shell.nix

let
  pkgs = {
    ihaskell = builtins.fetchTarball {
      url = "https://github.com/gibiansky/IHaskell/tarball/cc427517a59bfc8e1014c7e02fe5cfe0ce7e5eef";
      sha256 = "0lpy70zagc1h3i1ihq83fm3af9ypfkwsi0b21hjiz5lkrplp9cna";
    };
    nixpkgs = builtins.fetchTarball {
      url = "https://github.com/NixOS/nixpkgs/archive/19.09.tar.gz";
      sha256 = "0mhqhq21y5vrr1f30qd2bvydv4bbbslvyzclhw0kdxmkgg3z4c92";
    };
  };

  rOverlay = rself: rsuper: {
    myR = rsuper.rWrapper.override {
      packages = with rsuper.rPackages; [ ggplot2 dplyr xts purrr cmaes cubature ];
    };
  };

  foo = self: super: {
    haskell = super.haskell // { packageOverrides =
	    hself: hsuper: {
        my-random-fu-multivariate = hself.callPackage ./pkgs/random-fu-multivariate { };
      };
    };
  };

  nixpkgs  = import pkgs.nixpkgs { overlays = [ rOverlay foo ]; };

  r-libs-site = nixpkgs.runCommand "r-libs-site" {
    buildInputs = with nixpkgs; [ R rPackages.ggplot2 rPackages.dplyr rPackages.xts rPackages.purrr rPackages.cmaes rPackages.cubature ];
  } ''echo $R_LIBS_SITE > $out'';

  ihaskellEnv = (import "${pkgs.ihaskell}/release.nix" {
    compiler = "ghc864";
    nixpkgs  = nixpkgs;
  packages = self: [
    self.inline-r
    self.cassava
    # we can re-introduce this when it gets fixed
    # self.hmatrix-sundials
    self.random-fu
    self.random-source
    self.my-random-fu-multivariate
  ];
  }).passthru.ihaskellEnv;

  systemPackages = self: [ self.myR ];

  jupyterlab = nixpkgs.python3.withPackages (ps: [ ps.jupyterlab ]);

  rtsopts = "-M3g -N2";

  ihaskellJupyterCmdSh = cmd: extraArgs: nixpkgs.writeScriptBin "ihaskell-${cmd}" ''
    #! ${nixpkgs.stdenv.shell}
    export GHC_PACKAGE_PATH="$(echo ${ihaskellEnv}/lib/*/package.conf.d| tr ' ' ':'):$GHC_PACKAGE_PATH"
    export R_LIBS_SITE=${builtins.readFile r-libs-site}
    export PATH="${nixpkgs.stdenv.lib.makeBinPath ([ ihaskellEnv jupyterlab ] ++ systemPackages nixpkgs)}''${PATH:+:}$PATH"
    ${ihaskellEnv}/bin/ihaskell install \
      -l $(${ihaskellEnv}/bin/ghc --print-libdir) \
      --use-rtsopts="${rtsopts}" \
      && ${jupyterlab}/bin/jupyter ${cmd} ${extraArgs} "$@"
  '';
in
nixpkgs.buildEnv {
  name = "ihaskell-with-packages";
  buildInputs = [ nixpkgs.makeWrapper ];
  paths = [ ihaskellEnv jupyterlab ];
  postBuild = ''
    echo "Hello"
    ln -s ${ihaskellJupyterCmdSh "lab" ""}/bin/ihaskell-lab $out/bin/
    ln -s ${ihaskellJupyterCmdSh "notebook" ""}/bin/ihaskell-notebook $out/bin/
    ln -s ${ihaskellJupyterCmdSh "nbconvert" ""}/bin/ihaskell-nbconvert $out/bin/
    ln -s ${ihaskellJupyterCmdSh "console" "--kernel=haskell"}/bin/ihaskell-console $out/bin/
    echo $out/bin
    for prg in $out/bin"/"*;do
      if [[ -f $prg && -x $prg ]]; then
        wrapProgram $prg --set PYTHONPATH "$(echo ${jupyterlab}/lib/*/site-packages)"
      fi
    done
  '';
}