add japanese fonts and input

modules/system/default.nix

@@ -11,6 +11,7 @@
     ./podman
     ./yubikey
     ./tailscale
+    ./japanese
     ./vpns
     ./vpn-confinement
     ./syncthing

modules/system/japanese/default.nix

@@ -0,0 +1,52 @@
+{
+  pkgs,
+  inputs,
+  config,
+  lib,
+  ...
+}: let
+  cfg = config.system.japanese;
+in {
+  options.system.japanese = {
+    enable = lib.mkEnableOption "enables japanese tools";
+  };
+
+  config = lib.mkIf cfg.enable {
+
+    # japanese input
+    i18n.inputMethod = {
+      enabled = "fcitx5";
+  
+      fcitx5.addons = with pkgs; [
+        fcitx5-mozc
+        fcitx5-gtk
+        fcitx5-qt
+      ];
+    };
+  
+    environment.systemPackages = with pkgs; [
+      fcitx5
+      fcitx5-configtool
+    ];
+
+    # fonts for japanese
+    fonts = {
+      enableDefaultPackages = true;
+      packages = with pkgs; [
+        noto-fonts
+        noto-fonts-cjk
+        noto-fonts-emoji
+        source-han-sans
+        source-han-serif
+      ];
+  
+      fontconfig = {
+        defaultFonts = {
+          serif = [ "Noto Serif CJK JP" ];
+          sansSerif = [ "Noto Sans CJK JP" ];
+          monospace = [ "Noto Sans Mono CJK JP" ];
+        };
+      };
+    };
+  };
+}