feat: add admin-only billing status donut and top gutachter charts to Dashboard

Extends DashboardKPIs with total_abgerechnet/pending_abrechnung. Adds
new GET /reports/dashboard/top-gutachter endpoint (admin-only). Frontend
shows Abrechnungsstatus donut + Gutachter-Verteilung progress bars in a
new third row, visible only to admins.

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

backend/app/api/reports.py

@@ -110,6 +110,27 @@ def top_icd(
     return {"items": items}
 
 
+@router.get("/dashboard/top-gutachter")
+def top_gutachter(
+    jahr: int | None = Query(None),
+    db: Session = Depends(get_db),
+    user: User = Depends(require_admin),
+):
+    """Return the top 10 Gutachter by case count for the given year.
+
+    Admin only. Defaults to the current ISO year if *jahr* is not provided.
+    """
+    if not jahr:
+        from app.utils.kw_utils import date_to_jahr
+
+        jahr = date_to_jahr(date.today())
+
+    from app.services.report_service import calculate_top_gutachter
+
+    items = calculate_top_gutachter(db, jahr)
+    return {"items": items}
+
+
 @router.get("/gutachten-statistik")
 def gutachten_statistik(
     jahr: int | None = Query(None),

backend/app/schemas/report.py

@@ -13,6 +13,8 @@ class DashboardKPIs(BaseModel):
     pending_icd: int
     pending_coding: int
     total_gutachten: int
+    total_abgerechnet: int = 0
+    pending_abrechnung: int = 0
     fallgruppen: dict[str, int]  # e.g. {"onko": 123, "kardio": 45, ...}
 
 

backend/app/services/report_service.py

@@ -599,11 +599,26 @@ def calculate_dashboard_kpis(db: Session, jahr: int, max_kw: int | None = None)
         else:
             gutachten_typen["uncodiert"] = _int(row.cnt)
 
+    # Abrechnung stats (only among cases with gutachten)
+    total_abgerechnet = (
+        db.query(func.count(Case.id))
+        .filter(
+            *base_filters,
+            Case.gutachten == True,  # noqa: E712
+            Case.abgerechnet == True,  # noqa: E712
+        )
+        .scalar()
+        or 0
+    )
+    pending_abrechnung = total_gutachten - total_abgerechnet
+
     return {
         "total_cases": total_cases,
         "pending_icd": pending_icd,
         "pending_coding": pending_coding,
         "total_gutachten": total_gutachten,
+        "total_abgerechnet": total_abgerechnet,
+        "pending_abrechnung": pending_abrechnung,
         "total_ablehnungen": total_ablehnungen,
         "total_unterlagen": total_unterlagen,
         "fallgruppen": fallgruppen,
@@ -697,6 +712,40 @@ def calculate_top_icd(db: Session, jahr: int, limit: int = 10) -> list[dict]:
     return [{"icd": row.icd_code, "count": int(row.cnt)} for row in rows]
 
 
+# ---------------------------------------------------------------------------
+# Dashboard: Top Gutachter
+# ---------------------------------------------------------------------------
+
+def calculate_top_gutachter(db: Session, jahr: int, limit: int = 10) -> list[dict]:
+    """Return the most prolific Gutachter for the given year.
+
+    Returns::
+
+        [{"gutachter": "Dr. Müller", "count": 42}, ...]
+    """
+    v_filter = Case.versicherung == settings.VERSICHERUNG_FILTER
+
+    rows = (
+        db.query(
+            func.trim(Case.gutachter).label("name"),
+            func.count(Case.id).label("cnt"),
+        )
+        .filter(
+            v_filter,
+            Case.jahr == jahr,
+            Case.gutachten == True,  # noqa: E712
+            Case.gutachter != None,  # noqa: E711
+            Case.gutachter != "",
+        )
+        .group_by(func.trim(Case.gutachter))
+        .order_by(func.count(Case.id).desc())
+        .limit(limit)
+        .all()
+    )
+
+    return [{"gutachter": row.name, "count": int(row.cnt)} for row in rows]
+
+
 # ---------------------------------------------------------------------------
 # Dashboard: Gutachten-Statistik (combined sheet3 + sheet4 + KPIs)
 # ---------------------------------------------------------------------------

frontend/src/hooks/useDashboard.ts

@@ -1,6 +1,6 @@
 import { useQuery } from '@tanstack/react-query'
 import api from '@/services/api'
-import type { DashboardResponse, YearlyComparisonResponse, TopIcdResponse, GutachtenStatistikResponse } from '@/types'
+import type { DashboardResponse, YearlyComparisonResponse, TopIcdResponse, TopGutachterResponse, GutachtenStatistikResponse } from '@/types'
 
 export function useDashboard(jahr: number) {
   return useQuery({
@@ -24,6 +24,14 @@ export function useTopIcd(jahr: number) {
   })
 }
 
+export function useTopGutachter(jahr: number, enabled = true) {
+  return useQuery({
+    queryKey: ['dashboard', 'top-gutachter', jahr],
+    queryFn: () => api.get<TopGutachterResponse>('/reports/dashboard/top-gutachter', { params: { jahr } }).then(r => r.data),
+    enabled,
+  })
+}
+
 export function useGutachtenStatistik(jahr: number) {
   return useQuery({
     queryKey: ['gutachten-statistik', jahr],

frontend/src/pages/DashboardPage.tsx

@@ -6,7 +6,7 @@ import {
 } from 'recharts'
 import { FileText, Clock, Code, Stethoscope, Info, TrendingUp, TrendingDown, Minus } from 'lucide-react'
 import { useAuth } from '@/context/AuthContext'
-import { useDashboard, useYearlyComparison, useTopIcd } from '@/hooks/useDashboard'
+import { useDashboard, useYearlyComparison, useTopIcd, useTopGutachter } from '@/hooks/useDashboard'
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
 import {
   Select, SelectContent, SelectItem, SelectTrigger, SelectValue,
@@ -47,6 +47,7 @@ export function DashboardPage() {
   const { data: comparisonData } = useYearlyComparison()
   const { data: topIcdData } = useTopIcd(jahr)
   const { isAdmin } = useAuth()
+  const { data: topGutachterData } = useTopGutachter(jahr, isAdmin)
 
   // Extract year keys from comparison data (e.g. ["2022", "2023", ...])
   const comparisonYears = useMemo(() => {
@@ -67,6 +68,15 @@ export function DashboardPage() {
   // Top ICD with max for progress bars
   const topIcdMax = topIcdData?.items?.[0]?.count ?? 1
 
+  // Top Gutachter with max for progress bars (admin only)
+  const topGutachterMax = topGutachterData?.items?.[0]?.count ?? 1
+
+  // Abrechnungsstatus donut data (admin only)
+  const abrechnungsData = data ? [
+    { name: 'Abgerechnet', value: data.kpis.total_abgerechnet },
+    { name: 'Offen', value: data.kpis.pending_abrechnung },
+  ].filter(d => d.value > 0) : []
+
   const fallgruppenData = data
     ? Object.entries(data.kpis.fallgruppen)
         .filter(([, value]) => value > 0)
@@ -331,6 +341,87 @@ export function DashboardPage() {
           </Card>
         )}
       </div>
+
+      {/* Row 3: Admin-only — Abrechnungsstatus + Gutachter-Verteilung */}
+      {isAdmin && data && (
+        <div className="grid grid-cols-1 gap-6 lg:grid-cols-3">
+          {/* Abrechnungsstatus Donut */}
+          {abrechnungsData.length > 0 && (
+            <Card>
+              <CardHeader>
+                <CardTitle>Abrechnungsstatus</CardTitle>
+                <p className="text-xs text-muted-foreground">Gutachten: abgerechnet vs. offen</p>
+              </CardHeader>
+              <CardContent>
+                <ResponsiveContainer width="100%" height={300}>
+                  <PieChart>
+                    <Pie
+                      data={abrechnungsData}
+                      cx="50%"
+                      cy="45%"
+                      innerRadius={50}
+                      outerRadius={85}
+                      paddingAngle={3}
+                      dataKey="value"
+                      label={({ value }) => value}
+                    >
+                      <Cell fill="var(--chart-3)" />
+                      <Cell fill="var(--chart-1)" />
+                    </Pie>
+                    <Tooltip
+                      contentStyle={{
+                        backgroundColor: 'var(--popover)',
+                        border: '1px solid var(--border)',
+                        borderRadius: '8px',
+                        color: 'var(--popover-foreground)',
+                      }}
+                    />
+                    <Legend
+                      verticalAlign="bottom"
+                      iconType="circle"
+                      iconSize={10}
+                      formatter={(value: string) => (
+                        <span style={{ color: 'var(--foreground)', fontSize: '13px' }}>{value}</span>
+                      )}
+                    />
+                  </PieChart>
+                </ResponsiveContainer>
+              </CardContent>
+            </Card>
+          )}
+
+          {/* Gutachter-Verteilung */}
+          {topGutachterData && topGutachterData.items.length > 0 && (
+            <Card className="lg:col-span-2">
+              <CardHeader>
+                <CardTitle>Top 10 Gutachter</CardTitle>
+                <p className="text-xs text-muted-foreground">Gutachten pro Gutachter in {jahr}</p>
+              </CardHeader>
+              <CardContent>
+                <div className="space-y-3">
+                  {topGutachterData.items.map((item, idx) => (
+                    <div key={item.gutachter} className="space-y-1">
+                      <div className="flex items-center justify-between text-sm">
+                        <span className="font-medium truncate max-w-[200px]">{item.gutachter}</span>
+                        <span className="text-muted-foreground tabular-nums">{item.count}</span>
+                      </div>
+                      <div className="h-2 w-full rounded-full bg-muted overflow-hidden">
+                        <div
+                          className="h-full rounded-full transition-all duration-300"
+                          style={{
+                            width: `${(item.count / topGutachterMax) * 100}%`,
+                            backgroundColor: CHART_COLORS[idx % CHART_COLORS.length],
+                          }}
+                        />
+                      </div>
+                    </div>
+                  ))}
+                </div>
+              </CardContent>
+            </Card>
+          )}
+        </div>
+      )}
     </div>
   )
 }

frontend/src/test/mocks/data.ts

@@ -158,6 +158,8 @@ export const mockDashboardKPIs: DashboardKPIs = {
   pending_icd: 18,
   pending_coding: 7,
   total_gutachten: 89,
+  total_abgerechnet: 72,
+  pending_abrechnung: 17,
   fallgruppen: {
     onko: 65,
     ortho: 42,

frontend/src/types/index.ts

@@ -98,6 +98,8 @@ export interface DashboardKPIs {
   pending_icd: number
   pending_coding: number
   total_gutachten: number
+  total_abgerechnet: number
+  pending_abrechnung: number
   fallgruppen: Record<string, number>
 }
 
@@ -134,6 +136,15 @@ export interface TopIcdResponse {
   items: TopIcdItem[]
 }
 
+export interface TopGutachterItem {
+  gutachter: string
+  count: number
+}
+
+export interface TopGutachterResponse {
+  items: TopGutachterItem[]
+}
+
 export interface GutachtenStatistikKPIs {
   total_gutachten: number
   bestaetigung: number