"""Regression tests for the code_interpreter PTC allowlist and the
``EvoCodeInterpreterMiddleware`` subclass shape.

langchain-quickjs >=0.3 reserves the ``task`` sub-agent dispatch tool as the
top-level REPL global and raises ``ValueError`` if ``task`` appears in the
``ptc`` allowlist. EvoScientist must therefore keep ``task`` out of the
allowlist (``task()`` stays reachable as the REPL global, with responseSchema).
"""

from __future__ import annotations

from unittest.mock import MagicMock

import pytest
from langchain_core.messages import AIMessage, HumanMessage

from EvoScientist.middleware.code_interpreter import (
    _DEFAULT_PTC_ALLOWLIST,
    create_code_interpreter_middleware,
)


def test_task_excluded_from_ptc_allowlist():
    # Exposing `task` via ptc raises on quickjs >=0.3 — it is the REPL global.
    assert "task" not in _DEFAULT_PTC_ALLOWLIST


def test_async_dispatch_tools_remain_in_allowlist():
    # Guard against over-deletion: async fan-out is the killer PTC use case.
    for name in ("start_async_task", "check_async_task", "list_async_tasks"):
        assert name in _DEFAULT_PTC_ALLOWLIST


def test_filter_tools_for_ptc_accepts_default_allowlist():
    # End-to-end guard: the live quickjs filter must accept our allowlist even
    # when a `task` tool is present in the agent toolset.
    _ptc = pytest.importorskip("langchain_quickjs._ptc")
    from langchain_core.tools import tool

    @tool
    def task(description: str) -> str:
        """dummy sub-agent dispatch tool"""
        return "ok"

    _ptc.filter_tools_for_ptc(
        [task], _DEFAULT_PTC_ALLOWLIST, self_tool_name="code_interpreter"
    )


def test_create_code_interpreter_middleware_builds():
    assert create_code_interpreter_middleware() is not None


def test_middleware_uses_thread_mode():
    """Upstream ``mode="thread"`` (the default) preserves cross-turn REPL
    state as ``langchain-ai/deepagents#3064`` shipped it. The wire-cost
    bloat that motivated the earlier ``mode="turn"`` regression guard is
    fixed at the API serialization layer (``EvoFilteredGraph`` in
    ``EvoScientist/langgraph_dev/main_graph.py``), not by revoking the
    persistence feature.
    """
    mw = create_code_interpreter_middleware()
    assert mw._mode == "thread"


def test_after_agent_evicts_slot_on_untouched_turn():
    """Regression guard against reintroducing a conditional-snapshot gate
    that skips ``after_agent`` on untouched turns.

    Upstream ``after_agent`` in ``langchain_quickjs/middleware.py`` performs
    two things: snapshot the REPL AND evict the slot (``finally:
    self._registry.evict(thread_id)``). ``before_agent`` restores the REPL
    on any turn that follows a touched one via ``self._registry.get`` —
    which is get-or-create. So if ``after_agent`` returns early without
    evicting, one ``ThreadWorker`` + QuickJS Runtime leaks per persistent
    ``thread_id`` that ever went touched → quiet.

    Fix: don't override ``after_agent`` / ``aafter_agent`` at all — inherit
    upstream's unconditional snapshot+evict behavior. This test creates a
    slot the way ``before_agent`` would, calls ``after_agent`` with an
    untouched-state input, and asserts the slot was evicted.
    """
    mw = create_code_interpreter_middleware()
    tid = mw._fallback_thread_id

    # Simulate the slot creation that ``before_agent`` performs when it sees
    # a prior turn's snapshot payload in state.
    mw._registry.get(tid)
    assert len(mw._registry._slots) == 1

    # Untouched-turn state: no ``code_interpreter`` tool call between the
    # last ``HumanMessage`` and end. Under the earlier buggy gate this
    # returned ``{}`` without evicting — leaking the slot created above.
    untouched_state = {
        "_quickjs_snapshot_payload": b"payload-from-prior-turn",
        "messages": [
            HumanMessage(content="thanks"),
            AIMessage(content="you're welcome"),
        ],
    }
    mw.after_agent(untouched_state, runtime=None)

    assert len(mw._registry._slots) == 0, (
        "after_agent must evict the slot even on untouched turns, because "
        "before_agent already restored a REPL that owns a ThreadWorker + "
        "QuickJS Runtime. Skipping eviction leaks those resources."
    )


def test_evo_filtered_graph_strips_private_snapshot_field():
    """The ``StateSnapshot`` returned by ``EvoScientist_agent.get_state`` must
    not contain ``_quickjs_snapshot_payload`` in either ``values`` (the
    materialized channel payload) or ``metadata['writes']`` (the raw write
    records surfaced by ``get_state_history``).
    """
    from EvoScientist.langgraph_dev.main_graph import _EvoFilteredGraph, _strip_private

    snap = MagicMock()
    snap.values = {
        "messages": ["m1"],
        "_quickjs_snapshot_payload": b"x" * 100,
        "skills_metadata": [],
    }
    snap.metadata = {
        "source": "loop",
        "step": 42,
        "writes": {
            "CodeInterpreterMiddleware.after_agent": {
                "_quickjs_snapshot_payload": ("snap", b"y" * 1_400_000),
                "messages": [],
            },
            "model": {"messages": ["m1"]},
        },
        "parents": {},
    }
    _strip_private(snap)
    snap._replace.assert_called_once()
    kwargs = snap._replace.call_args.kwargs
    assert "_quickjs_snapshot_payload" not in kwargs["values"]
    assert "messages" in kwargs["values"]
    assert "skills_metadata" in kwargs["values"]
    scrubbed_writes = kwargs["metadata"]["writes"]
    assert (
        "_quickjs_snapshot_payload"
        not in scrubbed_writes["CodeInterpreterMiddleware.after_agent"]
    )
    assert "messages" in scrubbed_writes["CodeInterpreterMiddleware.after_agent"]
    assert scrubbed_writes["model"] == {"messages": ["m1"]}
    # Non-writes metadata keys are preserved.
    assert kwargs["metadata"]["source"] == "loop"
    assert kwargs["metadata"]["step"] == 42
    # Sanity: the class exists and inherits from CompiledStateGraph.
    from langgraph.graph.state import CompiledStateGraph

    assert issubclass(_EvoFilteredGraph, CompiledStateGraph)


def test_strip_private_handles_missing_metadata_writes():
    """``metadata['writes']`` can be missing or ``None`` on some snapshots
    (e.g. initial state). The filter must not crash and must still strip
    values.
    """
    from EvoScientist.langgraph_dev.main_graph import _strip_private

    snap = MagicMock()
    snap.values = {"_quickjs_snapshot_payload": b"x", "messages": []}
    snap.metadata = {"source": "input", "step": -1, "writes": None}
    snap.tasks = ()
    _strip_private(snap)
    kwargs = snap._replace.call_args.kwargs
    assert "_quickjs_snapshot_payload" not in kwargs["values"]
    # writes was None, metadata passes through unchanged.
    assert kwargs["metadata"]["writes"] is None


def test_strip_private_scrubs_task_result_snapshot_blob():
    """``tasks[*].result`` is where ``after_agent``'s return dict lands.
    When the middleware snapshots, ``result`` carries
    ``{"_quickjs_snapshot_payload": ("snap", ~1.4 MB bytes)}``. Verified
    on live history: this is the dominant per-response leak, larger than
    ``values`` and ``metadata.writes`` combined for anchor checkpoints.
    """
    from EvoScientist.langgraph_dev.main_graph import _strip_private

    class FakeTask:
        def __init__(self, id_, result):
            self.id = id_
            self.name = "CodeInterpreterMiddleware.after_agent"
            self.result = result

        def _replace(self, **kwargs):
            for k, v in kwargs.items():
                setattr(self, k, v)
            return self

    leaking_task = FakeTask(
        "t1", {"_quickjs_snapshot_payload": ("snap", b"z" * 1_400_000), "messages": []}
    )
    clean_task = FakeTask("t2", {"messages": ["hi"]})
    snap = MagicMock()
    snap.values = {}
    snap.metadata = {"source": "loop", "step": 5}
    snap.tasks = (leaking_task, clean_task)
    _strip_private(snap)
    kwargs = snap._replace.call_args.kwargs
    tasks_after = kwargs["tasks"]
    assert "_quickjs_snapshot_payload" not in tasks_after[0].result
    assert "messages" in tasks_after[0].result
    # Clean task is passed through untouched.
    assert tasks_after[1] is clean_task


def test_agent_uses_filtered_graph_class():
    """The ``__class__`` swap in ``main_graph.py`` is the load-bearing wiring
    that makes ``_strip_private`` reach the langgraph-api endpoints.
    ``_strip_private`` and ``_EvoFilteredGraph`` in isolation don't prove the
    swap ran; every other test in this file passes even if someone drops the
    swap line. This asserts the compiled agent is actually the filtered
    subclass at module-load time, and that the subclass survives
    ``Pregel.copy(update=...)`` — the call langgraph-api makes in
    ``get_graph`` before yielding the graph to endpoint handlers.
    """
    from EvoScientist.langgraph_dev.main_graph import (
        EvoScientist_agent,
        _EvoFilteredGraph,
    )

    assert isinstance(EvoScientist_agent, _EvoFilteredGraph)
    assert isinstance(EvoScientist_agent.copy(update={}), _EvoFilteredGraph)


def test_all_registered_graphs_use_filtered_graph_class():
    """Every graph registered in ``langgraph.json`` (main + all subagents)
    gets the ``__class__`` swap via ``_apply_filter_to_all_registered_graphs``.
    Iterating the config directly matches the auto-detect refactor: adding
    a new subagent to ``langgraph.json`` should not require a corresponding
    test update.

    Subagents get ``create_code_interpreter_middleware`` unconditionally
    (``EvoScientist.py:_build_middleware_stack``), so they can touch the
    QuickJS REPL and write ``_quickjs_snapshot_payload`` on their own
    checkpoint namespace. Async subagents also get their own ``thread_id``
    and their ``/threads/{id}/state`` endpoint runs on their own compiled
    graph — without the swap on those graphs, our filter would miss that
    endpoint entirely.
    """
    import json
    from importlib import import_module
    from pathlib import Path

    # Import triggers ``main_graph``'s swap loop.
    from EvoScientist.langgraph_dev import main_graph
    from EvoScientist.langgraph_dev.main_graph import _EvoFilteredGraph

    config_path = Path(main_graph.__file__).parent / "langgraph.json"
    config = json.loads(config_path.read_text())
    for name, path in config["graphs"].items():
        module_path, attr = path.rsplit(":", 1)
        graph = getattr(import_module(module_path), attr)
        assert isinstance(graph, _EvoFilteredGraph), (
            f"graph {name!r} ({path}) did not receive the class swap"
        )


def test_strip_private_recurses_into_nested_subgraph_state():
    """When ``subgraphs=True``, ``PregelTask.state`` holds a nested
    ``StateSnapshot`` for the subgraph. Its ``values`` (and its own nested
    tasks) can carry ``_quickjs_snapshot_payload`` just like the parent.
    Recursion covers the compound leak path CodeRabbit flagged.
    """
    from langgraph.types import StateSnapshot

    from EvoScientist.langgraph_dev.main_graph import _strip_private

    nested_snap = StateSnapshot(
        values={"_quickjs_snapshot_payload": b"n" * 1_400_000, "messages": []},
        next=(),
        config={},
        metadata={"source": "loop", "step": 3},
        created_at="2026-07-01T12:00:00Z",
        parent_config=None,
        tasks=(),
        interrupts=(),
    )

    class FakeTask:
        def __init__(self, state):
            self.id = "sub-1"
            self.name = "subgraph"
            self.result = None
            self.state = state

        def _replace(self, **kwargs):
            for k, v in kwargs.items():
                setattr(self, k, v)
            return self

    task_with_nested = FakeTask(nested_snap)
    task_with_config_state = FakeTask({"configurable": {"thread_id": "t"}})
    snap = MagicMock()
    snap.values = {}
    snap.metadata = {"source": "loop", "step": 5}
    snap.tasks = (task_with_nested, task_with_config_state)
    _strip_private(snap)
    kwargs = snap._replace.call_args.kwargs
    tasks_after = kwargs["tasks"]
    # Nested StateSnapshot got recursively scrubbed.
    assert "_quickjs_snapshot_payload" not in tasks_after[0].state.values
    assert "messages" in tasks_after[0].state.values
    # A dict (RunnableConfig-shaped) state passes through unchanged — we only
    # recurse into ``StateSnapshot`` instances.
    assert tasks_after[1].state == {"configurable": {"thread_id": "t"}}


def test_strip_private_scrubs_delta_counters():
    """``metadata['counters_since_delta_snapshot']`` is a small
    ``{channel: [count, superstep]}`` bookkeeping map. Not a size problem,
    but leaks the channel name — strip for consistency with the private
    annotation.
    """
    from EvoScientist.langgraph_dev.main_graph import _strip_private

    snap = MagicMock()
    snap.values = {}
    snap.metadata = {
        "source": "loop",
        "step": 5,
        "counters_since_delta_snapshot": {
            "_quickjs_snapshot_payload": [1, 14],
            "messages": [3, 14],
        },
    }
    snap.tasks = ()
    _strip_private(snap)
    kwargs = snap._replace.call_args.kwargs
    counters = kwargs["metadata"]["counters_since_delta_snapshot"]
    assert "_quickjs_snapshot_payload" not in counters
    assert "messages" in counters