"""scripts/backfill_app_fingerprints.py against a real (SQLite) session.

The unique index on (assetid, appfingerprint) turns two identical inventory rows
on one asset into an IntegrityError mid-backfill. The script must keep the
lowest id, delete the rest and report how many, and a failing batch must be
rolled back rather than left half-applied.
"""

import importlib.util
from pathlib import Path

import pytest

SCRIPT = Path(__file__).resolve().parent.parent / 'scripts' / 'backfill_app_fingerprints.py'


@pytest.fixture
def backfill(app):
    spec = importlib.util.spec_from_file_location('backfillfingerprints', SCRIPT)
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module


def _asset(db, number):
    from shopdb.core.models import Asset, AssetType

    atype = AssetType.query.filter_by(assettype='computer').first()
    if not atype:
        atype = AssetType(assettype='computer')
        db.session.add(atype)
        db.session.flush()
    asset = Asset(assetnumber=number, assettypeid=atype.assettypeid,
                  isactive=True)
    db.session.add(asset)
    db.session.commit()
    return asset.assetid


def _row(db, assetid, name, version='1.0', publisher='Vendor',
         fingerprint=None):
    from plugins.endpoints.models import EndpointApplication

    row = EndpointApplication(assetid=assetid, displayname=name,
                              displayversion=version, publisher=publisher,
                              **{'appfingerprint': fingerprint})
    db.session.add(row)
    db.session.commit()
    return row.endpointapplicationid


def test_self_check_uses_fixed_expected_values(backfill, monkeypatch):
    assert backfill.verify_fingerprint_algorithm() is True
    monkeypatch.setattr(backfill, 'compute_fingerprint',
                        lambda name, version, publisher: '0' * 64)
    with pytest.raises(ValueError):
        backfill.verify_fingerprint_algorithm()


def test_duplicates_keep_the_lowest_id(backfill, db):
    from plugins.endpoints.models import EndpointApplication

    first = _asset(db, 'FP01')
    second = _asset(db, 'FP02')
    keep = _row(db, first, 'Chrome')
    _row(db, first, 'Chrome')
    _row(db, first, 'Chrome')
    other = _row(db, first, 'Office')
    elsewhere = _row(db, second, 'Chrome')

    summary = backfill.backfill_fingerprints(batch_size=2)

    assert summary['duplicatesremoved'] == 2
    assert summary['failed'] == 0
    rows = EndpointApplication.query.order_by(
        EndpointApplication.endpointapplicationid).all()
    assert [r.endpointapplicationid for r in rows] == [keep, other, elsewhere]
    assert all(r.appfingerprint for r in rows)


def test_an_existing_higher_id_holder_gives_way(backfill, db):
    from plugins.endpoints.models import EndpointApplication

    assetid = _asset(db, 'FP03')
    fingerprint = backfill.compute_fingerprint('Chrome', '1.0', 'Vendor')
    older = _row(db, assetid, 'Chrome')
    _row(db, assetid, 'Chrome', fingerprint=fingerprint)

    summary = backfill.backfill_fingerprints()

    assert summary['duplicatesremoved'] == 1
    rows = EndpointApplication.query.all()
    assert [(r.endpointapplicationid, r.appfingerprint) for r in rows] == \
        [(older, fingerprint)]


def test_a_failing_batch_is_rolled_back(backfill, db, monkeypatch):
    from plugins.endpoints.models import EndpointApplication

    assetid = _asset(db, 'FP04')
    _row(db, assetid, 'Chrome')
    _row(db, assetid, 'Office')

    def broken(apps):
        for app in apps:
            app.appfingerprint = 'x' * 64
        raise RuntimeError('simulated failure')

    monkeypatch.setattr(backfill, '_fingerprint_batch', broken)

    summary = backfill.backfill_fingerprints()

    assert summary['failed'] == 2
    assert summary['processed'] == 0
    db.session.expire_all()
    assert EndpointApplication.query.filter(
        EndpointApplication.appfingerprint.isnot(None)).count() == 0