better errorhandling, slimmed down optimizer

backend/src/main.py

@@ -29,9 +29,11 @@ def new_trip(preferences: Preferences, start: tuple[float, float], end: tuple[fl
     :return: the uuid of the first landmark in the optimized route
     '''
     if preferences is None:
-        raise ValueError("Please provide preferences in the form of a 'Preference' BaseModel class.")
+        raise HTTPException(status_code=406, detail="Preferences not provided")
+    if preferences.shopping.score == 0 and preferences.sightseeing.score == 0 and preferences.nature.score == 0:
+        raise HTTPException(status_code=406, detail="All preferences are 0.")
     if start is None:
-        raise ValueError("Please provide the starting coordinates as a tuple of floats.")
+        raise HTTPException(status_code=406, detail="Start coordinates not provided")
     if end is None:
         end = start
         logger.info("No end coordinates provided. Using start=end.")
@@ -50,7 +52,12 @@ def new_trip(preferences: Preferences, start: tuple[float, float], end: tuple[fl
     landmarks_short.append(end_landmark)
     
     # First stage optimization
-    base_tour = optimizer.solve_optimization(preferences.max_time_minute, landmarks_short)
+    try:
+        base_tour = optimizer.solve_optimization(preferences.max_time_minute, landmarks_short)
+    except ArithmeticError:
+        raise HTTPException(status_code=500, detail="No solution found")
+    except TimeoutError:
+        raise HTTPException(status_code=500, detail="Optimzation took too long")
     
     # Second stage optimization
     refined_tour = refiner.refine_optimization(landmarks, base_tour, preferences.max_time_minute, preferences.detour_tolerance_minute)