"""Tests for the two reservation-deletion guard mechanisms.

1. _AirbnbClient._had_bookings — stale-replica cache detection
2. fetch_reservations per-service guard — skip deletions when a service errors
   or silently returns 0 reservations while the store has upcoming ones.
"""
from datetime import date, timedelta

import pytest

from room_cal.reservations import Reservation
from room_cal.actions.fetch_reservations import fetch_reservations


# ── Helpers ───────────────────────────────────────────────────────────────────

def _airbnb_client():
  from room_cal.service_api._airbnb import _AirbnbClient
  return _AirbnbClient(cookies='test', listing_id='12345678')


def _days(booked=False):
  day = {'day': '2026-07-10', 'priceData': {'price': 100}, 'available': True}
  if booked:
    day['reservationData'] = {'confirmationCode': 'TEST123'}
  return [day]


class _BaseAPI:
  """Minimal stub: only get_reservations is called by fetch_reservations."""
  async def get_reservations(self, start, end, *, _out_errors=None):
    return []


class _ErrorAPI(_BaseAPI):
  """Simulates a service throwing an exception (e.g. Booking.com 502)."""
  def __init__(self, error_service: str):
    self._svc = error_service

  async def get_reservations(self, start, end, *, _out_errors=None):
    if _out_errors is not None:
      _out_errors.add(self._svc)
    return []


# Window used by the integration tests — far enough out to not collide with
# real reservations but still within any plausible sync window.
_CHECKIN  = date.today() + timedelta(days=45)
_CHECKOUT = _CHECKIN + timedelta(days=2)


async def _seed(service: str, rid: str) -> None:
  await Reservation().set({
    'checkin_date':   _CHECKIN,
    'checkout_date':  _CHECKOUT,
    'guest_name':     'Test Guest',
    'service':        service,
    'reservation_id': rid,
    'service_data':   {},
  })


async def _exists(rid: str) -> bool:
  return await Reservation()._find(rid, _CHECKIN, _CHECKOUT) is not None


async def _delete(rid: str) -> None:
  event = await Reservation()._find(rid, _CHECKIN, _CHECKOUT)
  if event:
    await Reservation().delete(event)


# ── _had_bookings unit tests ───────────────────────────────────────────────────

class TestHadBookings:
  """Unit tests for _AirbnbClient._had_bookings stale-cache detection.

  _fetch_month_days is replaced on the instance so no network calls are made.
  """

  async def test_first_fetch_with_bookings_marks_month(self):
    client = _airbnb_client()
    async def _fetch(m, y): return _days(booked=True)
    client._fetch_month_days = _fetch

    await client._get_month_days(7, 2026)
    assert (7, 2026) in client._had_bookings

  async def test_first_fetch_without_bookings_does_not_mark(self):
    client = _airbnb_client()
    async def _fetch(m, y): return _days(booked=False)
    client._fetch_month_days = _fetch

    await client._get_month_days(7, 2026)
    assert (7, 2026) not in client._had_bookings

  async def test_stale_cache_forces_refetch(self):
    """Cache shows 0 booked but _had_bookings marks month → refetch triggered."""
    client = _airbnb_client()
    key = (7, 2026)
    client._had_bookings.add(key)
    client._raw_months[key] = _days(booked=False)  # stale: no bookings

    calls = []
    async def _fetch(m, y):
      calls.append((m, y))
      return _days(booked=True)
    client._fetch_month_days = _fetch

    result = await client._get_month_days(7, 2026)
    assert calls == [(7, 2026)], "expected exactly one refetch"
    assert any(d.get('reservationData') for d in result)

  async def test_no_refetch_without_prior_bookings(self):
    """Cache has 0 booked and _had_bookings has no entry → served from cache."""
    client = _airbnb_client()
    key = (7, 2026)
    client._raw_months[key] = _days(booked=False)

    calls = []
    async def _fetch(m, y):
      calls.append((m, y))
      return _days(booked=True)
    client._fetch_month_days = _fetch

    await client._get_month_days(7, 2026)
    assert calls == [], "cache hit should not trigger refetch"

  async def test_forced_refetch_confirms_empty_removes_mark(self):
    """Forced refetch still shows 0 booked → month removed from _had_bookings."""
    client = _airbnb_client()
    key = (7, 2026)
    client._had_bookings.add(key)
    client._raw_months[key] = _days(booked=False)

    async def _fetch(m, y): return _days(booked=False)  # still 0 on refetch
    client._fetch_month_days = _fetch

    await client._get_month_days(7, 2026)
    assert key not in client._had_bookings, "confirmed empty — guard should be lifted"

  async def test_refetch_invalidates_fetched_months_and_cache(self):
    """Forcing a refetch must also clear _fetched_months and _cache for that month."""
    from room_cal.service_api.types import DayInfo
    _dummy = DayInfo(date='2026-07-10', price=100, available=True, booked=False, rooms_to_sell=None)

    client = _airbnb_client()
    key = (7, 2026)
    client._had_bookings.add(key)
    client._raw_months[key] = _days(booked=False)
    client._fetched_months.add(key)
    client._cache['2026-07-10'] = _dummy
    client._cache['2026-08-01'] = _dummy  # different month — must survive

    async def _fetch(m, y): return _days(booked=True)
    client._fetch_month_days = _fetch

    await client._get_month_days(7, 2026)
    assert key not in client._fetched_months
    assert '2026-07-10' not in client._cache
    assert '2026-08-01' in client._cache, "different month must not be evicted"

  async def test_had_bookings_survives_clear_cache(self):
    """_had_bookings must not be cleared by clear_cache() — that's the whole point."""
    client = _airbnb_client()
    client._had_bookings.add((7, 2026))
    client.clear_cache()
    assert (7, 2026) in client._had_bookings


# ── fetch_reservations per-service guard integration tests ────────────────────

class TestFetchReservationsGuard:
  """Integration tests: real Reservation store, stub API."""

  async def test_errored_service_skips_deletion(self):
    """When a service throws (e.g. 502), its stored reservations are preserved."""
    rid = 'TEST-GUARD-ERROR-001'
    await _seed('airbnb', rid)
    try:
      await fetch_reservations(_CHECKIN, _CHECKOUT, api=_ErrorAPI('airbnb'))
      assert await _exists(rid), "reservation must survive when its service errored"
    finally:
      await _delete(rid)

  async def test_silent_zero_return_skips_deletion(self):
    """When a service returns [] with stored upcoming reservations, those are preserved."""
    rid = 'TEST-GUARD-ZERO-001'
    await _seed('airbnb', rid)
    try:
      await fetch_reservations(_CHECKIN, _CHECKOUT, api=_BaseAPI())
      assert await _exists(rid), "reservation must survive when service silently returned 0"
    finally:
      await _delete(rid)

  async def test_no_guard_when_store_is_empty(self):
    """Guard does not fire when there are no stored reservations to protect."""
    # Nothing seeded — fetch with empty API should succeed without error.
    result = await fetch_reservations(_CHECKIN, _CHECKOUT, api=_BaseAPI())
    assert result.data == []