From 45321072fc40b94bf7f1ef87401a9a3ac391b374 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Wed, 15 Sep 2021 16:47:49 +0200
Subject: [PATCH 1/4] modules: add 'programs' directory

---
 modules/default.nix          | 1 +
 modules/programs/default.nix | 8 ++++++++
 2 files changed, 9 insertions(+)
 create mode 100644 modules/programs/default.nix

diff --git a/modules/default.nix b/modules/default.nix
index 798fb0d..d9c6c68 100644
--- a/modules/default.nix
+++ b/modules/default.nix
@@ -5,6 +5,7 @@
   imports = [
     ./hardware
     ./home.nix
+    ./programs
     ./services
     ./system
   ];
diff --git a/modules/programs/default.nix b/modules/programs/default.nix
new file mode 100644
index 0000000..85be70e
--- /dev/null
+++ b/modules/programs/default.nix
@@ -0,0 +1,8 @@
+# Program-related modules
+{ ... }:
+
+{
+  imports = [
+    # FIXME
+  ];
+}

From 37bb7fd6256093f2f305c5a4ec672370975ca9fb Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Wed, 15 Sep 2021 16:48:39 +0200
Subject: [PATCH 2/4] modules: programs: add steam

---
 modules/programs/default.nix |  2 +-
 modules/programs/steam.nix   | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 modules/programs/steam.nix

diff --git a/modules/programs/default.nix b/modules/programs/default.nix
index 85be70e..a6f14ed 100644
--- a/modules/programs/default.nix
+++ b/modules/programs/default.nix
@@ -3,6 +3,6 @@
 
 {
   imports = [
-    # FIXME
+    ./steam.nix
   ];
 }
diff --git a/modules/programs/steam.nix b/modules/programs/steam.nix
new file mode 100644
index 0000000..e9f2a2b
--- /dev/null
+++ b/modules/programs/steam.nix
@@ -0,0 +1,15 @@
+{ config, lib, ... }:
+let
+  cfg = config.my.programs.steam;
+in
+{
+  options.my.programs.steam = with lib; {
+    enable = mkEnableOption "steam configuration";
+  };
+
+  config = lib.mkIf cfg.enable {
+    programs.steam = {
+      enable = true;
+    };
+  };
+}

From 5c95ba11136f6025bd26ee59005dc340f0472c51 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Wed, 15 Sep 2021 16:49:22 +0200
Subject: [PATCH 3/4] machines: aramis: programs: enable steam

---
 machines/aramis/default.nix  | 1 +
 machines/aramis/programs.nix | 7 +++++++
 2 files changed, 8 insertions(+)
 create mode 100644 machines/aramis/programs.nix

diff --git a/machines/aramis/default.nix b/machines/aramis/default.nix
index bb78127..878f2c9 100644
--- a/machines/aramis/default.nix
+++ b/machines/aramis/default.nix
@@ -11,6 +11,7 @@
     ./home.nix
     ./networking.nix
     ./profiles.nix
+    ./programs.nix
     ./services.nix
     ./sound.nix
   ];
diff --git a/machines/aramis/programs.nix b/machines/aramis/programs.nix
new file mode 100644
index 0000000..426ca2a
--- /dev/null
+++ b/machines/aramis/programs.nix
@@ -0,0 +1,7 @@
+{ ... }:
+{
+  my.programs = {
+    # Steam configuration
+    steam.enable = true;
+  };
+}

From 9f3811ea3b76d0feae75540157310351b9d7ce76 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Wed, 15 Sep 2021 18:13:47 +0200
Subject: [PATCH 4/4] modules: programs: steam: respect XDG conventions

Steam wants to pollute HOME with `.steam*` files and folders, which are
useless and annoying.

We want to make sure the wrappers are preferred when installing, so use
`lib.hiPrio` to ensure they get chosen.
---
 modules/programs/steam.nix | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/modules/programs/steam.nix b/modules/programs/steam.nix
index e9f2a2b..dbdc0ce 100644
--- a/modules/programs/steam.nix
+++ b/modules/programs/steam.nix
@@ -1,15 +1,39 @@
-{ config, lib, ... }:
+{ config, lib, pkgs, ... }:
 let
   cfg = config.my.programs.steam;
 in
 {
   options.my.programs.steam = with lib; {
     enable = mkEnableOption "steam configuration";
+
+    dataDir = mkOption {
+      type = types.str;
+      default = "$XDG_DATA_HOME/steamlib";
+      example = "/mnt/steam/";
+      description = ''
+        Which directory should be used as HOME to run steam.
+      '';
+    };
   };
 
   config = lib.mkIf cfg.enable {
     programs.steam = {
       enable = true;
     };
+
+    environment.systemPackages = builtins.map lib.hiPrio [
+      # Respect XDG conventions, leave my HOME alone
+      (pkgs.writeScriptBin "steam" ''
+        #!/bin/sh
+        mkdir -p "${cfg.dataDir}"
+        HOME="${cfg.dataDir}" exec ${pkgs.steam}/bin/steam "$@"
+      '')
+      # Same, for GOG and other such games
+      (pkgs.writeScriptBin "steam-run" ''
+        #!/bin/sh
+        mkdir -p "${cfg.dataDir}"
+        HOME="${cfg.dataDir}" exec ${pkgs.steam-run-native}/bin/steam-run "$@"
+      '')
+    ];
   };
 }