"""Tests for services/trash.py — mocks async_session (no real DB)."""
from unittest.mock import AsyncMock, MagicMock, patch

import pytest


def _make_mock_session():
    s = AsyncMock()
    s.__aenter__ = AsyncMock(return_value=s)
    s.__aexit__ = AsyncMock(return_value=False)
    s.commit = AsyncMock()
    return s


def _exists_result(found=True):
    r = MagicMock()
    r.first.return_value = (1,) if found else None
    return r


@pytest.mark.asyncio
async def test_delete_note_returns_batch_and_commits():
    session = _make_mock_session()
    # 1 execute for _exists_alive, then 2 for the note cascade (sub-tasks + self)
    session.execute = AsyncMock(side_effect=[_exists_result(True), MagicMock(), MagicMock()])
    with patch("fabledassistant.services.trash.async_session") as cls:
        cls.return_value = session
        from fabledassistant.services.trash import delete
        batch = await delete(user_id=1, entity_type="note", entity_id=5)
    assert isinstance(batch, str) and len(batch) > 0
    assert session.commit.called
    # exists-check + 2 cascade updates
    assert session.execute.await_count == 3


@pytest.mark.asyncio
async def test_delete_returns_none_when_not_found():
    session = _make_mock_session()
    session.execute = AsyncMock(return_value=_exists_result(False))
    with patch("fabledassistant.services.trash.async_session") as cls:
        cls.return_value = session
        from fabledassistant.services.trash import delete
        batch = await delete(user_id=1, entity_type="task", entity_id=999)
    assert batch is None
    assert not session.commit.called
    # only the existence check ran
    assert session.execute.await_count == 1


@pytest.mark.asyncio
async def test_delete_project_cascades_three_tables():
    session = _make_mock_session()
    # exists-check + 3 cascade updates (notes, milestones, project)
    session.execute = AsyncMock(side_effect=[
        _exists_result(True), MagicMock(), MagicMock(), MagicMock(),
    ])
    with patch("fabledassistant.services.trash.async_session") as cls:
        cls.return_value = session
        from fabledassistant.services.trash import delete
        batch = await delete(user_id=1, entity_type="project", entity_id=3)
    assert isinstance(batch, str)
    assert session.execute.await_count == 4


@pytest.mark.asyncio
async def test_delete_rulebook_cascades_topics_and_rules():
    session = _make_mock_session()
    topic_ids_result = MagicMock()
    topic_ids_result.scalars.return_value.all.return_value = [10, 11]
    # exists-check, topic-id select, then 3 updates (rules, topics, rulebook)
    session.execute = AsyncMock(side_effect=[
        _exists_result(True), topic_ids_result, MagicMock(), MagicMock(), MagicMock(),
    ])
    with patch("fabledassistant.services.trash.async_session") as cls:
        cls.return_value = session
        from fabledassistant.services.trash import delete
        batch = await delete(user_id=7, entity_type="rulebook", entity_id=2)
    assert isinstance(batch, str)
    assert session.execute.await_count == 5