feat(frontend): Ernten- und Schleuderungs-Ansichten (Modul 10)

/harvests/new (Bienenstand + Mehrfachauswahl Völker), /harvests/[id]
und /extractions/new (Mehrfachauswahl Ernten). Bienenstand- und
Ernte-Detailseiten verlinken direkt in die Kette.

ApiCore-Frontend/src/app/(app)/apiaries/[id]/page.tsx

@@ -1,8 +1,10 @@
 "use client";
 
+import Link from "next/link";
 import { useParams } from "next/navigation";
 import { useQuery } from "@tanstack/react-query";
 import { fetchApiary } from "@/lib/apiaries/api";
+import { Button } from "@/components/ui/button";
 import { ApiaryEditCard } from "./apiary-edit-card";
 
 export default function ApiaryDetailPage() {
@@ -24,8 +26,15 @@ export default function ApiaryDetailPage() {
   }
 
   return (
-    <main className="p-4 sm:p-6">
+    <main className="flex flex-col gap-4 p-4 sm:p-6">
       <ApiaryEditCard key={apiary.id} apiary={apiary} />
+      <Button
+        className="w-fit"
+        nativeButton={false}
+        render={<Link href={`/harvests/new?apiaryId=${apiary.id}`} />}
+      >
+        Neue Ernte
+      </Button>
     </main>
   );
 }

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

@@ -0,0 +1,166 @@
+"use client";
+
+import { FormEvent, useState } from "react";
+import { useRouter, useSearchParams } from "next/navigation";
+import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { fetchHarvests } from "@/lib/harvests/api";
+import { createExtraction } from "@/lib/extractions/api";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { Textarea } from "@/components/ui/textarea";
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+
+function todayIsoDate(): string {
+  return new Date().toISOString().slice(0, 10);
+}
+
+export default function NewExtractionPage() {
+  const router = useRouter();
+  const searchParams = useSearchParams();
+  const queryClient = useQueryClient();
+
+  const { data: harvests } = useQuery({ queryKey: ["harvests"], queryFn: fetchHarvests });
+
+  const preselectedHarvestId = searchParams.get("harvestId");
+  const [date, setDate] = useState(todayIsoDate());
+  const [harvestIds, setHarvestIds] = useState<string[]>(
+    preselectedHarvestId ? [preselectedHarvestId] : [],
+  );
+  const [amount, setAmount] = useState("");
+  const [room, setRoom] = useState("");
+  const [waterContent, setWaterContent] = useState("");
+  const [notes, setNotes] = useState("");
+  const [error, setError] = useState<string | null>(null);
+
+  const mutation = useMutation({
+    mutationFn: createExtraction,
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: ["extractions"] });
+      router.push("/colonies");
+    },
+    onError: () => {
+      setError("Schleuderung konnte nicht gespeichert werden.");
+    },
+  });
+
+  function toggleHarvest(harvestId: string, checked: boolean) {
+    setHarvestIds((current) =>
+      checked ? [...current, harvestId] : current.filter((id) => id !== harvestId),
+    );
+  }
+
+  function handleSubmit(event: FormEvent<HTMLFormElement>) {
+    event.preventDefault();
+    setError(null);
+    if (harvestIds.length === 0) {
+      setError("Bitte mindestens eine Ernte auswählen.");
+      return;
+    }
+    mutation.mutate({
+      date: new Date(date).toISOString(),
+      harvestIds,
+      amount: amount ? Number(amount) : undefined,
+      room: room || undefined,
+      waterContent: waterContent ? Number(waterContent) : undefined,
+      notes: notes || undefined,
+    });
+  }
+
+  return (
+    <main className="p-4 sm:p-6">
+      <Card className="max-w-lg">
+        <CardHeader>
+          <CardTitle>Neue Schleuderung</CardTitle>
+        </CardHeader>
+        <CardContent>
+          <form className="flex flex-col gap-5" onSubmit={handleSubmit}>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="extraction-date">Datum</Label>
+              <Input
+                id="extraction-date"
+                type="date"
+                required
+                className="h-11"
+                value={date}
+                onChange={(event) => setDate(event.target.value)}
+              />
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label>Ernten</Label>
+              {harvests?.length === 0 ? (
+                <p className="text-sm text-muted-foreground">Noch keine Ernten vorhanden.</p>
+              ) : null}
+              <div className="flex flex-col gap-2">
+                {harvests?.map((harvest) => (
+                  <label
+                    key={harvest.id}
+                    className="flex h-11 items-center gap-3 text-sm"
+                    htmlFor={`extraction-harvest-${harvest.id}`}
+                  >
+                    <input
+                      id={`extraction-harvest-${harvest.id}`}
+                      type="checkbox"
+                      className="size-5"
+                      checked={harvestIds.includes(harvest.id)}
+                      onChange={(event) => toggleHarvest(harvest.id, event.target.checked)}
+                    />
+                    {new Date(harvest.date).toLocaleDateString("de-DE")} ·{" "}
+                    {harvest.colonies.map((entry) => entry.colony.code).join(", ")}
+                  </label>
+                ))}
+              </div>
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="extraction-amount">Menge (kg)</Label>
+              <Input
+                id="extraction-amount"
+                type="number"
+                inputMode="decimal"
+                className="h-11"
+                value={amount}
+                onChange={(event) => setAmount(event.target.value)}
+              />
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="extraction-room">Schleuderraum</Label>
+              <Input
+                id="extraction-room"
+                className="h-11"
+                value={room}
+                onChange={(event) => setRoom(event.target.value)}
+              />
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="extraction-water">Wassergehalt (%)</Label>
+              <Input
+                id="extraction-water"
+                type="number"
+                inputMode="decimal"
+                className="h-11"
+                value={waterContent}
+                onChange={(event) => setWaterContent(event.target.value)}
+              />
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="extraction-notes">Notizen</Label>
+              <Textarea
+                id="extraction-notes"
+                value={notes}
+                onChange={(event) => setNotes(event.target.value)}
+              />
+            </div>
+            {error ? (
+              <p role="alert" className="text-sm text-red-600">
+                {error}
+              </p>
+            ) : null}
+            <Button type="submit" className="h-12 text-base" disabled={mutation.isPending}>
+              {mutation.isPending ? "Wird gespeichert…" : "Schleuderung speichern"}
+            </Button>
+          </form>
+        </CardContent>
+      </Card>
+    </main>
+  );
+}

ApiCore-Frontend/src/app/(app)/harvests/[id]/page.tsx

@@ -0,0 +1,60 @@
+"use client";
+
+import Link from "next/link";
+import { useParams } from "next/navigation";
+import { useQuery } from "@tanstack/react-query";
+import { fetchHarvest } from "@/lib/harvests/api";
+import { Button } from "@/components/ui/button";
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+
+export default function HarvestDetailPage() {
+  const params = useParams<{ id: string }>();
+  const { data: harvest, isLoading, isError } = useQuery({
+    queryKey: ["harvests", params.id],
+    queryFn: () => fetchHarvest(params.id),
+  });
+
+  if (isLoading) {
+    return <p className="p-4 text-sm text-muted-foreground sm:p-6">Lädt…</p>;
+  }
+  if (isError || !harvest) {
+    return (
+      <p role="alert" className="p-4 text-sm text-red-600 sm:p-6">
+        Ernte konnte nicht geladen werden.
+      </p>
+    );
+  }
+
+  return (
+    <main className="flex flex-col gap-4 p-4 sm:p-6">
+      <Card className="max-w-lg">
+        <CardHeader>
+          <CardTitle>Ernte vom {new Date(harvest.date).toLocaleDateString("de-DE")}</CardTitle>
+        </CardHeader>
+        <CardContent className="flex flex-col gap-3 text-sm">
+          {harvest.honeyType ? <p>Honigsorte: {harvest.honeyType}</p> : null}
+          {harvest.netWeight !== null ? <p>Nettogewicht: {harvest.netWeight} kg</p> : null}
+          {harvest.honeySuperCount !== null ? (
+            <p>Honigräume: {harvest.honeySuperCount}</p>
+          ) : null}
+          {harvest.notes ? <p>Notizen: {harvest.notes}</p> : null}
+          <div>
+            <p className="font-medium">Beteiligte Völker</p>
+            <ul className="list-disc pl-5">
+              {harvest.colonies.map((entry) => (
+                <li key={entry.id}>{entry.colony.code}</li>
+              ))}
+            </ul>
+          </div>
+          <Button
+            className="w-fit"
+            nativeButton={false}
+            render={<Link href={`/extractions/new?harvestId=${harvest.id}`} />}
+          >
+            Zur Schleuderung
+          </Button>
+        </CardContent>
+      </Card>
+    </main>
+  );
+}

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

@@ -0,0 +1,191 @@
+"use client";
+
+import { FormEvent, useState } from "react";
+import { useRouter, useSearchParams } from "next/navigation";
+import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { fetchApiaries } from "@/lib/apiaries/api";
+import { fetchColonies } from "@/lib/colonies/api";
+import { createHarvest } from "@/lib/harvests/api";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { Textarea } from "@/components/ui/textarea";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+
+function todayIsoDate(): string {
+  return new Date().toISOString().slice(0, 10);
+}
+
+export default function NewHarvestPage() {
+  const router = useRouter();
+  const searchParams = useSearchParams();
+  const queryClient = useQueryClient();
+
+  const { data: apiaries } = useQuery({ queryKey: ["apiaries"], queryFn: fetchApiaries });
+  const { data: colonies } = useQuery({ queryKey: ["colonies"], queryFn: fetchColonies });
+
+  const [apiaryId, setApiaryId] = useState(searchParams.get("apiaryId") ?? "");
+  const [date, setDate] = useState(todayIsoDate());
+  const [colonyIds, setColonyIds] = useState<string[]>([]);
+  const [honeyType, setHoneyType] = useState("");
+  const [netWeight, setNetWeight] = useState("");
+  const [notes, setNotes] = useState("");
+  const [error, setError] = useState<string | null>(null);
+
+  const apiaryColonies = (colonies ?? []).filter(
+    (colony) => colony.apiaryId === apiaryId && colony.status === "ACTIVE",
+  );
+
+  const mutation = useMutation({
+    mutationFn: createHarvest,
+    onSuccess: (harvest) => {
+      void queryClient.invalidateQueries({ queryKey: ["harvests"] });
+      router.push(`/harvests/${harvest.id}`);
+    },
+    onError: () => {
+      setError("Ernte konnte nicht gespeichert werden.");
+    },
+  });
+
+  function toggleColony(colonyId: string, checked: boolean) {
+    setColonyIds((current) =>
+      checked ? [...current, colonyId] : current.filter((id) => id !== colonyId),
+    );
+  }
+
+  function handleSubmit(event: FormEvent<HTMLFormElement>) {
+    event.preventDefault();
+    setError(null);
+    if (!apiaryId) {
+      setError("Bitte einen Bienenstand auswählen.");
+      return;
+    }
+    if (colonyIds.length === 0) {
+      setError("Bitte mindestens ein Volk auswählen.");
+      return;
+    }
+    mutation.mutate({
+      apiaryId,
+      date: new Date(date).toISOString(),
+      colonyIds,
+      honeyType: honeyType || undefined,
+      netWeight: netWeight ? Number(netWeight) : undefined,
+      notes: notes || undefined,
+    });
+  }
+
+  return (
+    <main className="p-4 sm:p-6">
+      <Card className="max-w-lg">
+        <CardHeader>
+          <CardTitle>Neue Ernte</CardTitle>
+        </CardHeader>
+        <CardContent>
+          <form className="flex flex-col gap-5" onSubmit={handleSubmit}>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="harvest-apiary">Bienenstand</Label>
+              <Select
+                value={apiaryId}
+                onValueChange={(value) => {
+                  setApiaryId(value ?? "");
+                  setColonyIds([]);
+                }}
+              >
+                <SelectTrigger id="harvest-apiary" className="h-11 w-full">
+                  <SelectValue placeholder="Bienenstand wählen" />
+                </SelectTrigger>
+                <SelectContent>
+                  {apiaries?.map((apiary) => (
+                    <SelectItem key={apiary.id} value={apiary.id}>
+                      {apiary.name}
+                    </SelectItem>
+                  ))}
+                </SelectContent>
+              </Select>
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="harvest-date">Datum</Label>
+              <Input
+                id="harvest-date"
+                type="date"
+                required
+                className="h-11"
+                value={date}
+                onChange={(event) => setDate(event.target.value)}
+              />
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label>Beteiligte Völker</Label>
+              {apiaryId && apiaryColonies.length === 0 ? (
+                <p className="text-sm text-muted-foreground">
+                  Keine aktiven Völker an diesem Bienenstand.
+                </p>
+              ) : null}
+              <div className="flex flex-col gap-2">
+                {apiaryColonies.map((colony) => (
+                  <label
+                    key={colony.id}
+                    className="flex h-11 items-center gap-3 text-sm"
+                    htmlFor={`harvest-colony-${colony.id}`}
+                  >
+                    <input
+                      id={`harvest-colony-${colony.id}`}
+                      type="checkbox"
+                      className="size-5"
+                      checked={colonyIds.includes(colony.id)}
+                      onChange={(event) => toggleColony(colony.id, event.target.checked)}
+                    />
+                    {colony.code}
+                  </label>
+                ))}
+              </div>
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="harvest-honey-type">Honigsorte</Label>
+              <Input
+                id="harvest-honey-type"
+                className="h-11"
+                value={honeyType}
+                onChange={(event) => setHoneyType(event.target.value)}
+              />
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="harvest-net-weight">Nettogewicht (kg)</Label>
+              <Input
+                id="harvest-net-weight"
+                type="number"
+                inputMode="decimal"
+                className="h-11"
+                value={netWeight}
+                onChange={(event) => setNetWeight(event.target.value)}
+              />
+            </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="harvest-notes">Notizen</Label>
+              <Textarea
+                id="harvest-notes"
+                value={notes}
+                onChange={(event) => setNotes(event.target.value)}
+              />
+            </div>
+            {error ? (
+              <p role="alert" className="text-sm text-red-600">
+                {error}
+              </p>
+            ) : null}
+            <Button type="submit" className="h-12 text-base" disabled={mutation.isPending}>
+              {mutation.isPending ? "Wird gespeichert…" : "Ernte speichern"}
+            </Button>
+          </form>
+        </CardContent>
+      </Card>
+    </main>
+  );
+}

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

@@ -0,0 +1,13 @@
+import { apiFetch } from "@/lib/auth/api-client";
+import { CreateExtractionInput, Extraction } from "./types";
+
+export function fetchExtractions(): Promise<Extraction[]> {
+  return apiFetch<Extraction[]>("/extractions");
+}
+
+export function createExtraction(input: CreateExtractionInput): Promise<Extraction> {
+  return apiFetch<Extraction>("/extractions", {
+    method: "POST",
+    body: JSON.stringify(input),
+  });
+}

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

@@ -0,0 +1,35 @@
+export interface ExtractionHarvestEntry {
+  id: string;
+  harvestId: string;
+  harvest: {
+    id: string;
+    date: string;
+    colonies: {
+      colonyId: string;
+      colony: { id: string; code: string };
+    }[];
+  };
+}
+
+export interface Extraction {
+  id: string;
+  date: string;
+  userId: string;
+  amount: number | null;
+  room: string | null;
+  waterContent: number | null;
+  temperature: number | null;
+  notes: string | null;
+  createdAt: string;
+  harvests: ExtractionHarvestEntry[];
+}
+
+export interface CreateExtractionInput {
+  date: string;
+  harvestIds: string[];
+  amount?: number;
+  room?: string;
+  waterContent?: number;
+  temperature?: number;
+  notes?: string;
+}

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

@@ -0,0 +1,17 @@
+import { apiFetch } from "@/lib/auth/api-client";
+import { CreateHarvestInput, Harvest } from "./types";
+
+export function fetchHarvests(): Promise<Harvest[]> {
+  return apiFetch<Harvest[]>("/harvests");
+}
+
+export function fetchHarvest(id: string): Promise<Harvest> {
+  return apiFetch<Harvest>(`/harvests/${id}`);
+}
+
+export function createHarvest(input: CreateHarvestInput): Promise<Harvest> {
+  return apiFetch<Harvest>("/harvests", {
+    method: "POST",
+    body: JSON.stringify(input),
+  });
+}

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

@@ -0,0 +1,33 @@
+export interface HarvestColonyEntry {
+  id: string;
+  colonyId: string;
+  colony: {
+    id: string;
+    code: string;
+  };
+}
+
+export interface Harvest {
+  id: string;
+  apiaryId: string;
+  userId: string;
+  date: string;
+  honeyType: string | null;
+  honeySuperCount: number | null;
+  grossWeight: number | null;
+  netWeight: number | null;
+  notes: string | null;
+  createdAt: string;
+  colonies: HarvestColonyEntry[];
+}
+
+export interface CreateHarvestInput {
+  apiaryId: string;
+  date: string;
+  colonyIds: string[];
+  honeyType?: string;
+  honeySuperCount?: number;
+  grossWeight?: number;
+  netWeight?: number;
+  notes?: string;
+}

TASKS.md

@@ -91,7 +91,7 @@ Abgeleitet aus [`docs/lastenheft.md`](docs/lastenheft.md) Abschnitt 26. Reihenfo
 - Endpunkte: `GET/POST /api/v1/harvests`, `GET /api/v1/harvests/:id`, `GET/POST /api/v1/extractions`, `GET /api/v1/extractions/:id`
 - Frontend: `/harvests/new`, `/harvests/[id]`, `/extractions/new`
 - [x] Backend-Modul fertig, getestet, grün, committet
-- [ ] Frontend-Views fertig, getestet, grün, committet
+- [x] Frontend-Views fertig, getestet, grün, committet
 
 ### 11. Honigchargen