# Copyright (C) 2017  The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information

"""Module in charge of defining some uncoupled actions on deposit.

   Typically, checking that the archives deposited are ok are not
   directly testing in the request/answer to avoid too long
   computations.

   So this is done in the deposit_on_status_ready_for_check callback.

"""

from django.db.models.signals import post_save
from django.dispatch import receiver

from .models import Deposit
from .config import SWHDefaultConfig, DEPOSIT_STATUS_READY
from .config import DEPOSIT_STATUS_READY_FOR_CHECKS


@receiver(post_save, sender=Deposit)
def post_deposit_save(sender, instance, created, raw, using,
                      update_fields, **kwargs):
    """When a deposit is saved, check for the deposit's status change and
       schedule actions accordingly.

       When the status passes to ready-for-checks, schedule checks.
       When the status pass to ready, schedule loading.  Otherwise, do
       nothing.

    Args:
        sender (Deposit): The model class
        instance (Deposit): The actual instance being saved
        created (bool): True if a new record was created
        raw (bool): True if the model is saved exactly as presented
                    (i.e. when loading a fixture). One should not
                    query/modify other records in the database as the
                    database might not be in a consistent state yet
        using: The database alias being used
        update_fields: The set of fields to update as passed to
                       Model.save(), or None if update_fields wasn’t
                       passed to save()

    """
    default_config = SWHDefaultConfig()
    if not default_config.config['checks']:
        return

    if instance.status not in {DEPOSIT_STATUS_READY_FOR_CHECKS,
                               DEPOSIT_STATUS_READY}:
        return

    from django.core.urlresolvers import reverse
    from swh.scheduler.utils import create_oneshot_task_dict

    args = [instance.collection.name, instance.id]

    if instance.status == DEPOSIT_STATUS_READY_FOR_CHECKS:
        # schedule archive check
        from swh.deposit.config import PRIVATE_CHECK_DEPOSIT
        check_url = reverse(PRIVATE_CHECK_DEPOSIT, args=args)
        task = create_oneshot_task_dict(
            'swh-deposit-archive-checks',
            deposit_check_url=check_url)
    else:  # instance.status == DEPOSIT_STATUS_READY:
        # schedule loading
        from swh.deposit.config import PRIVATE_GET_RAW_CONTENT
        from swh.deposit.config import PRIVATE_GET_DEPOSIT_METADATA
        from swh.deposit.config import PRIVATE_PUT_DEPOSIT
        archive_url = reverse(PRIVATE_GET_RAW_CONTENT, args=args)
        meta_url = reverse(PRIVATE_GET_DEPOSIT_METADATA, args=args)
        update_url = reverse(PRIVATE_PUT_DEPOSIT, args=args)

        task = create_oneshot_task_dict(
            'swh-deposit-archive-loading',
            archive_url=archive_url,
            deposit_meta_url=meta_url,
            deposit_update_url=update_url)

    default_config.scheduler.create_tasks([task])