distrobox: add fishShellIntegration

modules/programs/distrobox.nix

@@ -46,16 +46,12 @@ let
       read -p "Distrobox's containers list have changed. Do you want to build them now? [y/N/i]: " answer
 
       if [[ $answer == "y" ]] || [[ $answer == "Y" ]]; then
-
         distrobox-nixos-build
         echo $new_hash > $prev_hash_file
-
       elif [[ $answer == "i" ]] || [[ $answer == "I" ]]; then
-
         echo "Changes ignored. Distrobox won't warn you before more changes are detected."
         echo "To manually build the containers run \'distrobox-nixos-build\'."
         echo $new_hash > $prev_hash_file
-
       fi
     fi
 
@@ -68,6 +64,41 @@ let
 
   zshInitExtra = bashInitExtra;
 
+  fishInitExtra = ''
+    function distrobox-nixos-build
+      distrobox-assemble create --file ${containersFile}
+    end
+
+    set containers_file ${containersFile}
+    set prev_hash_file ${prevHashFile}
+    set new_hash (sha256sum $containers_file | cut -f 1 -d " ")
+
+    if test -f $prev_hash_file
+      set prev_hash (cat $prev_hash_file)
+    else
+      set prev_hash 0
+    end
+
+    if not test $new_hash = $prev_hash
+      read -p "Distrobox's containers list have changed. Do you want to build them now? [y/N/i]: " answer
+
+      if test $answer = "y" -o $answer = "Y"
+        distrobox-nixos-build
+        echo $new_hash > $prev_hash_file
+      else if test $answer = "i" -o $answer = "I"
+        echo "Changes ignored. Distrobox won't warn you before more changes are detected."
+        echo "To manually build the containers run 'distrobox-nixos-build'."
+        echo $new_hash > $prev_hash_file
+      end
+    end
+
+    set -e containers_file
+    set -e prev_hash_file
+    set -e new_hash
+    set -e prev_hash
+    set -e answer
+  '';
+
 in {
   meta.maintainers = [ lib.hm.maintainers.aguirre-matteo ];
 
@@ -82,6 +113,9 @@ in {
     enableZshIntegration =
       lib.hm.shell.mkZshIntegrationOption { inherit config; };
 
+    enableFishIntegration =
+      lib.hm.shell.mkFishIntegrationOption { inherit config; };
+
     containers = mkOption {
       type = with types; attrsOf (attrsOf (either bool str));
       default = { };
@@ -117,5 +151,7 @@ in {
 
     programs.bash.initExtra = mkIf cfg.enableBashIntegration bashInitExtra;
     programs.zsh.initExtra = mkIf cfg.enableZshIntegration zshInitExtra;
+    programs.fish.interactiveShellInit =
+      mkIf cfg.enableFishIntegration fishInitExtra;
   };
 }