{ stdenv, lib, fetchurl, makeWrapper, jre, gnugrep, coreutils, nixosTests
, writeScript, common-updater-scripts, git, gnused, nix, nixfmt }:

with lib;

let
  repo = "git@github.com:scala/scala.git";

  common = { version, sha256, tests, pname }:
    stdenv.mkDerivation rec {
      inherit version;

      name = "scala-${version}";

      src = fetchurl {
        inherit sha256;
        url = "https://www.scala-lang.org/files/archive/scala-${version}.tgz";
      };

      propagatedBuildInputs = [ jre ];
      buildInputs = [ makeWrapper ];

      installPhase = ''
        mkdir -p $out
        rm bin/*.bat
        mv * $out

        # put docs in correct subdirectory
        mkdir -p $out/share/doc
        mv $out/doc $out/share/doc/${name}
        mv $out/man $out/share/man

        for p in $(ls $out/bin/) ; do
          wrapProgram $out/bin/$p \
            --prefix PATH ":" ${coreutils}/bin \
            --prefix PATH ":" ${gnugrep}/bin \
            --prefix PATH ":" ${jre}/bin \
            --set JAVA_HOME ${jre}
        done
      '';

      passthru = {
        inherit tests;

        updateScript = writeScript "update.sh" ''
          #!${stdenv.shell}
          set -o errexit
          PATH=${
            stdenv.lib.makeBinPath [
              common-updater-scripts
              coreutils
              git
              gnused
              nix
              nixfmt
            ]
          }
          versionSelect='v${versions.major version}.${versions.minor version}.*'
          oldVersion="$(nix-instantiate --eval -E "with import ./. {}; lib.getVersion ${pname}" | tr -d '"')"
          latestTag="$(git -c 'versionsort.suffix=-' ls-remote --exit-code --refs --sort='version:refname' --tags ${repo} "$versionSelect" | tail --lines=1 | cut --delimiter='/' --fields=3 | sed 's|^v||g')"
          if [ "$oldVersion" != "$latestTag" ]; then
            nixpkgs="$(git rev-parse --show-toplevel)"
            default_nix="$nixpkgs/pkgs/development/compilers/scala/2.x.nix"
            update-source-version ${pname} "$latestTag" --version-key=version --print-changes
            nixfmt "$default_nix"
          else
            echo "${pname} is already up-to-date"
          fi
        '';
      };

      meta = {
        description = "A general purpose programming language";
        longDescription = ''
          Scala is a general purpose programming language designed to express
          common programming patterns in a concise, elegant, and type-safe way.
          It smoothly integrates features of object-oriented and functional
          languages, enabling Java and other programmers to be more productive.
          Code sizes are typically reduced by a factor of two to three when
          compared to an equivalent Java application.
        '';
        homepage = "https://www.scala-lang.org/";
        license = licenses.bsd3;
        platforms = platforms.all;
        branch = versions.majorMinor version;
        maintainers = [ maintainers.nequissimus ];
      };
    };
in {
  scala_2_10 = common {
    version = "2.10.7";
    sha256 = "koMRmRb2u3cU4HaihAzPItWIGbNVIo7RWRrm92kp8RE=";
    tests = [ nixosTests.scala.scala_2_10 ];
    pname = "scala_2_10";
  };

  scala_2_11 = common {
    version = "2.11.12";
    sha256 = "sR19M2mcpPYLw7K2hY/ZU+PeK4UiyUP0zaS2dDFhlqg=";
    tests = [ nixosTests.scala.scala_2_11 ];
    pname = "scala_2_11";
  };

  scala_2_12 = common {
    version = "2.12.12";
    sha256 = "NSDNHzye//YrrudfMuUtHl3BIL4szzQGSeRw5I9Sfis=";
    tests = [ nixosTests.scala.scala_2_12 ];
    pname = "scala_2_12";
  };

  scala_2_13 = common {
    version = "2.13.4";
    sha256 = "1alcnzmxga00nsvgy8yky91zw5b4q0xg2697vrrdgjlglpxiqwdw";
    tests = [ nixosTests.scala.scala_2_13 ];
    pname = "scala_2_13";
  };
}