import asyncio
from django.core.management.base import BaseCommand
from django.db import transaction
from myapp.models import Order, OrderItem
 
class Command(BaseCommand):
    help = 'Process pending orders asynchronously with progress tracking'
 
    def add_arguments(self, parser):
        parser.add_argument('--batch-size', type=int, default=100)
        parser.add_argument('--dry-run', action='store_true')
 
    async def process_order_batch(self, orders):
        async_tasks = []
        for order in orders:
            task = asyncio.create_task(self.process_single_order(order))
            async_tasks.append(task)
        return await asyncio.gather(*async_tasks)
 
    async def process_single_order(self, order):
        await asyncio.sleep(0.1)
        return {'order_id': order.id, 'status': 'processed'}
 
    def handle(self, *args, **options):
        batch_size = options['batch_size']
        is_dry_run = options['dry_run']
 
        pending_orders = Order.objects.filter(status='pending').select_related('customer')
        total = pending_orders.count()
 
        self.stdout.write(f'Processing {total} orders...')
 
        for i in range(0, total, batch_size):
            batch = list(pending_orders[i:i + batch_size])
            results = asyncio.run(self.process_order_batch(batch))
 
            progress = min(i + batch_size, total)
            percent = (progress / total) * 100
            self.stdout.write(f'Progress: {progress}/{total} ({percent:.1f}%)')
 
        self.stdout.write(self.style.SUCCESS(f'Completed processing {total} orders'))