fix: use same KW range for year-over-year KPI comparison

The previous implementation compared a partial current year against a
full previous year, producing misleading percentages. Now determines the
max KW with data in the selected year and filters the previous year to
the same KW range for a fair comparison.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/api/reports.py

@@ -19,6 +19,7 @@ from app.schemas.report import (
     ReportListResponse,
     ReportMeta,
 )
+from app.config import get_settings
 from app.services.audit_service import log_action
 
 logger = logging.getLogger(__name__)
@@ -43,13 +44,27 @@ def dashboard(
         jahr = date_to_jahr(date.today())
 
     try:
+        from sqlalchemy import func as sa_func
+
+        from app.models.case import Case
         from app.services.report_service import (
             calculate_dashboard_kpis,
             calculate_sheet1_data,
         )
 
+        # Determine the highest KW with data in the selected year so
+        # the previous-year comparison covers the same calendar-week range.
+        max_kw = (
+            db.query(sa_func.max(Case.kw))
+            .filter(
+                Case.versicherung == get_settings().VERSICHERUNG_FILTER,
+                Case.jahr == jahr,
+            )
+            .scalar()
+        )
+
         kpis = calculate_dashboard_kpis(db, jahr)
-        prev_kpis = calculate_dashboard_kpis(db, jahr - 1)
+        prev_kpis = calculate_dashboard_kpis(db, jahr - 1, max_kw=max_kw)
         sheet1 = calculate_sheet1_data(db, jahr)
         return DashboardResponse(kpis=kpis, prev_kpis=prev_kpis, weekly=sheet1.get("weekly", []))
     except ImportError:

backend/app/services/report_service.py

@@ -497,9 +497,12 @@ def calculate_sheet5_data(db: Session, jahr: int, max_kw: int | None = None, fal
 # Dashboard KPIs
 # ---------------------------------------------------------------------------
 
-def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
+def calculate_dashboard_kpis(db: Session, jahr: int, max_kw: int | None = None) -> dict:
     """Calculate live KPIs for the dashboard.
 
+    If *max_kw* is given, only cases up to and including that calendar week
+    are counted.  This is used for fair year-over-year comparisons.
+
     Returns::
 
         {
@@ -513,18 +516,21 @@ def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
             "gutachten_typen": {"alternative": X, "bestaetigung": X, "uncodiert": X},
         }
     """
-    # Base filter for this portal's insurance
+    # Base filters for this portal's insurance + year (+ optional KW cutoff)
     v_filter = Case.versicherung == settings.VERSICHERUNG_FILTER
+    base_filters = [v_filter, Case.jahr == jahr]
+    if max_kw is not None:
+        base_filters.append(Case.kw <= max_kw)
 
     # Total cases for the year
     total_cases = (
-        db.query(func.count(Case.id)).filter(v_filter, Case.jahr == jahr).scalar() or 0
+        db.query(func.count(Case.id)).filter(*base_filters).scalar() or 0
     )
 
     # Cases without ICD codes entered
     pending_icd = (
         db.query(func.count(Case.id))
-        .filter(v_filter, Case.jahr == jahr, Case.icd == None)  # noqa: E711
+        .filter(*base_filters, Case.icd == None)  # noqa: E711
         .scalar()
         or 0
     )
@@ -533,8 +539,7 @@ def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
     pending_coding = (
         db.query(func.count(Case.id))
         .filter(
-            v_filter,
+            *base_filters,
-            Case.jahr == jahr,
             Case.gutachten == True,  # noqa: E712
             Case.gutachten_typ == None,  # noqa: E711
         )
@@ -545,7 +550,7 @@ def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
     # Gutachten totals
     total_gutachten = (
         db.query(func.count(Case.id))
-        .filter(v_filter, Case.jahr == jahr, Case.gutachten == True)  # noqa: E712
+        .filter(*base_filters, Case.gutachten == True)  # noqa: E712
         .scalar()
         or 0
     )
@@ -553,7 +558,7 @@ def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
     # Ablehnungen
     total_ablehnungen = (
         db.query(func.count(Case.id))
-        .filter(v_filter, Case.jahr == jahr, Case.ablehnung == True)  # noqa: E712
+        .filter(*base_filters, Case.ablehnung == True)  # noqa: E712
         .scalar()
         or 0
     )
@@ -561,7 +566,7 @@ def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
     # Unterlagen
     total_unterlagen = (
         db.query(func.count(Case.id))
-        .filter(v_filter, Case.jahr == jahr, Case.unterlagen == True)  # noqa: E712
+        .filter(*base_filters, Case.unterlagen == True)  # noqa: E712
         .scalar()
         or 0
     )
@@ -569,7 +574,7 @@ def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
     # Per-Fallgruppe counts
     fg_rows = (
         db.query(Case.fallgruppe, func.count(Case.id).label("cnt"))
-        .filter(v_filter, Case.jahr == jahr)
+        .filter(*base_filters)
         .group_by(Case.fallgruppe)
         .all()
     )
@@ -581,7 +586,7 @@ def calculate_dashboard_kpis(db: Session, jahr: int) -> dict:
     # Gutachten type breakdown
     typ_rows = (
         db.query(Case.gutachten_typ, func.count(Case.id).label("cnt"))
-        .filter(v_filter, Case.jahr == jahr, Case.gutachten == True)  # noqa: E712
+        .filter(*base_filters, Case.gutachten == True)  # noqa: E712
         .group_by(Case.gutachten_typ)
         .all()
     )