"""Terminal ``TaskExecution`` signals fire exactly once (Part B2)."""

import pytest

from infrasynth.scheduler.models import ScheduledTask
from infrasynth.scheduler.services import TaskService
from infrasynth.scheduler.signals import task_completed, task_failed

pytestmark = pytest.mark.django_db


def _capture(signal):
    received = []
    receiver = lambda **kwargs: received.append(kwargs)  # noqa: E731
    signal.connect(receiver, weak=False)
    return received, receiver


@pytest.fixture
def plain_task():
    return ScheduledTask.objects.create(
        name="plain",
        task_path="os.getpid",
        schedule_type=ScheduledTask.ScheduleType.MANUAL,
    )


class TestTaskCompleted:
    def test_completed_fires_once(self, plain_task):
        received, receiver = _capture(task_completed)
        try:
            TaskService().run_now(plain_task.id)
        finally:
            task_completed.disconnect(receiver)
        assert len(received) == 1
        assert received[0]["task_name"] == "plain"
        assert received[0]["tenant_id"] == str(plain_task.tenant_id)
        assert received[0]["duration_ms"] is not None

    def test_completed_does_not_emit_failed(self, plain_task):
        received, receiver = _capture(task_failed)
        try:
            TaskService().run_now(plain_task.id)
        finally:
            task_failed.disconnect(receiver)
        assert received == []


class TestTaskFailed:
    def test_unimportable_fires_once(self):
        task = ScheduledTask.objects.create(
            name="broken",
            task_path="does.not.exist",
            schedule_type=ScheduledTask.ScheduleType.MANUAL,
        )
        received, receiver = _capture(task_failed)
        try:
            TaskService().run_now(task.id)
        finally:
            task_failed.disconnect(receiver)
        assert len(received) == 1
        assert received[0]["task_name"] == "broken"
        assert "Could not import" in received[0]["error"]

    def test_exception_fires_once(self):
        task = ScheduledTask.objects.create(
            name="boom",
            task_path="math.sqrt",
            schedule_type=ScheduledTask.ScheduleType.MANUAL,
            args=["not-a-number"],
        )
        received, receiver = _capture(task_failed)
        try:
            TaskService().run_now(task.id)
        finally:
            task_failed.disconnect(receiver)
        assert len(received) == 1
        assert received[0]["task_name"] == "boom"