"""Run against an isolated PostgreSQL test DB; SQLite cannot prove row-lock semantics.
USE_SQLITE=false POSTGRES_* ... pytest tests/test_payment_concurrency.py
Never point POSTGRES_DB at a production database.
"""
from concurrent.futures import ThreadPoolExecutor
from threading import Barrier
import pytest
from django.db import connection, close_old_connections
from django.core.exceptions import ValidationError
from apps.accounts.models import User
from apps.notifications.models import NotificationJob
from apps.payments import services
from apps.payments.models import PaymentReceipt, ReceiptDecision
from tests.test_payments import case, submit

pytestmark = [pytest.mark.django_db(transaction=True),
              pytest.mark.skipif(connection.vendor != 'postgresql', reason='Requires PostgreSQL row locks')]


@pytest.mark.parametrize('actors,actions,final', [
    (('first','second'), ('APPROVE','APPROVE'), 'APPROVED'),
    (('first','first'), ('APPROVE','APPROVE'), 'PARTIAL'),
    (('first','second'), ('APPROVE','REJECT'), 'REJECTED'),
    (('first','senior'), ('APPROVE','SENIOR_APPROVE'), 'APPROVED'),
])
def test_concurrent_decisions_have_one_consistent_final_result(case, actors, actions, final):
    receipt = submit(case)
    barrier = Barrier(2)
    def decide(index):
        close_old_connections()
        try:
            actor = User.objects.get(pk=case[actors[index]].pk)
            barrier.wait(timeout=10)
            try:
                services.decide_receipt(actor, receipt.public_id, 1, actions[index], 'بررسی پرداخت')
                return 'recorded'
            except ValidationError:
                return 'already finalized'
        finally:
            connection.close()
    with ThreadPoolExecutor(max_workers=2) as pool:
        outcomes = list(pool.map(decide, range(2)))
    receipt.refresh_from_db()
    assert receipt.status == final
    assert receipt.revisions.get().cycle.status == final
    assert outcomes.count('recorded') >= 1
    votes = ReceiptDecision.objects.filter(cycle__revision__receipt=receipt)
    assert votes.count() == (1 if actors[0] == actors[1] else outcomes.count('recorded'))
    assert NotificationJob.objects.filter(event_type='PAYMENT_RECEIPT_APPROVED').count() == (1 if final == 'APPROVED' else 0)