Refactor ParkLocation model to inherit from TrackedModel for enhanced history tracking. Update point handling to temporarily store coordinates as a string. Implement Haversine formula for distance calculation as a placeholder until PostGIS is enabled.

Refactor advanced search template to utilize Alpine.js for state management. Enhance search functionality with dynamic view modes and improved filter handling using HTMX.

apps/parks/models/location.py

@@ -2,10 +2,11 @@
 from django.db import models
 # from django.contrib.gis.geos import Point  # Disabled temporarily for setup
 import pghistory
+from apps.core.history import TrackedModel
 
 
 @pghistory.track()
-class ParkLocation(models.Model):
+class ParkLocation(TrackedModel):
     """
     Represents the geographic location and address of a park, with PostGIS support.
     """
@@ -53,15 +54,17 @@ class ParkLocation(models.Model):
     @property
     def latitude(self):
         """Return latitude from point field."""
-        if self.point:
-            return self.point.y
+        if self.point and ',' in self.point:
+            # Temporary string format: "longitude,latitude"
+            return float(self.point.split(',')[1])
         return None
 
     @property
     def longitude(self):
         """Return longitude from point field."""
-        if self.point:
-            return self.point.x
+        if self.point and ',' in self.point:
+            # Temporary string format: "longitude,latitude"
+            return float(self.point.split(',')[0])
         return None
 
     @property
@@ -97,7 +100,9 @@ class ParkLocation(models.Model):
         if not -180 <= longitude <= 180:
             raise ValueError("Longitude must be between -180 and 180.")
 
-        self.point = Point(longitude, latitude, srid=4326)
+        # Temporarily store as string until PostGIS is enabled
+        self.point = f"{longitude},{latitude}"
+        # self.point = Point(longitude, latitude, srid=4326)
 
     def distance_to(self, other_location):
         """
@@ -106,9 +111,26 @@ class ParkLocation(models.Model):
         """
         if not self.point or not other_location.point:
             return None
-        # Use geodetic distance calculation which returns meters, convert to km
-        distance_m = self.point.distance(other_location.point)
-        return distance_m / 1000.0
+        
+        # Temporary implementation using Haversine formula
+        # TODO: Replace with PostGIS distance calculation when enabled
+        import math
+        
+        lat1, lon1 = self.latitude, self.longitude
+        lat2, lon2 = other_location.latitude, other_location.longitude
+        
+        if None in (lat1, lon1, lat2, lon2):
+            return None
+            
+        # Haversine formula
+        R = 6371  # Earth's radius in kilometers
+        dlat = math.radians(lat2 - lat1)
+        dlon = math.radians(lon2 - lon1)
+        a = (math.sin(dlat/2) * math.sin(dlat/2) + 
+             math.cos(math.radians(lat1)) * math.cos(math.radians(lat2)) * 
+             math.sin(dlon/2) * math.sin(dlon/2))
+        c = 2 * math.atan2(math.sqrt(a), math.sqrt(1-a))
+        return R * c
 
     def __str__(self):
         return f"Location for {self.park.name}"