from collections import defaultdict from decimal import Decimal, ROUND_HALF_UP from django.core.management.base import BaseCommand from django.db import transaction from django.db.models import Prefetch from shop_management.models.data.stock import Stock from shop_management.models.data.stock_transfer import StockTransfer from shop_management.views.data.stock import normalize_currency_code TWOPLACES = Decimal("0.01") def _money(value): return Decimal(str(value or 0)).quantize(TWOPLACES, rounding=ROUND_HALF_UP) def _shop_stock_value_summary(shop_id): totals = {} qty_total = Decimal("0") for stock in Stock.objects.filter( shop_id=shop_id, is_deleted=False, quantity__gt=0, purchase_item__isnull=False, purchase_item__is_deleted=False, purchase_item__purchase__is_deleted=False, ).select_related( "purchase_item", "purchase_item__currency", "purchase_item__purchase__currency", ): qty = Decimal(str(stock.quantity or 0)) qty_total += qty code = normalize_currency_code(stock.currency.title if stock.currency else "") if not code: continue totals[code] = totals.get(code, Decimal("0")) + qty * Decimal( str(stock.average_buy_price or 0) ) return qty_total, { code: amount.quantize(TWOPLACES) for code, amount in sorted(totals.items()) } class Command(BaseCommand): help = ( "Recalculate destination stock average_buy_price from accepted stock " "transfers so Total Stock Value matches transfer Total Amount." ) def add_arguments(self, parser): parser.add_argument( "--shop", type=int, help="Only repair destination stocks for this shop id (e.g. Takhar).", ) parser.add_argument( "--dry-run", action="store_true", help="Show what would change without writing.", ) def handle(self, *args, **options): shop_id = options.get("shop") dry_run = options.get("dry_run") transfers = ( StockTransfer.objects.filter( status=StockTransfer.Status.ACCEPTED, target_stock__isnull=False, target_stock__is_deleted=False, ) .select_related( "target_stock", "target_stock__shop", "target_stock__purchase_item", "currency", "customer_branch", "supplier_branch", "product", ) .order_by("target_stock_id", "id") ) if shop_id: transfers = transfers.filter(customer_branch_id=shop_id) by_target = defaultdict(list) for transfer in transfers: by_target[transfer.target_stock_id].append(transfer) repaired = 0 skipped = 0 touched_shops = set() for target_stock_id, rows in by_target.items(): stock = rows[0].target_stock if not stock or int(stock.quantity or 0) <= 0: skipped += 1 continue transfer_qty = Decimal("0") transfer_value = Decimal("0") for transfer in rows: qty = Decimal(str(transfer.transfer_quantity or 0)) price = Decimal(str(transfer.sale_price or 0)) if qty <= 0: continue transfer_qty += qty transfer_value += qty * price if transfer_qty <= 0: skipped += 1 continue stock_qty = Decimal(str(stock.quantity or 0)) old_avg = Decimal(str(stock.average_buy_price or 0)) old_value = (stock_qty * old_avg).quantize(TWOPLACES) # Rebuild average so transferred qty is valued at transfer Total Amount # (qty × sale_price), not the old/wrong average. residual_qty = stock_qty - transfer_qty if residual_qty <= 0: new_avg = (transfer_value / transfer_qty).quantize( TWOPLACES, rounding=ROUND_HALF_UP ) elif old_avg == 0: # Residual has no recorded cost; put full transfer amount onto the row. new_avg = (transfer_value / stock_qty).quantize( TWOPLACES, rounding=ROUND_HALF_UP ) else: residual_value = residual_qty * old_avg new_avg = ((residual_value + transfer_value) / stock_qty).quantize( TWOPLACES, rounding=ROUND_HALF_UP ) new_value = (stock_qty * new_avg).quantize(TWOPLACES) if new_avg == old_avg: skipped += 1 continue currency = normalize_currency_code( (stock.currency.title if stock.currency else "") or (rows[0].currency.title if rows[0].currency else "") ) product_name = ( stock.purchase_item.product.name if stock.purchase_item and stock.purchase_item.product else (rows[0].product.name if rows[0].product else "?") ) self.stdout.write( f"Stock #{stock.id} ({stock.shop.name}) {product_name} " f"qty={stock_qty} {currency or '?'}: " f"avg {old_avg} -> {new_avg} | " f"value {old_value} -> {new_value} " f"(from {len(rows)} transfer line(s), transfer_qty={transfer_qty}, " f"transfer_amount={_money(transfer_value)})" ) touched_shops.add(stock.shop_id) if dry_run: repaired += 1 continue with transaction.atomic(): locked = Stock.objects.select_for_update().filter(pk=stock.id).first() if not locked: skipped += 1 continue locked.average_buy_price = new_avg locked.save(update_fields=["average_buy_price", "updated_at"]) purchase_item = locked.purchase_item if purchase_item: # Keep buy_price aligned for UI / reports when this row is # transfer-driven (qty fully covered by transfers). if residual_qty <= 0: purchase_item.buy_price = new_avg purchase_item.save(update_fields=["buy_price", "updated_at"]) repaired += 1 shops = sorted(touched_shops) if touched_shops else ( [shop_id] if shop_id else [] ) for sid in shops: qty_total, values = _shop_stock_value_summary(sid) value_text = ", ".join(f"{amount} {code}" for code, amount in values.items()) or "0" self.stdout.write( self.style.NOTICE( f"Shop {sid} valuation after repair: qty={qty_total} value=[{value_text}]" ) ) # Also print expected incoming value from accepted transfers for this shop. if shop_id: expected = defaultdict(lambda: Decimal("0")) expected_qty = Decimal("0") qs = StockTransfer.objects.filter( status=StockTransfer.Status.ACCEPTED, customer_branch_id=shop_id, ).select_related("currency") for transfer in qs: qty = Decimal(str(transfer.transfer_quantity or 0)) price = Decimal(str(transfer.sale_price or 0)) code = normalize_currency_code( transfer.currency.title if transfer.currency else "" ) or "?" expected[code] += qty * price expected_qty += qty expected_text = ", ".join( f"{_money(amount)} {code}" for code, amount in sorted(expected.items()) ) or "0" self.stdout.write( self.style.NOTICE( f"Shop {shop_id} accepted-transfer totals: " f"qty={expected_qty} amount=[{expected_text}]" ) ) action = "Would repair" if dry_run else "Repaired" self.stdout.write( self.style.SUCCESS( f"{action} {repaired} destination stock row(s); skipped {skipped}." ) )