alsa-lib: provide wrapper for run-time access to plugins

{ lib

, pkgs

, alsa-lib

, plugins ? [ pkgs.alsa-plugins ]

, lndir

, symlinkJoin

, runCommand

}:

let

  merged = symlinkJoin { name = "alsa-plugins-merged"; paths = plugins; };

in

runCommand "${alsa-lib.pname}-${alsa-lib.version}" {

  meta = with lib; {

    description = "wrapper to ease access to ALSA plugins";

    platforms = platforms.linux;

    maintainers = with maintainers; [ gm6k ];

  };

  outputs = alsa-lib.outputs;

} (

    (

      lib.concatMapStringsSep "\n" (

        output: ''

          mkdir ${builtins.placeholder output}

          ${lndir}/bin/lndir ${lib.attrByPath [output] null alsa-lib} \

            ${builtins.placeholder output}

        ''

      ) alsa-lib.outputs

    ) + ''

    cp -r ${merged}/lib/alsa-lib $out/lib

    (

      echo $out | wc -c

      echo ${alsa-lib} | wc -c

    ) | xargs echo | grep -q "^\(.*\) \1$" || (

      echo cannot binary patch

      exit 1

    )

    rm $out/lib/libasound.la

    rm $out/lib/libasound.so.?.?.?

    rm $dev/lib/pkgconfig/alsa.pc

    rm $dev/nix-support/propagated-build-inputs

    cp ${alsa-lib}/lib/libasound.la $out/lib

    cp ${alsa-lib}/lib/libasound.so.?.?.? $out/lib

    cp ${alsa-lib.dev}/lib/pkgconfig/alsa.pc $dev/lib/pkgconfig

    cp ${alsa-lib.dev}/nix-support/propagated-build-inputs $dev/nix-support

    sed -i \

        $out/lib/libasound.la \

        $out/lib/libasound.so.?.?.? \

        $dev/lib/pkgconfig/alsa.pc \

        $dev/nix-support/propagated-build-inputs \

      -e "s@${alsa-lib}@$out@g"

  ''

)