from django.core.management.base import BaseCommand
from django.db import transaction
from django.db.models import F
from apps.hadis.models import Hadis, HadisTransmitter, NarratorLayer

class Command(BaseCommand):
    help = "Fast chunked fix for HadisTransmitter narrator_layer foreign keys."

    def handle(self, *args, **options):
        self.stdout.write("Finding unique Hadiths with mismatched transmitter layers...")

        mismatched_hadis_ids = list(set(
            HadisTransmitter.objects.filter(narrator_layer__isnull=False)
            .exclude(narrator_layer__hadis=F('hadis'))
            .values_list('hadis_id', flat=True)
        ))

        total = len(mismatched_hadis_ids)
        self.stdout.write(f"Found {total} Hadiths to fix. Processing in chunks of 50...")

        chunk_size = 50
        for i in range(0, total, chunk_size):
            chunk = mismatched_hadis_ids[i:i + chunk_size]
            with transaction.atomic():
                for hadis_id in chunk:
                    hadis = Hadis.objects.get(id=hadis_id)
                    layers = list(hadis.narrator_layers.all().order_by('number'))

                    if not layers:
                        l1 = NarratorLayer.objects.create(
                            hadis=hadis,
                            number=1,
                            name=[{"language_code": "en", "text": "Primary Transmitters"}],
                            description=[{"language_code": "en", "text": "Primary transmitters layer"}]
                        )
                        l2 = NarratorLayer.objects.create(
                            hadis=hadis,
                            number=2,
                            name=[{"language_code": "en", "text": "Secondary Transmitters"}],
                            description=[{"language_code": "en", "text": "Secondary transmitters layer"}]
                        )
                        layers = [l1, l2]

                    if len(layers) == 1:
                        HadisTransmitter.objects.filter(hadis_id=hadis_id).update(narrator_layer=layers[0])
                    else:
                        HadisTransmitter.objects.filter(hadis_id=hadis_id, order__lte=1).update(narrator_layer=layers[0])
                        HadisTransmitter.objects.filter(hadis_id=hadis_id, order__gt=1).update(narrator_layer=layers[1])

            self.stdout.write(f"Fixed {min(i + chunk_size, total)}/{total} Hadiths...")

        self.stdout.write(self.style.SUCCESS("Done! All Hadiths transmitter layers successfully fixed!"))