from types import SimpleNamespace

from app import screenshot_storage


def test_new_screenshot_is_stored_only_as_server_file(tmp_path, monkeypatch):
    monkeypatch.setattr(screenshot_storage.settings, "screenshot_storage_dir", tmp_path)

    fields = screenshot_storage.screenshot_fields(
        b"image-content", "proof.png", "image/png", "answers"
    )

    assert fields["image_data"] is None
    assert (tmp_path / fields["file_path"]).read_bytes() == b"image-content"


def test_missing_file_falls_back_to_database_copy(tmp_path, monkeypatch):
    monkeypatch.setattr(screenshot_storage.settings, "screenshot_storage_dir", tmp_path)
    image = SimpleNamespace(
        file_path="answers/missing.png",
        image_data=b"database-backup",
        content_type="image/png",
    )

    assert screenshot_storage.screenshot_bytes(image) == b"database-backup"


def test_file_write_failure_returns_clear_service_error(tmp_path, monkeypatch):
    monkeypatch.setattr(screenshot_storage.settings, "screenshot_storage_dir", tmp_path)
    monkeypatch.setattr(
        screenshot_storage,
        "store_screenshot",
        lambda *args, **kwargs: (_ for _ in ()).throw(PermissionError("read-only")),
    )

    try:
        screenshot_storage.screenshot_fields(
            b"image-content", "proof.png", "image/png", "answers"
        )
    except screenshot_storage.HTTPException as exc:
        assert exc.status_code == 503
        assert "图片存储目录不可用" in exc.detail
    else:
        raise AssertionError("expected screenshot storage error")