# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

from spack.package import *


class PyTorchScatter(PythonPackage):
    """This package consists of a small extension library of
    highly optimized sparse update (scatter and segment)
    operations for the use in PyTorch, which are missing in the
    main package."""

    homepage = "https://github.com/rusty1s/pytorch_scatter"
    url = "https://github.com/rusty1s/pytorch_scatter/archive/2.0.5.tar.gz"

    license("MIT")

    version("2.0.5", sha256="e29b364beaa9c84a99e0e236be89ed19d4452d89010ff736184ddcce488b47f6")

    variant("cuda", default=False, description="Enable CUDA support")

    depends_on("python@3.6:", type=("build", "run"))
    depends_on("py-setuptools", type="build")
    depends_on("py-pytest-runner", type="build")
    depends_on("py-torch+cuda", when="+cuda")
    depends_on("py-torch~cuda", when="~cuda")

    def setup_build_environment(self, env):
        if "+cuda" in self.spec:
            cuda_arches = list(self.spec["py-torch"].variants["cuda_arch"].value)
            for i, x in enumerate(cuda_arches):
                cuda_arches[i] = "{0}.{1}".format(x[0:-1], x[-1])
            env.set("TORCH_CUDA_ARCH_LIST", str.join(" ", cuda_arches))

            env.set("FORCE_CUDA", "1")
            env.set("CUDA_HOME", self.spec["cuda"].prefix)
        else:
            env.set("FORCE_CUDA", "0")