# SlicerPyTorch: the PyTorchUtils module that other Slicer extensions use to get
# PyTorch (20 extensions in the ExtensionsIndex list "PyTorch" as a dependency:
# NNUNet, MONAIAuto3DSeg, TotalSegmentator-style AI modules, ...). Upstream
# downloads a PyTorch wheel with light-the-torch, matched to the NVIDIA driver.
#
# Here PyTorch is the python3-torch RPM, and Patch0 turns PyTorchUtils into a
# reporter for it: it never downloads PyTorch, says which backend Fedora's build
# has (CPU, or ROCm), and says plainly that NVIDIA GPUs are not used, because
# Fedora's PyTorch has no CUDA. PURE-SCRIPTED: nothing to compile.

%global commit      74f8216f4841d84b8ceca3026aa18d022be78e78
%global shortcommit %(c=%{commit}; echo ${c:0:8})
%global snapdate    20260730

%global slicer_inst   %{_prefix}/lib/slicer
%global slicer_subdir Slicer-5.12
%global qtsm          %{slicer_inst}/lib/%{slicer_subdir}/qt-scripted-modules

Name:           3dslicer-pytorch
Version:        0
Release:        0.1.%{snapdate}git%{shortcommit}%{?dist}
Summary:        PyTorch for 3D Slicer extensions, from Fedora's python3-torch

# The extension ships 3D Slicer's own License.txt, which 3dslicer.spec records as BSD-3-Clause.
License:        BSD-3-Clause
URL:            https://github.com/fepegar/SlicerPyTorch
Source0:        %{url}/archive/%{commit}/SlicerPyTorch-%{shortcommit}.tar.gz
# Use the system PyTorch; never download one:
# - torchInstalled(): upstream read importlib.metadata.files('torch'), which is None for
#   the RPM (its dist-info has no RECORD), and raised TypeError. Now an import test.
# - installTorch(): returns the system torch when it meets the version requirement,
#   otherwise raises with a "dnf install python3-torch" hint. No light-the-torch.
# - uninstallTorch(): refuses; dnf owns PyTorch.
# - getCompatibleComputationBackends(): the installed build's backend (cpu or rocm).
# - The version text names the backend and says NVIDIA GPUs are not used (no CUDA).
Patch0:         3dslicer-pytorch-fedora-torch.patch

BuildArch:      noarch

Requires:       3dslicer
Requires:       python3-torch
Requires:       python3-torchvision
Requires:       python3-packaging

%description
SlicerPyTorch provides the PyTorchUtils module, which other 3D Slicer
extensions use to get PyTorch. In this package PyTorch is Fedora's
python3-torch: the module reports that installation, never downloads PyTorch,
and states which backend it has. Fedora's PyTorch runs on the CPU, or on AMD
GPUs through ROCm; it has no CUDA support, so NVIDIA GPUs are not used.

%prep
%autosetup -n SlicerPyTorch-%{commit} -p1

%build
# Pure-scripted: nothing to compile.

%install
# Install exactly what PyTorchUtils/CMakeLists.txt lists, at the paths
# slicerMacroBuildScriptedModule uses.
_mod=PyTorchUtils; _n=0
for _f in $(sed -n '/^set(MODULE_PYTHON_\(SCRIPTS\|RESOURCES\)$/,/^  )$/p' $_mod/CMakeLists.txt \
            | grep -vE '^set\(|^  \)$' | sed -e 's/^ *//' -e "s/\${MODULE_NAME}/$_mod/g"); do
    test -f "$_mod/$_f" || { echo "ERROR: $_mod lists $_f, which is missing" >&2; exit 1; }
    install -Dpm0644 "$_mod/$_f" "%{buildroot}%{qtsm}/$_f"
    _n=$((_n + 1))
done
test "$_n" -eq 3 || { echo "ERROR: installed $_n PyTorchUtils files, expected 3" >&2; exit 1; }
! grep -q 'light_the_torch._patch' <(sed -n '/def installTorch/,/^  def uninstallTorch/p' %{buildroot}%{qtsm}/PyTorchUtils.py | sed -n '1,/^    return torch$/p') \
    || { echo "ERROR: installTorch can still reach light-the-torch" >&2; exit 1; }

%files
%license LICENSE
%doc README.md
%{qtsm}/PyTorchUtils.py
%{qtsm}/Resources/Icons/PyTorchUtils.png
%{qtsm}/Resources/UI/PyTorchUtils.ui

%changelog
* Sat Oct 10 2026 Morgan Hough <morgan.hough@gmail.com> - 0-0.1.20260730git74f8216f
- Initial package. SlicerPyTorch's PyTorchUtils on Fedora's python3-torch: no
  download path, backend and no-CUDA stated (Patch0).