From 3b56e252630ae53a44053897b64b49f4dc8fd315 Mon Sep 17 00:00:00 2001
From: Alexy Pellegrini <alexy.pellegrini@kitware.com>
Date: Mon, 25 Mar 2024 10:41:24 +0100
Subject: [PATCH] Add support for packaging VTK SDK as a wheel

This pulls a tar.xz archive from https://vtk.org/files/wheel-sdks and
package it as a wheel using scikit-build-core.

This wheel will then be added to a pip repository to be fetch through build
requirements.
---
 CMakeLists.txt                    | 65 ++++++++++++++++++++++++++++---
 cmake/vtk-config-version.cmake.in |  1 +
 cmake/vtk-config.cmake.in         |  1 +
 cmake/vtk-sdk-urls.cmake          | 13 +++++++
 pyproject.toml                    |  2 +
 src/main.cpp                      | 27 -------------
 src/vtk_sdk/_core.pyi             |  4 --
 src/vtk_sdk/cmake/__init__.py     |  1 +
 tests/test_compiled.py            | 11 ------
 9 files changed, 77 insertions(+), 48 deletions(-)
 create mode 100644 cmake/vtk-config-version.cmake.in
 create mode 100644 cmake/vtk-config.cmake.in
 create mode 100644 cmake/vtk-sdk-urls.cmake
 delete mode 100644 src/main.cpp
 delete mode 100644 src/vtk_sdk/_core.pyi
 create mode 100644 src/vtk_sdk/cmake/__init__.py
 delete mode 100644 tests/test_compiled.py

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 791b1e4..7496dc9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,8 +1,61 @@
-cmake_minimum_required(VERSION 3.15...3.26)
-project(${SKBUILD_PROJECT_NAME} LANGUAGES CXX)
+cmake_minimum_required(VERSION 3.21)
 
-set(PYBIND11_FINDPYTHON ON)
-find_package(pybind11 CONFIG REQUIRED)
+set(VTK_VERSION
+    "9.2.6"
+    CACHE STRING "VTK SDK version to package")
+project(
+  vtk-sdk
+  VERSION ${VTK_VERSION}
+  DESCRIPTION "VTK SDK python distributions"
+  HOMEPAGE_URL "https://github.com/Kitware/vtk-sdk-python-distributions"
+  LANGUAGES NONE)
 
-pybind11_add_module(_core MODULE src/main.cpp)
-install(TARGETS _core DESTINATION ${SKBUILD_PROJECT_NAME})
+find_package(
+  Python
+  COMPONENTS Interpreter Development.Module
+  REQUIRED)
+
+include(cmake/vtk-sdk-urls.cmake)
+include(FetchContent)
+
+set(download_dir ${PROJECT_BINARY_DIR})
+set(extract_dir ${PROJECT_BINARY_DIR}/vtk-wheel-sdk)
+# FetchContent will download and extract our archive!
+FetchContent_Populate(
+  vtkwheelsdk
+  URL ${VTK_SDK_BINARY_URL} DOWNLOAD_DIR ${download_dir}
+  SOURCE_DIR ${extract_dir})
+
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/vtk-config.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/vtk_sdk/cmake/vtk-config.cmake @ONLY)
+
+configure_file(
+  ${CMAKE_CURRENT_SOURCE_DIR}/cmake/vtk-config-version.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/vtk_sdk/cmake/vtk-config-version.cmake @ONLY)
+
+# "/" after ${extract_dir} is required so the folder content is copied to dest,
+# instead of the folder itself!
+install(
+  DIRECTORY ${extract_dir}/
+  DESTINATION vtk_sdk
+  PATTERN "bin/*" EXCLUDE)
+
+install(
+  DIRECTORY ${extract_dir}/bin/
+  DESTINATION vtk_sdk/bin
+  PATTERN
+    "*"
+    PERMISSIONS
+      OWNER_READ
+      OWNER_WRITE
+      OWNER_EXECUTE
+      GROUP_READ
+      GROUP_EXECUTE
+      WORLD_READ
+      WORLD_EXECUTE)
+
+install(
+  FILES ${CMAKE_CURRENT_SOURCE_DIR}/src/vtk_sdk/cmake/__init__.py
+        ${CMAKE_CURRENT_BINARY_DIR}/vtk_sdk/cmake/vtk-config.cmake
+        ${CMAKE_CURRENT_BINARY_DIR}/vtk_sdk/cmake/vtk-config-version.cmake
+  DESTINATION vtk_sdk/cmake)
diff --git a/cmake/vtk-config-version.cmake.in b/cmake/vtk-config-version.cmake.in
new file mode 100644
index 0000000..aa0b38b
--- /dev/null
+++ b/cmake/vtk-config-version.cmake.in
@@ -0,0 +1 @@
+include(${CMAKE_CURRENT_LIST_DIR}/../vtk-@VTK_VERSION@.data/headers/cmake/vtk-config-version.cmake)
diff --git a/cmake/vtk-config.cmake.in b/cmake/vtk-config.cmake.in
new file mode 100644
index 0000000..79b77d5
--- /dev/null
+++ b/cmake/vtk-config.cmake.in
@@ -0,0 +1 @@
+include(${CMAKE_CURRENT_LIST_DIR}/../vtk-@VTK_VERSION@.data/headers/cmake/vtk-config.cmake)
diff --git a/cmake/vtk-sdk-urls.cmake b/cmake/vtk-sdk-urls.cmake
new file mode 100644
index 0000000..608593a
--- /dev/null
+++ b/cmake/vtk-sdk-urls.cmake
@@ -0,0 +1,13 @@
+# VTK SDK is currently stored as a tar.xz archive on a Kitware hosted server
+set(python_cp "cp${Python_VERSION_MAJOR}${Python_VERSION_MINOR}")
+
+# enable any linux to download the right tar.xz
+if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
+  set(VTK_SDK_BINARY_URL
+      "https://vtk.org/files/wheel-sdks/vtk-wheel-sdk-${VTK_VERSION}-${python_cp}-${python_cp}-manylinux_2_17_x86_64.manylinux2014_x86_64.tar.xz"
+  )
+else()
+  set(VTK_SDK_BINARY_URL
+      "https://vtk.org/files/wheel-sdks/vtk-wheel-sdk-${VTK_VERSION}-${python_cp}-${Python_SOABI}.tar.xz"
+  )
+endif()
diff --git a/pyproject.toml b/pyproject.toml
index 0002726..0af9b33 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -56,6 +56,8 @@ Homepage = "https://github.com/Kitware/vtk-sdk-python-distributions"
 Discussions = "https://github.com/Kitware/vtk-sdk-python-distributions/discussions"
 Changelog = "https://github.com/Kitware/vtk-sdk-python-distributions/releases"
 
+[project.entry-points."cmake.prefix"]
+any = "vtk_sdk.cmake"
 
 [tool.scikit-build]
 minimum-version = "0.8.2"
diff --git a/src/main.cpp b/src/main.cpp
deleted file mode 100644
index d570cd0..0000000
--- a/src/main.cpp
+++ /dev/null
@@ -1,27 +0,0 @@
-#include <pybind11/pybind11.h>
-
-int add(int i, int j) { return i + j; }
-
-namespace py = pybind11;
-
-PYBIND11_MODULE(_core, m) {
-  m.doc() = R"pbdoc(
-      Pybind11 example plugin
-      -----------------------
-      .. currentmodule:: python_example
-      .. autosummary::
-         :toctree: _generate
-         add
-         subtract
-  )pbdoc";
-
-  m.def("add", &add, R"pbdoc(
-      Add two numbers
-      Some other explanation about the add function.
-  )pbdoc");
-
-  m.def("subtract", [](int i, int j) { return i - j; }, R"pbdoc(
-      Subtract two numbers
-      Some other explanation about the subtract function.
-  )pbdoc");
-}
diff --git a/src/vtk_sdk/_core.pyi b/src/vtk_sdk/_core.pyi
deleted file mode 100644
index 537c611..0000000
--- a/src/vtk_sdk/_core.pyi
+++ /dev/null
@@ -1,4 +0,0 @@
-from __future__ import annotations
-
-def add(_x: int, _y: int) -> int: ...
-def subtract(_x: int, _y: int) -> int: ...
diff --git a/src/vtk_sdk/cmake/__init__.py b/src/vtk_sdk/cmake/__init__.py
new file mode 100644
index 0000000..7739ada
--- /dev/null
+++ b/src/vtk_sdk/cmake/__init__.py
@@ -0,0 +1 @@
+# This module is here because the path of the actual vtk-config.cmake file is not a valid module name
diff --git a/tests/test_compiled.py b/tests/test_compiled.py
deleted file mode 100644
index d0342ca..0000000
--- a/tests/test_compiled.py
+++ /dev/null
@@ -1,11 +0,0 @@
-from __future__ import annotations
-
-import vtk_sdk._core as m
-
-
-def test_add():
-    assert m.add(2, 3) == 5
-
-
-def test_subtract():
-    assert m.subtract(7, 5) == 2