#!/usr/bin/env bash
# Stand up a *viewable* desktop inside the dev container so you can see and
# click the headed Elmhurst browser. Pipeline:
#
#   Xvfb (:99 virtual screen) -> fluxbox (window manager)
#     -> x11vnc (exposes :99 over VNC on 5900)
#       -> websockify/noVNC (serves VNC in a browser tab on 6080)
#
# Then: forward port 6080 (VS Code does this automatically), open it, and run
# Playwright with DISPLAY=:99 so the browser appears on this desktop.
#
#   bash scripts/hyde/start_viewer.sh          # start it
#   bash scripts/hyde/start_viewer.sh stop     # tear it down
#
# Idempotent: re-running won't stack duplicate servers.
set -euo pipefail

DISPLAY_NUM=":99"
SCREEN="1600x1000x24"
VNC_PORT=5900
WEB_PORT=6080
RUN_DIR="/tmp/hyde-viewer"
mkdir -p "$RUN_DIR"

_pids() { pgrep -f "$1" 2>/dev/null || true; }

stop() {
  echo "Stopping viewer..."
  for pat in "websockify.*$WEB_PORT" "x11vnc.*$DISPLAY_NUM" "fluxbox" "Xvfb $DISPLAY_NUM"; do
    for pid in $(_pids "$pat"); do kill "$pid" 2>/dev/null || true; done
  done
  rm -f "/tmp/.X${DISPLAY_NUM#:}-lock" 2>/dev/null || true
  echo "Stopped."
}

start() {
  # Xvfb — the virtual screen everything draws into.
  if [ -z "$(_pids "Xvfb $DISPLAY_NUM")" ]; then
    Xvfb "$DISPLAY_NUM" -screen 0 "$SCREEN" -ac >"$RUN_DIR/xvfb.log" 2>&1 &
    sleep 1
    echo "Xvfb up on $DISPLAY_NUM ($SCREEN)"
  else
    echo "Xvfb already running on $DISPLAY_NUM"
  fi

  # fluxbox — a window manager so the browser window is movable/resizable.
  if [ -z "$(_pids "fluxbox")" ]; then
    DISPLAY="$DISPLAY_NUM" fluxbox >"$RUN_DIR/fluxbox.log" 2>&1 &
    sleep 1
    echo "fluxbox window manager up"
  fi

  # x11vnc — exposes the screen over VNC. -forever keeps it alive across
  # client reconnects; -nopw is fine because the port is only reachable
  # through the container's forwarded port, not the public internet.
  if [ -z "$(_pids "x11vnc.*$DISPLAY_NUM")" ]; then
    x11vnc -display "$DISPLAY_NUM" -rfbport "$VNC_PORT" -forever -shared \
      -nopw -quiet -bg -o "$RUN_DIR/x11vnc.log"
    echo "x11vnc up on VNC port $VNC_PORT"
  else
    echo "x11vnc already running"
  fi

  # noVNC/websockify — serves the VNC stream as a web page on WEB_PORT.
  if [ -z "$(_pids "websockify.*$WEB_PORT")" ]; then
    websockify --web=/usr/share/novnc "$WEB_PORT" "localhost:$VNC_PORT" \
      >"$RUN_DIR/websockify.log" 2>&1 &
    sleep 1
    echo "noVNC up on web port $WEB_PORT"
  fi

  cat <<EOF

Desktop ready.
  1. Open the forwarded port $WEB_PORT in your browser:
       http://localhost:$WEB_PORT/vnc.html?autoconnect=1&resize=remote
     (In VS Code: PORTS tab -> forward $WEB_PORT -> open in browser.)
  2. Run the Playwright login pointing at this display:
       DISPLAY=$DISPLAY_NUM python scripts/hyde/elmhurst_session.py login --url <elmhurst-url>
     The browser window will appear on the desktop you opened in step 1.
EOF
}

case "${1:-start}" in
  start) start ;;
  stop) stop ;;
  restart) stop; start ;;
  *) echo "usage: $0 [start|stop|restart]"; exit 2 ;;
esac