"""A skill snapshot is reusable only inside one explicitly enabled tool call."""

from collections.abc import Callable
from contextvars import ContextVar
from dataclasses import dataclass
from functools import wraps
from typing import TYPE_CHECKING

from deerflow.config.runtime_performance_config import get_runtime_performance_config

if TYPE_CHECKING:
    from deerflow.sandbox.skill_view import SkillSandboxView


@dataclass
class SkillViewScope:
    view: "SkillSandboxView | None" = None
    error: Exception | None = None


_scope: ContextVar[SkillViewScope | None] = ContextVar("sandbox_skill_view_scope", default=None)


def get_active_skill_view_scope() -> SkillViewScope | None:
    return _scope.get()


def with_skill_view_scope[**P, R](func: Callable[P, R]) -> Callable[P, R]:
    @wraps(func)
    def wrapped(*args: P.args, **kwargs: P.kwargs) -> R:
        if not get_runtime_performance_config().skill_view_reuse_enabled:
            return func(*args, **kwargs)
        token = _scope.set(SkillViewScope())
        try:
            return func(*args, **kwargs)
        finally:
            # Do not leak a previously enabled skill into the next tool call,
            # including when a tool raises or shares an executor thread.
            _scope.reset(token)

    return wrapped