{ system ? builtins.currentSystem }:

with import ../../top-level/all-packages.nix {inherit system;};

rec {


  # We want coreutils without ACL support.
  coreutilsMinimal = coreutils.override (args: {
    aclSupport = false;
  });

  curlMinimal = curl.override {
    zlibSupport = false;
    sslSupport = false;
    scpSupport = false;
  };

  busyboxMinimal = busybox.override {
    useUclibc = true;
    enableStatic = true;
    enableMinimal = true;
    extraConfig = ''
      CONFIG_ASH y
      CONFIG_ASH_BUILTIN_ECHO y
      CONFIG_ASH_BUILTIN_TEST y
      CONFIG_ASH_OPTIMIZE_FOR_SIZE y
      CONFIG_MKDIR y
      CONFIG_TAR y
      CONFIG_UNXZ y
    '';
  };

  build =

    stdenv.mkDerivation {
      name = "build";

      buildInputs = [nukeReferences cpio];

      buildCommand = ''
        set -x
        mkdir -p $out/bin $out/lib $out/libexec

        # Copy what we need of Glibc.
        cp -d ${glibc}/lib/ld*.so* $out/lib
        cp -d ${glibc}/lib/libc*.so* $out/lib
        cp -d ${glibc}/lib/libc_nonshared.a $out/lib
        cp -d ${glibc}/lib/libm*.so* $out/lib
        cp -d ${glibc}/lib/libdl*.so* $out/lib
        cp -d ${glibc}/lib/librt*.so*  $out/lib
        cp -d ${glibc}/lib/libpthread*.so* $out/lib
        cp -d ${glibc}/lib/libnsl*.so* $out/lib
        cp -d ${glibc}/lib/libutil*.so* $out/lib
        cp -d ${glibc}/lib/crt?.o $out/lib

        cp -rL ${glibc}/include $out
        chmod -R u+w $out/include

        # Hopefully we won't need these.
        rm -rf $out/include/mtd $out/include/rdma $out/include/sound $out/include/video
        find $out/include -name .install -exec rm {} \;
        find $out/include -name ..install.cmd -exec rm {} \;
        mv $out/include $out/include-glibc

        # Copy coreutils, bash, etc.
        cp ${coreutilsMinimal}/bin/* $out/bin
        (cd $out/bin && rm vdir dir sha*sum pinky factor pathchk runcon shuf who whoami shred users)

        cp ${bash}/bin/bash $out/bin
        cp ${findutils}/bin/find $out/bin
        cp ${findutils}/bin/xargs $out/bin
        cp -d ${diffutils}/bin/* $out/bin
        cp -d ${gnused}/bin/* $out/bin
        cp -d ${gnugrep}/bin/grep $out/bin
        cp ${gawk}/bin/gawk $out/bin
        cp -d ${gawk}/bin/awk $out/bin
        cp ${gnutar}/bin/tar $out/bin
        cp ${gzip}/bin/gzip $out/bin
        cp ${bzip2}/bin/bzip2 $out/bin
        cp -d ${gnumake}/bin/* $out/bin
        cp -d ${patch}/bin/* $out/bin
        cp ${patchelf}/bin/* $out/bin
        cp ${curlMinimal}/bin/curl $out/bin
        cp -d ${curlMinimal}/lib/libcurl* $out/lib

        cp -d ${gnugrep.pcre}/lib/libpcre*.so* $out/lib # needed by grep

        # Copy what we need of GCC.
        cp -d ${gcc.gcc}/bin/gcc $out/bin
        cp -d ${gcc.gcc}/bin/cpp $out/bin
        cp -d ${gcc.gcc}/bin/g++ $out/bin
        cp -d ${gcc.gcc}/lib*/libgcc_s.so* $out/lib
        cp -d ${gcc.gcc}/lib*/libstdc++.so* $out/lib
        cp -rd ${gcc.gcc}/lib/gcc $out/lib
        chmod -R u+w $out/lib
        rm -f $out/lib/gcc/*/*/include*/linux
        rm -f $out/lib/gcc/*/*/include*/sound
        rm -rf $out/lib/gcc/*/*/include*/root
        rm -f $out/lib/gcc/*/*/include-fixed/asm
        rm -rf $out/lib/gcc/*/*/plugin
        #rm -f $out/lib/gcc/*/*/*.a
        cp -rd ${gcc.gcc}/libexec/* $out/libexec
        chmod -R u+w $out/libexec
        rm -rf $out/libexec/gcc/*/*/plugin
        mkdir $out/include
        cp -rd ${gcc.gcc}/include/c++ $out/include
        chmod -R u+w $out/include
        rm -rf $out/include/c++/*/ext/pb_ds
        rm -rf $out/include/c++/*/ext/parallel

        cp -d ${gmpxx}/lib/libgmp*.so* $out/lib
        cp -d ${mpfr}/lib/libmpfr*.so* $out/lib
        cp -d ${mpc}/lib/libmpc*.so* $out/lib
        cp -d ${zlib}/lib/libz.so* $out/lib
        cp -d ${libelf}/lib/libelf.so* $out/lib

        # Copy binutils.
        for i in as ld ar ranlib nm strip readelf objdump; do
          cp ${binutils}/bin/$i $out/bin
        done
        cp -d ${binutils}/lib/lib*.so* $out/lib

        chmod -R u+w $out

        # Strip executables even further.
        for i in $out/bin/* $out/libexec/gcc/*/*/*; do
            if test -x $i -a ! -L $i; then
                chmod +w $i
                strip -s $i || true
            fi
        done

        nuke-refs $out/bin/*
        nuke-refs $out/lib/*
        nuke-refs $out/libexec/gcc/*/*/*

        mkdir $out/.pack
        mv $out/* $out/.pack
        mv $out/.pack $out/pack

        mkdir $out/on-server
        tar cvfJ $out/on-server/bootstrap-tools.tar.xz -C $out/pack .
        cp ${busyboxMinimal}/bin/busybox $out/on-server
        chmod u+w $out/on-server/busybox
        nuke-refs $out/on-server/busybox
      ''; # */

      # The result should not contain any references (store paths) so
      # that we can safely copy them out of the store and to other
      # locations in the store.
      allowedReferences = [];
    };


  unpack =

    derivation {
      name = "unpack";
      inherit system;
      builder = "${build}/on-server/busybox";
      args = [ "ash" "-e" "-c" "eval \"$buildCommand\"" ];

      buildCommand = ''
        export PATH=${build}/on-server:$out/bin

        busybox mkdir $out
        < ${build}/on-server/bootstrap-tools.tar.xz busybox unxz | busybox tar x -C $out

        for i in $out/bin/* $out/libexec/gcc/*/*/*; do
            if [ -L "$i" ]; then continue; fi
            if [ -z "''${i##*/liblto*}" ]; then continue; fi
            echo patching "$i"
            LD_LIBRARY_PATH=$out/lib $out/lib/ld-linux*.so.2 \
                $out/bin/patchelf --set-interpreter $out/lib/ld-linux*.so.2 --set-rpath $out/lib --force-rpath "$i"
        done

        for i in $out/lib/libpcre*; do
            if [ -L "$i" ]; then continue; fi
            echo patching "$i"
            $out/bin/patchelf --set-rpath $out/lib --force-rpath "$i"
        done

        # Fix the libc linker script.
        for i in $out/lib/libc.so; do
            cat $i | sed "s|/nix/store/e*-[^/]*/|$out/|g" > $i.tmp
            mv $i.tmp $i
        done
      ''; # " */

      allowedReferences = ["out"];
    };


  test =

    derivation {
      name = "test";
      inherit system;
      builder = "${build}/on-server/busybox";
      args = [ "ash" "-e" "-c" "eval \"$buildCommand\"" ];

      buildCommand = ''
        export PATH=${unpack}/bin
        ls -l
        mkdir $out
        mkdir $out/bin
        sed --version
        find --version
        diff --version
        patch --version
        make --version
        awk --version
        grep --version
        gcc --version
        curl --version

        ldlinux=$(echo ${unpack}/lib/ld-linux*.so.2)

        export CPP="cpp -idirafter ${unpack}/include-glibc -B${unpack}"
        export CC="gcc -idirafter ${unpack}/include-glibc -B${unpack} -Wl,-dynamic-linker,$ldlinux -Wl,-rpath,${unpack}/lib"
        export CXX="g++ -idirafter ${unpack}/include-glibc -B${unpack} -Wl,-dynamic-linker,$ldlinux -Wl,-rpath,${unpack}/lib"

        echo '#include <stdio.h>' >> foo.c
        echo '#include <limits.h>' >> foo.c
        echo 'int main() { printf("Hello World\\n"); return 0; }' >> foo.c
        $CC -o $out/bin/foo foo.c
        $out/bin/foo

        echo '#include <iostream>' >> bar.cc
        echo 'int main() { std::cout << "Hello World\\n"; }' >> bar.cc
        $CXX -v -o $out/bin/bar bar.cc
        $out/bin/bar

        tar xvf ${hello.src}
        cd hello-*
        ./configure --prefix=$out
        make
        make install
      ''; # */
    };

}