Add weight for clustering and heatmap

1 files changed, 97 insertions, 3 deletions

diff --git a/chimere/models.py b/chimere/models.py
index 8ab0b22..48e7f4b 100644
--- a/chimere/models.py
+++ b/chimere/models.py
@@ -36,7 +36,7 @@ from django.conf import settings
 from django.contrib.auth.models import User, Permission, ContentType, Group
 from django.contrib.gis.db import models
 from django.core.files import File
-from django.core.exceptions import ObjectDoesNotExist
+from django.core.exceptions import ObjectDoesNotExist, MultipleObjectsReturned
 from django.core.urlresolvers import reverse
 from django.db.models import Q, Count
 from django.db.models.signals import post_save, pre_save, m2m_changed
@@ -267,6 +267,8 @@ class SubCategory(models.Model):
                                     blank=True, null=True)
     as_layer = models.BooleanField(_(u"Displayed in the layer menu"),
                                    default=False)
+    weight_formula = models.TextField(_(u"Weight formula"), default="",
+                                      blank=True, null=True)
     routing_warn = models.BooleanField(_(u"Routing warn"), default=False)
     order = models.IntegerField(_(u"Order"), default=1000)
     keywords = models.TextField(_(u"Keywords"), max_length=200,
@@ -529,6 +531,15 @@ class GeographicItem(models.Model):
         _(u"End date"), blank=True, null=True,
         help_text=_(u"Not mandatory. Set it only if you have a multi-day "
                     u"event. Format YYYY-MM-DD"))
+    weight = models.FloatField(
+        _(u"Weight"), blank=True, null=True,
+        help_text=_(
+            u"Weight are used for heatmap and clustering. A formula must "
+            u"defined in the associated category."))
+    normalised_weight = models.FloatField(
+        _(u"Normalised weight"), blank=True, null=True,
+        help_text=_(u"The weight normalised to be between 0 and 1. "
+                    u"Automatically recalculated."))
 
     class Meta:
         abstract = True
@@ -551,6 +562,9 @@ class GeographicItem(models.Model):
                 setattr(self, attr_name + '_set',
                         property_setter(self.__class__, pm))
 
+    def get_geometry(self):
+        return getattr(self, self.geom_attr)
+
     @property
     def geometry(self):
         return getattr(self, self.geom_attr).wkt
@@ -689,6 +703,64 @@ class GeographicItem(models.Model):
                  for pict in self.pictures.all()]
         return picts
 
+    def get_full_dict(self):
+        dct = {}
+        # get all property even the one not displayed
+        for pm in PropertyModel.objects.all():
+            dct[pm.slug] = unicode(self.getProperty(pm))
+        return dct
+
+    def calculate_weight(self, formula):
+        try:
+            # try to eval the formula
+            # safe because open to admin only
+            return round(eval(formula.format(**self.get_full_dict())), 10)
+        except:
+            return 0
+
+    def get_weight_formula(self, get_associated_cat=False):
+        for sub in self.categories.order_by('order').all():
+            if sub.weight_formula:
+                if get_associated_cat:
+                    return sub.weight_formula, sub
+                return sub.weight_formula
+        if get_associated_cat:
+            return None, None
+        return None
+
+    def normalise_weight(self):
+        formula, cat = self.get_weight_formula(get_associated_cat=True)
+        if not formula:
+            return
+        q = self.__class__.objects.filter(
+            categories__pk=cat.pk, weight__isnull=False)
+        if not q.count():
+            return 0
+        min_weight = q.order_by('weight')[0].weight or 0
+        max_weight = q.order_by('-weight')[0].weight or 0
+        return 1 - round(
+            (max_weight - self.weight or 0) /
+            (float((max_weight - min_weight)) or 1), 5)
+
+
+def weighted_post_save(sender, **kwargs):
+    if not kwargs['instance']:
+        return
+    obj = kwargs['instance']
+    formula = obj.get_weight_formula()
+    weight, normalised_weight = None, None
+    if formula:
+        weight = obj.calculate_weight(formula)
+        if weight != obj.weight:
+            obj.weight = weight
+            obj.save()
+            return
+        normalised_weight = obj.normalise_weight()
+    if weight != obj.weight or normalised_weight != obj.normalised_weight:
+        obj.weight = weight
+        obj.normalised_weight = normalised_weight
+        obj.save()
+
 
 def property_setter(cls, propertymodel):
     def setter(self, value):
@@ -880,6 +952,7 @@ def geometry_post_save(pre_save_geom_values):
 
 
 def marker_post_save(sender, **kwargs):
+    weighted_post_save(sender, **kwargs)
     if not kwargs['instance'] or kwargs['created']:
         return
     geometry_post_save(pre_save_marker_values)(sender, **kwargs)
@@ -971,6 +1044,15 @@ class Polygon(GeographicItem):
             added.append(polygon['pk'])
         return vals
 
+    def get_full_dict(self):
+        dct = super(Polygon, self).get_full_dict()
+        # to be done - use local unity
+        dct['area'] = self.polygon.area
+        dct['length'] = self.polygon.length
+        return dct
+
+post_save.connect(weighted_post_save, sender=Polygon)
+
 
 class MultimediaType(models.Model):
     MEDIA_TYPES = (('A', _(u"Audio")),
@@ -1362,6 +1444,12 @@ class Route(GeographicItem):
                                      "color": color}}
         return json.dumps(attributes)
 
+    def get_full_dict(self):
+        dct = super(Route, self).get_full_dict()
+        # to be done - use local unity
+        dct['length'] = self.route.length
+        return dct
+
 pre_save_route_values = {}
 
 
@@ -1376,6 +1464,7 @@ def route_post_save(sender, **kwargs):
     if not kwargs['instance']:
         return
     geometry_post_save(pre_save_route_values)(sender, **kwargs)
+    weighted_post_save(sender, **kwargs)
     instance = kwargs['instance']
 
     # manage associated marker
@@ -1387,8 +1476,13 @@ def route_post_save(sender, **kwargs):
              if k in route_fields and k not in ('id', 'ref_item_id')])
         marker_dct['point'] = "SRID=%d;POINT(%f %f)" % (
             instance.route.srid, instance.route[0][0], instance.route[0][1])
-        marker, created = Marker.objects.get_or_create(route=instance,
-                                                       defaults=marker_dct)
+        try:
+            marker, created = Marker.objects.get_or_create(route=instance,
+                                                           defaults=marker_dct)
+        except MultipleObjectsReturned:
+            # db error - trying to continue...
+            marker = Marker.objects.filter(route=instance).all()[0]
+            created = False
         if not created:
             marker.status = instance.status
             marker.point = marker_dct['point']