"""
Snapshot tests for the JSON schemas emitted for librarian tools.

Ollama's OpenAI-compatible API mishandles anyOf[X, null] parameter
schemas, so tool parameters must use empty-string/empty-list sentinels
translated to None inside the tool (same pattern as the biographer
tools, commit 9d7ce39). This test fails if a X | None parameter ever
creeps back in.
"""

import pytest
from pydantic_ai.tools import Tool

from src.agents.librarian.tools import LIBRARIAN_TOOLS


def _nullable_anyof_paths(schema: object, path: str = "") -> list[str]:
    """Recursively collect JSON-schema paths that are anyOf[..., null]."""
    offenders: list[str] = []
    if isinstance(schema, dict):
        any_of = schema.get("anyOf")
        if isinstance(any_of, list) and any(
            isinstance(sub, dict) and sub.get("type") == "null" for sub in any_of
        ):
            offenders.append(path or "<root>")
        for key, value in schema.items():
            offenders.extend(_nullable_anyof_paths(value, f"{path}/{key}"))
    elif isinstance(schema, list):
        for i, item in enumerate(schema):
            offenders.extend(_nullable_anyof_paths(item, f"{path}[{i}]"))
    return offenders


@pytest.mark.unit
class TestLibrarianToolSchemas:
    """All registered librarian tools emit Ollama-safe parameter schemas."""

    @pytest.mark.parametrize("tool_func", LIBRARIAN_TOOLS, ids=lambda f: f.__name__)
    def test_no_nullable_anyof_in_schema(self, tool_func):
        schema = Tool(tool_func).function_schema.json_schema

        offenders = _nullable_anyof_paths(schema)

        assert offenders == [], (
            f"{tool_func.__name__} emits anyOf[..., null] at {offenders}; "
            "use empty-string/empty-list sentinels instead of X | None"
        )