"""Unit tests for RoomCalApiBackend."""
from contextlib import asynccontextmanager
from datetime import date, time, timedelta
from unittest.mock import AsyncMock, MagicMock, patch

import pytest
from homeassistant.core import HomeAssistant

from custom_components.room_cal_ha.backends import BackendAuthError, BackendConnectError
from custom_components.room_cal_ha.backends.api import RoomCalApiBackend, _parse_reservation
from custom_components.room_cal_ha.const import CONF_API_BASE_URL, CONF_API_TOKEN, CONF_SYNC_MODE, SYNC_MODE_API
from custom_components.room_cal_ha.models import ReservationData


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

def _make_entry(base_url="https://api.example.com", token="test-token"):
  entry = MagicMock()
  entry.options = {CONF_API_BASE_URL: base_url, CONF_SYNC_MODE: SYNC_MODE_API}
  entry.data = {CONF_API_TOKEN: token}
  return entry


def _mock_session(status: int, json_data=None):
  """Return a mock aiohttp session that yields one response."""
  resp = MagicMock()
  resp.status = status
  resp.json = AsyncMock(return_value=json_data)
  if status >= 400 and status not in (401, 403):
    resp.raise_for_status.side_effect = Exception(f"HTTP {status}")

  @asynccontextmanager
  async def _get(*args, **kwargs):
    yield resp

  session = MagicMock()
  session.get = _get
  return session


def _mock_session_raises(exc):
  """Return a session whose .get() call raises immediately."""
  session = MagicMock()
  session.get = MagicMock(side_effect=exc)
  return session


def _reservation_slot(guest, checkin, checkout, checkin_time="14:00", checkout_time="11:00"):
  return {
    "guest_name": guest,
    "checkin_date": str(checkin),
    "checkin_time": checkin_time,
    "checkout_date": str(checkout),
    "checkout_time": checkout_time,
    "wifi_ssid": "GuestNet",
    "wifi_key": "wifikey",
    "door_code": "1234",
  }


# ---------------------------------------------------------------------------
# _parse_reservation
# ---------------------------------------------------------------------------

def test_parse_reservation_maps_fields():
  raw = {
    "guest_name": "Alice",
    "checkin_date": "2026-07-01",
    "checkin_time": "14:00",
    "checkout_date": "2026-07-05",
    "checkout_time": "11:00",
    "wifi_ssid": "GuestNet",
    "wifi_key": "secret",
    "door_code": "4567",
  }
  res = _parse_reservation(raw)
  assert isinstance(res, ReservationData)
  assert res.guest_name == "Alice"
  assert res.check_in_date == date(2026, 7, 1)
  assert res.check_in_time == time(14, 0)
  assert res.check_out_date == date(2026, 7, 5)
  assert res.check_out_time == time(11, 0)
  assert res.wifi_ssid == "GuestNet"
  assert res.wifi_key == "secret"
  assert res.door_code == "4567"


def test_parse_reservation_none_returns_none():
  assert _parse_reservation(None) is None


def test_parse_reservation_missing_dates_gives_none_fields():
  res = _parse_reservation({"guest_name": "Bob"})
  assert res.guest_name == "Bob"
  assert res.check_in_date is None
  assert res.check_in_time is None
  assert res.check_out_date is None
  assert res.check_out_time is None


# ---------------------------------------------------------------------------
# async_fetch — reservation classification
# ---------------------------------------------------------------------------

async def test_fetch_current_today_no_next(hass: HomeAssistant):
  # checkin yesterday at 14:00, checkout tomorrow at 11:00 — window always active
  today = date.today()
  yesterday = today - timedelta(days=1)
  tomorrow = today + timedelta(days=1)
  response = {str(today): _reservation_slot("Alice", yesterday, tomorrow)}

  session = _mock_session(200, response)
  entry = _make_entry()
  backend = RoomCalApiBackend(hass, entry)

  with patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session):
    current, nxt = await backend.async_fetch()

  assert current is not None
  assert current.guest_name == "Alice"
  assert nxt is None


async def test_fetch_no_current_next_upcoming(hass: HomeAssistant):
  today = date.today()
  future = today + timedelta(days=5)
  future_end = today + timedelta(days=8)
  response = {
    str(today): None,
    str(future): _reservation_slot("Bob", future, future_end),
  }

  session = _mock_session(200, response)
  backend = RoomCalApiBackend(hass, _make_entry())

  with patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session):
    current, nxt = await backend.async_fetch()

  assert current is None
  assert nxt is not None
  assert nxt.guest_name == "Bob"


async def test_fetch_both_current_and_next(hass: HomeAssistant):
  # Alice: window always active (checked in yesterday, out tomorrow)
  # Bob: future (5 days from now)
  today = date.today()
  yesterday = today - timedelta(days=1)
  tomorrow = today + timedelta(days=1)
  future = today + timedelta(days=5)
  future_end = today + timedelta(days=8)
  response = {
    str(today): _reservation_slot("Alice", yesterday, tomorrow),
    str(future): _reservation_slot("Bob", future, future_end),
  }

  session = _mock_session(200, response)
  backend = RoomCalApiBackend(hass, _make_entry())

  with patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session):
    current, nxt = await backend.async_fetch()

  assert current.guest_name == "Alice"
  assert nxt.guest_name == "Bob"


async def test_fetch_multiday_current_not_duplicated_as_next(hass: HomeAssistant):
  """A multi-day stay appearing on multiple date keys should produce one current, not also next."""
  # checkin yesterday, checkout in 3 days — window always active regardless of test time
  today = date.today()
  yesterday = today - timedelta(days=1)
  checkout = today + timedelta(days=3)
  slot = _reservation_slot("Alice", yesterday, checkout)
  # Same reservation appears on each day it spans
  response = {
    str(today): slot,
    str(today + timedelta(days=1)): slot,
    str(today + timedelta(days=2)): slot,
  }

  session = _mock_session(200, response)
  backend = RoomCalApiBackend(hass, _make_entry())

  with patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session):
    current, nxt = await backend.async_fetch()

  assert current.guest_name == "Alice"
  assert nxt is None


async def test_fetch_current_not_promoted_before_checkin_time(hass: HomeAssistant):
  """Next guest's slot should not become current just because their check-in DATE is today."""
  # Guest A: checked in 2 days ago, checks out today at 23:59 — window active
  # Guest B: checks in today at 14:00 — should be next, not current
  # This covers the midnight-transition bug where a date-key lookup would wrongly
  # promote Guest B to current at midnight of their check-in date.
  from datetime import datetime as _dt, time as _time
  today = date.today()
  two_days_ago = today - timedelta(days=2)
  tomorrow = today + timedelta(days=1)
  response = {
    str(today): _reservation_slot("Alice", two_days_ago, today, checkout_time="23:59"),
    str(tomorrow): _reservation_slot("Bob", today, tomorrow, checkin_time="14:00"),
  }

  # Pin now to 09:00 — before Alice's checkout AND before Bob's check-in
  fake_now = _dt.combine(today, _time(9, 0))
  session = _mock_session(200, response)
  backend = RoomCalApiBackend(hass, _make_entry())

  with (
    patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session),
    patch("custom_components.room_cal_ha.backends.api.datetime") as mock_dt,
  ):
    mock_dt.now.return_value = fake_now
    mock_dt.combine = _dt.combine
    current, nxt = await backend.async_fetch()

  assert current is not None
  assert current.guest_name == "Alice"
  assert nxt is not None
  assert nxt.guest_name == "Bob"


async def test_fetch_empty_response(hass: HomeAssistant):
  session = _mock_session(200, {})
  backend = RoomCalApiBackend(hass, _make_entry())

  with patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session):
    current, nxt = await backend.async_fetch()

  assert current is None
  assert nxt is None


# ---------------------------------------------------------------------------
# async_fetch — error handling
# ---------------------------------------------------------------------------

async def test_fetch_401_raises_backend_auth_error(hass: HomeAssistant):
  session = _mock_session(401, {})
  backend = RoomCalApiBackend(hass, _make_entry())

  with (
    patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session),
    pytest.raises(BackendAuthError),
  ):
    await backend.async_fetch()


async def test_fetch_403_raises_backend_auth_error(hass: HomeAssistant):
  session = _mock_session(403, {})
  backend = RoomCalApiBackend(hass, _make_entry())

  with (
    patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session),
    pytest.raises(BackendAuthError),
  ):
    await backend.async_fetch()


async def test_fetch_network_error_raises_backend_connect_error(hass: HomeAssistant):
  session = _mock_session_raises(Exception("connection refused"))
  backend = RoomCalApiBackend(hass, _make_entry())

  with (
    patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session),
    pytest.raises(BackendConnectError),
  ):
    await backend.async_fetch()


async def test_fetch_500_raises_backend_connect_error(hass: HomeAssistant):
  session = _mock_session(500, {})
  backend = RoomCalApiBackend(hass, _make_entry())

  with (
    patch("custom_components.room_cal_ha.backends.api.async_get_clientsession", return_value=session),
    pytest.raises(BackendConnectError),
  ):
    await backend.async_fetch()