#!/bin/bash
# rebuild_wechathook.sh — compile WeChatHook, repackage into com.example.wechathook APK
# Uses the existing APK from device as a base (preserves binary AndroidManifest).
set -e

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
ADB="${ADB:-$SCRIPT_DIR/../platform-tools/adb}"
[ ! -f "$ADB" ] && ADB=adb

ANDROID_HOME="${ANDROID_HOME:-/opt/homebrew/share/android-commandlinetools}"
ANDROID_JAR="$ANDROID_HOME/platforms/android-36/android.jar"
D8="$ANDROID_HOME/build-tools/36.0.0/d8"
APKSIGNER="$ANDROID_HOME/build-tools/36.0.0/apksigner"
LSPOSED_DIR="${LSPOSED_DIR:-/tmp/LSPosed}"
LEGACY_JAR="$LSPOSED_DIR/legacy/build/intermediates/compile_library_classes_jar/release/bundleLibCompileToJarRelease/classes.jar"

if [ ! -f "$LEGACY_JAR" ]; then
  echo "LSPosed legacy JAR not found at $LEGACY_JAR"
  echo "Run: git clone --depth 1 --recursive https://github.com/JingMatrix/LSPosed.git $LSPOSED_DIR && cd $LSPOSED_DIR && ./gradlew :legacy:assembleRelease"
  exit 1
fi

BUILD_DIR=/tmp/wechathook_rebuild
rm -rf "$BUILD_DIR"
mkdir -p "$BUILD_DIR/compiled" "$BUILD_DIR/dex" "$BUILD_DIR/pack/assets"

# Pull current APK from device to reuse its binary AndroidManifest and resources.arsc
echo "== Pulling current wechathook APK from device =="
WH_PATH=$($ADB shell "pm path com.example.wechathook 2>/dev/null | tr -d '\r' | sed 's/package://'" 2>/dev/null)
if [ -z "$WH_PATH" ]; then
  echo "ERROR: com.example.wechathook not installed on device"
  exit 1
fi
$ADB shell "su -c \"cp $WH_PATH /data/local/tmp/wh_base.apk && chmod 644 /data/local/tmp/wh_base.apk\""
$ADB pull /data/local/tmp/wh_base.apk "$BUILD_DIR/pack/base.apk" 2>/dev/null

# Extract AndroidManifest and resources from existing APK
cd "$BUILD_DIR/pack" && unzip -o base.apk AndroidManifest.xml resources.arsc -d . > /dev/null 2>&1
rm -f base.apk

echo "== Compiling WeChatHook.java =="
javac --release 11 \
  -classpath "$ANDROID_JAR:$LEGACY_JAR" \
  -d "$BUILD_DIR/compiled" \
  "$SCRIPT_DIR/WeChatHook.java"

echo "== Converting to DEX =="
$D8 \
  --classpath "$ANDROID_JAR" \
  --classpath "$LEGACY_JAR" \
  --min-api 27 \
  --output "$BUILD_DIR/dex" \
  $(find "$BUILD_DIR/compiled/com/example/wechathook" -name "*.class")

echo "== Packing APK =="
cp "$BUILD_DIR/dex/classes.dex" "$BUILD_DIR/pack/"
# Put xposed_init in assets/ (required by lspd) AND root (belt+suspenders)
echo "com.example.wechathook.WeChatHook" > "$BUILD_DIR/pack/assets/xposed_init"
echo "com.example.wechathook.WeChatHook" > "$BUILD_DIR/pack/xposed_init"

cd "$BUILD_DIR/pack"
zip -0 wechathook.apk AndroidManifest.xml resources.arsc classes.dex xposed_init 2>/dev/null || true
zip -0 wechathook.apk assets/xposed_init

# Sign
if [ ! -f /tmp/debug.keystore ]; then
  keytool -genkey -v -keystore /tmp/debug.keystore -alias androiddebugkey \
    -keyalg RSA -keysize 2048 -validity 10000 \
    -storepass android -keypass android \
    -dname "CN=Android Debug,O=Android,C=US" 2>/dev/null
fi

echo "== Signing =="
OUT="$SCRIPT_DIR/wechathook_v2_signed.apk"
$APKSIGNER sign \
  --ks /tmp/debug.keystore \
  --ks-key-alias androiddebugkey \
  --ks-pass pass:android \
  --key-pass pass:android \
  --out "$OUT" \
  "$BUILD_DIR/pack/wechathook.apk" 2>/dev/null

echo "== Done: $OUT =="
echo "APK size: $(wc -c < "$OUT") bytes"
echo ""
echo "Next steps:"
echo "  adb install -r --no-incremental $OUT"
echo "  bash $SCRIPT_DIR/update_wechathook_db.sh"
echo "  adb reboot"