#!/usr/bin/env bash
# Wait until screen_id.py reports <class>, instead of sleeping a guessed number
# of seconds.
#
# Written because `launch_mission.sh` allowed a fixed 28 s for LOAD -> READY
# ROOM and neither run on 2026-08-23 was ready in time: the next press was
# swallowed by the transition, which left one run in OPTIONS and the next in
# BRIEFINGS, and `wait_flight.sh` then tapped A into the wrong screen for five
# minutes. See docs/re/dynamic-re-state-restore.md.
#
# `--tap BTN` presses BTN every 6 s *until the class is first seen* — that is
# what clears a dialog the caller cannot know about, such as the
# "Auto-Save is active. OK?" that a freshly restored profile puts up. Tapping
# STOPS at the first match, because on most screens the button that dismisses a
# dialog also leaves the screen you are waiting for.
#
# Two consecutive matches are required, so a single frame caught mid-fade does
# not count as arrival.
#
# Usage: wait_screen.sh <class> [timeout_s] [--tap BTN]
set -u
CLASS="${1:?usage: wait_screen.sh <class> [timeout_s] [--tap BTN]}"
TIMEOUT="${2:-180}"
TAP=""
[ "${3:-}" = "--tap" ] && TAP="${4:-A}"
export HOME=/sylph-home/re
DISP="${DISPLAY:-:98}"
SD="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Same liveness rule as skip_intro.sh/wait_flight.sh: a failed screenshot must
# not be indistinguishable from "the screen is not there yet".
alive(){ ps -o pid=,stat= -C xenia_canary 2>/dev/null | awk '$2 !~ /^Z/ {print $1}'; }

DEADLINE=$(( SECONDS + TIMEOUT ))
hits=0; seen=0; last_tap=0
while [ $SECONDS -lt $DEADLINE ]; do
  rm -f /tmp/ws.png
  if ! screenshot /tmp/ws.png >/dev/null 2>&1 || [ ! -s /tmp/ws.png ]; then
    xdpyinfo -display "$DISP" >/dev/null 2>&1 \
      || { echo "DISPLAY LOST at ${SECONDS}s"; exit 3; }
    sleep 2; continue
  fi
  [ -n "$(alive)" ] || { echo "EMULATOR GONE at ${SECONDS}s"; exit 4; }
  got="$(python3 "$SD/screen_id.py" /tmp/ws.png | awk '{print $1}')"
  if [ "$got" = "$CLASS" ]; then
    seen=1; hits=$(( hits + 1 ))
    [ $hits -ge 2 ] && { echo "$CLASS at ${SECONDS}s"; exit 0; }
  else
    hits=0
    if [ -n "$TAP" ] && [ $seen -eq 0 ] && [ $(( SECONDS - last_tap )) -ge 6 ]; then
      python3 "$SD/pad.py" tap "$TAP" 0.3
      last_tap=$SECONDS
    fi
  fi
  sleep 2
done
echo "NO $CLASS within ${TIMEOUT}s (last seen: ${got:-none})"; exit 1