Added checks to Flight creation

simulator/models/flight.py

@@ -58,17 +58,53 @@ class Flight(models.Model):
         return self.departure_time + self.duration
 
     def clean(self):
-        overlapping = Flight.objects.filter(
-            equipment=self.equipment,
-            departure_time__lt=self.arrival_time,
-            arrival_time__gt=self.departure_time,
-        ).exclude(pk=self.pk)
-
-        if overlapping.exists():
+        # Validate flight distance is within aircraft range
+        if self.distance_nm > self.equipment.model.range_nm:
             raise ValidationError(
-                f"{self.equipment} is already assigned to another flight in this timeframe."
+                f"Flight distance ({self.distance_nm:.0f} nm) exceeds {self.equipment.model} "
+                f"maximum range ({self.equipment.model.range_nm} nm)."
             )
 
+        # Validate equipment is at the origin airport
+        # Get the last flight before this one chronologically
+        previous_flight = (
+            Flight.objects.filter(
+                equipment=self.equipment, departure_time__lt=self.departure_time
+            )
+            .order_by("-departure_time")
+            .exclude(pk=self.pk)
+            .first()
+        )
+
+        if previous_flight:
+            # Equipment must be at the destination of the previous flight
+            if previous_flight.destination != self.origin:
+                raise ValidationError(
+                    f"{self.equipment} will be at {previous_flight.destination.icao} "
+                    f"after flight {previous_flight.carrier.icao}{previous_flight.flight_number}. "
+                    f"Cannot depart from {self.origin.icao}."
+                )
+
+            # Ensure enough time between arrival and next departure (at least arrival happens before departure)
+            if previous_flight.arrival_time > self.departure_time:
+                raise ValidationError(
+                    f"{self.equipment} arrives at {self.origin.icao} at {previous_flight.arrival_time}. "
+                    f"Cannot depart before arrival."
+                )
+        else:
+            # No previous flights, equipment must be at base location
+            if (
+                self.equipment.base_location
+                and self.equipment.base_location != self.origin
+            ):
+                raise ValidationError(
+                    f"{self.equipment} is based at {self.equipment.base_location.icao}. "
+                    f"First flight must depart from base location, not {self.origin.icao}."
+                )
+
+        # Calculate arrival time for this flight
+        arrival = self.arrival_time
+
     @property
     def status(self):
         now = timezone.now()