"""Tests for the gateway loop-level transient-network-error safety net.

Issues #31066 / #31110: unhandled ``telegram.error.TimedOut`` (or peer
``NetworkError`` / ``httpx`` connection error) propagating to the
asyncio event loop killed the gateway process, taking down every
profile attached to the same runner. The safety net installed in
:func:`gateway.run.start_gateway` catches the transient crash class
and logs+swallows it; non-transient errors still surface.

These tests pin the classifier and the loop handler so the safety net
can't silently regress to swallowing every exception.
"""

from __future__ import annotations

import asyncio

import pytest

from gateway.run import (
    _gateway_loop_exception_handler,
    _is_transient_network_error,
)

# ----- Fake exception classes that mimic the real wire types ----------
# We avoid importing telegram / httpx here so the test runs in environments
# without those packages installed (the classifier matches on class name).

class TimedOut(Exception):
    """Stand-in for ``telegram.error.TimedOut``."""

class NetworkError(Exception):
    """Stand-in for ``telegram.error.NetworkError``."""

class ConnectError(Exception):
    """Stand-in for ``httpx.ConnectError``."""

class ReadTimeout(Exception):
    """Stand-in for ``httpx.ReadTimeout``."""

class PoolTimeout(Exception):
    """Stand-in for ``httpx.PoolTimeout``."""

class ClientConnectorError(Exception):
    """Stand-in for ``aiohttp.ClientConnectorError``."""

class SomeUnrelatedBug(Exception):
    """A non-transient error that should NOT be swallowed."""

# ---------------------------------------------------------------------
# Classifier
# ---------------------------------------------------------------------

@pytest.mark.parametrize(
    "exc_cls",
    [
        TimedOut,
        NetworkError,
        ConnectError,
        ReadTimeout,
        PoolTimeout,
        ClientConnectorError,
    ],
)
def test_transient_classifier_matches_known_network_errors(exc_cls):
    """Every well-known transient network exception class is classified."""
    assert _is_transient_network_error(exc_cls("boom")) is True

# ---------------------------------------------------------------------
# Loop handler
# ---------------------------------------------------------------------

def test_handler_delegates_unknown_errors_to_default(monkeypatch):
    """A non-transient error is forwarded to ``loop.default_exception_handler``."""
    loop = asyncio.new_event_loop()
    try:
        forwarded: list[dict] = []

        def fake_default(ctx):
            forwarded.append(ctx)

        monkeypatch.setattr(loop, "default_exception_handler", fake_default)

        context = {
            "message": "Something else broke",
            "exception": SomeUnrelatedBug("real bug"),
        }
        _gateway_loop_exception_handler(loop, context)
        assert forwarded == [context]
    finally:
        loop.close()

# ---------------------------------------------------------------------
# End-to-end: task-level
# ---------------------------------------------------------------------