feat: warn against harvesting honey during a treatment's Wartezeit

Treatments (Ameisensäure, Oxalsäure, etc.) can require a legally
mandated withdrawal period before honey from that colony may be sold.
Nothing in the app tracked this before, so a beekeeper had no
safeguard against harvesting into an active withdrawal window.

Treatments now optionally record withdrawalPeriodDays (from the
product's Packungsbeilage). The new harvest form fetches each
candidate colony's active withdrawal window and shows an inline
warning naming the product and the date it clears, computed as
max(endDate ?? date) + withdrawalPeriodDays across a colony's
treatments, restricted to windows still in the future.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

ApiCore-Backend/prisma/migrations/20260906120000_add_treatment_withdrawal_period/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "Treatment" ADD COLUMN "withdrawalPeriodDays" INTEGER;

ApiCore-Backend/prisma/schema.prisma

@@ -584,6 +584,7 @@ model Treatment {
   reason               String?
   batchNumber          String?
   notes                String?
+  withdrawalPeriodDays Int?
   createdAt            DateTime  @default(now())
 
   @@index([colonyId, date])

ApiCore-Backend/src/treatments/dto/create-treatment.dto.ts

@@ -1,5 +1,11 @@
 import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
-import { IsDateString, IsOptional, IsString } from 'class-validator';
+import {
+  IsDateString,
+  IsInt,
+  IsOptional,
+  IsString,
+  Min,
+} from 'class-validator';
 
 export class CreateTreatmentDto {
   @ApiProperty()
@@ -53,4 +59,13 @@ export class CreateTreatmentDto {
   @IsOptional()
   @IsString()
   notes?: string;
+
+  @ApiPropertyOptional({
+    description:
+      'Wartezeit in Tagen ab Behandlungsende, bevor Honig aus diesem Volk geerntet werden darf.',
+  })
+  @IsOptional()
+  @IsInt()
+  @Min(0)
+  withdrawalPeriodDays?: number;
 }

ApiCore-Backend/src/treatments/dto/update-treatment.dto.ts

@@ -13,5 +13,6 @@ export class UpdateTreatmentDto extends PartialType(
     'reason',
     'batchNumber',
     'notes',
+    'withdrawalPeriodDays',
   ] as const),
 ) {}

ApiCore-Backend/src/treatments/treatments.controller.ts

@@ -1,4 +1,12 @@
-import { Body, Controller, Get, Param, Patch, Post } from '@nestjs/common';
+import {
+  Body,
+  Controller,
+  Get,
+  Param,
+  Patch,
+  Post,
+  Query,
+} from '@nestjs/common';
 import { ApiBearerAuth, ApiTags } from '@nestjs/swagger';
 import { RequirePermission } from '../auth/decorators/require-permission.decorator';
 import { CurrentUser } from '../auth/decorators/current-user.decorator';
@@ -19,6 +27,13 @@ export class TreatmentsController {
     return this.treatmentsService.findAll();
   }
 
+  @RequirePermission('treatments:read')
+  @Get('withdrawal-status')
+  getWithdrawalStatus(@Query('colonyIds') colonyIds?: string) {
+    const ids = colonyIds ? colonyIds.split(',').filter(Boolean) : [];
+    return this.treatmentsService.getWithdrawalStatus(ids);
+  }
+
   @RequirePermission('treatments:read')
   @Get(':id')
   findOne(@Param('id') id: string) {

ApiCore-Backend/src/treatments/treatments.service.spec.ts

@@ -97,4 +97,58 @@ describe('TreatmentsService', () => {
     expect(queryArg.where.colonyId).toBe('colony-1');
     expect(queryArg.orderBy.date).toBe('asc');
   });
+
+  describe('getWithdrawalStatus', () => {
+    it('returns an empty array without querying when no colony ids are given', async () => {
+      const result = await service.getWithdrawalStatus([]);
+
+      expect(result).toEqual([]);
+      expect(prisma.treatment.findMany).not.toHaveBeenCalled();
+    });
+
+    it('reports the treatment whose withdrawal window reaches furthest into the future', async () => {
+      const now = Date.now();
+      const inTenDays = new Date(now + 10 * 24 * 60 * 60 * 1000);
+      const inFiveDays = new Date(now + 5 * 24 * 60 * 60 * 1000);
+      prisma.treatment.findMany.mockResolvedValue([
+        {
+          colonyId: 'colony-1',
+          date: inTenDays,
+          endDate: null,
+          withdrawalPeriodDays: 0,
+          product: 'Ameisensäure',
+        },
+        {
+          colonyId: 'colony-1',
+          date: inFiveDays,
+          endDate: null,
+          withdrawalPeriodDays: 21,
+          product: 'Api Bioxal',
+        },
+      ]);
+
+      const result = await service.getWithdrawalStatus(['colony-1']);
+
+      expect(result).toHaveLength(1);
+      expect(result[0].colonyId).toBe('colony-1');
+      expect(result[0].product).toBe('Api Bioxal');
+    });
+
+    it('omits a colony whose withdrawal window has already passed', async () => {
+      const longAgo = new Date('2020-01-01');
+      prisma.treatment.findMany.mockResolvedValue([
+        {
+          colonyId: 'colony-1',
+          date: longAgo,
+          endDate: null,
+          withdrawalPeriodDays: 14,
+          product: 'Ameisensäure',
+        },
+      ]);
+
+      const result = await service.getWithdrawalStatus(['colony-1']);
+
+      expect(result).toEqual([]);
+    });
+  });
 });

ApiCore-Backend/src/treatments/treatments.service.ts

@@ -6,6 +6,12 @@ import { Treatment } from '../../generated/prisma';
 import { CreateTreatmentDto } from './dto/create-treatment.dto';
 import { UpdateTreatmentDto } from './dto/update-treatment.dto';
 
+export interface WithdrawalStatus {
+  colonyId: string;
+  activeUntil: string;
+  product: string;
+}
+
 @Injectable()
 export class TreatmentsService {
   constructor(
@@ -33,6 +39,44 @@ export class TreatmentsService {
     });
   }
 
+  // For each colony, returns the treatment whose withdrawal window (its
+  // end date, or start date if the treatment is still ongoing, plus its
+  // withdrawalPeriodDays) reaches furthest into the future - only when
+  // that window is still active. Colonies with no active window are
+  // omitted rather than returned as null, since most colonies have none.
+  async getWithdrawalStatus(colonyIds: string[]): Promise<WithdrawalStatus[]> {
+    if (colonyIds.length === 0) {
+      return [];
+    }
+    const treatments = await this.prisma.treatment.findMany({
+      where: {
+        colonyId: { in: colonyIds },
+        withdrawalPeriodDays: { not: null },
+      },
+    });
+    const now = new Date();
+    const activeByColony = new Map<string, WithdrawalStatus>();
+    for (const treatment of treatments) {
+      const referenceDate = treatment.endDate ?? treatment.date;
+      const activeUntil = new Date(referenceDate);
+      activeUntil.setUTCDate(
+        activeUntil.getUTCDate() + (treatment.withdrawalPeriodDays ?? 0),
+      );
+      if (activeUntil <= now) {
+        continue;
+      }
+      const current = activeByColony.get(treatment.colonyId);
+      if (!current || activeUntil > new Date(current.activeUntil)) {
+        activeByColony.set(treatment.colonyId, {
+          colonyId: treatment.colonyId,
+          activeUntil: activeUntil.toISOString(),
+          product: treatment.product,
+        });
+      }
+    }
+    return [...activeByColony.values()];
+  }
+
   async create(
     dto: CreateTreatmentDto,
     actingUserId: string,

ApiCore-Frontend/src/app/(app)/colonies/[id]/colony-treatments.tsx

@@ -49,6 +49,9 @@ export function ColonyTreatmentsCard({ colonyId }: { colonyId: string }) {
               {treatment.method ? ` · ${treatment.method}` : ""}
             </p>
             {treatment.reason ? <p>Grund: {treatment.reason}</p> : null}
+            {treatment.withdrawalPeriodDays !== null ? (
+              <p>Wartezeit: {treatment.withdrawalPeriodDays} Tag(e)</p>
+            ) : null}
           </div>
         ))}
       </CardContent>

ApiCore-Frontend/src/app/(app)/colonies/[id]/treatment-edit-dialog.tsx

@@ -26,6 +26,9 @@ export function TreatmentEditDialog({ treatment }: { treatment: Treatment }) {
   const [method, setMethod] = useState(treatment.method ?? "");
   const [reason, setReason] = useState(treatment.reason ?? "");
   const [notes, setNotes] = useState(treatment.notes ?? "");
+  const [withdrawalPeriodDays, setWithdrawalPeriodDays] = useState(
+    treatment.withdrawalPeriodDays?.toString() ?? "",
+  );
 
   const mutation = useMutation({
     mutationFn: () =>
@@ -36,6 +39,7 @@ export function TreatmentEditDialog({ treatment }: { treatment: Treatment }) {
         method: method || undefined,
         reason: reason || undefined,
         notes: notes || undefined,
+        withdrawalPeriodDays: withdrawalPeriodDays ? Number(withdrawalPeriodDays) : undefined,
       }),
     onSuccess: () => {
       void queryClient.invalidateQueries({
@@ -107,6 +111,17 @@ export function TreatmentEditDialog({ treatment }: { treatment: Treatment }) {
               onChange={(event) => setReason(event.target.value)}
             />
           </div>
+          <div className="flex flex-col gap-2">
+            <Label htmlFor="treatment-edit-withdrawal">Wartezeit (Tage)</Label>
+            <Input
+              id="treatment-edit-withdrawal"
+              type="number"
+              inputMode="numeric"
+              min={0}
+              value={withdrawalPeriodDays}
+              onChange={(event) => setWithdrawalPeriodDays(event.target.value)}
+            />
+          </div>
           <div className="flex flex-col gap-2">
             <Label htmlFor="treatment-edit-notes">Notizen</Label>
             <Textarea

ApiCore-Frontend/src/app/(app)/harvests/new/page.tsx

@@ -4,10 +4,11 @@ import { FormEvent, useState } from "react";
 import { useRouter, useSearchParams } from "next/navigation";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { toast } from "sonner";
-import { Boxes } from "lucide-react";
+import { Boxes, AlertTriangle } from "lucide-react";
 import { fetchApiaries } from "@/lib/apiaries/api";
 import { fetchColonies } from "@/lib/colonies/api";
 import { createHarvest } from "@/lib/harvests/api";
+import { fetchWithdrawalStatus } from "@/lib/treatments/api";
 import { ApiError } from "@/lib/auth/api-client";
 import { queueHarvest } from "@/lib/offline/db";
 import { Button } from "@/components/ui/button";
@@ -47,6 +48,15 @@ export default function NewHarvestPage() {
   const apiaryColonies = (colonies ?? []).filter(
     (colony) => colony.apiaryId === apiaryId && colony.status === "ACTIVE",
   );
+  const apiaryColonyIds = apiaryColonies.map((colony) => colony.id);
+  const { data: withdrawalStatuses } = useQuery({
+    queryKey: ["treatments", "withdrawal-status", apiaryColonyIds],
+    queryFn: () => fetchWithdrawalStatus(apiaryColonyIds),
+    enabled: apiaryColonyIds.length > 0,
+  });
+  const withdrawalByColony = new Map(
+    (withdrawalStatuses ?? []).map((status) => [status.colonyId, status]),
+  );
 
   const mutation = useMutation({
     mutationFn: createHarvest,
@@ -144,9 +154,11 @@ export default function NewHarvestPage() {
                 </p>
               ) : null}
               <div className="flex flex-col gap-2">
-                {apiaryColonies.map((colony) => (
+                {apiaryColonies.map((colony) => {
+                  const withdrawal = withdrawalByColony.get(colony.id);
+                  return (
+                    <div key={colony.id} className="flex flex-col gap-1">
                       <label
-                    key={colony.id}
                         className="flex h-11 items-center gap-3 text-sm"
                         htmlFor={`harvest-colony-${colony.id}`}
                       >
@@ -159,7 +171,16 @@ export default function NewHarvestPage() {
                         />
                         {colony.code}
                       </label>
-                ))}
+                      {withdrawal ? (
+                        <p className="flex items-center gap-1.5 pl-8 text-xs text-destructive">
+                          <AlertTriangle className="size-3.5 shrink-0" />
+                          Wartezeit ({withdrawal.product}) bis{" "}
+                          {new Date(withdrawal.activeUntil).toLocaleDateString("de-DE")}
+                        </p>
+                      ) : null}
+                    </div>
+                  );
+                })}
               </div>
             </div>
             <div className="flex flex-col gap-2">

ApiCore-Frontend/src/app/(app)/treatments/new/page.tsx

@@ -45,6 +45,7 @@ export default function NewTreatmentPage() {
   const [method, setMethod] = useState("");
   const [reason, setReason] = useState("");
   const [notes, setNotes] = useState("");
+  const [withdrawalPeriodDays, setWithdrawalPeriodDays] = useState("");
   const [error, setError] = useState<string | null>(null);
 
   const mutation = useMutation({
@@ -83,6 +84,7 @@ export default function NewTreatmentPage() {
       method: method || undefined,
       reason: reason || undefined,
       notes: notes || undefined,
+      withdrawalPeriodDays: withdrawalPeriodDays ? Number(withdrawalPeriodDays) : undefined,
     });
   }
 
@@ -160,6 +162,22 @@ export default function NewTreatmentPage() {
                 onChange={(event) => setReason(event.target.value)}
               />
             </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="treatment-withdrawal">Wartezeit (Tage)</Label>
+              <Input
+                id="treatment-withdrawal"
+                type="number"
+                inputMode="numeric"
+                min={0}
+                className="h-11"
+                value={withdrawalPeriodDays}
+                onChange={(event) => setWithdrawalPeriodDays(event.target.value)}
+              />
+              <p className="text-xs text-muted-foreground">
+                Laut Packungsbeilage des Mittels – solange darf aus diesem Volk kein Honig
+                geerntet werden.
+              </p>
+            </div>
             <div className="flex flex-col gap-2">
               <Label htmlFor="treatment-notes">Notizen</Label>
               <Textarea

ApiCore-Frontend/src/lib/treatments/api.ts

@@ -1,10 +1,26 @@
 import { apiFetch } from "@/lib/auth/api-client";
-import { CreateTreatmentInput, Treatment, UpdateTreatmentInput } from "./types";
+import {
+  CreateTreatmentInput,
+  Treatment,
+  UpdateTreatmentInput,
+  WithdrawalStatus,
+} from "./types";
 
 export function fetchColonyTreatments(colonyId: string): Promise<Treatment[]> {
   return apiFetch<Treatment[]>(`/colonies/${colonyId}/treatments`);
 }
 
+export function fetchWithdrawalStatus(
+  colonyIds: string[],
+): Promise<WithdrawalStatus[]> {
+  if (colonyIds.length === 0) {
+    return Promise.resolve([]);
+  }
+  return apiFetch<WithdrawalStatus[]>(
+    `/treatments/withdrawal-status?colonyIds=${colonyIds.join(",")}`,
+  );
+}
+
 export function createTreatment(input: CreateTreatmentInput): Promise<Treatment> {
   return apiFetch<Treatment>("/treatments", {
     method: "POST",

ApiCore-Frontend/src/lib/treatments/types.ts

@@ -12,6 +12,7 @@ export interface Treatment {
   reason: string | null;
   batchNumber: string | null;
   notes: string | null;
+  withdrawalPeriodDays: number | null;
   createdAt: string;
 }
 
@@ -27,6 +28,7 @@ export interface CreateTreatmentInput {
   reason?: string;
   batchNumber?: string;
   notes?: string;
+  withdrawalPeriodDays?: number;
 }
 
 export interface UpdateTreatmentInput {
@@ -40,4 +42,11 @@ export interface UpdateTreatmentInput {
   reason?: string;
   batchNumber?: string;
   notes?: string;
+  withdrawalPeriodDays?: number;
+}
+
+export interface WithdrawalStatus {
+  colonyId: string;
+  activeUntil: string;
+  product: string;
 }