flake.nix

{
  description = "Ema project";
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-parts.url = "github:hercules-ci/flake-parts";
    haskell-flake.url = "github:srid/haskell-flake";
    treefmt-nix.url = "github:numtide/treefmt-nix";
    flake-root.url = "github:srid/flake-root";
    emanote.url = "github:srid/emanote";
  };
  outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
    flake-parts.lib.mkFlake { inherit inputs; } {
      systems = nixpkgs.lib.systems.flakeExposed;
      imports = [
        inputs.haskell-flake.flakeModule
        inputs.flake-root.flakeModule
        inputs.treefmt-nix.flakeModule
        inputs.emanote.flakeModule
      ];
      perSystem = { config, pkgs, ... }: {
        # This attr is provided by https://github.com/srid/haskell-flake
        haskellProjects.default = {
          devShell.tools = hp: {
            treefmt = config.treefmt.build.wrapper;
          } // config.treefmt.build.programs;
        };

        # treefmt-nix configuration
        treefmt.config = {
          inherit (config.flake-root) projectRootFile;
          package = pkgs.treefmt;

          programs.ormolu.enable = true;
          programs.nixpkgs-fmt.enable = true;
          programs.cabal-fmt.enable = true;

          # We use fourmolu
          programs.ormolu.package = pkgs.haskellPackages.fourmolu;
          settings.formatter.ormolu = {
            options = [
              "--ghc-opt"
              "-XImportQualifiedPost"
              "--ghc-opt"
              "-XTypeApplications"
            ];
          };
        };

        emanote = {
          sites = {
            "docs" = {
              layers = [ ./docs ];
              layersString = [ "./docs" ];
              prettyUrls = true;
            };
          };
        };
      };
    };
}