"""
Test that the conftest gate catches missing required test dependencies
and fails fast with a clear error message.

This is a TDD test for the regression we just hit: sentence-transformers
was in [project.optional-dependencies] but the test suite requires it
unconditionally. A fresh `uv sync` (without --extra local-rag) produced
a confusing "rag_status = error: ... Install with manual_slop[local-rag]"
failure. The gate prevents this by failing at session start with the
exact fix command.

The check itself lives in conftest._check_required_test_dependencies()
so it can be unit-tested here without a real conftest import.
"""
import sys
import pytest


def test_check_succeeds_when_deps_present() -> None:
 """
 If sentence_transformers is importable, the gate is a no-op.
 This is the case for the test session that actually runs (sentence-
 transformers is installed via `uv sync --extra local-rag`).
 """
 from tests.conftest import _check_required_test_dependencies
 _check_required_test_dependencies()


def test_check_raises_on_missing_sentence_transformers(monkeypatch) -> None:
 """
 Simulate sentence_transformers not being installed. The gate must
 raise pytest.UsageError with a clear, actionable error message that
 tells the user exactly how to fix the issue.
 """
 # Block the import
 monkeypatch.setitem(sys.modules, "sentence_transformers", None)
 # Remove any cached successful import
 for mod_name in list(sys.modules):
  if mod_name == "sentence_transformers" or mod_name.startswith("sentence_transformers."):
   del sys.modules[mod_name]
 # Force ImportError on import
 import builtins
 original_import = builtins.__import__
 def _blocking_import(name, *args, **kwargs):
  if name == "sentence_transformers" or name.startswith("sentence_transformers."):
   raise ImportError(f"No module named {name!r} (simulated)")
  return original_import(name, *args, **kwargs)
 monkeypatch.setattr(builtins, "__import__", _blocking_import)

 # Also need to invalidate the conftest's already-cached import
 from tests import conftest
 # Clear the module so it re-imports and the gate re-runs
 # Note: the conftest's _check function does its own import so this
 # is just a sanity check that the function is callable.

 from tests.conftest import _check_required_test_dependencies
 with pytest.raises(pytest.UsageError) as exc_info:
  _check_required_test_dependencies()
 msg = str(exc_info.value)
 assert "sentence-transformers" in msg
 assert "uv sync" in msg
 assert "local-rag" in msg