#!/usr/bin/env bash
# Install, start, stop, or inspect hand tracking on the Frame: ft-camd (the camera broker) and
# ft-hands (the tracker), user services that start and stop with SteamVR.
# Usage: hands/run.sh install|uninstall
#        hands/run.sh caps      # give ft-camd its capabilities again (a rebuild clears them)
#        hands/run.sh start|stop|restart|status|log [lines]
# install and caps need the password (sudo setcap, once per build of ft-camd). On the Frame,
# sudo asks in the terminal. From a PC (or with no terminal), the password comes from
# steamos_root_pwd in the repo's .env and is sent to sudo -S on stdin, never on a command line.
set -euo pipefail
root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
. "$root/scripts/_env.sh"
frame="$root/scripts/frame.sh"
units="frametop-camd.service frametop-hands.service"
# pidfd_getfd on XRService (ptrace_scope=1), system-wide tracepoints, and their root-only
# format files. ft-camd drops them all once it has set up.
caps=cap_sys_ptrace,cap_perfmon,cap_dac_read_search+ep

sudo_run() {
  if [ "$FRAME_LOCAL" = 1 ] && [ -t 0 ]; then
    sudo bash -c "$1"  # asks for the password here
    return
  fi
  local pw
  pw=$(sed -n 's/^steamos_root_pwd=//p' "$root/.env" 2>/dev/null)
  pw=${pw#[\"\']}; pw=${pw%[\"\']}  # .env values may be quoted
  [ -n "$pw" ] || { echo "no terminal for sudo, and steamos_root_pwd is missing from $root/.env" >&2; exit 1; }
  printf '%s\n' "$pw" | on_frame "sudo -S -p '' bash -c $(printf %q "$1")"
}

set_caps() {
  local bin
  bin=$(printf %q "$FRAME_REPO/hands/build/ft-camd")
  sudo_run "setcap $caps $bin && getcap $bin"
}

states="for u in $units; do echo \"\$u: \$(systemctl --user is-active \$u)\"; done"

case ${1:-status} in
  install)
    "$root/hands/build.sh"
    set_caps
    for u in $units; do
      fill_template "$root/hands/$u" | on_frame "mkdir -p ~/.config/systemd/user && cat > ~/.config/systemd/user/$u"
    done
    "$frame" --host "set -e; systemctl --user daemon-reload; systemctl --user enable $units
if systemctl --user -q is-active steamvr.service; then systemctl --user restart $units; sleep 5; fi
$states" ;;
  caps) set_caps ;;
  uninstall) "$frame" --host "systemctl --user disable --now $units 2>/dev/null
for u in $units; do rm -f ~/.config/systemd/user/\$u; done; systemctl --user daemon-reload; echo removed" ;;
  start|stop|restart) "$frame" --host "systemctl --user $1 $units; $states" ;;
  status) "$frame" --host "$states; journalctl --user -u frametop-hands.service --no-pager -o cat -n 4" || true ;;
  log) "$frame" --host "journalctl --user -u frametop-camd.service -u frametop-hands.service --no-pager -o short -n ${2:-30}" ;;
  *) echo "usage: $0 install|uninstall|caps|start|stop|restart|status|log [lines]" >&2; exit 2 ;;
esac