from __future__ import annotations

import os
import sys
import types
from argparse import ArgumentParser
from collections.abc import Sequence
from pathlib import Path

import pytest

ENV_PREFIX = "SLIME_CONTRACT_"


def install_paths() -> None:
    current = Path(__file__).resolve()
    sys.path.insert(0, str(current.parent))
    sys.path.insert(0, str(current.parents[1]))
    sys.path.insert(0, str(current.parents[2]))


def install_stubs(*, with_sglang_router: bool = False, with_transformers: bool = False) -> None:
    if "ray" not in sys.modules:
        ray_mod = types.ModuleType("ray")
        ray_mod._private = types.SimpleNamespace(
            services=types.SimpleNamespace(get_node_ip_address=lambda: "127.0.0.1")
        )
        sys.modules["ray"] = ray_mod

    if with_sglang_router and "sglang_router" not in sys.modules:
        mod = types.ModuleType("sglang_router")
        mod.__version__ = "0.2.3"
        sys.modules["sglang_router"] = mod

    if with_transformers and "transformers" not in sys.modules:
        mod = types.ModuleType("transformers")
        mod.AutoTokenizer = type(
            "AutoTokenizer", (), {"from_pretrained": staticmethod(lambda *args, **kwargs: object())}
        )
        mod.AutoProcessor = type(
            "AutoProcessor",
            (),
            {"from_pretrained": staticmethod(lambda *args, **kwargs: (_ for _ in ()).throw(OSError()))},
        )
        mod.PreTrainedTokenizerBase = type("PreTrainedTokenizerBase", (), {})
        mod.ProcessorMixin = type("ProcessorMixin", (), {})
        sys.modules["transformers"] = mod


def contract_env_name(key: str) -> str:
    return f"{ENV_PREFIX}{key}"


def get_contract_path(key: str, default: str | None = None) -> str | None:
    return os.environ.get(contract_env_name(key), default)


def run_contract_test_for_file(
    file: str,
    path_args: Sequence[str] = (),
    extra_args: Sequence[tuple[str, dict]] = (),
    extra_setup=None,
) -> None:
    """Parse ``--xxx-path`` CLI arguments, store as ``SLIME_CONTRACT_XXX_PATH``
    env vars, then call pytest on *file*.

    Args:
        file:        ``__file__`` of the calling contract test module.
        path_args:   Argument names **without** the leading ``--``, e.g.
                     ``["rollout-function-path"]``.  Each is exposed as a
                     positional env var ``FOO_BAR_PATH`` automatically.
        extra_args:  Additional ``(flag, kwargs)`` pairs forwarded verbatim to
                     ``parser.add_argument``.  Useful for boolean flags like
                     ``("--group-rm", {"action": "store_true", "default": False})``.
        extra_setup: Optional callable ``fn(parsed_args)`` invoked after env
                     vars are set, for any file-specific side-effects.
    """
    parser = ArgumentParser()
    for arg in path_args:
        parser.add_argument(f"--{arg}", default=None)
    for flag, kwargs in extra_args:
        parser.add_argument(flag, **kwargs)
    parsed, remaining = parser.parse_known_args()
    for key, value in vars(parsed).items():
        if value and isinstance(value, str):
            os.environ[contract_env_name(key.upper())] = value
    if extra_setup is not None:
        extra_setup(parsed)
    raise SystemExit(pytest.main([file, *remaining]))