rewrite frontend and logic in core app

core/prediction.py

@@ -1,6 +1,9 @@
+from datetime import timedelta
 from decimal import Decimal
+from typing import Iterable
 
 from dateutil.relativedelta import relativedelta
+from django.utils import timezone
 
 from core.models import Subject, Transaction
 
@@ -85,3 +88,28 @@ def predict_transactions(subject: Subject):
             "day_of_month": day_of_month,
         }
     return transactions, prediction_info
+
+
+def predict_all(subjects: Iterable[Subject], past_days=30, future_days=60):
+    today = timezone.now().date()
+    past_lookup_bound = today - timedelta(days=past_days)
+    future_lookup_bound = today + timedelta(days=future_days)
+    lookup_bounds = (past_lookup_bound, future_lookup_bound)
+
+    prediction_list = []
+    for subject in subjects:
+        transactions = list(
+            subject.transactions.filter(booking_date__range=lookup_bounds).order_by("booking_date"))
+
+        predicted_transactions, prediction_info = predict_transactions(subject)
+        if predicted_transactions:
+            first_predicted_date = predicted_transactions[0].booking_date
+            if first_predicted_date >= past_lookup_bound:
+                # if two weeks after the first predicted transaction have passed, the subject is considered done
+                for transaction in predicted_transactions:
+                    if past_lookup_bound <= transaction.booking_date <= future_lookup_bound:
+                        transactions.append(transaction)
+
+        prediction_list.append((subject, transactions, prediction_info))
+
+    return prediction_list