fix weekly overview: use asof snapshot lookup and 5-day gap for last_week

invest/services.py

@@ -94,25 +94,53 @@ def _get_snapshot_total(date) -> Optional[float]:
 
 def get_weekly_overview() -> dict:
     """
-    Compute overview from the two most recent Saturday snapshots.
-    Returns totals, week-over-week change, and per-portfolio rows.
+    Compute overview from the two most recent weekly snapshots.
+    'This week' = most recent snapshot date.
+    'Last week' = most recent snapshot date at least 5 days earlier (ensuring different week).
+    Per-portfolio values use as-of lookups (latest snapshot on or before the target date).
     """
-    # Find the 2 most recent distinct snapshot dates
-    seen_days: list = []
-    for dt in (PortfolioSnapshot.objects
-               .values_list('captured_at', flat=True)
-               .order_by('-captured_at')):
-        day = dt.date() if hasattr(dt, 'date') else dt
-        if day not in seen_days:
-            seen_days.append(day)
-        if len(seen_days) == 2:
-            break
+    latest_ts = (
+        PortfolioSnapshot.objects.order_by('-captured_at')
+        .values_list('captured_at', flat=True)
+        .first()
+    )
+    if not latest_ts:
+        return {
+            'this_week_total': None, 'last_week_total': None,
+            'this_week_date': None, 'last_week_date': None,
+            'week_gain': None, 'week_change_pct': None,
+            'portfolio_rows': [], 'portfolio_count': Portfolio.objects.count(),
+        }
 
-    this_week_date = seen_days[0] if len(seen_days) >= 1 else None
-    last_week_date = seen_days[1] if len(seen_days) >= 2 else None
+    this_week_date = latest_ts.date() if hasattr(latest_ts, 'date') else latest_ts
+    last_week_cutoff = this_week_date - timedelta(days=5)
 
-    this_week_total = _get_snapshot_total(this_week_date) if this_week_date else None
-    last_week_total = _get_snapshot_total(last_week_date) if last_week_date else None
+    prev_ts = (
+        PortfolioSnapshot.objects
+        .filter(captured_at__date__lte=last_week_cutoff)
+        .order_by('-captured_at')
+        .values_list('captured_at', flat=True)
+        .first()
+    )
+    last_week_date = (prev_ts.date() if hasattr(prev_ts, 'date') else prev_ts) if prev_ts else None
+
+    def _snap_asof(portfolio, date):
+        """Most recent snapshot for portfolio on or before date."""
+        if not date:
+            return None
+        s = (
+            PortfolioSnapshot.objects
+            .filter(portfolio=portfolio, captured_at__date__lte=date)
+            .order_by('-captured_at')
+            .first()
+        )
+        return float(s.total_value) if s else None
+
+    portfolios = list(Portfolio.objects.all())
+    this_week_total = sum(v for p in portfolios if (v := _snap_asof(p, this_week_date)) is not None) or None
+    last_week_total = sum(v for p in portfolios if (v := _snap_asof(p, last_week_date)) is not None) if last_week_date else None
+    if last_week_total == 0:
+        last_week_total = None
 
     week_gain = None
     week_change_pct = None
@@ -130,16 +158,8 @@ def get_weekly_overview() -> dict:
     ]
     portfolio_rows = []
     for idx, portfolio in enumerate(Portfolio.objects.all()):
-        def _snap(date):
-            if not date:
-                return None
-            s = PortfolioSnapshot.objects.filter(
-                portfolio=portfolio, captured_at__date=date
-            ).first()
-            return float(s.total_value) if s else None
-
-        this_val = _snap(this_week_date)
-        last_val = _snap(last_week_date)
+        this_val = _snap_asof(portfolio, this_week_date)
+        last_val = _snap_asof(portfolio, last_week_date)
 
         change = change_pct = None
         if this_val is not None and last_val is not None and last_val > 0: