"""Tests for session-scoped-by-default model switching.

Covers:
- ``resolve_persist_behavior`` applies the config-gated default and the
  ``--session`` / ``--global`` overrides.
- The default (no flags) is session-only, which is the user-facing fix: a
  plain ``/model <name>`` affects only the current session unless the user
  passes ``--global`` or sets ``model.persist_switch_by_default: true``.
"""

from unittest.mock import patch

from hermes_cli.model_switch import resolve_persist_behavior


# ---------------------------------------------------------------------------
# resolve_persist_behavior
# ---------------------------------------------------------------------------


class TestResolvePersistBehavior:
    def test_session_flag_always_session_only(self):
        # --session opts out even if the config default is True.
        with _config({"model": {"persist_switch_by_default": True}}):
            assert resolve_persist_behavior(False, True) is False


    def test_no_provider_uses_config_default(self):
        # No --provider → respects config default (True).
        with _config({"model": {"persist_switch_by_default": True}}):
            assert resolve_persist_behavior(False, False, explicit_provider="") is True

    def test_first_pick_persists_then_session_only(self):
        # #90235 / #86414: the ONE policy every surface (CLI, gateway, Desktop
        # picker) defers to. With no default ever configured, the first pick
        # persists (even with --provider, which is how the Desktop picker
        # always sends it) so resolve_provider never falls through to a stray
        # env key on restart. Once a default exists, a plain pick is
        # session-only unless --global / persist_switch_by_default.
        with _config({"model": {}}):
            assert resolve_persist_behavior(False, False, explicit_provider="anthropic") is True
        with _config({"model": ""}):
            assert resolve_persist_behavior(False, False) is True
        with _config({"model": {"default": "gpt-5.6", "provider": "openai-codex"}}):
            assert resolve_persist_behavior(False, False, explicit_provider="openai-api") is False
            assert resolve_persist_behavior(False, False) is False
            assert resolve_persist_behavior(True, False, explicit_provider="openai-api") is True
        with _config({"model": "gpt-5.6"}):
            assert resolve_persist_behavior(False, False) is False


# ---------------------------------------------------------------------------
# helper
# ---------------------------------------------------------------------------


class _config:
    """Context manager that patches ``load_config`` to return a fixed dict."""

    def __init__(self, cfg: dict):
        self.cfg = cfg

    def __enter__(self):
        self._patch = patch(
            "hermes_cli.config.load_config",
            return_value=self.cfg,
        )
        # resolve_persist_behavior imports load_config lazily inside the
        # function, so patching the source module is sufficient.
        self._patch.start()
        return self

    def __exit__(self, *exc):
        self._patch.stop()