# Generated by Django 3.2 on 2021-06-01 05:25

import logging

from django.db import migrations


logger = logging.getLogger('inventree')


def assign_bom_items(apps, schema_editor):
    """
    Run through existing BuildItem objects,
    and assign a matching BomItem
    """

    BuildItem = apps.get_model('build', 'builditem')
    BomItem = apps.get_model('part', 'bomitem')
    Part = apps.get_model('part', 'part')
    
    logger.info("Assigning BomItems to existing BuildItem objects")

    count_valid = 0
    count_total = 0

    for build_item in BuildItem.objects.all():  # pragma: no cover

        # Try to find a BomItem which matches the BuildItem
        # Note: Before this migration, variant stock assignment was not allowed,
        #       so BomItem lookup should be pretty easy

        count_total += 1

        try:
            bom_item = BomItem.objects.get(
                part__id=build_item.build.part.pk,
                sub_part__id=build_item.stock_item.part.pk,
            )

            build_item.bom_item = bom_item
            build_item.save()

            count_valid += 1

        except BomItem.DoesNotExist:
            pass

    if count_total > 0:  # pragma: no cover
        logger.info(f"Assigned BomItem for {count_valid}/{count_total} entries")


def unassign_bom_items(apps, schema_editor):  # pragma: no cover
    """
    Reverse migration does not do anything.
    Function here to preserve ability to reverse migration
    """
    pass


class Migration(migrations.Migration):

    dependencies = [
        ('build', '0028_builditem_bom_item'),
    ]

    operations = [
        migrations.RunPython(assign_bom_items, reverse_code=unassign_bom_items),
    ]