#!/usr/bin/env bash
# One blocking foreground session: boot to flight, then measure angular rate with
# the per-frame probe instead of host polling.
#
# Everything (Xvfb, openbox, xenia) is a plain child of THIS script. Anything
# `setsid`'d is reaped at the agent's turn boundary — see the session-lifetime
# note in launch_mission.sh — so the whole run has to fit in one call.
#
# Usage: frame_session.sh [stage] [hold_s] [repeats]
set -u
STAGE="${1:-10}"; HOLD="${2:-3.0}"; REPS="${3:-2}"
export HOME=/sylph-home/re DISPLAY="${DISPLAY:-:99}" SDL_AUDIODRIVER=dummy
export XENIA_PAD_FILE=/tmp/xenia_pad.txt
export XENIA_FRAME_PROBE=/tmp/xenia_frame_probe.txt

HERE="$(cd "$(dirname "$0")" && pwd)"
OUT="$HOME/frameprobe"; mkdir -p "$OUT"
LOG="$OUT/frame-stage$STAGE.log"
say() { echo "[$(date +%H:%M:%S)] $*"; }

ensure_display() {
  if ! xdpyinfo -display "$DISPLAY" >/dev/null 2>&1; then
    rm -f "/tmp/.X${DISPLAY#:}-lock" 2>/dev/null || true
    nohup bash -c 'Xvfb "$0" -screen 0 1280x720x24 -ac -nolisten tcp \
        +extension GLX +extension RANDR >/tmp/xvfb${DISPLAY#:}.log 2>&1
      echo "$(date +%T) XVFB EXIT $? (128+N means signal N)" >>/tmp/xvfb-exit.log' \
      "$DISPLAY" </dev/null >/dev/null 2>&1 &
    for _ in $(seq 1 50); do xdpyinfo -display "$DISPLAY" >/dev/null 2>&1 && break; sleep 0.2; done
    nohup env DISPLAY="$DISPLAY" HOME=/sylph-home openbox </dev/null >/tmp/openbox${DISPLAY#:}.log 2>&1 &
    sleep 1
  fi
  xdpyinfo -display "$DISPLAY" >/dev/null 2>&1 || { say "DISPLAY UNAVAILABLE"; exit 1; }
}

ensure_display
# A stale control file would make the probe log the PREVIOUS run's addresses from
# the first frame, which land in whatever occupies them now.
rm -f "$XENIA_FRAME_PROBE"

# REUSE=1 drives a Canary that is already up (it must have been launched with the
# same --frame_probe_log). Booting to the title costs minutes under lavapipe and
# a run that only failed to navigate should not pay for it again.
if [ "${REUSE:-0}" = 1 ] && pgrep -x xenia_canary >/dev/null; then
  say "re-using the running emulator; navigating to stage $STAGE"
  "$HERE/nav_to_flight.sh" "$STAGE" 300 || { say "navigation failed ($?)"; exit 2; }
else
  rm -f "$LOG"
  say "booting to flight on stage $STAGE with the per-frame probe armed"
  CANARY_EXTRA="--frame_probe_log=$LOG --frame_probe=$XENIA_FRAME_PROBE" \
    "$HERE/fly_stage.sh" "$STAGE" 300 || { say "boot failed ($?)"; exit 2; }
fi

say "arming the probe on the player craft and driving the bursts"
python3 "$HERE/frame_burst.py" "$OUT/events-stage$STAGE.csv" "$HOLD" "$REPS"
rc=$?
# Stop sampling before the emulator is torn down, so the log ends cleanly.
rm -f "$XENIA_FRAME_PROBE"
say "frame log: $LOG ($(wc -l < "$LOG" 2>/dev/null || echo 0) lines)"
exit $rc