ntfy-sh: Add client module

Co-authored-by: Sumner Evans <me@sumnerevans.com>
Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

modules/programs/ntfy-sh.nix

@@ -0,0 +1,59 @@
+{ pkgs, lib, config, ... }:
+
+let
+  cfg = config.programs.ntfy-sh;
+  yamlFormat = pkgs.formats.yaml { };
+in with lib; {
+  options.programs.ntfy-sh = {
+    enable = mkEnableOption "ntfy-sh";
+    enableUserService = mkEnableOption "ntfy-sh user service";
+
+    package = mkPackageOption pkgs "ntfy-sh" { };
+
+    configFilePath = mkOption {
+      type = types.path;
+      default = "${config.xdg.configHome}/ntfy/client.yml";
+      defaultText = literalExpression
+        "''${config.xdg.configHome}/ntfy/client.yml";
+      description = "Path where the configuration file is placed.";
+    };
+
+    settings = mkOption {
+      type = yamlFormat.type;
+      default = { };
+      description = "Configuration for the ntfy binary";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    home.packages = [ cfg.package ];
+
+    home.file.ntfy-sh = {
+      enable = true;
+      target = cfg.configFilePath;
+
+      onChange = ''
+        systemctl --user restart ntfy-sh-client
+      '';
+
+      source = mkIf (cfg.settings != { })
+        (yamlFormat.generate "ntfy-sh-config" cfg.settings);
+    };
+
+    systemd.user.services.ntfy-sh-client = mkIf cfg.enableUserService {
+      Unit.Description = "ntfy-sh client service";
+
+      Install.WantedBy = [ "multi-user.target" ];
+
+      Service = {
+        Type = "simple";
+        Restart = "on-failure";
+        ExecStart = ''
+          ${cfg.package}/bin/ntfy subscribe --config ${cfg.configFilePath} --from-config
+        '';
+      };
+    };
+  };
+
+  meta.maintainers = [ maintainers.matthiasbeyer ];
+}