from decimal import Decimal, InvalidOperation from django.http import HttpResponse from django.template.loader import render_to_string from rest_framework import viewsets, status from rest_framework.decorators import action from rest_framework.permissions import IsAuthenticated from rest_framework.response import Response from rest_framework.views import APIView from weasyprint import HTML from apps.fields.models import Field from apps.plans.models import Plan, Variety from .models import Fertilizer, FertilizationPlan from .serializers import ( FertilizerSerializer, FertilizationPlanSerializer, FertilizationPlanWriteSerializer, ) class FertilizerViewSet(viewsets.ModelViewSet): permission_classes = [IsAuthenticated] queryset = Fertilizer.objects.all() serializer_class = FertilizerSerializer class FertilizationPlanViewSet(viewsets.ModelViewSet): permission_classes = [IsAuthenticated] def get_queryset(self): qs = FertilizationPlan.objects.select_related('variety', 'variety__crop').prefetch_related( 'entries', 'entries__field', 'entries__fertilizer' ) year = self.request.query_params.get('year') if year: qs = qs.filter(year=year) return qs def get_serializer_class(self): if self.action in ['create', 'update', 'partial_update']: return FertilizationPlanWriteSerializer return FertilizationPlanSerializer @action(detail=True, methods=['get']) def pdf(self, request, pk=None): plan = self.get_object() entries = plan.entries.select_related('field', 'fertilizer').order_by( 'field__display_order', 'field__id', 'fertilizer__name' ) # 圃場・肥料の一覧を整理 fields_map = {} fertilizers_map = {} for entry in entries: fields_map[entry.field_id] = entry.field fertilizers_map[entry.fertilizer_id] = entry.fertilizer fields = sorted(fields_map.values(), key=lambda f: (f.display_order, f.id)) fertilizers = sorted(fertilizers_map.values(), key=lambda f: f.name) # マトリクスデータ生成 matrix = {} for entry in entries: matrix[(entry.field_id, entry.fertilizer_id)] = entry.bags rows = [] for field in fields: cells = [matrix.get((field.id, fert.id), '') for fert in fertilizers] total = sum(v for v in cells if v != '') rows.append({ 'field': field, 'cells': cells, 'total': total, }) # 肥料ごとの合計 fert_totals = [] for fert in fertilizers: total = sum( matrix.get((field.id, fert.id), Decimal('0')) for field in fields ) fert_totals.append(total) context = { 'plan': plan, 'fertilizers': fertilizers, 'rows': rows, 'fert_totals': fert_totals, 'grand_total': sum(fert_totals), } html_string = render_to_string('fertilizer/pdf.html', context) pdf_file = HTML(string=html_string).write_pdf() response = HttpResponse(pdf_file, content_type='application/pdf') response['Content-Disposition'] = f'attachment; filename="fertilization_{plan.year}_{plan.id}.pdf"' return response class CandidateFieldsView(APIView): """作付け計画から圃場候補を返す""" permission_classes = [IsAuthenticated] def get(self, request): year = request.query_params.get('year') variety_id = request.query_params.get('variety_id') if not year or not variety_id: return Response({'error': 'year と variety_id が必要です'}, status=status.HTTP_400_BAD_REQUEST) field_ids = Plan.objects.filter( year=year, variety_id=variety_id ).values_list('field_id', flat=True) fields = Field.objects.filter(id__in=field_ids).order_by('display_order', 'id') data = [ { 'id': f.id, 'name': f.name, 'area_tan': str(f.area_tan), 'area_m2': f.area_m2, 'group_name': f.group_name, } for f in fields ] return Response(data) class CalculateView(APIView): """自動計算（保存しない）""" permission_classes = [IsAuthenticated] def post(self, request): method = request.data.get('method') # 'nitrogen' | 'even' | 'per_tan' param = request.data.get('param') # 数値パラメータ fertilizer_id = request.data.get('fertilizer_id') field_ids = request.data.get('field_ids', []) if not method or param is None or not field_ids: return Response({'error': 'method, param, field_ids が必要です'}, status=status.HTTP_400_BAD_REQUEST) try: param = Decimal(str(param)) except InvalidOperation: return Response({'error': 'param は数値で指定してください'}, status=status.HTTP_400_BAD_REQUEST) fields = Field.objects.filter(id__in=field_ids) if not fields.exists(): return Response({'error': '圃場が見つかりません'}, status=status.HTTP_400_BAD_REQUEST) results = [] if method == 'per_tan': # 反当袋数配分: S = Sa × A for field in fields: area = Decimal(str(field.area_tan)) bags = (param * area).quantize(Decimal('0.01')) results.append({'field_id': field.id, 'bags': float(bags)}) elif method == 'even': # 在庫/指定数量均等配分: S = (SS / Sum(A)) × A total_area = sum(Decimal(str(f.area_tan)) for f in fields) if total_area == 0: return Response({'error': '圃場の面積が0です'}, status=status.HTTP_400_BAD_REQUEST) for field in fields: area = Decimal(str(field.area_tan)) bags = (param * area / total_area).quantize(Decimal('0.01')) results.append({'field_id': field.id, 'bags': float(bags)}) elif method == 'nitrogen': # 反当チッソ成分量配分: S = (Nr / (C × Nd/100)) × A if not fertilizer_id: return Response({'error': 'nitrogen 方式には fertilizer_id が必要です'}, status=status.HTTP_400_BAD_REQUEST) try: fertilizer = Fertilizer.objects.get(id=fertilizer_id) except Fertilizer.DoesNotExist: return Response({'error': '肥料が見つかりません'}, status=status.HTTP_404_NOT_FOUND) if not fertilizer.capacity_kg or not fertilizer.nitrogen_pct: return Response( {'error': 'この肥料には1袋重量(kg)と窒素含有率(%)の登録が必要です'}, status=status.HTTP_400_BAD_REQUEST ) c = Decimal(str(fertilizer.capacity_kg)) nd = Decimal(str(fertilizer.nitrogen_pct)) # 1袋あたりの窒素量 (kg) nc = c * nd / Decimal('100') if nc == 0: return Response({'error': '窒素含有量が0のため計算できません'}, status=status.HTTP_400_BAD_REQUEST) for field in fields: area = Decimal(str(field.area_tan)) bags = (param / nc * area).quantize(Decimal('0.01')) results.append({'field_id': field.id, 'bags': float(bags)}) else: return Response({'error': 'method は nitrogen / even / per_tan のいずれかです'}, status=status.HTTP_400_BAD_REQUEST) return Response(results)