feat: Add dedicated buyer dashboard, buyer role assignment, Bavarian White-Blue light/dark mode and mobile drawer

app/main.py

@@ -527,6 +527,82 @@ def download_calendar_ics(event_id: int, request: Request, db: Session = Depends
     )
 
 
+# --- EINKAUFS- & KASSEN-ZENTRALE (/einkauf) ---
+
+@app.get("/einkauf", response_class=HTMLResponse)
+def buyer_dashboard(
+    request: Request,
+    event_id: Optional[int] = None,
+    success: Optional[str] = None,
+    error: Optional[str] = None,
+    db: Session = Depends(get_db)
+):
+    tenant = resolve_tenant(request, db)
+    if not tenant:
+        return templates.TemplateResponse(request, "not_found_tenant.html", context={})
+
+    current_user = get_current_user(request, db)
+    if not current_user:
+        return RedirectResponse(url="/login", status_code=status.HTTP_303_SEE_OTHER)
+
+    # Alle Events des Mandanten
+    all_events = db.query(Event).filter(Event.tenant_id == tenant.id).order_by(Event.event_date.desc(), Event.id.desc()).all()
+
+    # Ausgewähltes Event bestimmen:
+    # 1. Prio: explizit übergebenes event_id
+    # 2. Prio: Event, bei dem current_user als buyer zugewiesen ist und status == 'open'
+    # 3. Prio: erstes offenes Event
+    # 4. Prio: neuestes Event
+    selected_event = None
+    if event_id:
+        selected_event = db.query(Event).filter(Event.id == event_id, Event.tenant_id == tenant.id).first()
+
+    if not selected_event:
+        for ev in all_events:
+            if ev.buyer_id == current_user.id and ev.status == "open":
+                selected_event = ev
+                break
+        if not selected_event:
+            for ev in all_events:
+                if ev.status == "open":
+                    selected_event = ev
+                    break
+        if not selected_event and all_events:
+            selected_event = all_events[0]
+
+    orders = []
+    item_sums = {}
+    total_revenue = Decimal("0.00")
+    total_paid = Decimal("0.00")
+
+    if selected_event:
+        orders = db.query(Order).filter(Order.event_id == selected_event.id).order_by(Order.created_at.asc()).all()
+        for ord_obj in orders:
+            total_revenue += ord_obj.total_price
+            if ord_obj.is_paid:
+                total_paid += ord_obj.total_price
+
+            for it in ord_obj.items:
+                pname = it.product.name if it.product else "Artikel"
+                unit = it.product.unit if it.product else "Stk"
+                if pname not in item_sums:
+                    item_sums[pname] = {"quantity": 0, "unit": unit}
+                item_sums[pname]["quantity"] += it.quantity
+
+    return templates.TemplateResponse(request, "buyer.html", context={
+        "tenant": tenant,
+        "current_user": current_user,
+        "event": selected_event,
+        "all_events": all_events,
+        "orders": orders,
+        "item_sums": item_sums,
+        "total_revenue": total_revenue,
+        "total_paid": total_paid,
+        "success": success,
+        "error": error,
+    })
+
+
 # --- ADMIN COCKPIT (/admin) ---
 
 @app.get("/admin", response_class=HTMLResponse)
@@ -801,6 +877,7 @@ def admin_create_event(
     deadline_date: str = Form(...),
     deadline_time: str = Form(...),
     sponsor_name: Optional[str] = Form(None),
+    buyer_id: Optional[str] = Form(None),
     allow_guests: bool = Form(True),
     force: bool = Form(False),
     db: Session = Depends(get_db)
@@ -827,6 +904,13 @@ def admin_create_event(
                 status_code=status.HTTP_303_SEE_OTHER
             )
 
+    buyer_id_int: Optional[int] = None
+    if buyer_id and buyer_id.strip():
+        try:
+            buyer_id_int = int(buyer_id.strip())
+        except ValueError:
+            pass
+
     new_event = Event(
         tenant_id=tenant.id,
         title=title.strip(),
@@ -834,6 +918,7 @@ def admin_create_event(
         deadline=deadline_dt,
         status="open",
         sponsor_name=sponsor_name.strip() if sponsor_name and sponsor_name.strip() else None,
+        buyer_id=buyer_id_int,
         allow_guests=allow_guests,
         guest_token=secrets.token_urlsafe(16)
     )
@@ -854,6 +939,7 @@ def admin_edit_event(
     deadline_time: str = Form(...),
     status_val: str = Form(...),
     sponsor_name: Optional[str] = Form(None),
+    buyer_id: Optional[str] = Form(None),
     allow_guests: bool = Form(False),
     db: Session = Depends(get_db)
 ):
@@ -871,11 +957,19 @@ def admin_edit_event(
     except ValueError as e:
         raise HTTPException(status_code=400, detail=f"Ungültiges Datumsformat: {e}")
 
+    buyer_id_int: Optional[int] = None
+    if buyer_id and buyer_id.strip():
+        try:
+            buyer_id_int = int(buyer_id.strip())
+        except ValueError:
+            pass
+
     event.title = title.strip()
     event.event_date = ev_date
     event.deadline = deadline_dt
     event.status = status_val
     event.sponsor_name = sponsor_name.strip() if sponsor_name and sponsor_name.strip() else None
+    event.buyer_id = buyer_id_int
     event.allow_guests = allow_guests
     if not event.guest_token:
         event.guest_token = secrets.token_urlsafe(16)
@@ -1179,7 +1273,12 @@ def toggle_paid(order_id: int, request: Request, db: Session = Depends(get_db)):
     if order:
         order.is_paid = not order.is_paid
         db.commit()
-    return RedirectResponse(url=f"/admin?event_id={order.event_id}", status_code=status.HTTP_303_SEE_OTHER)
+
+    ev_id = order.event_id if order else ""
+    referer = request.headers.get("referer", "")
+    if "/einkauf" in referer:
+        return RedirectResponse(url=f"/einkauf?event_id={ev_id}", status_code=status.HTTP_303_SEE_OTHER)
+    return RedirectResponse(url=f"/admin?event_id={ev_id}&tab=orders", status_code=status.HTTP_303_SEE_OTHER)
 
 
 @app.get("/health")