# Generated by Django 3.2.12 on 2022-07-13 09:46

import time
from django.db import migrations


def migrate_asset_system_user_relations(apps, schema_editor):
    system_user_model = apps.get_model('assets', 'SystemUser')
    old_model = apps.get_model('assets', 'AuthBook')
    new_model = system_user_model.assets.through

    count = 0
    bulk_size = 1000
    print("\nStart migrate asset system user relations")
    while True:
        start = time.time()
        auth_books = old_model.objects.only('asset_id', 'systemuser_id')[count:count+bulk_size]
        auth_books = list(auth_books)
        count += len(auth_books)
        if not auth_books:
            break
        asset_system_users = []
        for auth_book in auth_books:
            if not auth_book.asset_id or not auth_book.systemuser_id:
                continue
            asset_system_user = new_model(
                asset_id=auth_book.asset_id,
                systemuser_id=auth_book.systemuser_id
            )
            asset_system_users.append(asset_system_user)
        new_model.objects.bulk_create(asset_system_users, ignore_conflicts=True)
        print("Create asset system user relations: {}-{} using: {:.2f}s".format(
            count - bulk_size, count, time.time()-start
        ))


class Migration(migrations.Migration):

    dependencies = [
        ('assets', '0094_alter_systemuser_assets'),
    ]

    operations = [
        migrations.RunPython(migrate_asset_system_user_relations)
    ]