#!/usr/bin/env bash
# Reproduce the gioui Android activity-recreation hang with a STOCK gioui
# example app (the "hello" example from gioui.org/example).
#
# What it does:
#   1. Builds gioui.org/example's hello app (unmodified) with gogio.
#   2. Installs it on an emulator (boots one if needed).
#   3. Recreates the activity via `cmd uimode night yes` (uiMode is not in
#      gioui's configChanges mask, so Android destroys/recreates the
#      activity in the same process).
#   4. Taps the app and checks logcat for NO_INPUT_CHANNEL.
#
# The bug (gioui v0.10.x, app/os_android.go onCreateView): on re-attach the
# second onCreateView sends the window-creation ack
# (mainWindow.windows <- struct{}{}) on the UI thread, but its only
# receiver (newWindow in Window.init) never re-runs on Android — the driver
# is never reset, so w.Event() never returns to re-init. The UI thread
# blocks forever, the activity never attaches an input channel, and the app
# is black and unresponsive (process still alive).
#
# Usage:
#   scripts/repro_gioui_hang.sh [avd-name] [path-to-apk]
#
# Exit codes: 0 = bug REPRODUCED, 1 = not reproduced, 2 = setup failure.
set -euo pipefail

AVD=${1:-pad_avd}
APK=${2:-}
SDK=${ANDROID_HOME:-$HOME/android-sdk}
export PATH=$PATH:$HOME/go/bin:$SDK/platform-tools:$SDK/build-tools/35.0.0

say() { printf '\n=== %s\n' "$*"; }
die() { say "FAIL: $*"; exit 2; }

# --- 1. Build the stock hello example, unless an APK was supplied ---------
if [ -z "$APK" ]; then
  SRC=$(mktemp -d)
  trap 'rm -rf "$SRC"' EXIT
  say "building stock gioui.org/example hello app (v0.10.3)"
  go mod download gioui.org/example@v0.10.3
  cp "$HOME/go/pkg/mod/gioui.org/example@v0.10.3/hello/hello.go" "$SRC/main.go"
  cat > "$SRC/go.mod" <<'EOF'
module hello

go 1.23

require gioui.org v0.10.3
EOF
  (cd "$SRC" && go mod tidy && gogio -target android -targetsdk 34 -arch amd64 -o /tmp/hello-gioui-repro.apk .)
  APK=/tmp/hello-gioui-repro.apk
fi
[ -f "$APK" ] || die "APK not found: $APK"

# --- 2. Emulator: reuse a booted one or start $AVD ------------------------
say "waiting for emulator (avd $AVD)"
EMU=""
for _ in $(seq 1 60); do
  EMU=$(adb devices | awk '$1 ~ /^emulator-/ {print $1; exit}')
  [ -n "$EMU" ] && break
  emulator -avd "$AVD" -no-window -no-audio -no-boot-anim -gpu swiftshader_indirect >/dev/null 2>&1 &
  sleep 5
done
[ -n "$EMU" ] || die "no emulator available"
for _ in $(seq 1 60); do
  bc=$(adb -s "$EMU" shell getprop sys.boot_completed 2>/dev/null | tr -d '\r')
  [ "$bc" = "1" ] && break
  sleep 5
done
[ "$(adb -s "$EMU" shell getprop sys.boot_completed | tr -d '\r')" = "1" ] || die "emulator did not boot"
say "emulator: $EMU"

# --- 3. Install + launch ---------------------------------------------------
APPID=localhost.hello   # gogio's default app id for module "hello"
adb -s "$EMU" install -r "$APK" >/dev/null
adb -s "$EMU" shell am force-stop "$APPID" >/dev/null 2>&1 || true
adb -s "$EMU" logcat -c
adb -s "$EMU" shell am start -n "$APPID/org.gioui.GioActivity" >/dev/null
sleep 5
adb -s "$EMU" shell pidof "$APPID" >/dev/null || die "app did not start"
say "baseline: app running"

# --- 4. Recreate the activity ----------------------------------------------
# uiMode is not in gioui's configChanges mask -> Android recreates the
# activity. Force a real state change (a no-op toggle recreates nothing).
cur=$(adb -s "$EMU" shell cmd uimode night | tr -d '\r')   # "Night mode: yes/no"
case $cur in
  *yes*) adb -s "$EMU" shell cmd uimode night no >/dev/null ;;
  *)     adb -s "$EMU" shell cmd uimode night yes >/dev/null ;;
esac
sleep 5
adb -s "$EMU" logcat -c
adb -s "$EMU" shell input tap 540 1200
sleep 2

# --- 5. Verdict -------------------------------------------------------------
adb -s "$EMU" exec-out screencap -p > /tmp/gioui-hang-repro.png
if adb -s "$EMU" logcat -d | grep -q NO_INPUT_CHANNEL; then
  say "REPRODUCED: activity recreation left the window with NO_INPUT_CHANNEL (see /tmp/gioui-hang-repro.png)"
  exit 0
fi
say "NOT reproduced: no NO_INPUT_CHANNEL after recreation (gioui handles re-attach correctly)"
exit 1