from __future__ import annotations

from dataclasses import FrozenInstanceError
from typing import cast

import pytest

from mdpolish import DocumentSnapshot, Modifier, ModifierContractError, ProposedChange


def no_changes(snapshot: DocumentSnapshot) -> tuple[ProposedChange, ...]:
    return ()


def test_plain_function_and_mapping_parameters_create_immutable_modifier() -> None:
    source_parameters: dict[str, object] = {
        "enabled": True,
        "nested": {"count": 2},
        "values": ["a", "b"],
    }

    modifier = Modifier(
        modifier_id="example.rule",
        version="1.2.3",
        parameters=source_parameters,
        applicability="处理虚构测试输入；排除其他文本。",
        propose=no_changes,
    )
    source_parameters["enabled"] = False

    assert modifier.propose is no_changes
    assert modifier.parameters == (
        ("enabled", True),
        ("nested", (("count", 2),)),
        ("values", ("a", "b")),
    )
    with pytest.raises(FrozenInstanceError):
        modifier.version = "2.0.0"  # type: ignore[misc]


def test_normalized_parameters_are_sorted_and_validated() -> None:
    modifier = Modifier(
        modifier_id="example.normalized",
        version="1.0.0",
        parameters=(("z", 1), ("a", ("x", 2))),
        applicability="处理虚构测试输入。",
        propose=no_changes,
    )

    assert modifier.parameters == (("a", ("x", 2)), ("z", 1))


@pytest.mark.parametrize("modifier_id", ["", "Upper", "has space", ".leading", "trailing."])
def test_invalid_modifier_id_is_rejected(modifier_id: str) -> None:
    with pytest.raises(ModifierContractError, match="modifier_id"):
        Modifier(
            modifier_id=modifier_id,
            version="1.0.0",
            parameters=(),
            applicability="测试。",
            propose=no_changes,
        )


@pytest.mark.parametrize("version", ["", "1", "1.0", "v1.0.0", "01.0.0", "1.0.0-beta"])
def test_invalid_version_is_rejected(version: str) -> None:
    with pytest.raises(ModifierContractError, match="version"):
        Modifier(
            modifier_id="example.rule",
            version=version,
            parameters=(),
            applicability="测试。",
            propose=no_changes,
        )


@pytest.mark.parametrize(
    "parameters",
    [
        {"bad": {1}},
        {"bad": float("inf")},
        (("duplicate", 1), ("duplicate", 2)),
        (("bad", object()),),
        ("not-a-pair",),
    ],
)
def test_invalid_parameters_are_rejected(parameters: object) -> None:
    with pytest.raises(ModifierContractError):
        Modifier(
            modifier_id="example.rule",
            version="1.0.0",
            parameters=parameters,  # type: ignore[arg-type]
            applicability="测试。",
            propose=no_changes,
        )


def test_empty_applicability_and_non_callable_proposal_are_rejected() -> None:
    with pytest.raises(ModifierContractError, match="applicability"):
        Modifier(
            modifier_id="example.rule",
            version="1.0.0",
            parameters=(),
            applicability=" ",
            propose=no_changes,
        )
    with pytest.raises(ModifierContractError, match="callable"):
        Modifier(
            modifier_id="example.rule",
            version="1.0.0",
            parameters=(),
            applicability="测试。",
            propose=cast(object, None),  # type: ignore[arg-type]
        )