major changes, including tailwind v4

core/history.py

@@ -0,0 +1,92 @@
+from django.db import models
+from django.contrib.contenttypes.models import ContentType
+from django.contrib.contenttypes.fields import GenericForeignKey
+from django.conf import settings
+from typing import Any, Dict, Optional
+from django.db.models import QuerySet
+
+class DiffMixin:
+    """Mixin to add diffing capabilities to models"""
+    
+    def get_prev_record(self) -> Optional[Any]:
+        """Get the previous record for this instance"""
+        try:
+            return type(self).objects.filter(
+                pgh_created_at__lt=self.pgh_created_at,
+                pgh_obj_id=self.pgh_obj_id
+            ).order_by('-pgh_created_at').first()
+        except (AttributeError, TypeError):
+            return None
+
+    def diff_against_previous(self) -> Dict:
+        """Compare this record against the previous one"""
+        prev_record = self.get_prev_record()
+        if not prev_record:
+            return {}
+
+        skip_fields = {
+            'pgh_id', 'pgh_created_at', 'pgh_label', 
+            'pgh_obj_id', 'pgh_context_id', '_state',
+            'created_at', 'updated_at'
+        }
+
+        changes = {}
+        for field, value in self.__dict__.items():
+            # Skip internal fields and those we don't want to track
+            if field.startswith('_') or field in skip_fields or field.endswith('_id'):
+                continue
+
+            try:
+                old_value = getattr(prev_record, field)
+                new_value = value
+                if old_value != new_value:
+                    changes[field] = {
+                        "old": str(old_value) if old_value is not None else "None",
+                        "new": str(new_value) if new_value is not None else "None"
+                    }
+            except AttributeError:
+                continue
+
+        return changes
+
+class TrackedModel(models.Model):
+    """Abstract base class for models that need history tracking"""
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        abstract = True
+
+    def get_history(self) -> QuerySet:
+        """Get all history records for this instance in chronological order"""
+        event_model = self.events.model  # pghistory provides this automatically
+        if event_model:
+            return event_model.objects.filter(
+                pgh_obj_id=self.pk
+            ).order_by('-pgh_created_at')
+        return self.__class__.objects.none()
+
+class HistoricalSlug(models.Model):
+    """Track historical slugs for models"""
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
+    object_id = models.PositiveIntegerField()
+    content_object = GenericForeignKey('content_type', 'object_id')
+    slug = models.SlugField(max_length=255)
+    created_at = models.DateTimeField(auto_now_add=True)
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        related_name='historical_slugs'
+    )
+
+    class Meta:
+        unique_together = ('content_type', 'slug')
+        indexes = [
+            models.Index(fields=['content_type', 'object_id']),
+            models.Index(fields=['slug']),
+        ]
+
+    def __str__(self) -> str:
+        return f"{self.content_type} - {self.object_id} - {self.slug}"