{ lib
, stdenv
, fetchFromGitHub
, unstableGitUpdater
, runCommand
, cmake
, rocm-cmake
, hip
, openmp
, clang-tools-extra
, gtest
, buildTests ? false
, buildExamples ? false
, gpuTargets ? [ ] # gpuTargets = [ "gfx803" "gfx900" "gfx1030" ... ]
}:

let
  # This is now over 3GB, to allow hydra caching we separate it
  ck = stdenv.mkDerivation (finalAttrs: {
    pname = "composable_kernel";
    version = "unstable-2023-01-16";

    outputs = [
      "out"
    ] ++ lib.optionals buildTests [
      "test"
    ] ++ lib.optionals buildExamples [
      "example"
    ];

    # ROCm 5.6 should release composable_kernel as stable with a tag in the future
    src = fetchFromGitHub {
      owner = "ROCmSoftwarePlatform";
      repo = "composable_kernel";
      rev = "80e05267417f948e4f7e63c0fe807106d9a0c0ef";
      hash = "sha256-+c0E2UtlG/abweLwCWWjNHDO5ZvSIVKwwwettT9mqR4=";
    };

    nativeBuildInputs = [
      cmake
      rocm-cmake
      hip
      clang-tools-extra
    ];

    buildInputs = [
      openmp
    ];

    cmakeFlags = [
      "-DCMAKE_C_COMPILER=hipcc"
      "-DCMAKE_CXX_COMPILER=hipcc"
    ] ++ lib.optionals (gpuTargets != [ ]) [
      "-DGPU_TARGETS=${lib.concatStringsSep ";" gpuTargets}"
      "-DAMDGPU_TARGETS=${lib.concatStringsSep ";" gpuTargets}"
    ] ++ lib.optionals buildTests [
      "-DGOOGLETEST_DIR=${gtest.src}" # Custom linker names
    ];

    # No flags to build selectively it seems...
    postPatch = lib.optionalString (!buildTests) ''
      substituteInPlace CMakeLists.txt \
        --replace "add_subdirectory(test)" ""
    '' + lib.optionalString (!buildExamples) ''
      substituteInPlace CMakeLists.txt \
        --replace "add_subdirectory(example)" ""
    '';

    postInstall = lib.optionalString buildTests ''
      mkdir -p $test/bin
      mv $out/bin/test_* $test/bin
    '' + lib.optionalString buildExamples ''
      mkdir -p $example/bin
      mv $out/bin/example_* $example/bin
    '';

    passthru.updateScript = unstableGitUpdater { };

    meta = with lib; {
      description = "Performance portable programming model for machine learning tensor operators";
      homepage = "https://github.com/ROCmSoftwarePlatform/composable_kernel";
      license = with licenses; [ mit ];
      maintainers = teams.rocm.members;
      platforms = platforms.linux;
    };
  });

  ckProfiler = runCommand "ckProfiler" { preferLocalBuild = true; } ''
    cp -a ${ck}/bin/ckProfiler $out
  '';
in stdenv.mkDerivation {
  inherit (ck) pname version outputs src passthru meta;

  dontUnpack = true;
  dontPatch = true;
  dontConfigure = true;
  dontBuild = true;

  installPhase = ''
    runHook preInstall

    mkdir -p $out/bin
    cp -as ${ckProfiler} $out/bin/ckProfiler
    cp -an ${ck}/* $out
  '' + lib.optionalString buildTests ''
    cp -a ${ck.test} $test
  '' + lib.optionalString buildExamples ''
    cp -a ${ck.example} $example
  '' + ''
    runHook postInstall
  '';

  # Fix paths
  preFixup = ''
    substituteInPlace $out/lib/cmake/composable_kernel/*.cmake \
      --replace "${ck}" "$out"
  '';
}