from decimal import Decimal from rest_framework import serializers from api.models.data.currency import currency_details as _currency_details_fn, get_currency as _get_currency from api.models.data.sales import Sales, SalesItems from api.serializers.data.base import DataRootSerializer from api.mixins.base_currency import BaseCurrencySerializerMixin from api.utils.order_numeric import quantize_order_amount def _currency_code(currency_id): c = _get_currency(currency_id) return c['code'] if c else str(currency_id or '') def sales_item_commission_total(item) -> Decimal: """Line commission in AFN = quantity (selected unit) × commission per unit. Commission is always AFN and must never be FX-converted with the sale currency. """ qty = Decimal(str(getattr(item, 'quantity', 0) or 0)) rate = Decimal(str(getattr(item, 'commission_amount', 0) or 0)) return quantize_order_amount(qty * rate) class SalesItemsSerializer(DataRootSerializer): product_details = serializers.SerializerMethodField() stock_details = serializers.SerializerMethodField() storage_tank_details = serializers.SerializerMethodField() commission_total = serializers.SerializerMethodField() class Meta: model = SalesItems fields = "__all__" def get_commission_total(self, obj): return float(sales_item_commission_total(obj)) def get_product_details(self, obj): if obj.sale_source == SalesItems.SOURCE_TANK and obj.storage_tank_id: from api.services.tank_inventory import tank_product_label return { 'id': None, 'name': tank_product_label(obj.storage_tank), 'is_tank_fill': True, } if obj.stock and obj.stock.product: from api.serializers.data.products import serialize_product return serialize_product(obj.stock.product, self.context.get('request')) return None def get_stock_details(self, obj): if not obj.stock_id: return None from api.utils.packaging import ( bottles_per_carton, cartons_from_pieces, price_per_carton_from_piece, remainder_pieces, ) from api.serializers.data.products import serialize_product pieces = obj.stock.piece_amount or 0 piece_price = obj.stock.buy_price or 0 carton_size = bottles_per_carton(obj.stock.product) return { "id": obj.stock.id, "product_details": serialize_product(obj.stock.product, self.context.get('request')), "piece_amount": pieces, "bottles_per_carton": int(carton_size), "carton_amount": float(cartons_from_pieces(pieces, carton_size)), "loose_pieces": float(remainder_pieces(pieces, carton_size)), "buy_price": piece_price, "buy_price_per_carton": float(price_per_carton_from_piece(piece_price, carton_size)), "condition": getattr(obj.stock, 'condition', 'good'), "currency": obj.stock.currency, "currency_code": _currency_code(obj.stock.currency), } def get_storage_tank_details(self, obj): if not obj.storage_tank_id: return None from api.services.tank_inventory import get_tank_liquid_totals, tank_product_label tank = obj.storage_tank try: current_liters, _, cost_per_liter = get_tank_liquid_totals( tank, exclude_sale_item_id=obj.pk, ) except Exception: current_liters, cost_per_liter = 0, 0 return { 'id': tank.id, 'name': tank.name, 'product_name': tank_product_label(tank), 'current_liters': str(current_liters), 'liquid_cost_per_liter_afn': str(cost_per_liter), 'capacity_liters': str(tank.capacity_liters), } def validate(self, attrs): from api.utils.packaging import bottles_per_carton, pieces_from_units attrs = super().validate(attrs) source = attrs.get('sale_source') if source is None and self.instance is not None: source = self.instance.sale_source source = source or SalesItems.SOURCE_STOCK unit = attrs.get('unit') quantity = attrs.get('quantity') stock = attrs.get('stock', serializers.empty) tank = attrs.get('storage_tank', serializers.empty) if self.instance: if unit is None: unit = self.instance.unit if quantity is None: quantity = self.instance.quantity if stock is serializers.empty: stock = self.instance.stock if tank is serializers.empty: tank = self.instance.storage_tank else: if stock is serializers.empty: stock = None if tank is serializers.empty: tank = None attrs['sale_source'] = source if source == SalesItems.SOURCE_TANK: if tank is None: raise serializers.ValidationError({ 'storage_tank': 'Select a storage tank for tank-fill sales.', }) if stock is not None: attrs['stock'] = None attrs['unit'] = SalesItems.UNIT_LITER unit = SalesItems.UNIT_LITER if quantity is not None: attrs['quantity'] = quantize_order_amount(quantity) attrs['liter_amount'] = attrs['quantity'] else: if stock is None: raise serializers.ValidationError({ 'stock': 'Select packed stock for this sale line.', }) if tank is not None: attrs['storage_tank'] = None if unit == SalesItems.UNIT_LITER: raise serializers.ValidationError({ 'unit': 'Packed stock sales use carton, bottle, or plastic units.', }) # Normalize legacy dana → bottle if unit == SalesItems.UNIT_DANA: unit = SalesItems.UNIT_BOTTLE unit = unit or SalesItems.UNIT_CARTON if unit not in { SalesItems.UNIT_CARTON, SalesItems.UNIT_BOTTLE, SalesItems.UNIT_PLASTIC, SalesItems.UNIT_DANA, }: raise serializers.ValidationError({ 'unit': 'Packed stock sales use carton, bottle, or plastic.', }) attrs['unit'] = unit if quantity is not None: carton_size = bottles_per_carton(getattr(stock, 'product', None)) attrs['quantity'] = quantize_order_amount(quantity) attrs['liter_amount'] = quantize_order_amount( pieces_from_units(attrs['quantity'], unit, carton_size) ) for field in ('liter_amount', 'sell_price', 'unit_cost', 'quantity', 'commission_amount'): if field in attrs and attrs[field] is not None: attrs[field] = quantize_order_amount(attrs[field]) commission = attrs.get('commission_amount') if commission is None and self.instance is not None: commission = self.instance.commission_amount if commission is not None and commission < 0: raise serializers.ValidationError({ 'commission_amount': 'Commission cannot be negative.', }) return attrs class SalesSerializer(BaseCurrencySerializerMixin, DataRootSerializer): base_currency_amount_fields = ('total_amount', 'paid_amount') base_currency_date_field = 'sale_date' currency = serializers.IntegerField() customer_details = serializers.SerializerMethodField() salesman_details = serializers.SerializerMethodField() currency_details = serializers.SerializerMethodField() items = SalesItemsSerializer(many=True, read_only=True, source='sales_items') subtotal_amount = serializers.SerializerMethodField() discount_amount = serializers.SerializerMethodField() final_total = serializers.SerializerMethodField() remaining_amount = serializers.SerializerMethodField() total_commission = serializers.SerializerMethodField() documents = serializers.SerializerMethodField() class Meta: model = Sales fields = "__all__" read_only_fields = ( 'exchange_rate', 'total_amount_base', 'paid_amount_base', ) def validate(self, attrs): attrs = super().validate(attrs) for field in ('total_amount', 'paid_amount'): if field in attrs and attrs[field] is not None: attrs[field] = quantize_order_amount(attrs[field]) customer = attrs.get('customer') if customer is None and self.instance is not None: customer = self.instance.customer if customer is None: raise serializers.ValidationError({'customer': 'Customer is required.'}) currency = attrs.get('currency') if currency is None and self.instance is not None: currency = self.instance.currency # Sales invoices are AFN (1) or USD (2) only — inventory costs are AFN. if currency is not None and int(currency) not in (1, 2): raise serializers.ValidationError({ 'currency': 'Sales currency must be AFN or USD.', }) salesman = attrs.get('salesman', serializers.empty) if salesman is serializers.empty and self.instance is not None: salesman = self.instance.salesman if salesman is serializers.empty: salesman = None # Empty string / 0 from clients → null if salesman in ('', 0, '0'): attrs['salesman'] = None salesman = None return attrs def get_customer_details(self, obj): if obj.customer: return { "id": obj.customer.id, "name": obj.customer.name, "phone": obj.customer.phone, "email": obj.customer.email, "address": obj.customer.address, } return None def get_salesman_details(self, obj): if obj.salesman_id and obj.salesman: return { "id": obj.salesman.id, "name": obj.salesman.name, "phone": obj.salesman.phone, } return None def get_total_commission(self, obj): """Sum of line commissions in AFN (independent of sale invoice currency).""" total = Decimal('0') for item in obj.sales_items.all(): total += sales_item_commission_total(item) return float(total) def get_currency_details(self, obj): return _currency_details_fn(obj.currency) def get_subtotal_amount(self, obj): return float(obj.subtotal_amount) def get_discount_amount(self, obj): return float(obj.discount_amount) def get_final_total(self, obj): return float(obj.final_total) def get_remaining_amount(self, obj): total = float(obj.final_total if hasattr(obj, 'final_total') else (obj.total_amount or 0)) paid = float(obj.paid_amount or 0) return max(0.0, total - paid) def get_documents(self, obj): from api.services.attachments import serialize_document docs = getattr(obj, 'documents', None) if docs is None: return [] request = self.context.get('request') return [serialize_document(doc, request) for doc in docs.all()] class SalesListSerializer(SalesSerializer): """Lightweight list/picker payload — no line items.""" class Meta(SalesSerializer.Meta): fields = ( 'id', 'invoice_number', 'sale_date', 'status', 'customer', 'customer_details', 'salesman', 'salesman_details', 'currency', 'currency_details', 'total_amount', 'total_amount_base', 'paid_amount', 'paid_amount_base', 'exchange_rate', 'final_total', 'remaining_amount', 'total_commission', 'discount_percentage', 'notes', ) def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.fields.pop('documents', None)