"""公开 API 契约测试。

这组测试**不测算法本身**，只守两件事：
1. `__all__` 里承诺的名字，必须真的存在且可调用；
2. 子包的导出必须与顶层一致。

它现在就能通过，并且在后续实现过程中会立刻抓到"改了导出忘了改 `__all__`"这类问题。
"""

from __future__ import annotations

import importlib

import pytest

import mcm_toolkit as mcm

SUBPACKAGES = ["core", "data", "stats", "models", "solve", "decision", "viz"]


def test_version_is_string():
    assert isinstance(mcm.__version__, str)
    assert mcm.__version__.count(".") == 2


@pytest.mark.parametrize("name", SUBPACKAGES)
def test_subpackage_importable(name):
    mod = importlib.import_module(f"mcm_toolkit.{name}")
    assert hasattr(mod, "__all__"), f"mcm_toolkit.{name} 缺 __all__"
    assert hasattr(mcm, name), f"顶层未导出子包 {name}"


@pytest.mark.parametrize("name", SUBPACKAGES)
def test_subpackage_all_resolves(name):
    mod = importlib.import_module(f"mcm_toolkit.{name}")
    missing = [n for n in mod.__all__ if not hasattr(mod, n)]
    assert not missing, f"mcm_toolkit.{name}.__all__ 里有不存在的名字：{missing}"


def test_toplevel_all_resolves():
    missing = [n for n in mcm.__all__ if not hasattr(mcm, n)]
    assert not missing, f"顶层 __all__ 里有不存在的名字：{missing}"


def test_toplevel_shortcuts_are_callable():
    for name in ["monte_carlo", "bootstrap_ci", "parameter_sweep", "topsis", "compare_models"]:
        assert callable(getattr(mcm, name)), f"{name} 应当是可调用的快捷函数"


def test_no_star_import_pollution():
    """顶层不应把子包内部的函数全部摊平——只允许 __all__ 里那批。"""
    allowed = set(mcm.__all__) | {"annotations"}  # annotations 来自 __future__ 导入
    leaked = [n for n in dir(mcm) if not n.startswith("_") and n not in allowed]
    assert not leaked, f"顶层出现了 __all__ 之外的公开名字：{leaked}"


def test_result_dataclass_defaults():
    r = mcm.Result("demo")
    assert r.success is True
    assert r.params is None
    assert r.metrics is None
    assert r.message == ""


def test_random_helpers_exist():
    assert callable(mcm.set_seed)
    assert callable(mcm.get_rng)