#!/usr/bin/env bash
# Inject the Vulkan interposer (shim/vkshim.c, built to shim/out/libvulkan.so)
# into a gallery APK as lib/<abi>/libvulkan.so, so the app's linker namespace
# serves it to wgpu-hal's dlopen("libvulkan.so") INSTEAD of /system/lib64.
#
#   scripts/inject_vkshim.sh <abi> <in.apk> <out.apk>
#     abi: arm64-v8a | x86_64
#
# Steps: python adds the .so as an UNCOMPRESSED (STORED) zip entry (required
# for extractNativeLibs=false), zipalign page-aligns it, apksigner re-signs
# (the plain zip write invalidates the old signature).
set -euo pipefail
cd "$(dirname "$0")/.."

ABI=${1:?usage: inject_vkshim.sh <abi> <in.apk> <out.apk>}
IN=${2:?missing in.apk}
OUT=${3:?missing out.apk}

case $ABI in
  arm64-v8a) SHIM=shim/out/libvulkan.so ;;
  x86_64)
    NDK=$HOME/android-sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin
    $NDK/x86_64-linux-android26-clang -shared -fPIC -O2 shim/vkshim.c -o shim/out/libvulkan.so.x86_64 -lunwind
    SHIM=shim/out/libvulkan.so.x86_64 ;;
  *) echo "bad abi: $ABI" >&2; exit 1 ;;
esac

SDK=$HOME/android-sdk
BT=$SDK/build-tools/35.0.0
[ -x "$BT/zipalign" ] || { echo "build-tools zipalign missing: $BT" >&2; exit 1; }

python3 - "$IN" "$OUT" "$ABI" "$SHIM" <<'EOF'
import sys, zipfile, shutil, os
src, dst, abi, shim = sys.argv[1:5]
# Copy the APK, replacing/adding our entry, forcing STORED for the shim.
with zipfile.ZipFile(src) as zin, zipfile.ZipFile(dst, "w") as zout:
    for item in zin.infolist():
        if item.filename == f"lib/{abi}/libvulkan.so":
            continue  # replaced by ours
        zout.writestr(item, zin.read(item.filename))
    with open(shim, "rb") as f:
        data = f.read()
    info = zipfile.ZipInfo(f"lib/{abi}/libvulkan.so")
    info.compress_type = zipfile.ZIP_STORED
    info.external_attr = 0o755 << 16
    zout.writestr(info, data)
EOF

"$BT/zipalign" -f 4 "$OUT" "${OUT%.apk}_aligned.apk"
mv -f "${OUT%.apk}_aligned.apk" "$OUT"
"$BT/apksigner" sign --ks "$HOME/.android/debug.keystore" --ks-pass pass:android \
    --out "${OUT%.apk}_signed.apk" "$OUT"
mv -f "${OUT%.apk}_signed.apk" "$OUT"
"$BT/apksigner" verify --print-certs "$OUT" | head -2
echo "OK: $OUT ($(du -h "$OUT" | cut -f1))"