{ }:

let
  sources = import nix/sources.nix { };
  pkgs = import sources.nixpkgs { };

  darwinInputs = with pkgs;
    lib.optionals stdenv.isDarwin (with pkgs.darwin.apple_sdk.frameworks; [
      AppKit
      CoreFoundation
      CoreServices
      CoreVideo
      Foundation
      Metal
      Security
    ]);

  linuxInputs = with pkgs;
    lib.optionals stdenv.isLinux [
      valgrind
      vulkan-headers
      vulkan-loader
      vulkan-tools
      vulkan-validation-layers
      xorg.libX11
      xorg.libXcursor
      xorg.libXrandr
      xorg.libXi
      xorg.libxcb
    ];

  llvmPkgs = pkgs.llvmPackages_12;

  zig = import ./nix/zig.nix { inherit pkgs; };

  inputs = with pkgs; [
    # build libraries
    rustc
    cargo
    clippy
    rustfmt
    cmake
    git
    python3
    llvmPkgs.llvm.dev
    llvmPkgs.clang
    pkg-config
    zig

    # lib deps
    llvmPkgs.libcxx
    llvmPkgs.libcxxabi
    libffi
    libunwind
    libxml2
    ncurses
    zlib
    libiconv

    # faster builds - see https://github.com/rtfeldman/roc/blob/trunk/BUILDING_FROM_SOURCE.md#use-lld-for-the-linker
    llvmPkgs.lld

    # meta-tools
    # note: niv manages its own nixpkgs so it doesn't need pkgs.callPackage. Do
    # `cachix use niv` to get cached builds!
    (import sources.niv { }).niv
  ];
in pkgs.mkShell {
  buildInputs = inputs ++ darwinInputs ++ linuxInputs;

  # Additional Env vars
  LLVM_SYS_120_PREFIX = "${llvmPkgs.llvm.dev}";
  LD_LIBRARY_PATH = with pkgs;
    lib.makeLibraryPath ([
      pkg-config
      stdenv.cc.cc.lib
      llvmPkgs.libcxx
      llvmPkgs.libcxxabi
      libunwind
      libffi
      ncurses
      zlib
    ] ++ linuxInputs);
}