flake.nix

{
  description = "My Haskell project";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
  };

  outputs = { self, nixpkgs }:
    let
      supportedSystems =
        [ "aarch64-linux" "x86_64-linux" "aarch64-darwin" "x86_64-darwin" ];

      forAllSystems =
        nixpkgs.lib.genAttrs supportedSystems;

      nixpkgsFor = forAllSystems (system:
        import nixpkgs {
          inherit system;
        });

      haskellPackages = system:
        nixpkgsFor.${system}.haskellPackages;

      packageName = system: with builtins;
        let
          cabalFileName =
            let
              cabalFiles =
                ((filter ((nixpkgsFor.${system}).lib.hasSuffix ".cabal")) (attrNames (readDir ./.)));
            in
              head cabalFiles;

          matches =
            (match "^.*name\:\ *([^[:space:]]*).*$" (readFile "${./.}\/${cabalFileName}"));
        in
          head matches;
      in
        {
          packages =
            forAllSystems (system:
              let
                pkgs =
                  nixpkgsFor.${system};
              in
                {
                  default =
                    # (haskellPackages system).callCabal2nix (packageName system) self {};
                    import ./default.nix ((haskellPackages system) // { lib = pkgs.lib; SDL = pkgs.SDL; });
                }
            );


          devShell =
            forAllSystems (system:
              let
                pkgs =
                  nixpkgsFor.${system};
              in
                (haskellPackages system).shellFor {
                  # The packages that the shell is for.
                  packages = p: [
                    self.packages.${system}.default
                  ];

                  buildInputs = with (haskellPackages system);
                    [ haskell-language-server
                      cabal-install
                      pkgs.SDL
                      pkgs.SDL.dev
                    ];

                  # Add build inputs of the following derivations.
                  inputsFrom = [ ];

                  # Enables Hoogle for the builtin packages.
                  withHoogle = true;
                }
            );
        };
}