#!/usr/bin/env bash
# Decompose a screen transition's ~0.4 s fade-out into RAMP + HOLD, at the
# emulator's own frame granularity.
#
# docs/re/screen-transitions.md measures the fade-out as ~0.4 s (~24 units) while
# `pteff00.prm`'s final declared ramp is 70->80 = 10 units. The remainder is
# currently ARITHMETIC THAT FITS -- "the other 14 units must be the black hold"
# -- and that page says so itself. This measures it instead.
#
# The design point: arm the UI draw capture ON THE MAIN MENU, then press (B).
# One capture window then contains
#   * the menu's fade-OUT   -- the unknown, and
#   * the title's fade-IN   -- whose ramp IS decoded from the file (build 4's
#                              pteff00.prm, t=16 a=255 -> t=261 a=0, 245 units),
# so the run carries its own control: an instrument that cannot reproduce the
# known fade-in cannot be trusted on the unknown fade-out.
#
# Traps inherited from menu_draw_capture.sh, both already paid for:
#   * F10 arms the capture AND opens the emulator menu bar; any Xenia UI makes
#     IsUIActive() true and every later guest keystroke is swallowed. Click the
#     game surface to dismiss before touching the pad.
#   * a 0.12 s tap gets missed; hold (B) 0.5 s and confirm [RE-INPUT] delivery.
#
# WHERE=menu (default) arms on the main menu and presses (B)  -> menu -> title.
# WHERE=title            arms on the boot title and presses (A) -> title -> menu.
# WHERE=extras           navigates to EXTRAS, arms there, presses (B) -> menu.
#                        Tests whether "(B) has no black interval" is a rule or
#                        one screen pair -- sylpheed-port's BLOCKED.md ask #1.
# The two transitions have DIFFERENT declared fade-ins for the incoming screen --
# build 4 is 0->16 (16 units, 8 frames), build 5 is 0->12 (12 units, 6 frames) --
# which is what makes the pair a discriminator rather than a fit.
#
# Usage: WHERE=title fade_decompose.sh [out_dir]
set -u
export HOME=/sylph-home/re SDL_AUDIODRIVER=dummy DISPLAY=:98
SD="$(cd "$(dirname "$0")" && pwd)"
OUT="${1:-/sylph-home/re/fadecap}"
mkdir -p "$OUT"; rm -f "$OUT"/xenia_re_ui_draws_*.log
alive(){ ps -o pid=,stat= -C xenia_canary 2>/dev/null | awk '$2 !~ /^Z/ {print $1}'; }
shot(){ screenshot "$1" >/dev/null 2>&1; }
screen(){ shot /tmp/fdc.png; python3 "$SD/screen_id.py" /tmp/fdc.png | awk '{print $1}'; }

( cd "$OUT" && nohup run-canary --mem_watch=false --log_ui_draws=true \
    --ui_draw_capture_frames="${FRAMES:-260}" \
    --ui_draw_capture_max="${MAXDRAWS:-400000}" \
    --logged_profile_slot_0_xuid=B13EBABEBABEBABE \
    >"$OUT/canary.stdout" 2>"$OUT/canary.stderr" & )
sleep 8
until xdotool search --name "Xenia-canary" >/dev/null 2>&1; do
  [ -n "$(alive)" ] || { echo "EMULATOR GONE"; exit 4; }; sleep 1
done
win="$(xdotool search --name "Xenia-canary" | tail -1)"

# 1. wait for the boot title; do not tap through the intro (a run that tapped
#    every 4 s delivered 88 presses and ended on a black screen).
deadline=$(( SECONDS + 420 )); s=""
while [ $SECONDS -lt $deadline ]; do
  s="$(screen)"; echo "t=${SECONDS}s $s"
  [ "$s" = "title" ] && break
  sleep 4
done
[ "$s" = "title" ] || { echo "NEVER REACHED THE TITLE"; exit 1; }

WHERE="${WHERE:-menu}"
if [ "$WHERE" = "menu" ]; then
  # 2. one (A) on the boot title -> main menu; we arm THERE and press (B).
  python3 "$SD/pad.py" tap A 0.5
  for _ in 1 2 3 4 5 6; do
    sleep 4; s="$(screen)"; echo "  after A: $s"
    [ "$s" = "menu" ] && break
  done
  [ "$s" = "menu" ] || { echo "NO MENU (screen=$s)"; exit 2; }
  BTN=B
elif [ "$WHERE" = "extras" ]; then
  python3 "$SD/pad.py" tap A 0.5
  for _ in 1 2 3 4 5 6; do
    sleep 4; s="$(screen)"; echo "  after A: $s"
    [ "$s" = "menu" ] && break
  done
  [ "$s" = "menu" ] || { echo "NO MENU (screen=$s)"; exit 2; }
  # EXTRAS is the only main-menu button that stays inside GP_TITLE, and initial
  # focus varies boot to boot, so search: press (A), ask which screen we got, and
  # if it is not EXTRAS come back with (B) and step the cursor. screen_id.py
  # cannot tell EXTRAS from the main menu -- both are dark blue GP_TITLE screens
  # -- so the check is which_title_screen.py, whose control separates them by
  # ~11 RMSE against ~18 within-class.
  found=""
  for try in 1 2 3 4 5 6; do
    python3 "$SD/pad.py" tap A 0.5; sleep 5
    shot "$OUT/try$try.png"
    w="$(python3 "$SD/which_title_screen.py" "$OUT/try$try.png")"
    echo "  try $try: $w"
    case "$w" in extras*) found=1; break;; esac
    python3 "$SD/pad.py" tap B 0.5; sleep 5
    python3 "$SD/pad.py" dpad UP 0.3; sleep 2
  done
  [ -n "$found" ] || { echo "NEVER REACHED EXTRAS"; exit 3; }
  BTN=B
else
  # arm on the title itself and press (A): the incoming screen is then build 5,
  # whose declared fade-in is 12 units where build 4's is 16.
  BTN=A
fi
shot "$OUT/armed-on-$WHERE.png"

# 3. arm the capture, dismiss the menu bar F10 opened, then press (B).
#    Everything between F10 and (B) is spent inside the capture window, so keep
#    it short: the window is FRAMES submitted frames, not seconds.
xdotool windowactivate --sync "$win"; sleep 1
xdotool key F10; sleep 0.6
xdotool mousemove 900 400 click 1; sleep 0.6
echo "-- ($BTN) at $(date +%S.%N) --"
python3 "$SD/pad.py" tap $BTN 0.5
sleep 12
shot "$OUT/after-press.png"; echo "screen after $BTN: $(screen)"

grep -c "RE-INPUT" "$OUT/canary.stdout" 2>/dev/null | sed 's/^/[RE-INPUT] lines: /'
ls -l "$OUT"/xenia_re_ui_draws_*.log 2>/dev/null || echo "NO CAPTURE LOG"
grep -i "UI-CAP" "$OUT/canary.stdout" | tail -3
echo "FADE CAPTURE DONE (emulator left running)"