"""Fixtures every test gets.

All three are about not touching the machine the tests run on, or anyone
else's.

The cache: a lookup writes to ``~/.cache`` by default, and a test run that
touches the real one leaves entries behind and reads back entries an earlier
version wrote.  Redirecting it per test makes each run start from nothing.

The settings: locking a frequency out writes it into ``config.yaml``, and a
test that reached the real one would silently change what the next real scan
does.  The constant is replaced in every module that holds a copy, so that
forgetting to pass a directory somewhere cannot end in someone's own settings.

The network: a licence lookup goes to a public database and returns a real
person's name and address.  No test has any business doing that.
"""
import pytest

import bandsaunter.browse
import bandsaunter.callsign
import bandsaunter.cli
import bandsaunter.config
import bandsaunter.tui


@pytest.fixture(autouse=True)
def isolated_cache(tmp_path_factory, monkeypatch):
    monkeypatch.setenv("XDG_CACHE_HOME",
                       str(tmp_path_factory.mktemp("cache")))


@pytest.fixture(autouse=True)
def no_licence_lookups(monkeypatch):
    """No test may contact the licence database.

    One did, silently, and passed -- it was only visible because the
    assertion it failed printed a real operator's address.  A test that wants
    answers stubs this itself; anything else fails loudly rather than going
    to the network and being slow, flaky and rude about it.
    """
    def refuse(self, url, call):
        raise AssertionError(f"a test tried to look up {call} for real")

    monkeypatch.setattr(bandsaunter.callsign.CallsignBook, "_request", refuse)


class NoNetwork(BaseException):
    """Raised when a test reaches for the network.

    Deliberately not an ``Exception``: the code that fetches map tiles and
    looks aircraft up treats any ordinary failure as "no map today" and
    carries on, which would turn this guard into a silent pass.
    """


@pytest.fixture(autouse=True)
def no_aircraft_lookups(monkeypatch):
    """Nor may a test ask a register who an aircraft is."""
    import bandsaunter.flights

    def refuse(self, url):
        raise NoNetwork(f"a test tried to fetch {url} for real")

    monkeypatch.setattr(bandsaunter.flights.FlightBook, "_request", refuse)


@pytest.fixture(autouse=True)
def no_map_tiles(monkeypatch):
    """Nor fetch map tiles from somebody's tile server.

    A test that wants a map builds its own tiles and passes them in; one
    that forgets fails here rather than drawing an evening's worth of
    requests at a volunteer-funded service.
    """
    import bandsaunter.basemap

    def refuse(request, timeout=None):
        where = getattr(request, "full_url", request)
        raise NoNetwork(f"a test tried to fetch {where} for real")

    monkeypatch.setattr(bandsaunter.basemap.urllib.request, "urlopen", refuse)


@pytest.fixture(autouse=True)
def isolated_settings(tmp_path_factory, monkeypatch):
    where = tmp_path_factory.mktemp("config")
    for module in (bandsaunter.config, bandsaunter.browse, bandsaunter.cli,
                   bandsaunter.tui):
        if hasattr(module, "DEFAULT_CONFIG_DIR"):
            monkeypatch.setattr(module, "DEFAULT_CONFIG_DIR", where)
        if hasattr(module, "DEFAULT_CONFIG_PATH"):
            monkeypatch.setattr(module, "DEFAULT_CONFIG_PATH",
                                where / "config.yaml")
    monkeypatch.setenv("BANDSAUNTER_CONFIG_DIR", str(where))
    return where