release.nix

# If you would like to test and build changes quickly using `cabal`, run:
#
#     $ nix-shell
#     [nix-shell]$ cabal configure --enable-tests && cabal test
#
# This will open up a Nix shell where all of your Haskell tools will work like
# normal, except that all dependencies (including C libraries) are managed by
# Nix.  The only thing that won't work is running tests inside this shell
# (although you can still build them).  Fixing the test suite requires
# extensive patching of the test scripts (see `postPatch` below)
#
# Note that this will compile the library once without tests using Nix.  This
# is due to the fact that `grpc-haskell`'s test suite cannot test code
# generation without the library being built at least once.
#
# If you want to build and test this repository using `nix`, you can run the
# following command:
#
#     $ nix-build --attr grpc-haskell release.nix
#
# ... but this is not recommended for normal development because this will
# rebuild the repository from scratch every time, which is extremely slow.  Only
# do this if you want to exactly reproduce our continuous integration build.
#
# By default, Nix will pick a version for each one of your Haskell dependencies.
# If you would like to select a different version then, run:
#
#     $ cabal2nix cabal://${package-name}-${version} > nix/${package-name}.nix
#
# ... and then add this line below in the Haskell package overrides section:
#
#     ${package-name} =
#       haskellPackagesNew.callPackage ./nix/${package-name}.nix { };
#
# ... replacing `${package-name}` with the name of the package that you would
# like to upgrade and `${version}` with the version you want to upgrade to.
#
# You can also add private Git dependencies in the same way, except supplying
# the `git` URL to clone:
#
#     $ cabal2nix <your private git url>/${package-name}.git > ./nix/${package-name}.nix
#
# ...but also be sure to supply `fetchgit = pkgs.fetchgitPrivate` in the
# `haskellPackagesNew.callPackage` invocation for your private package.
#
# Note that `cabal2nix` also takes an optional `--revision` flag if you want to
# pick a revision other than the latest to depend on.
#
# If you want to test a local source checkout of a dependency, then run:
#
#     $ cabal2nix path/to/dependency/repo > nix/${package-name}.nix
#
# Finally, if you want to add grpc-haskell to your own package set, you can
# setup the overlay with:
#
#     grpc-nixpkgs = import path/to/gRPC-haskell/nixpkgs.nix;
#     grpc-overlay = (import path/to/gRPC-haskell/release.nix).overlay;
#     # optionally use the same nixpkgs source
#     pkgs = grpc-nixpkgs { overlays = [ grpc-overlay ]; };
#
# ... and use the extend function to setup haskell package override:
#
#     # see https://github.com/NixOS/nixpkgs/issues/25887
#     haskellPackages = pkgs.haskellPackages.extend (self: super: {
#       your-package = self.callCabal2nix "your-package" ./. { };
#     };);

let
  overlay = pkgsNew: pkgsOld: {

    grpc = pkgsNew.callPackage ./nix/grpc.nix { };

    haskellPackages = pkgsOld.haskellPackages.override {
      overrides = haskellPackagesNew: haskellPackagesOld: rec {
        parameterized =
          pkgsNew.haskell.lib.overrideCabal
          haskellPackagesOld.parameterized
          (old: {
            broken = false;
            patches = (old.patches or [ ]) ++ [ ./nix/parameterized.patch ];
          });

        haskell-src =
          haskellPackagesNew.callHackage "haskell-src" "1.0.3.1" {};

        proto3-wire =
          haskellPackagesNew.callPackage ./nix/proto3-wire.nix { };

        proto3-suite =
          pkgsNew.haskell.lib.dontCheck
            (haskellPackagesNew.callPackage ./nix/proto3-suite.nix {});

        grpc-haskell-core =
          pkgsNew.haskell.lib.buildFromSdist (pkgsNew.usesGRPC
            (haskellPackagesNew.callCabal2nix "grpc-haskell-core" ./core {
                 gpr = pkgsNew.grpc;
               }
            )
          );

        grpc-haskell-no-tests =
          pkgsNew.haskell.lib.buildFromSdist (pkgsNew.usesGRPC
            (pkgsNew.haskell.lib.dontCheck
              (haskellPackagesNew.callCabal2nix "grpc-haskell" ./. { })
            ));

        grpc-haskell =
          pkgsNew.usesGRPC
            (pkgsNew.haskell.lib.overrideCabal
              (pkgsNew.haskell.lib.buildFromSdist (haskellPackagesNew.callCabal2nix "grpc-haskell" ./. { }))
              (oldDerivation:
                let
                  ghc =
                    haskellPackagesNew.ghcWithPackages (pkgs: [
                      pkgs.grpc-haskell-no-tests
                      # Include some additional packages in this custom ghc for
                      # running tests in the nix-shell environment.
                      pkgs.tasty-quickcheck
                      pkgs.turtle
                    ]);

                  python = pkgsNew.python.withPackages (pkgs: [
                    pkgs.grpcio-tools
                  ]);

                in {
                  configureFlags = (oldDerivation.configureFlags or []) ++ [
                    "--flags=with-examples"
                  ];

                  buildDepends = (oldDerivation.buildDepends or [ ]) ++ [
                    pkgsNew.makeWrapper
                    # Give our nix-shell its own cabal so we don't pick up one
                    # from the user's environment by accident.
                    haskellPackagesNew.cabal-install

                    # And likewise for c2hs
                    haskellPackagesNew.c2hs
                  ];

                  patches =
                    (oldDerivation.patches or [ ]) ++ [ ./tests/tests.patch ];

                  postPatch = (oldDerivation.postPatch or "") + ''
                    patchShebangs tests
                    substituteInPlace tests/simple-client.sh \
                      --replace @makeWrapper@ ${pkgsNew.makeWrapper} \
                      --replace @grpc@ ${pkgsNew.grpc}
                    substituteInPlace tests/simple-server.sh \
                      --replace @makeWrapper@ ${pkgsNew.makeWrapper} \
                      --replace @grpc@ ${pkgsNew.grpc}
                    wrapProgram tests/protoc.sh \
                      --prefix PATH : ${python}/bin
                    wrapProgram tests/test-client.sh \
                      --prefix PATH : ${python}/bin
                    wrapProgram tests/test-server.sh \
                      --prefix PATH : ${python}/bin
                    wrapProgram tests/simple-client.sh \
                      --prefix PATH : ${ghc}/bin
                    wrapProgram tests/simple-server.sh \
                      --prefix PATH : ${ghc}/bin
                  '';

                  shellHook = (oldDerivation.shellHook or "") + ''
                    # This lets us use our custom ghc and python environments in the shell.
                    export PATH=${ghc}/bin:${python}/bin''${PATH:+:}$PATH
                  '';
                })
            );


      };
    };

    test-grpc-haskell =
      pkgsNew.mkShell {
        nativeBuildInputs = [
          (pkgsNew.haskellPackages.ghcWithPackages (pkgs: [
                pkgs.grpc-haskell
              ]
            )
          )
        ];
      };

    usesGRPC = haskellPackage:
      # On Linux, LD_LIBRARY_PATH needs to be set for loading
      # grpc-haskell{-,core} code into `ghci` from within `nix-shell`
      # environments.
      #
      # TODO: We might try using pkgsNew.fixDarwinDylibNames (see PR#129)
      # instead of setting DYLD_LIBRARY_PATH, but we might still need them
      # around for `ghci` as on Linux.

      pkgsNew.haskell.lib.overrideCabal haskellPackage (oldAttributes: {
          preBuild = (oldAttributes.preBuild or "") +
            pkgsNew.lib.optionalString pkgsNew.stdenv.isDarwin ''
              export DYLD_LIBRARY_PATH=${pkgsNew.grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
            '';

          shellHook = (oldAttributes.shellHook or "") +
            pkgsNew.lib.optionalString pkgsNew.stdenv.isDarwin ''
              export DYLD_LIBRARY_PATH=${pkgsNew.grpc}/lib''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH
            '' +
            pkgsNew.lib.optionalString pkgsNew.stdenv.isLinux ''
              export LD_LIBRARY_PATH=${pkgsNew.grpc}/lib''${LD_LIBRARY_PATH:+:}$LD_LIBRARY_PATH
            '';
        }
      );
  };

  overlays = [ overlay ];

  config  = { };

   nixpkgs = import ./nixpkgs.nix;
   linuxPkgs = nixpkgs { inherit config overlays; system = "x86_64-linux" ; };
  darwinPkgs = nixpkgs { inherit config overlays; system = "x86_64-darwin"; };
        pkgs = nixpkgs { inherit config overlays; };

in
  {
    grpc-haskell-core-linux    =  linuxPkgs.haskellPackages.grpc-haskell-core;
    grpc-haskell-core-darwin   = darwinPkgs.haskellPackages.grpc-haskell-core;
    grpc-haskell-core          =       pkgs.haskellPackages.grpc-haskell-core;

    grpc-haskell-linux         =  linuxPkgs.haskellPackages.grpc-haskell;
    grpc-haskell-darwin        = darwinPkgs.haskellPackages.grpc-haskell;
    grpc-haskell               =       pkgs.haskellPackages.grpc-haskell;
    grpc-haskell-no-tests      =       pkgs.haskellPackages.grpc-haskell-no-tests;

    grpc-linux                 =  linuxPkgs.grpc;
    grpc-darwin                = darwinPkgs.grpc;

    grpc                       =       pkgs.grpc;

    inherit pkgs config overlay;
    inherit (pkgs) test-grpc-haskell;
  }