import pytest
from unittest.mock import AsyncMock


@pytest.fixture
def mock_col():
    return AsyncMock()


@pytest.fixture
def svc(mock_col):
    from app.services.user_memory import UserMemoryService
    instance = UserMemoryService.__new__(UserMemoryService)
    instance._collection = mock_col
    instance._ready = True
    return instance


@pytest.mark.asyncio
async def test_load_returns_document(svc, mock_col):
    mock_col.find_one.return_value = {"_id": "u1", "summary": "loves beach trips"}
    result = await svc.load("u1")
    assert result["summary"] == "loves beach trips"
    mock_col.find_one.assert_called_once_with({"_id": "u1"})


@pytest.mark.asyncio
async def test_load_returns_none_for_new_user(svc, mock_col):
    mock_col.find_one.return_value = None
    result = await svc.load("new_user")
    assert result is None


@pytest.mark.asyncio
async def test_load_returns_none_when_not_ready(svc, mock_col):
    svc._ready = False
    result = await svc.load("u1")
    assert result is None
    mock_col.find_one.assert_not_called()


@pytest.mark.asyncio
async def test_update_slots_sets_last_destination(svc, mock_col):
    await svc.update_slots("u1", entities={}, context={"destination_name": "Đà Nẵng"})
    mock_col.update_one.assert_called()
    update_doc = mock_col.update_one.call_args_list[0][0][1]
    assert update_doc["$set"]["lastDestination"] == "Đà Nẵng"


@pytest.mark.asyncio
async def test_update_slots_noop_when_not_ready(svc, mock_col):
    svc._ready = False
    await svc.update_slots("u1", entities={}, context={"destination_name": "Đà Nẵng"})
    mock_col.update_one.assert_not_called()


@pytest.mark.asyncio
async def test_update_slots_sets_budget(svc, mock_col):
    await svc.update_slots(
        "u1",
        entities={"budget": {"amount": 5000000, "currency": "VND", "level": "mid"}},
        context={},
    )
    mock_col.update_one.assert_called()
    update_doc = mock_col.update_one.call_args_list[0][0][1]
    assert update_doc["$set"]["structured.budget_range"]["amount"] == 5000000