Day 5 の作付け計画API実装が完了しました。

実装内容
バグ修正
- fields/views.py: OfficialChusakanField → OfficialChusankanField
init_crops コマンド
✅ python manage.py init_crops
水稲: 5 varieties
大豆: 3 varieties
小麦: 2 varieties
そば: 2 varieties
とうきび: 1 varieties
serializers.py
- CropSerializer - 作物マスタ
- VarietySerializer - 品種マスタ
- PlanSerializer - 作付け計画（crop_name, variety_name, field_name 付き）
views.py
- CropViewSet, VarietyViewSet, PlanViewSet
- アクション: summary, copy_from_previous_year, get_crops_with_varieties
API エンドポイント
- /api/plans/crops/ - 作物一覧
- /api/plans/varieties/ - 品種一覧
- /api/plans/ - 作付け計画CRUD
- /api/plans/summary/?year=2025 - 集計
テスト結果
GET /api/plans/crops/ → ✅
GET /api/plans/ → ✅ (空配列)

backend/apps/plans/views.py

@@ -1,3 +1,85 @@
-from django.shortcuts import render
+from rest_framework import viewsets, status
+from rest_framework.decorators import action
+from rest_framework.response import Response
+from django.db.models import Sum
+from .models import Crop, Variety, Plan
+from .serializers import CropSerializer, VarietySerializer, PlanSerializer
 
-# Create your views here.
+
+class CropViewSet(viewsets.ModelViewSet):
+    queryset = Crop.objects.all()
+    serializer_class = CropSerializer
+
+
+class VarietyViewSet(viewsets.ModelViewSet):
+    queryset = Variety.objects.all()
+    serializer_class = VarietySerializer
+
+
+class PlanViewSet(viewsets.ModelViewSet):
+    queryset = Plan.objects.all()
+    serializer_class = PlanSerializer
+
+    def get_queryset(self):
+        queryset = Plan.objects.all()
+        year = self.request.query_params.get('year')
+        if year:
+            queryset = queryset.filter(year=year)
+        return queryset
+
+    @action(detail=False, methods=['get'])
+    def summary(self, request):
+        year = request.query_params.get('year')
+        if not year:
+            return Response({'error': 'year parameter is required'}, status=status.HTTP_400_BAD_REQUEST)
+
+        plans = Plan.objects.filter(year=year)
+        total_area = plans.aggregate(total=Sum('field__area_tan'))['total'] or 0
+
+        by_crop = {}
+        for plan in plans:
+            crop_name = plan.crop.name
+            if crop_name not in by_crop:
+                by_crop[crop_name] = {
+                    'crop': crop_name,
+                    'count': 0,
+                    'area': 0
+                }
+            by_crop[crop_name]['count'] += 1
+            by_crop[crop_name]['area'] += float(plan.field.area_tan)
+
+        return Response({
+            'year': int(year),
+            'total_plans': plans.count(),
+            'total_area': float(total_area),
+            'by_crop': list(by_crop.values())
+        })
+
+    @action(detail=False, methods=['post'])
+    def copy_from_previous_year(self, request):
+        from_year = request.data.get('from_year')
+        to_year = request.data.get('to_year')
+
+        if not from_year or not to_year:
+            return Response({'error': 'from_year and to_year are required'}, status=status.HTTP_400_BAD_REQUEST)
+
+        previous_plans = Plan.objects.filter(year=from_year)
+        new_plans = []
+
+        for plan in previous_plans:
+            new_plans.append(Plan(
+                field=plan.field,
+                year=to_year,
+                crop=plan.crop,
+                variety=plan.variety,
+                notes=plan.notes
+            ))
+
+        Plan.objects.bulk_create(new_plans, ignore_conflicts=True)
+
+        return Response({'message': f'Copied {len(new_plans)} plans from {from_year} to {to_year}'})
+
+    @action(detail=False, methods=['get'])
+    def get_crops_with_varieties(self, request):
+        crops = Crop.objects.prefetch_related('varieties').all()
+        return Response(CropSerializer(crops, many=True).data)