#!/usr/bin/env bash
# Point an Android device at this machine's Metro dev server, permanently.
#
# The app is a plain `expo run:android` debug build (no expo-dev-client), so it
# looks for the packager at localhost:8081 unless told otherwise. Over USB that
# works via `adb reverse`; over Wi-Fi it doesn't, and the app fails with
# "Unable to load script". Writing `debug_http_host` into the app's own
# SharedPreferences fixes it for good: the setting lives in the app's data dir
# and survives app restarts, reboots and adb reconnects.
#
# Usage:
#   scripts/point-device.sh                        # auto-detect device and host IP
#   scripts/point-device.sh 192.168.1.50:5555      # explicit device
#   scripts/point-device.sh 192.168.1.50:5555 192.168.1.10   # explicit host IP
#
# Re-run this after the dev machine's IP changes — and update
# EXPO_PUBLIC_SERVER_URL in .env to match, since the API calls use that.

set -euo pipefail

PKG="com.waseel.app"
PORT="8081"

DEVICE="${1:-}"
HOST_IP="${2:-}"

if [ -z "$DEVICE" ]; then
  mapfile -t TARGETS < <(adb devices | awk 'NR>1 && $2=="device" {print $1}')
  if [ "${#TARGETS[@]}" -eq 0 ]; then
    echo "No device attached. Connect one first (adb connect <ip>:<port>)." >&2
    exit 1
  fi

  # One phone commonly shows up as several transports at once (a TCP address
  # plus one or two auto-reconnecting mDNS entries). Group by hardware serial
  # so that isn't mistaken for two phones, and prefer the ip:port form, which
  # is the stable one to keep addressing.
  declare -A BY_SERIAL=()
  for target in "${TARGETS[@]}"; do
    serial="$(adb -s "$target" shell getprop ro.serialno 2>/dev/null | tr -d '\r\n')"
    [ -z "$serial" ] && serial="$target"
    if [ -z "${BY_SERIAL[$serial]:-}" ] || [[ "$target" == *:* && "${BY_SERIAL[$serial]}" != *:* ]]; then
      BY_SERIAL["$serial"]="$target"
    fi
  done

  if [ "${#BY_SERIAL[@]}" -gt 1 ]; then
    echo "More than one phone attached; pass the one you want:" >&2
    for serial in "${!BY_SERIAL[@]}"; do
      printf '  %s  (serial %s)\n' "${BY_SERIAL[$serial]}" "$serial" >&2
    done
    exit 1
  fi

  for serial in "${!BY_SERIAL[@]}"; do DEVICE="${BY_SERIAL[$serial]}"; done
fi

if [ -z "$HOST_IP" ]; then
  # The address this machine reaches the LAN on — the one the phone can see.
  HOST_IP="$(ip route get 1.1.1.1 2>/dev/null | grep -oP 'src \K[0-9.]+' | head -1)"
fi

if [ -z "$HOST_IP" ]; then
  echo "Could not determine this machine's LAN IP; pass it as the second argument." >&2
  exit 1
fi

echo "Device : $DEVICE"
echo "Metro  : $HOST_IP:$PORT"

if ! adb -s "$DEVICE" shell "run-as $PKG id" >/dev/null 2>&1; then
  echo "Cannot run-as $PKG — the installed build isn't debuggable." >&2
  echo "Rebuild with 'npx expo run:android' (a debug build), then re-run this." >&2
  exit 1
fi

# A running app holds its prefs in memory and rewrites the file on exit, so the
# write only sticks if the app is stopped first.
adb -s "$DEVICE" shell "am force-stop $PKG"

PREFS="/data/data/$PKG/shared_prefs/${PKG}_preferences.xml"
TMP="/data/local/tmp/waseel_prefs.xml"

cat <<EOF > /tmp/waseel_prefs.xml
<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
<map>
    <boolean name="remote_js_debug" value="false" />
    <string name="debug_http_host">$HOST_IP:$PORT</string>
</map>
EOF

adb -s "$DEVICE" push /tmp/waseel_prefs.xml "$TMP" >/dev/null
# Piped through run-as so the file lands owned by the app uid, not shell.
adb -s "$DEVICE" shell "cat $TMP | run-as $PKG sh -c 'cat > $PREFS'"
adb -s "$DEVICE" shell "rm -f $TMP"
rm -f /tmp/waseel_prefs.xml

# Fallback path for USB sessions; harmless over Wi-Fi and not relied upon.
adb -s "$DEVICE" reverse "tcp:$PORT" "tcp:$PORT" >/dev/null 2>&1 || true

echo "Set debug_http_host:"
adb -s "$DEVICE" shell "run-as $PKG cat $PREFS" | tr -d '\r' | grep debug_http_host

# `am start` on the explicit activity, rather than `monkey`, which silently
# drops the launch often enough to be untrustworthy in a script.
adb -s "$DEVICE" shell "am start -n $PKG/.MainActivity" >/dev/null 2>&1
sleep 3
if adb -s "$DEVICE" shell dumpsys window 2>/dev/null | grep -q "mCurrentFocus.*$PKG"; then
  echo "Launched $PKG — now loading from $HOST_IP:$PORT."
else
  echo "Wrote the setting, but $PKG didn't come to the foreground. Open it by hand." >&2
fi