# Generated by Django 2.2.13 on 2020-06-17 19:06

from django.db import migrations, models
import django.db.models.deletion
from seminar.treelib import get_parent

def najdi_cislo(apps, schema_editor):
	#
	Clanek = apps.get_model('seminar', 'Clanek')
	Hodnoceni = apps.get_model('seminar', 'Hodnoceni')
	Reseni = apps.get_model('seminar', 'Reseni')
	ReseniNode = apps.get_model('seminar', 'ReseniNode')
	CisloNode = apps.get_model('seminar', 'CisloNode')
	
	for c in Clanek.objects.all():
		reseni = c.reseni_set
		if (len(reseni) != 1):
			raise ValueError("Článek k sobě má nejedno řešení!")
		r = reseni[0]
		aktualniNode = r.reseninode
		while aktualniNode is not None:
			if isinstance(aktualniNode, CisloNode):
				c.cislo = aktualniNode.cislo
				c.save()
				break
			aktualniNode = get_parent()
		


class Migration(migrations.Migration):

    dependencies = [
        ('seminar', '0083_auto_20200506_1952'),
    ]

    operations = [
        migrations.AddField(
            model_name='clanek',
            name='cislo',
            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.PROTECT, related_name='vydane_clanky', to='seminar.Cislo', verbose_name='číslo vydání'),
        ),
	migrations.RunPython(najdi_cislo),
    ]