).get_cell_extra_context(context)
        ctx['title'] = self.title
        default_position = self.get_default_position()
        ctx['init_lat'] = default_position['lat']
        ctx['init_lng'] = default_position['lng']
        ctx['initial_zoom'] = self.initial_zoom
        ctx['min_zoom'] = self.min_zoom
        ctx['max_zoom'] = self.max_zoom
        ctx['geojson_url'] = reverse_lazy('mapcell-geojson', kwargs={'cell_id': self.pk})
        ctx['tile_urltemplate'] = settings.COMBO_MAP_TILE_URLTEMPLATE
        ctx['map_attribution'] = settings.COMBO_MAP_ATTRIBUTION
        return ctx