DankMaterialShell/nix/greeter.nix

{
    lib,
    config,
    pkgs,
    dmsPkgs,
    ...
}: let
    inherit (lib) types;
    cfg = config.programs.dankMaterialShell.greeter;

    user = config.services.greetd.settings.default_session.user;

    buildCompositorConfig = conf: pkgs.writeText "dmsgreeter-compositor-config" ''
        ${(lib.replaceString "_DMS_PATH_" "${dmsPkgs.dankMaterialShell}/etc/xdg/quickshell/dms" (lib.fileContents conf))}
        ${cfg.compositor.extraConfig}
    '';

    sessionCommands = {
        niri = ''
            export PATH=$PATH:${lib.makeBinPath [ config.programs.niri.package ]}
            niri -c ${buildCompositorConfig ../Modules/Greetd/assets/dms-niri.kdl} \
        '';
        hyprland = ''
            export PATH=$PATH:${lib.makeBinPath [ config.programs.hyprland.package ]}
            hyprland -c ${buildCompositorConfig ../Modules/Greetd/assets/dms-niri.kdl} \
        '';
    };

    greeterScript = pkgs.writeShellScriptBin "dms-greeter" ''
        export QT_QPA_PLATFORM=wayland
        export XDG_SESSION_TYPE=wayland
        export QT_WAYLAND_DISABLE_WINDOWDECORATION=1
        export EGL_PLATFORM=gbm
        export DMS_GREET_CFG_DIR="/var/lib/dmsgreeter/"
        export PATH=$PATH:${lib.makeBinPath [ cfg.quickshell.package ]}
        ${sessionCommands.${cfg.compositor.name}} ${lib.optionalString cfg.logs.save "> ${cfg.logs.path} 2>&1"}
    '';
in {
    options.programs.dankMaterialShell.greeter = {
        enable = lib.mkEnableOption "DankMaterialShell greeter";
        compositor.name = lib.mkOption {
            type = types.enum ["niri" "hyprland"];
            description = "Compositor to run greeter in";
        };
        compositor.extraConfig = lib.mkOption {
            type = types.lines;
            default = "";
            description = "Exra compositor config to include";
        };
        configFiles = lib.mkOption {
            type = types.listOf types.path;
            default = [];
            description = "Config files to copy into data directory";
            example = [
                "/home/user/.config/DankMaterialShell/settings.json"
            ];
        };
        configHome = lib.mkOption {
            type = types.nullOr types.str;
            default = null;
            example = "/home/user";
            description = ''
                User home directory to copy configurations for greeter
                If DMS config files are in non-standard locations then use the configFiles option instead
            '';
        };
        quickshell = {
            package = lib.mkPackageOption pkgs "quickshell" {};
        };
        logs.save = lib.mkEnableOption "saving logs from DMS greeter to file";
        logs.path = lib.mkOption {
            type = types.path;
            default = "/tmp/dms-greeter.log";
            description = ''
                File path to save DMS greeter logs to
            '';
        };
    };
    config = lib.mkIf cfg.enable {
        assertions = [
            {
                assertion = (config.users.users.${user} or { }) != { };
                message = ''
                    dmsgreeter: user set for greetd default_session ${user} does not exist. Please create it before referencing it.
                '';
            }
        ];
        services.greetd = {
            enable = lib.mkDefault true;
            settings.default_session.command = lib.mkDefault (lib.getExe greeterScript);
        };
        fonts.packages = with pkgs; [
            fira-code
            inter
            material-symbols
        ];
        systemd.tmpfiles.settings."10-dmsgreeter" = {
            "/var/lib/dmsgreeter".d = {
                user = user;
                group = if config.users.users.${user}.group != ""
                    then config.users.users.${user}.group else "greeter";
                mode = "0755";
            };
        };
        systemd.services.greetd.preStart = ''
            cd /var/lib/dmsgreeter
            ${lib.concatStringsSep "\n" (lib.map (f: ''
                if [ -f "${f}" ]; then
                    cp "${f}" .
                fi
            '') cfg.configFiles)}

            if [ -f session.json ]; then
                if cp "$(${lib.getExe pkgs.jq} -r '.wallpaperPath' session.json)" wallpaper.jpg; then
                    mv session.json session.orig.json
                    ${lib.getExe pkgs.jq} '.wallpaperPath = "/var/lib/dmsgreeter/wallpaper.jpg"' session.orig.json > session.json
                fi
            fi
            chown ${user}: *
        '';
        programs.dankMaterialShell.greeter.configFiles = lib.mkIf (cfg.configHome != null) [
            "${cfg.configHome}/.config/DankMaterialShell/settings.json"
            "${cfg.configHome}/.local/state/DankMaterialShell/session.json"
            "${cfg.configHome}/.cache/quickshell/dankshell/dms-colors.json"
        ];
    };
}