# Sourced by bar-<name> modules: one daemon skeleton, one publishing contract.
#
# A module defines render() (prints its segment, tmux markup allowed, empty to
# hide) and INTERVAL, then calls bar_main "$@". The segment lands in the tmux
# user option @bar_<name>; `bar mount` builds status-format[1] from those, so
# no #() ever runs on the status line and each module keeps its own clock.
#
#   bar-<name> --on | --off | --toggle | render | (status)

set -uo pipefail
BAR_STORE="${BAR_HOME:-$HOME/.local/state/bar}"
BAR_NAME="${BAR_MODULE:-${0##*/bar-}}"
BAR_PIDFILE="$BAR_STORE/$BAR_NAME.pid"
INTERVAL="${INTERVAL:-15}"
mkdir -p "$BAR_STORE"

bar_running() { [ -s "$BAR_PIDFILE" ] && kill -0 "$(cat "$BAR_PIDFILE")" 2>/dev/null; }

# refresh-client needs a named client; a daemon has none of its own.
bar_publish() {
  tmux set -g "@bar_$BAR_NAME" "$1" 2>/dev/null || return 1
  tmux list-clients -F '#{client_name}' 2>/dev/null |
    while read -r c; do tmux refresh-client -S -t "$c" 2>/dev/null; done
}

bar_on() {
  bar_running && return 0
  (
    trap 'bar_publish ""; rm -f "$BAR_PIDFILE"' EXIT
    while tmux has-session 2>/dev/null; do
      bar_publish "$(render)" || break
      sleep "$INTERVAL"
    done
  ) >/dev/null 2>&1 &
  echo $! >"$BAR_PIDFILE"
}

bar_off() {
  bar_running && kill "$(cat "$BAR_PIDFILE")" 2>/dev/null
  rm -f "$BAR_PIDFILE"
  bar_publish ""
}

bar_main() {
  case "${1:-}" in
    --on) bar_on ;;
    --off) bar_off ;;
    --toggle) bar_running && bar_off || bar_on ;;
    render) render; echo ;;
    *) bar_running && echo "$BAR_NAME: running (pid $(cat "$BAR_PIDFILE"))" || echo "$BAR_NAME: off" ;;
  esac
}