"""
Команда для исправления Stock после обработки заказов.
Пересчитывает quantity_reserved для всех товаров.
"""
from django.core.management.base import BaseCommand
from inventory.models import Stock, Reservation
from django.db.models import Sum
from decimal import Decimal


class Command(BaseCommand):
    help = 'Исправляет quantity_reserved в Stock после обработки заказов'

    def add_arguments(self, parser):
        parser.add_argument(
            '--order',
            type=int,
            help='Номер заказа для исправления (опционально)'
        )

    def handle(self, *args, **options):
        order_number = options.get('order')
        
        if order_number:
            self.stdout.write(f"Исправление Stock для заказа {order_number}...")
            self.fix_for_order(order_number)
        else:
            self.stdout.write("Исправление всех Stock...")
            self.fix_all_stock()

    def fix_for_order(self, order_number):
        """Исправить Stock для конкретного заказа"""
        from orders.models import Order
        
        try:
            order = Order.objects.get(order_number=order_number)
        except Order.DoesNotExist:
            self.stdout.write(
                self.style.ERROR(f"Заказ {order_number} не найден!")
            )
            return
        
        # Получаем все резервы для этого заказа
        reservations = Reservation.objects.filter(
            order_item__order=order
        ).values('product_id', 'warehouse_id').distinct()
        
        fixed_count = 0
        for res in reservations:
            product_id = res['product_id']
            warehouse_id = res['warehouse_id']
            
            try:
                stock = Stock.objects.get(
                    product_id=product_id,
                    warehouse_id=warehouse_id
                )
                
                old_reserved = stock.quantity_reserved
                stock.refresh_from_batches()
                new_reserved = stock.quantity_reserved
                
                if old_reserved != new_reserved:
                    self.stdout.write(
                        self.style.SUCCESS(
                            f"✓ Обновлено: product_id={product_id}, "
                            f"warehouse_id={warehouse_id}, "
                            f"reserved: {old_reserved} → {new_reserved}"
                        )
                    )
                    fixed_count += 1
                else:
                    self.stdout.write(
                        f"  Без изменений: product_id={product_id}"
                    )
                    
            except Stock.DoesNotExist:
                self.stdout.write(
                    self.style.WARNING(
                        f"⚠ Stock не найден: product_id={product_id}, "
                        f"warehouse_id={warehouse_id}"
                    )
                )
        
        self.stdout.write(
            self.style.SUCCESS(
                f"\n✅ Готово! Обновлено {fixed_count} Stock для заказа {order_number}"
            )
        )

    def fix_all_stock(self):
        """Пересчитать все Stock"""
        stocks = Stock.objects.all()
        total = stocks.count()
        fixed_count = 0
        
        self.stdout.write(f"Найдено {total} Stock записей...")
        
        for stock in stocks:
            old_reserved = stock.quantity_reserved
            stock.refresh_from_batches()
            new_reserved = stock.quantity_reserved
            
            if old_reserved != new_reserved:
                self.stdout.write(
                    self.style.SUCCESS(
                        f"✓ {stock.product.name} на {stock.warehouse.name}: "
                        f"reserved {old_reserved} → {new_reserved}"
                    )
                )
                fixed_count += 1
        
        self.stdout.write(
            self.style.SUCCESS(
                f"\n✅ Готово! Обновлено {fixed_count} из {total} Stock"
            )
        )