# from django.http import JsonResponse # from django.utils import timezone # import math # from django.contrib import messages # from django.db import IntegrityError,transaction # from django.views import View # from rest_framework.views import APIView # from rest_framework.response import Response # from rest_framework.permissions import AllowAny # from rest_framework import status # from django.shortcuts import get_object_or_404, redirect, render # from django.core.paginator import Paginator # from django.db.models import RestrictedError # from django.core.exceptions import ObjectDoesNotExist # from codesofy.custom_config import get_global_master_details, get_privilleges, is_authorized, set_menu_items, set_user_profile # from codesofy.master_details import PerPageSelector, ProductType, UserAccountStatus # from constants.general_const import ActiveStatus # from core.utils import get_api_message # from cropmanagement.models import Crop # from usermanagement.models import UserProfile # from decimal import Decimal, InvalidOperation # from .models import ProductCropMapping # from products.models import Product # from .serializers import ProductCropMappingLiteSerializer # from django.views.decorators.cache import cache_control # from django.utils.decorators import method_decorator # menu_item = "cropmapping_registry" # def get_active_counsellors(): # counsellors = UserProfile.objects.filter(user__is_active=True) # return counsellors # def set_sub_menu_item(sub_menu_item,context): # context = set_menu_items(menu_item,sub_menu_item,context) # return context # def get_local_master_details(): # context = get_global_master_details() # return context # def get_local_master_details_for_user_details(): # context = get_local_master_details() # user_account_statuses = UserAccountStatus.to_list_for_reports() # context["user_account_statuses"] = user_account_statuses # return context # def get_local_master_details_for_add_update_cropmapping(): # context = get_local_master_details() # product_list = Product.objects.all() # crop_list = Crop.objects.all() # mapping_status = ActiveStatus.to_list() # context["mapping_status_list"] = mapping_status # context['product_list'] = product_list # context['crop_list'] = crop_list # return context # def get_local_master_details_for_cropmapping_details(): # context = get_local_master_details() # product_list = Product.objects.all() # mapping_status = ActiveStatus.to_list_for_reports() # context["mapping_status_list"] = mapping_status # context['product_list'] = product_list # return context # def find_reverse_dependencies(instance, sample_per_relation: int = 3): # """ # Return a dict of {relation_label: [pk,...]} for reverse related objects # that currently exist referencing `instance`. Uses model metadata, so you # don't have to hardcode table names. # """ # blockers = {} # # Walk all reverse relations declared on the model # for rel in instance._meta.related_objects: # # rel is a ManyToOneRel / ManyToManyRel / OneToOneRel (reverse side) # accessor = rel.get_accessor_name() # e.g. "order_items", "results" # manager = getattr(instance, accessor, None) # if manager is None: # continue # # For O2O, manager is a single object accessor; handle safely # try: # if rel.one_to_one: # try: # obj = manager # # If it exists, accessing .pk will not raise # _ = obj.pk # blockers[rel.related_model._meta.label] = [obj.pk] # except rel.related_model.DoesNotExist: # pass # continue # except AttributeError: # # Older Django or unusual relation – skip # continue # # For reverse FK/M2M, manager is a RelatedManager # try: # qs = manager.all() # except Exception: # continue # # Only flag if there are rows # if qs.exists(): # # Sample a few PKs for the message # blockers[rel.related_model._meta.label] = list(qs.values_list("pk", flat=True)[:sample_per_relation]) # return blockers # @method_decorator(cache_control(no_cache=True, must_revalidate=True, no_store=True), name='dispatch') # class AddCropMappingView(View): # this_feature = "add_cropmapping" # sub_menu_item = "add_cropmapping" # def get(self, request): # context = get_local_master_details_for_add_update_cropmapping() # user_profile = set_user_profile(request, context) # if user_profile is None: # return redirect("login") # get_privilleges(user_profile, context) # if not is_authorized(user_profile, self.this_feature): # return redirect("unauthorized-access") # set_sub_menu_item(self.sub_menu_item, context) # return render(request, "add-cropmapping.html", context) # def post(self, request): # context = get_local_master_details_for_add_update_cropmapping() # user_profile = set_user_profile(request, context) # if user_profile is None: # return redirect("login") # get_privilleges(user_profile, context) # if not is_authorized(user_profile, self.this_feature): # return redirect("unauthorized-access") # set_sub_menu_item(self.sub_menu_item, context) # # ---- Raw inputs (IDs for FKs expected from the form) ---- # product_id = (request.POST.get("product") or "").strip() # crop_id = (request.POST.get("crop") or "").strip() # scale_order_number = (request.POST.get("scale_order_number") or "").strip() # universal_moisture_threshold = (request.POST.get("universal_moisture_threshold") or "").strip() # # Keep what the user typed to re-fill the form on error # def keep_form_values(): # context["form_values"] = { # "product": product_id, # "crop": crop_id, # "scale_order_number": scale_order_number, # "universal_moisture_threshold": universal_moisture_threshold, # } # # ---- Required fields check ---- # if not product_id or not crop_id: # messages.error(request, "Product and crop are required.") # keep_form_values() # return render(request, "add-cropmapping.html", context) # # ---- Resolve FKs ---- # try: # product = Product.objects.get(pk=product_id) # crop = Crop.objects.get(pk=crop_id) # except ObjectDoesNotExist: # messages.error(request, "Invalid product or crop selection.") # keep_form_values() # return render(request, "add-cropmapping.html", context) # # ---- Parse optional numeric field (no range validation) ---- # umt = None # if universal_moisture_threshold: # try: # # Use Decimal to match DecimalField and avoid float quirks # umt = Decimal(universal_moisture_threshold) # except (InvalidOperation, ValueError): # messages.error(request, "Moisture threshold must be a numeric value.") # keep_form_values() # return render(request, "add-cropmapping.html", context) # # ---- Create with race-safety & unique-pair handling ---- # try: # with transaction.atomic(): # mapping = ProductCropMapping.objects.create( # product=product, # crop=crop, # scale_order_number=scale_order_number, # universal_moisture_threshold=umt, # created_user=user_profile, # updated_user=user_profile, # ) # except IntegrityError: # # UniqueConstraint(fields=['product','crop']) hit # messages.error(request, "That product is already mapped to this crop.") # keep_form_values() # return render(request, "add-cropmapping.html", context) # messages.success( # request, f'Mapping created: "{mapping.product.name} ↔ {mapping.crop.name}".' # ) # return redirect("view-cropmapping", id=mapping.id) # @method_decorator(cache_control(no_cache=True, must_revalidate=True, no_store=True), name='dispatch') # class ViewCropMappingView(View): # this_feature = "view_cropmapping" # sub_menu_item = "cropmapping_details" # def get(self, request, id): # context = get_local_master_details_for_cropmapping_details() # user_profile = set_user_profile(request, context) # if user_profile is None: # return redirect('login') # get_privilleges(user_profile, context) # if not is_authorized(user_profile, self.this_feature): # return redirect('unauthorized-access') # set_sub_menu_item(self.sub_menu_item, context) # # Read-only fetch; no transaction needed # mapping = get_object_or_404( # ProductCropMapping.objects.select_related('product', 'crop'), # pk=id # ) # context["mapping"] = mapping # return render(request, 'view-cropmapping.html', context) # @method_decorator(cache_control(no_cache=True, must_revalidate=True,no_store=True), name='dispatch') # class CropMappingDetailsView(View): # this_feature = "cropmapping_details" # sub_menu_item = "cropmapping_details" # def get(self, request): # context = get_local_master_details_for_cropmapping_details() # user_profile = set_user_profile(request,context) # if user_profile==None: # return redirect('login') # get_privilleges(user_profile,context) # if not is_authorized(user_profile,self.this_feature): # return redirect('unauthorized-access') # set_sub_menu_item(self.sub_menu_item,context) # crop = request.GET.get('crop') # product = request.GET.get('product') # scale_order_number = request.GET.get('scale_order_number') # # is_active = request.GET.get('is_active') # per_page_count = request.GET.get('per_page_count') # page_number = request.GET.get('page_number') # start_index = request.GET.get('start_index') # if not page_number: # page_number = 1 # if not per_page_count: # per_page_count = PerPageSelector.get_default().value # if start_index: # page_number = math.ceil(int(start_index)/int(per_page_count)) # #filter logic applies here # filter_kwargs = {} # if scale_order_number: # context["default_scale_order_number"] = scale_order_number # filter_kwargs['scale_order_number__icontains']= scale_order_number # if product: # # filter by product code (case-insensitive exact) # filter_kwargs["product__code__iexact"] = product # context ["default_product"] = product # if crop: # context["default_crop"] = crop # filter_kwargs['crop__name']= crop # # if is_active: # # if is_active.lower()!="all": # # context["default_is_active"] = ActiveStatus(is_active).value # # filter_kwargs['is_active']= ActiveStatus(is_active).value # mapping_list = ProductCropMapping.objects.filter(**filter_kwargs).order_by('-id') # if len(mapping_list)>0: # context["has_entries"] = True # else: # context["has_entries"] = False # paginator = Paginator(mapping_list,per_page_count) # page = Paginator.get_page(paginator,page_number) # page_list = list(paginator.get_elided_page_range(page_number, on_each_side=1)) # context["page"] = page # context["page_list"] = page_list # return render(request, 'cropmapping-details.html', context) # @method_decorator(cache_control(no_cache=True, must_revalidate=True, no_store=True), name='dispatch') # class UpdateCropMappingView(View): # this_feature = "update_cropmapping" # sub_menu_item = "cropmapping_details" # def get(self, request, id): # context = get_local_master_details_for_add_update_cropmapping() # user_profile = set_user_profile(request, context) # if user_profile is None: # return redirect('login') # get_privilleges(user_profile, context) # if not is_authorized(user_profile, self.this_feature): # return redirect('unauthorized-access') # set_sub_menu_item(self.sub_menu_item, context) # # Load mapping (NOT Crop) # mapping = get_object_or_404(ProductCropMapping, pk=id) # context["mapping"] = mapping # # Pre-fill form fields (useful if your template reads old_input_field_values) # context["old_input_field_values"] = { # "product": str(mapping.product_id), # "crop": str(mapping.crop_id), # "scale_order_number": mapping.scale_order_number or "", # "universal_moisture_threshold": ( # "" if mapping.universal_moisture_threshold is None # else str(mapping.universal_moisture_threshold) # ), # } # return render(request, 'update-cropmapping.html', context) # def post(self, request, id): # context = get_local_master_details_for_add_update_cropmapping() # user_profile = set_user_profile(request, context) # if user_profile is None: # return redirect('login') # get_privilleges(user_profile, context) # if not is_authorized(user_profile, self.this_feature): # return redirect('unauthorized-access') # set_sub_menu_item(self.sub_menu_item, context) # mapping = ProductCropMapping.objects.filter(pk=id).select_related("product", "crop").first() # if not mapping: # messages.error(request, "Product–Crop mapping not found.") # return render(request, 'update-cropmapping.html', context) # # Read & normalize inputs (expecting **IDs** from the form) # product_id = (request.POST.get("product") or "").strip() # crop_id = (request.POST.get("crop") or "").strip() # scale_order_number = (request.POST.get("scale_order_number") or "").strip() # universal_moisture_threshold = (request.POST.get("universal_moisture_threshold") or "").strip() # # Preserve user input on error # context["old_input_field_values"] = { # "product": product_id, # "crop": crop_id, # "scale_order_number": scale_order_number, # "universal_moisture_threshold": universal_moisture_threshold, # } # # Basic required fields for FKs # if not product_id or not crop_id: # messages.error(request, "Product and crop are required.") # return render(request, 'update-cropmapping.html', context) # # Resolve FKs by primary key (IDs). If your template posts codes/names instead, # # switch to filtering by unique fields (code__iexact/name__iexact) as shown earlier. # try: # product = Product.objects.get(pk=product_id) # crop = Crop.objects.get(pk=crop_id) # except (Product.DoesNotExist, Crop.DoesNotExist): # messages.error(request, "Invalid product or crop selection.") # return render(request, 'update-cropmapping.html', context) # # Parse optional numeric field (Decimal to match DecimalField; no range enforcement here) # umt = None # if universal_moisture_threshold: # try: # umt = Decimal(universal_moisture_threshold) # except (InvalidOperation, ValueError): # messages.error(request, "Moisture threshold must be a numeric value.") # return render(request, 'update-cropmapping.html', context) # # Update safely; handle unique (product, crop) collisions # try: # with transaction.atomic(): # mapping.product = product # mapping.crop = crop # mapping.scale_order_number = scale_order_number # mapping.universal_moisture_threshold = umt # can be None # mapping.updated_user = user_profile # mapping.updated_at = timezone.now() # mapping.save() # may raise IntegrityError on unique constraint # except IntegrityError: # # Likely violates UniqueConstraint('product', 'crop') # messages.error(request, "Another mapping already exists for that Product ↔ Crop pair.") # return render(request, 'update-cropmapping.html', context) # except Exception: # messages.error(request, "Unexpected error. Please contact the system administrator.") # return render(request, 'update-cropmapping.html', context) # messages.success( # request, # f'Updated mapping: "{mapping.product.name} ↔ {mapping.crop.name}".' # ) # # Choose the redirect that matches your URLs: # # return redirect('cropmapping-details') # if it’s an index/list page # return redirect('view-cropmapping', id=mapping.id) # if you have a detail view # @method_decorator(cache_control(no_cache=True, must_revalidate=True, no_store=True), name='dispatch') # class DeleteCropMappingView(View): # this_feature = "delete_cropmapping" # sub_menu_item = "cropmapping_details" # def post(self, request): # context = get_local_master_details_for_cropmapping_details() # user_profile = set_user_profile(request, context) # if user_profile is None: # return redirect('login') # get_privilleges(user_profile, context) # if not is_authorized(user_profile, self.this_feature): # return redirect('unauthorized-access') # set_sub_menu_item(self.sub_menu_item, context) # mapping_id = (request.POST.get('mapping_id') or '').strip() # if not mapping_id: # messages.error(request, "No mapping id provided.") # return redirect('cropmapping-details') # # Fetch the mapping first (no lock yet) # mapping = ProductCropMapping.objects.select_related("product", "crop").filter(pk=mapping_id).first() # if not mapping: # messages.error(request, "Product–Crop mapping not found.") # return redirect('cropmapping-details') # # 1) Pre-check for dependencies (reverse relations) # blockers = find_reverse_dependencies(mapping) # if blockers: # # Build a friendly message listing what blocks the deletion # lines = [] # for label, ids in blockers.items(): # lines.append(f"{label} (example ids: {', '.join(map(str, ids))})") # msg = "Cannot delete: this mapping is referenced by other records → " + "; ".join(lines) # messages.error(request, msg) # return redirect('cropmapping-details') # # 2) No blockers found; lock + delete atomically to prevent race # try: # with transaction.atomic(): # # Lock the same row before deleting, to avoid a new reference being created mid-flight # locked = ProductCropMapping.objects.select_for_update().get(pk=mapping.pk) # # Double-check dependencies right before delete (TOCTOU safety) # blockers_now = find_reverse_dependencies(locked) # if blockers_now: # lines = [] # for label, ids in blockers_now.items(): # lines.append(f"{label} (example ids: {', '.join(map(str, ids))})") # msg = "Cannot delete (just referenced): " + "; ".join(lines) # messages.error(request, msg) # return redirect('cropmapping-details') # product_name = locked.product.name # crop_name = locked.crop.name # locked.delete() # messages.success(request, f'Mapping "{product_name} ↔ {crop_name}" deleted.') # return redirect('cropmapping-details') # except ProductCropMapping.DoesNotExist: # messages.error(request, "Product–Crop mapping not found.") # return redirect('cropmapping-details') # except Exception as e: # # Fallback: if your DB-level FKs are RESTRICT/PROTECT, this will still be safe. # messages.error(request, f"Could not delete. {e}") # return redirect('cropmapping-details') # @method_decorator(cache_control(no_cache=True, must_revalidate=True, no_store=True), name="dispatch") # class ProductCropMappingsByQuery(APIView): # permission_classes = [AllowAny] # def get(self, request): # product_id = request.query_params.get("product_id") # # Validate query param # if not product_id: # return JsonResponse( # { # "success": False, # "message": get_api_message("MISSING_PRODUCT_ID", request), # "code": "MISSING_PRODUCT_ID", # "errors": {"product_id": ["This query parameter is required."]}, # }, # status=400, # ) # # Validate product exists # if not Product.objects.filter(pk=product_id).exists(): # return JsonResponse( # { # "success": False, # "message": get_api_message("PRODUCT_NOT_FOUND", request), # "code": "PRODUCT_NOT_FOUND", # "errors": {"product_id": [f"No product with id {product_id}."]}, # }, # status=404, # ) # # Fetch relevant mappings # qs = ( # ProductCropMapping.objects # .filter(product_id=product_id) # .select_related("crop") # .order_by("scale_order_number") # ) # data = ProductCropMappingLiteSerializer(qs, many=True).data # return JsonResponse( # { # "success": True, # "message": get_api_message("MAPPINGS_FETCHED", request), # "code": "MAPPINGS_FETCHED", # "data": data, # list directly # }, # status=200, # )