Override ^p/^n in agent session to switch between root windows

agent-nav.sh

@@ -0,0 +1,111 @@
+#!/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).
+#
+# 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.
+
+set -e
+
+direction=${1:-next}
+us=$'\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 $direction in
+    prev) tmux previous-window -t agent ;;
+    *) tmux next-window -t agent ;;
+  esac
+  exit 0
+}
+
+popup_client=$(tmux display-message -p '#{@agent_popup_client}' 2>/dev/null || true)
+[ -n "$popup_client" ] || fallback
+
+# The session and window underneath the popup, as the client sees them now.
+client_info=$(tmux list-clients -F "#{client_name}$us#{session_name}$us#{window_id}" \
+  | awk -v FS="$us" -v client="$popup_client" '$1 == client { print $2 FS $3; exit }')
+[ -n "$client_info" ] || fallback
+IFS=$us read -r client_session client_window <<<"$client_info"
+
+# Every agent window, with what it is keyed to.
+agent_ids=()
+agent_dirs=()
+agent_origins=()
+while IFS=$us read -r window_id dir origin; do
+  [ -n "$dir" ] || continue
+  agent_ids+=("$window_id")
+  agent_dirs+=("$dir")
+  agent_origins+=("$origin")
+done < <(tmux list-windows -t agent \
+  -F "#{window_id}$us#{@agent_dir}$us#{@agent_origin_window}" 2>/dev/null || true)
+[ ${#agent_ids[@]} -gt 0 ] || exit 0
+
+# The agent window serving a root window: by recorded origin first, then by the
+# directory its first pane sits in. Mirrors agent-sync.sh's resolution, reversed.
+agent_window_for() {
+  local root_window=$1 start_path=$2 current_path=$3 i
+  for i in "${!agent_ids[@]}"; do
+    if [ -n "${agent_origins[$i]}" ] && [ "${agent_origins[$i]}" = "$root_window" ]; then
+      printf '%s\n' "${agent_ids[$i]}"
+      return 0
+    fi
+  done
+  for i in "${!agent_ids[@]}"; do
+    if [ "${agent_dirs[$i]}" = "$start_path" ] || [ "${agent_dirs[$i]}" = "$current_path" ]; then
+      printf '%s\n' "${agent_ids[$i]}"
+      return 0
+    fi
+  done
+  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.
+root_windows=()
+root_paths=()
+seen_window=""
+while IFS=$us read -r window_id start_path current_path; do
+  [ "$window_id" != "$seen_window" ] || continue
+  seen_window=$window_id
+  root_windows+=("$window_id")
+  root_paths+=("$start_path$us$current_path")
+done < <(tmux list-panes -s -t "$client_session" \
+  -F "#{window_id}$us#{pane_start_path}$us#{pane_current_path}" 2>/dev/null || true)
+
+count=${#root_windows[@]}
+[ "$count" -gt 0 ] || exit 0
+
+# Where the client sits in that order.
+current=0
+for i in "${!root_windows[@]}"; do
+  if [ "${root_windows[$i]}" = "$client_window" ]; then
+    current=$i
+    break
+  fi
+done
+
+if [ "$direction" = prev ]; then step=-1; else step=1; fi
+
+# Walk in that direction for the first window with an agent window, wrapping.
+# Landing back on the starting window means nothing else has one: selecting it
+# again is a no-op, which is the wanted behaviour.
+i=$current
+for _ in $(seq 1 "$count"); do
+  i=$(( (i + step + count) % count ))
+  target_root=${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
+done