From 6031ae21f6b69b04701e06fbeadf6585c5e3e0cd Mon Sep 17 00:00:00 2001
From: Vonfry <mail@vonfry.name>
Date: Sat, 2 Apr 2022 18:43:39 +0800
Subject: [PATCH 1/2] fcitx5-rime: add an environment variable for shared data
 dir passing librime.

The original RIME_DATA_DIR is fixed at build time which is set to the package
dir under nix store. A such dir is read only for users so if some one want to
add a shared data, he has to override fcitx5-rime or librime, which isn't
user-friendly.

On other distributions, RIME_DATA_DIR may be under /usr/local/share/fcitx5 which
is not existed on NixOS. If we set its to /run/current-system/sw/share/..., this
will break for non-NixOS user.

Therefore, we patch it with a special environment variable to let user to load
it dynamically.

Co-Authored-by: Lan Tian <xuyh0120@outlook.com>
---
 .../fcitx5-rime-with-nix-env-variable.patch    | 18 ++++++++++++++++++
 pkgs/tools/inputmethods/fcitx5/fcitx5-rime.nix |  2 ++
 2 files changed, 20 insertions(+)
 create mode 100644 pkgs/tools/inputmethods/fcitx5/fcitx5-rime-with-nix-env-variable.patch

diff --git a/pkgs/tools/inputmethods/fcitx5/fcitx5-rime-with-nix-env-variable.patch b/pkgs/tools/inputmethods/fcitx5/fcitx5-rime-with-nix-env-variable.patch
new file mode 100644
index 000000000000..428a0232dc3b
--- /dev/null
+++ b/pkgs/tools/inputmethods/fcitx5/fcitx5-rime-with-nix-env-variable.patch
@@ -0,0 +1,18 @@
+:100644 100644 fac4f53 aed9617 M	src/rimeengine.cpp
+
+diff --git a/src/rimeengine.cpp b/src/rimeengine.cpp
+index fac4f53..aed9617 100644
+--- a/src/rimeengine.cpp
++++ b/src/rimeengine.cpp
+@@ -164,7 +164,10 @@ void RimeEngine::rimeStart(bool fullcheck) {
+             RIME_ERROR() << "Failed to create user directory: " << userDir;
+         }
+     }
+-    const char *sharedDataDir = RIME_DATA_DIR;
++    const char *sharedDataDir = getenv("NIX_RIME_DATA_DIR");
++    if (!sharedDataDir) {
++        sharedDataDir = RIME_DATA_DIR;
++    }
+ 
+     RIME_STRUCT(RimeTraits, fcitx_rime_traits);
+     fcitx_rime_traits.shared_data_dir = sharedDataDir;
diff --git a/pkgs/tools/inputmethods/fcitx5/fcitx5-rime.nix b/pkgs/tools/inputmethods/fcitx5/fcitx5-rime.nix
index 3743d6cb9fc8..fac81c8dea12 100644
--- a/pkgs/tools/inputmethods/fcitx5/fcitx5-rime.nix
+++ b/pkgs/tools/inputmethods/fcitx5/fcitx5-rime.nix
@@ -35,6 +35,8 @@ stdenv.mkDerivation rec {
     librime
   ];
 
+  patches = [ ./fcitx5-rime-with-nix-env-variable.patch ];
+
   meta = with lib; {
     description = "RIME support for Fcitx5";
     homepage = "https://github.com/fcitx/fcitx5-rime";

From 2474c8c89a3af7c88a653fc040056d600414307b Mon Sep 17 00:00:00 2001
From: Vonfry <mail@vonfry.name>
Date: Sat, 2 Apr 2022 19:22:24 +0800
Subject: [PATCH 2/2] nixos/fcitx5: add the setting of RIME_DATA_DIR and
 options for rime-data

---
 nixos/modules/i18n/input-method/fcitx5.nix | 27 +++++++++++++++++-----
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/nixos/modules/i18n/input-method/fcitx5.nix b/nixos/modules/i18n/input-method/fcitx5.nix
index 6fea28e22345..b4b887606e95 100644
--- a/nixos/modules/i18n/input-method/fcitx5.nix
+++ b/nixos/modules/i18n/input-method/fcitx5.nix
@@ -5,7 +5,9 @@ with lib;
 let
   im = config.i18n.inputMethod;
   cfg = im.fcitx5;
-  fcitx5Package = pkgs.fcitx5-with-addons.override { inherit (cfg) addons; };
+  addons = cfg.addons ++ optional cfg.enableRimeData pkgs.rime-data;
+  fcitx5Package = pkgs.fcitx5-with-addons.override { inherit addons; };
+  whetherRimeDataDir = any (p: p.pname == "fcitx5-rime") cfg.addons;
 in {
   options = {
     i18n.inputMethod.fcitx5 = {
@@ -17,16 +19,29 @@ in {
           Enabled Fcitx5 addons.
         '';
       };
+
+      enableRimeData = mkEnableOption "default rime-data with fcitx5-rime";
     };
   };
 
   config = mkIf (im.enabled == "fcitx5") {
     i18n.inputMethod.package = fcitx5Package;
 
-    environment.variables = {
-      GTK_IM_MODULE = "fcitx";
-      QT_IM_MODULE = "fcitx";
-      XMODIFIERS = "@im=fcitx";
-    };
+    environment = mkMerge [{
+      variables = {
+        GTK_IM_MODULE = "fcitx";
+        QT_IM_MODULE = "fcitx";
+        XMODIFIERS = "@im=fcitx";
+      };
+    }
+    (mkIf whetherRimeDataDir {
+      pathsToLink = [
+        "/share/rime-data"
+      ];
+
+      variables =  {
+        NIX_RIME_DATA_DIR = "/run/current-system/sw/share/rime-data";
+      };
+    })];
   };
 }