"""Tool-using playbook loop — the read-only MVP.

Run from nexus-core/ with the Promethean venv active:  pytest -q

Hermetic: a fake manager stands in for Ollama, so no network/model is needed.
Guards the two pieces that would silently break the feature: the allowlist
filter and the tool-call loop's terminate-on-content behaviour.
"""
import asyncio

from synapse import tools
from synapse.chat import _run_tool_loop


def test_schemas_for_drops_unknown_names():
    schemas = tools.schemas_for(["search_memory", "not_a_tool"])
    names = [s["function"]["name"] for s in schemas]
    assert names == ["search_memory"]
    assert tools.schemas_for([]) == []


async def _drain(gen):
    return [s async for s in gen]


class _FakeManager:
    """Returns a tool_call on the first chat() call, plain content after."""
    def __init__(self):
        self.calls = 0

    async def chat(self, **_):
        self.calls += 1
        if self.calls == 1:
            return {
                "role": "assistant",
                "tool_calls": [
                    {"function": {"name": "search_memory", "arguments": {"query": "gpu"}}}
                ],
            }
        return {"role": "assistant", "content": "here is the answer"}


def test_tool_loop_runs_tool_then_stops(monkeypatch):
    async def fake_dispatch(name, args):
        assert name == "search_memory"
        assert args == {"query": "gpu"}
        return '[{"section": "GPU", "text": "Vega 20 4GB"}]'

    monkeypatch.setattr(tools, "dispatch", fake_dispatch)

    messages = [{"role": "user", "content": "what gpu do i have?"}]
    schemas = tools.schemas_for(["search_memory"])
    statuses = asyncio.run(_drain(
        _run_tool_loop(_FakeManager(), messages, "m", schemas, None, None)
    ))

    # one status sentinel per tool run
    assert statuses == ["__status__search_memory"]
    # messages mutated in place: user -> assistant(tool_calls) -> tool(result);
    # the final content turn is NOT appended (the streaming turn regenerates it).
    assert [m["role"] for m in messages] == ["user", "assistant", "tool"]
    assert "Vega 20" in messages[-1]["content"]


def test_tool_loop_degrades_when_model_returns_no_dict():
    class _NoToolManager:
        async def chat(self, **_):
            return None  # model can't do tools / errored

    messages = [{"role": "user", "content": "hi"}]
    before = list(messages)
    statuses = asyncio.run(_drain(_run_tool_loop(_NoToolManager(), messages, "m", [{}], None, None)))
    assert statuses == []          # no tool ran
    assert messages == before      # untouched -> falls back to a plain stream