From f7c94a461c954e9ddf7965eec32dc5615503b6eb Mon Sep 17 00:00:00 2001
From: Evie Litherland-Smith <evie.litherland-smith@ukaea.uk>
Date: Tue, 7 Jan 2025 15:15:47 +0000
Subject: [PATCH] Switch to Zsh as default shell

---
 system/default.nix              |  2 ++
 system/home/shell/default.nix   | 31 +++++++++++++++++++++++++++++++
 system/home/shell/transient.zsh | 31 +++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 system/home/shell/transient.zsh

diff --git a/system/default.nix b/system/default.nix
index f3481475..831fb023 100644
--- a/system/default.nix
+++ b/system/default.nix
@@ -110,6 +110,7 @@
         isNormalUser = true;
         group = "users";
         description = "Evie Litherland-Smith";
+        shell = pkgs.zsh;
         extraGroups = [
           "networkmanager"
           "wheel"
@@ -171,6 +172,7 @@
     localBinInPath = true;
   };
   programs = {
+    zsh.enable = true;
     command-not-found.enable = false;
     ssh.startAgent = true;
     nano = {
diff --git a/system/home/shell/default.nix b/system/home/shell/default.nix
index 282a9a02..e5cd6839 100644
--- a/system/home/shell/default.nix
+++ b/system/home/shell/default.nix
@@ -21,6 +21,37 @@
     # Shells
     bash.enable = true;
     nushell.enable = true;
+    zsh = {
+      enable = true;
+      enableCompletion = true;
+      autocd = true;
+      autosuggestion.enable = true;
+      defaultKeymap = "emacs";
+      syntaxHighlighting = {
+        enable = true;
+        highlighters = [
+          "brackets"
+          "cursor"
+        ];
+      };
+      historySubstringSearch.enable = true;
+      history = {
+        extended = true;
+        share = true;
+        ignoreDups = true;
+        ignoreAllDups = true;
+        ignoreSpace = true;
+        expireDuplicatesFirst = true;
+      };
+      initExtra = ''
+        ## completion config and styling
+        zstyle ':completion:*' matcher-list 'm:{a-z}={A-Za-z}'
+        zstyle ':completion:*' menu 'select=long-list'
+
+        ## transient prompt
+        source ${./transient.zsh}
+      '';
+    };
     # CLI programs and utilities
     btop.enable = true;
     carapace.enable = true;
diff --git a/system/home/shell/transient.zsh b/system/home/shell/transient.zsh
new file mode 100644
index 00000000..1f7bbd82
--- /dev/null
+++ b/system/home/shell/transient.zsh
@@ -0,0 +1,31 @@
+#!/usr/bin/env zsh
+
+zle-line-init() {
+    emulate -L zsh
+
+    [[ $CONTEXT == start ]] || return 0
+
+    while true; do
+        zle .recursive-edit
+        local -i ret=$?
+        [[ $ret == 0 && $KEYS == $'\4' ]] || break
+        [[ -o ignore_eof ]] || exit 0
+    done
+
+    local saved_prompt=$PROMPT
+    local saved_rprompt=$RPROMPT
+    PROMPT='󰁔 '
+    RPROMPT=''
+    zle .reset-prompt
+    PROMPT=$saved_prompt
+    RPROMPT=$saved_rprompt
+
+    if ((ret)); then
+        zle .send-break
+    else
+        zle .accept-line
+    fi
+    return ret
+}
+
+zle -N zle-line-init