alistral: add module

modules/programs/alistral.nix

@@ -0,0 +1,52 @@
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+let
+  inherit (lib)
+    mkIf
+    mkEnableOption
+    mkPackageOption
+    mkOption
+    ;
+
+  cfg = config.programs.alistral;
+  jsonFormat = pkgs.formats.json { };
+in
+{
+  meta.maintainers = with lib.hm.maintainers; [ aguirre-matteo ];
+  options.programs.alistral = {
+    enable = mkEnableOption "alistral";
+    package = mkPackageOption pkgs "alistral" { nullable = true; };
+    settings = mkOption {
+      inherit (jsonFormat) type;
+      default = { };
+      example = {
+        default_user = "spanish_inquisition";
+        listenbrainz_url = "https://api.listenbrainz.org/1/";
+        musicbrainz_url = "http://musicbrainz.org/ws/2";
+      };
+      description = ''
+        Configuration settings for alistral. You can see the details here:
+        <https://rustynova016.github.io/Alistral/config/config.html>.
+      '';
+    };
+  };
+
+  config =
+    let
+      configDir =
+        if pkgs.stdenv.hostPlatform.isDarwin then
+          "Library/Application Support/alistral"
+        else
+          ".config/alistral";
+    in
+    mkIf cfg.enable {
+      home.packages = mkIf (cfg.package != null) [ cfg.package ];
+      home.file."${configDir}/config.json" = mkIf (cfg.settings != { }) {
+        source = jsonFormat.generate "alistral-config.json" cfg.settings;
+      };
+    };
+}