"""Tests for flow.core.platform."""

import platform as _platform

import pytest

from flow.core.platform import PlatformInfo, detect_container_runtime, detect_platform


def test_detect_platform_returns_platforminfo():
    info = detect_platform()
    assert isinstance(info, PlatformInfo)
    assert info.os in ("linux", "macos")
    assert info.arch in ("amd64", "arm64")
    assert info.platform == f"{info.os}-{info.arch}"


def test_detect_platform_unsupported_os(monkeypatch):
    monkeypatch.setattr(_platform, "system", lambda: "FreeBSD")
    with pytest.raises(RuntimeError, match="Unsupported operating system"):
        detect_platform()


def test_detect_platform_unsupported_arch(monkeypatch):
    monkeypatch.setattr(_platform, "machine", lambda: "mips")
    with pytest.raises(RuntimeError, match="Unsupported architecture"):
        detect_platform()


def test_detect_container_runtime_returns_string_or_none():
    result = detect_container_runtime()
    assert result is None or result in ("docker", "podman")