fonts/flake.nix

{
  description = "Various fonts I've found online";
  inputs = {
    flake-utils.url = "github:numtide/flake-utils";
    nixpkgs.url = "github:nixos/nixpkgs";
  };

  outputs = { self, nixpkgs, flake-utils, }:
    with builtins;
    with nixpkgs.lib;
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          config.allowUnfree = true;
        };

        pathEndsWith = suffix: path:
          let
            str = toString path;
            sufLen = stringLength suffix;
            sLen = stringLength str;
          in sufLen <= sLen && suffix == substring (sLen - sufLen) sufLen str;

        buildFont = { name, files ? [ ], dir ? null, license, author }:
          let
            types = {
              ttf = "truetype";
              otf = "opentype";
            };

            copyType = extension: pathName:
              let
                filteredFiles = filter (pathEndsWith ("." + extension)) files;
                filename = file:
                  lists.last (strings.splitString "/" (toString file));
              in (optionalString (filteredFiles != [ ]) ''
                mkdir -p $out/share/fonts/${pathName}
              '') + concatStringsSep "\n" (map (file:
                "cp -v ${file} $out/share/fonts/${pathName}/${filename file}")
                filteredFiles);

            copyTypeDir = extension: pathName: ''
              if [ -n "$(shopt -s nullglob; echo ${dir}/*.${extension})" ]; then
                mkdir -p $out/share/fonts/${pathName}
                cp -v -t $out/share/fonts/${pathName} ${dir}/*.${extension}
              fi
            '';
          in pkgs.stdenvNoCC.mkDerivation {
            inherit name;

            dontUnpack = true;
            installPhase = mapAttrsToList copyType types
              ++ optional (dir != null) (mapAttrsToList copyTypeDir types);

            meta = {
              inherit license;
              platforms = platforms.all;
              description = "${name} font by ${author}";
            };
          };

        fonts = [
          {
            # Popular font, used on NYC Subway
            name = "Akzidenz-Grotesk Pro";
            dir = ./Akzidenz-Grotesk-Pro;
            license = licenses.unfree;
            author = "Berthold Type Foundry";
          }
          {
            # Free handwriting font
            name = "Caveat";
            files = [ ./Caveat.ttf ];
            license = licenses.ofl;
            author = "Pablo Impallari and Alexi Vanyashin";
          }
          {
            # Deutsche Bahn website font
            name = "DB Screen";
            dir = ./DB-Screen;
            license = licenses.unfree;
            author = "URW Type Foundry";
          }
          {
            # Popular font, used on Amtrak
            name = "Frutiger";
            dir = ./Frutiger;
            license = licenses.unfree;
            author = "Adrian Frutiger";
          }
          {
            # Discord custom font
            name = "gg sans";
            dir = ./ggsans;
            license = licenses.unfree;
            author = "Colophon Foundry";
          }
          {
            # Also called "NR Brunel, used on UK railways in 2010s
            name = "New Brunel";
            dir = ./New-Brunel;
            license = licenses.unfree;
            author = "David Quay";
          }
          {
            # Modern expansion of machine-readable font
            name = "OCR-B";
            files = [ ./OCR-B-Regular.otf ];
            license = licenses.cc-by-40;
            author = "Matthew Anderson";
          }
          {
            # Modern expansion of Johnston Sans, used on London Underground
            name = "P22 Underground";
            dir = ./P22-Underground;
            license = licenses.unfree;
            author = "P22 Type Foundry";
          }
        ];
      in {
        packages = listToAttrs (map (font: {
          name = replaceStrings [ " " ] [ "-" ] (toLower font.name);
          value = buildFont font;
        }) fonts);

        formatter = pkgs.nixfmt;
      });
}