From 94b22720b6614c5a85bf4e01ad019f269bd71f48 Mon Sep 17 00:00:00 2001
From: Manuel Thalmann <m@nuth.ch>
Date: Fri, 1 Nov 2024 14:13:41 +0100
Subject: [PATCH] Create a script for managing `nix`

---
 archiso/scripts/build.fish     | 19 ++++++-------------
 scripts/Common/OS/install.fish | 14 +++++---------
 scripts/lib/config.fish        |  5 ++++-
 scripts/lib/nix.fish           | 26 ++++++++++++++++++++++++++
 4 files changed, 41 insertions(+), 23 deletions(-)
 create mode 100644 scripts/lib/nix.fish

diff --git a/archiso/scripts/build.fish b/archiso/scripts/build.fish
index a21b0832..92454d8c 100755
--- a/archiso/scripts/build.fish
+++ b/archiso/scripts/build.fish
@@ -1,31 +1,24 @@
 #!/bin/env fish
 begin
-    source "$(status dirname)/../../scripts/lib/config.fish"
+    set -l dir (status dirname)
+    source "$dir/../../scripts/lib/config.fish"
+    source "$dir/../../scripts/lib/nix.fish"
     set -l projectName archiso-valhalla
     set -l overlayDir (mktemp -d)
     set -l upperDir (mktemp -d)
     set -l workDir (mktemp -d)
-    set -l cacheRoot ~/".cache/$projectName"
-    set -l nixCache "$cacheRoot/nixpkgs/$nixVersion"
     set -l root airootfs
     set -l rootHome "$overlayDir/$root/root"
     set -l profileDir "/mnt/$projectName"
     set -l projectDir "$rootHome/PortValhalla"
-    set -l nixDir "$profileDir/$root/nix/var/nix/profiles/per-user/root/channels/nixpkgs"
+    set -l nixDir "$profileDir/$root$nixPkgsDir"
 
     mkdir -p "$rootHome"
     and fish "$(status dirname)/../../scripts/lib/copy-repo.fish" "$projectDir"
-
-    and begin
-        if [ ! -d "$nixCache" ]
-            mkdir -p "$nixCache"
-            and git clone https://github.com/NixOS/nixpkgs.git --depth=1 -b "$nixVersion" "$nixCache"
-            and rm -rf "$nixCache/.git"
-        end
-    end
+    downloadNixPkgs
 
     and sudo mount --mkdir -t overlay overlay -o lowerdir=.:"$overlayDir",upperdir="$upperDir",workdir="$workDir" "$profileDir"
-    and sudo mount --mkdir --bind "$nixCache" "$nixDir"
+    and sudo mount --mkdir --bind "$nixPkgsCache" "$nixDir"
     and sudo mkarchiso $argv "$profileDir"
     sudo umount "$nixDir"
     and sudo umount "$profileDir"
diff --git a/scripts/Common/OS/install.fish b/scripts/Common/OS/install.fish
index 4429fe18..5719c39c 100755
--- a/scripts/Common/OS/install.fish
+++ b/scripts/Common/OS/install.fish
@@ -6,8 +6,8 @@ source "$dir/../../lib/hooks.fish"
 
 if [ (id -u) -eq 0 ]
     source "$dir/../../lib/config.fish"
+    source "$dir/../../lib/nix.fish"
     set -l sudoConfig "/etc/sudoers.d/PortValhalla"
-    set -l channelDir /nix/var/nix/profiles/per-user/root/channels/nixpkgs
     rm ~/.bash_profile
 
     if ! git status -C (status dirname) &> /dev/null
@@ -20,13 +20,8 @@ if [ (id -u) -eq 0 ]
             and set -x CONFIG_NAME "$config"
         end
 
-        if [ ! -d "$channelDir" ]
-            mkdir -p "$channelDir"
-            and git clone https://github.com/NixOS/nixpkgs.git --depth=1 -b "$nixVersion" "$channelDir"
-            and rm -rf "$channelDir/.git"
-        end
-
         and runHook --force installValhallaDeps 'Please set up a function `installValhallaDeps` for installing `fish`, `git`, `jq`, `nix`, `sudo` and `tmux`.'
+        installNixPkgs
         and tmux new-session $cmdline
     else
         set -l name (getOSConfig setupUser.name)
@@ -51,7 +46,8 @@ if [ (id -u) -eq 0 ]
         and sudo --preserve-env --set-home --user "$name" $cmdline
         rm "$sudoConfig"
         userdel -rf "$name"
-        rm -rf "$channelDir"
+        uninstallNixPkgs
+        read -P "finished. press enter"
     end
 else
     if not type -q getDeploymentScript
@@ -95,7 +91,7 @@ else
         echo "Cleaning installation scripts..."
         set -l projectPath (realpath "$(status dirname)/../../..")
         cd (dirname "$projectPath")
-        sudo rm -rf "$projectPath"
+        # sudo rm -rf "$projectPath"
     end
 
     and echo "The installation finished successfully!"
diff --git a/scripts/lib/config.fish b/scripts/lib/config.fish
index 42442e2c..84655f89 100644
--- a/scripts/lib/config.fish
+++ b/scripts/lib/config.fish
@@ -1 +1,4 @@
-set nixVersion nixos-24.05
+set projectName port-valhalla
+set nixPkgsVersion nixos-24.05
+set cacheRoot ~/".cache/$projectName"
+set nixPkgsCache "$cacheRoot/nixpkgs/$nixPkgsVersion"
diff --git a/scripts/lib/nix.fish b/scripts/lib/nix.fish
new file mode 100644
index 00000000..62e74cbd
--- /dev/null
+++ b/scripts/lib/nix.fish
@@ -0,0 +1,26 @@
+begin
+    set -l dir (status dirname)
+    set -l config "$dir/config.fish"
+    set nixPkgsDir "/nix/var/nix/profiles/per-user/root/channels/nixpkgs"
+
+    function downloadNixPkgs -V config
+        source "$config"
+
+        if [ ! -d "$nixPkgsCache" ]
+            mkdir -p "$nixPkgsCache"
+            and git clone https://github.com/NixOS/nixpkgs.git --depth=1 -b "$nixPkgsVersion" "$nixPkgsCache"
+            and rm -rf "$nixPkgsCache/.git"
+        end
+    end
+
+    function installNixPkgs -V config -V nixPkgsDir
+        source "$config"
+        downloadNixPkgs
+        mkdir -p "$nixPkgsDir"
+        cp -r "$nixPkgsCache"/* "$nixPkgsDir"
+    end
+
+    function uninstallNixPkgs -V nixPkgsDir
+        rm -rf "$nixPkgsDir"
+    end
+end