zsh: configure fzf

modules/zsh.nix

@@ -1,9 +1,26 @@
-{ pkgs, ... }:
+{ pkgs, lib, ... }:
 let
   promptColours.success = "cyan";
   promptColours.failure = "red";
 in
 {
+  programs.fzf = {
+    fuzzyCompletion = true;
+    keybindings = true;
+  };
+
+  environment.variables =
+    let
+      defaultFzf = "${lib.getExe pkgs.fd}/bin/fd --type f --strip-cwd-prefix --no-ignore-vcs --exclude .git";
+    in
+    {
+      FZF_DEFAULT_COMMAND = defaultFzf;
+      FZF_DEFAULT_OPTS = "--height 40%";
+      FZF_CTRL_T_COMMAND = defaultFzf;
+      FZF_CTRL_T_OPTS = "--preview='head -$LINES {}'";
+      FZF_ALT_C_COMMAND = "${lib.getExe pkgs.fd}/bin/fd --type d";
+    };
+
   programs.zsh =
     let
       zsh-completions = pkgs.fetchFromGitHub {