from importlib.metadata import PackageNotFoundError
from pathlib import Path

import pytest

import arm_statements.version as version_module
from arm_statements.version import statements_version

FULL_HASH = "abc1234def5678abc1234def5678abc1234def56"


def test_version_absent_file_is_none(tmp_path: Path) -> None:
    assert statements_version(tmp_path / "VERSION") is None


def test_version_read_from_file(tmp_path: Path) -> None:
    marker = tmp_path / "VERSION"
    marker.write_text(f"{FULL_HASH}\n", encoding="utf-8")
    assert statements_version(marker) == FULL_HASH


def test_version_empty_file_is_none(tmp_path: Path) -> None:
    marker = tmp_path / "VERSION"
    marker.write_text("  \n", encoding="utf-8")
    assert statements_version(marker) is None


@pytest.mark.parametrize("contents", [None, "  \n"])
def test_default_marker_falls_back_to_distribution(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, contents: str | None
) -> None:
    marker = tmp_path / "VERSION"
    if contents is not None:
        marker.write_text(contents, encoding="utf-8")
    monkeypatch.setattr(version_module, "_DEFAULT_MARKER", marker)
    monkeypatch.setattr(version_module, "version", lambda name: "0.1.1" if name == "pylib-ai-arm-statements" else None)
    assert statements_version() == "0.1.1"


def test_default_marker_takes_priority(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    marker = tmp_path / "VERSION"
    marker.write_text(f"  {FULL_HASH}\n", encoding="utf-8")
    monkeypatch.setattr(version_module, "_DEFAULT_MARKER", marker)

    def unexpected_metadata_lookup(name: str) -> str:
        raise AssertionError(f"Unexpected metadata lookup: {name}")

    monkeypatch.setattr(version_module, "version", unexpected_metadata_lookup)
    assert statements_version() == FULL_HASH


def test_default_version_without_metadata_is_none(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setattr(version_module, "_DEFAULT_MARKER", tmp_path / "VERSION")

    def missing_distribution(name: str) -> str:
        raise PackageNotFoundError(name)

    monkeypatch.setattr(version_module, "version", missing_distribution)
    assert statements_version() is None


@pytest.mark.parametrize("contents", [None, "  \n"])
def test_explicit_marker_does_not_use_distribution(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, contents: str | None
) -> None:
    marker = tmp_path / "VERSION"
    if contents is not None:
        marker.write_text(contents, encoding="utf-8")

    def unexpected_metadata_lookup(name: str) -> str:
        raise AssertionError(f"Unexpected metadata lookup: {name}")

    monkeypatch.setattr(version_module, "version", unexpected_metadata_lookup)
    assert statements_version(marker) is None