"""A concurrent application insert must not sink the whole check-in.

The unique index on (assetid, appfingerprint) detects a second writer inserting
the same application row; it does not resolve one. Before the savepoint went in,
the IntegrityError from the insert flush escaped generic_collect, reached the
global handler, rolled back the WHOLE check-in - state, events and hardware -
and answered the agent with operator-facing 409 form copy.

The insert now behaves like the delete-count mismatch beside it: warn, keep the
telemetry, and let the next check-in (which reports the full list again) settle
the inventory.
"""

import hashlib

from sqlalchemy.exc import IntegrityError

from shopdb.core.models import Asset, AssetType
from plugins.endpoints.models import (
    EndpointApplication, EndpointEvent, EndpointState,
)
from plugins.endpoints.plugin import EndpointsPlugin


def _fingerprint(name, version, publisher):
    data = '{}|{}|{}'.format(name or '', version or '', publisher or '')
    return hashlib.sha256(data.encode('utf-8')).hexdigest()


def _computer(db, hostname):
    from plugins.computers.models import Computer

    assettype = AssetType.query.filter_by(assettype='computer').first()
    if assettype is None:
        assettype = AssetType(assettype='computer')
        db.session.add(assettype)
        db.session.flush()
    asset = Asset(assetnumber=hostname, name=hostname,
                  assettypeid=assettype.assettypeid, isactive=True)
    db.session.add(asset)
    db.session.flush()
    db.session.add(Computer(assetid=asset.assetid, hostname=hostname))
    db.session.commit()
    return asset.assetid


def _payload(hostname, applications):
    return {
        'hostname': hostname,
        'pendingreboot': True,
        'applications': applications,
        'events': [{
            'eventid': 4625,
            'eventrecordid': 501,
            'eventchannel': 'Security',
            'eventsource': 'Microsoft-Windows-Security-Auditing',
            'eventmessage': 'Failed logon',
        }],
    }


def test_insert_conflict_keeps_the_checkin(db, monkeypatch):
    """A REAL IntegrityError on the insert flush leaves the check-in intact.

    The first (bulk) insert adds a genuine duplicate row, so the flush raises on
    the unique index exactly as a concurrent check-in would make it. The
    reconcile then re-reads and re-inserts, and state plus events still commit.
    """
    assetid = _computer(db, 'APPRACE01')
    plugin = EndpointsPlugin()

    real_insert = EndpointsPlugin._insert_applications
    calls = []

    def conflicting_insert(assetid_arg, incoming, fingerprints):
        rows = real_insert(assetid_arg, incoming, fingerprints)
        calls.append(list(fingerprints))
        if len(calls) == 1:
            # The conflicting row a second writer would have committed.
            first = rows[0]
            db.session.add(EndpointApplication(
                assetid=first.assetid,
                displayname=first.displayname,
                displayversion=first.displayversion,
                publisher=first.publisher,
                appfingerprint=first.appfingerprint,
            ))
        return rows

    monkeypatch.setattr(EndpointsPlugin, '_insert_applications',
                        staticmethod(conflicting_insert))

    applications = [
        {'displayname': 'Alpha', 'displayversion': '1.0', 'publisher': 'ACME',
         'fingerprint': _fingerprint('Alpha', '1.0', 'ACME')},
        {'displayname': 'Beta', 'displayversion': '2.0', 'publisher': 'ACME',
         'fingerprint': _fingerprint('Beta', '2.0', 'ACME')},
    ]

    result = plugin.apply_collector_payload(_payload('APPRACE01', applications))
    db.session.commit()

    # The collision was detected and reported rather than raised.
    assert len(calls) > 1, 'the bulk insert should have collided and reconciled'
    assert any('application insert conflict' in w for w in result['warnings'])

    # The telemetry the check-in carried is still there.
    state = EndpointState.query.filter_by(assetid=assetid).first()
    assert state is not None
    assert state.pendingreboot is True
    assert state.lastreportedat is not None
    assert EndpointEvent.query.filter_by(assetid=assetid).count() == 1

    # And the inventory reconciled rather than being abandoned.
    stored = {row.appfingerprint for row
              in EndpointApplication.query.filter_by(assetid=assetid).all()}
    assert stored == {app['fingerprint'] for app in applications}


def test_reconcile_skips_fingerprints_that_now_exist(db):
    """Reconcile inserts only what is missing and counts the rest as skipped."""
    assetid = _computer(db, 'APPRACE02')
    plugin = EndpointsPlugin()

    taken = _fingerprint('Alpha', '1.0', 'ACME')
    missing = _fingerprint('Beta', '2.0', 'ACME')
    db.session.add(EndpointApplication(
        assetid=assetid, displayname='Alpha', displayversion='1.0',
        publisher='ACME', appfingerprint=taken))
    db.session.commit()

    incoming = {
        taken: {'displayname': 'Alpha', 'displayversion': '1.0',
                'publisher': 'ACME'},
        missing: {'displayname': 'Beta', 'displayversion': '2.0',
                  'publisher': 'ACME'},
    }
    warnings = []
    stored = plugin._reconcile_applications(assetid, incoming,
                                            [taken, missing], warnings)
    db.session.commit()

    assert stored == 1
    assert warnings == ['application insert conflict: stored 1, skipped 1 '
                        'of 2 new (concurrent update?)']
    rows = EndpointApplication.query.filter_by(assetid=assetid).all()
    assert len(rows) == 2
    assert {r.appfingerprint for r in rows} == {taken, missing}


def test_the_unique_index_is_really_there(db):
    """The whole fix rests on the constraint raising. Prove it does."""
    assetid = _computer(db, 'APPRACE03')
    fingerprint = _fingerprint('Alpha', '1.0', 'ACME')
    for _ in range(2):
        db.session.add(EndpointApplication(
            assetid=assetid, displayname='Alpha', displayversion='1.0',
            publisher='ACME', appfingerprint=fingerprint))
    raised = False
    try:
        db.session.flush()
    except IntegrityError:
        raised = True
        db.session.rollback()
    assert raised, 'endpointapplications has no unique (assetid, appfingerprint)'