feat(home/fish): move fish's code to external files

It's easier to edit / debug / test the code that way.

This also add a new function (`find-ssh-agent') to find or start a new
ssh agent when a shell is started.

5 files changed, 43 insertions, 20 deletions

diff --git a/home/shell/fish/default.nix b/home/shell/fish/default.nix
index d000cd9..f3e41d9 100644
--- a/home/shell/fish/default.nix
+++ b/home/shell/fish/default.nix
@@ -1,7 +1,6 @@
 { config, lib, pkgs, ... }:
 let
   cfg = config.my.home.shell;
-  swayEnabled = config.my.home.wm.windowManager == "sway";
   aliases = config.my.home.shell.aliases;
 in
 {
@@ -9,24 +8,10 @@ in
     programs.fish = {
       enable = true;
       shellAliases = aliases;
-      interactiveShellInit = ''
-        set fish_greeting
-
-        # Tmux on terminal start, unless we're in a SSH connection
-        if status is-interactive
-          if test -z "$SSH_CONNECTION"
-            if not tmux has-session 2>/dev/null; or test -z "$TMUX"
-              exec tmux new-session -A -s 0
-            end
-          end
-        end
-      '';
-      loginShellInit = lib.mkIf swayEnabled ''
-        if test -z "$DISPLAY"; and test (tty) = "/dev/tty1"
-          exec sway
-        end
-      '';
+      interactiveShellInit = builtins.readFile ./interactive.fish;
+      loginShellInit = builtins.readFile ./login.fish;
     };
+
     xdg.configFile."fish/functions" = {
       source = ./functions;
       recursive = true;
diff --git a/home/shell/fish/functions/find-ssh-agent.fish b/home/shell/fish/functions/find-ssh-agent.fish
new file mode 100644
index 0000000..9e2de8d
--- /dev/null
+++ b/home/shell/fish/functions/find-ssh-agent.fish
@@ -0,0 +1,20 @@
+function find-ssh-agent --description "find or run ssh-agent"
+    # let's avoid storing the agent's socket under /tmp
+    set -l ssh_auth_sock $XDG_RUNTIME_DIR/ssh-agent.sock
+
+    if set -q SSH_AGENT_PID; and set -q SSH_AUTH_SOCK
+        # if variables already defined, then try to connect to agent
+        ssh-add -l &>/dev/null
+        test $status -ne 2; and return
+    end
+
+    set -l user_id (id -u)
+    set -l ssh_agent_pid (pgrep --exact --newest --uid $user_id ssh-agent)
+
+    if test -S $ssh_auth_sock
+        set --global --export SSH_AUTH_SOCK $ssh_auth_sock
+        set --global --export SSH_AGENT_PID $ssh_agent_pid
+    else
+        eval (ssh-agent -c -a $ssh_auth_sock)
+    end
+end
diff --git a/home/shell/fish/functions/nix-rebuild-host.fish b/home/shell/fish/functions/nix-rebuild-host.fish
index 1ec7daa..02c0050 100644
--- a/home/shell/fish/functions/nix-rebuild-host.fish
+++ b/home/shell/fish/functions/nix-rebuild-host.fish
@@ -1,4 +1,4 @@
 function nix-rebuild-host --description "rebuild the current host"
-  cd ~/workspace/world
-  sudo nixos-rebuild switch --flake .
+    cd ~/workspace/world
+    sudo nixos-rebuild switch --flake .
 end
diff --git a/home/shell/fish/interactive.fish b/home/shell/fish/interactive.fish
new file mode 100644
index 0000000..4adcba8
--- /dev/null
+++ b/home/shell/fish/interactive.fish
@@ -0,0 +1,8 @@
+# Tmux on terminal start, unless we're in a SSH connection
+if status is-interactive
+    if test -z "$SSH_CONNECTION"
+        if not tmux has-session 2>/dev/null; or test -z "$TMUX"
+            exec tmux new-session -A -s 0
+        end
+    end
+end
diff --git a/home/shell/fish/login.fish b/home/shell/fish/login.fish
new file mode 100644
index 0000000..8f29553
--- /dev/null
+++ b/home/shell/fish/login.fish
@@ -0,0 +1,10 @@
+# disable greeting
+set -U fish_greeting ''
+
+# set up ssh-agent
+find-ssh-agent
+
+# start sway
+if test -z "$DISPLAY"; and test (tty) = "/dev/tty1"
+    exec sway
+end