from __future__ import annotations

from types import SimpleNamespace

import pytest

from app.core.config import Settings
from app.core.errors import AppError
from app.services.segmentation_adapter import YoloSegmentationAdapter


def _settings(*, require_cuda: bool, device: str) -> Settings:
    return Settings(
        _env_file=None,
        YOLO_REQUIRE_CUDA=require_cuda,
        YOLO_DEVICE=device,
    )


def test_segmentation_runtime_allows_cpu_only_when_cuda_is_not_required() -> None:
    adapter = YoloSegmentationAdapter(_settings(require_cuda=False, device="cpu"))

    adapter.validate_runtime()


def test_segmentation_runtime_rejects_missing_cuda(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setitem(
        __import__("sys").modules,
        "torch",
        SimpleNamespace(cuda=SimpleNamespace(is_available=lambda: False)),
    )
    adapter = YoloSegmentationAdapter(_settings(require_cuda=True, device="cuda:0"))

    with pytest.raises(AppError) as exc_info:
        adapter.validate_runtime()

    assert exc_info.value.code == "SEGMENTATION_ACCELERATOR_UNAVAILABLE"


def test_segmentation_runtime_rejects_cpu_device_when_cuda_is_required(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    monkeypatch.setitem(
        __import__("sys").modules,
        "torch",
        SimpleNamespace(cuda=SimpleNamespace(is_available=lambda: True)),
    )
    adapter = YoloSegmentationAdapter(_settings(require_cuda=True, device="cpu"))

    with pytest.raises(AppError) as exc_info:
        adapter.validate_runtime()

    assert exc_info.value.code == "SEGMENTATION_ACCELERATOR_MISCONFIGURED"


def test_segmentation_runtime_accepts_configured_cuda(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setitem(
        __import__("sys").modules,
        "torch",
        SimpleNamespace(cuda=SimpleNamespace(is_available=lambda: True)),
    )
    adapter = YoloSegmentationAdapter(_settings(require_cuda=True, device="cuda:0"))

    adapter.validate_runtime()