#!/usr/bin/env bash
# Save and restore the state of tmux sessions and windows.
# TODO: persist and restore the state & position of panes.
set -e

dump() {
  local d=$'\t'
  tmux list-windows -a -F "#S${d}#W${d}#{pane_current_path}"
}

save() {
  dump >~/.tmux-session
}

terminal_size() {
  stty size 2>/dev/null | awk '{ printf "-x%d -y%d", $2, $1 }'
}

session_exists() {
  tmux has-session -t "$1" 2>/dev/null
}

add_window() {
  tmux new-window -d -t "$1:" -n "$2" -c "$3"
}

new_session() {
  cd "$3" &&
    tmux new-session -d -s "$1" -n "$2" $4
}

restore() {
  tmux start-server
  local count=0
  local dimensions="$(terminal_size)"

  while IFS=$'\t' read session_name window_name dir; do
    if [[ -d "$dir" && $window_name != "log" && $window_name != "man" ]]; then
      if session_exists "$session_name"; then
        add_window "$session_name" "$window_name" "$dir"
      else
        new_session "$session_name" "$window_name" "$dir" "$dimensions"
        count=$((count + 1))
      fi
    fi
  done <~/.tmux-session

  echo "restored $count sessions"
}

case "$1" in
save | restore)
  $1
  ;;
*)
  echo "valid commands: save, restore" >&2
  exit 1
  ;;
esac
