Extend agent-nav.sh to also work with windows indices

agent-nav.sh

@@ -1,24 +1,27 @@
 #!/usr/bin/env bash
-# Cycle the agent popup through the windows of the session underneath it rather
-# than through the agent session's own window list. Bound to <prefix>C-n and
-# <prefix>C-p inside the agent session (see tmux.conf).
+# Drive the agent popup from the windows of the session underneath it rather
+# than from the agent session's own window list. Bound inside the agent session
+# to <prefix>C-n and <prefix>C-p ("next"/"prev") and to <prefix>0..9 (a window
+# index) -- see tmux.conf.
 #
-# Root windows with no agent window are stepped over; cycling never creates an
-# agent window, only <prefix>A does. Both the client underneath and the popup
-# move, so closing the popup leaves you on the window you cycled to.
+# Root windows with no agent window are stepped over when cycling and do nothing
+# when named by index, so the popup and the session below it never disagree.
+# Neither ever creates an agent window; only <prefix>A does. Both the client
+# underneath and the popup move, so closing the popup leaves you where you went.
 
 set -e
 
-direction=${1:-next}
+target=${1:-next}
 us=$'\x1f'
 
 # Fall back to plain window cycling within the agent session when there is no
 # usable client underneath (popup opened before this was configured, or the
 # recorded client has gone away).
 fallback() {
-  case $direction in
+  case $target in
+    next) tmux next-window -t agent ;;
     prev) tmux previous-window -t agent ;;
-    *) tmux next-window -t agent ;;
+    *) tmux select-window -t "agent:$target" 2>/dev/null || true ;;
   esac
   exit 0
 }
@@ -64,22 +67,48 @@ agent_window_for() {
   return 1
 }
 
-# The underlying session's windows, in its own order, each with its first pane's
-# directory. Panes are listed grouped by window in index order.
+# Move the client underneath and the popup together. The agent window is re-keyed
+# to the window being moved to, so the sync hook that the select below fires
+# agrees with what happened here instead of dragging the client back to wherever
+# that window was last opened from.
+move_to() { # move_to <root window id> <agent window id>
+  tmux set-window-option -t "$2" @agent_origin_window "$1"
+  tmux select-window -t "$1"
+  tmux select-window -t "$2"
+  exit 0
+}
+
+# The underlying session's windows, in its own order, each with its index and its
+# first pane's directory. Panes are listed grouped by window in index order.
 root_windows=()
+root_indexes=()
 root_paths=()
 seen_window=""
-while IFS=$us read -r window_id start_path current_path; do
+while IFS=$us read -r window_id window_index start_path current_path; do
   [ "$window_id" != "$seen_window" ] || continue
   seen_window=$window_id
   root_windows+=("$window_id")
+  root_indexes+=("$window_index")
   root_paths+=("$start_path$us$current_path")
 done < <(tmux list-panes -s -t "$client_session" \
-  -F "#{window_id}$us#{pane_start_path}$us#{pane_current_path}" 2>/dev/null || true)
+  -F "#{window_id}$us#{window_index}$us#{pane_start_path}$us#{pane_current_path}" \
+  2>/dev/null || true)
 
 count=${#root_windows[@]}
 [ "$count" -gt 0 ] || exit 0
 
+# <prefix>0..9: the window with that index in the session underneath. Doing
+# nothing when it has no agent window keeps the popup and that session in step.
+if [ -n "$target" ] && [ -z "${target//[0-9]/}" ]; then
+  for i in "${!root_windows[@]}"; do
+    [ "${root_indexes[$i]}" = "$target" ] || continue
+    IFS=$us read -r start_path current_path <<<"${root_paths[$i]}"
+    target_agent=$(agent_window_for "${root_windows[$i]}" "$start_path" "$current_path") || exit 0
+    move_to "${root_windows[$i]}" "$target_agent"
+  done
+  exit 0
+fi
+
 # Where the client sits in that order.
 current=0
 for i in "${!root_windows[@]}"; do
@@ -89,7 +118,7 @@ for i in "${!root_windows[@]}"; do
   fi
 done
 
-if [ "$direction" = prev ]; then step=-1; else step=1; fi
+if [ "$target" = prev ]; then step=-1; else step=1; fi
 
 # Walk in that direction for the first window with an agent window, wrapping.
 # Landing back on the starting window means nothing else has one: selecting it
@@ -100,12 +129,5 @@ for _ in $(seq 1 "$count"); do
   target_root=${root_windows[$i]}
   IFS=$us read -r start_path current_path <<<"${root_paths[$i]}"
   target_agent=$(agent_window_for "$target_root" "$start_path" "$current_path") || continue
-
-  # Re-key the agent window to the window being moved to, so the sync hook that
-  # the select below fires agrees with what happened here instead of dragging
-  # the client back to wherever that window was last opened from.
-  tmux set-window-option -t "$target_agent" @agent_origin_window "$target_root"
-  tmux select-window -t "$target_root"
-  tmux select-window -t "$target_agent"
-  exit 0
+  move_to "$target_root" "$target_agent"
 done