#!/usr/bin/env bash
# Build libvpx, opus, and speex for a single Android ABI using the NDK.
# Usage: ./scripts/build-native-codecs.sh arm64-v8a [armeabi-v7a|x86_64]
#
# Output: build/native/<ABI>/libvpx.a, libopus.a, libspeex.a
# The CMakeLists.txt picks these up automatically during the Gradle build.

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT="$(dirname "$SCRIPT_DIR")"
THIRD_PARTY="$ROOT/third-party"
BUILD_NATIVE="$ROOT/build/native"

# Work around make's inability to handle paths with spaces by using symlinks.
SAFE_ROOT="/tmp/ac-mobile-android-build"
if [[ ! -L "$SAFE_ROOT" ]] || [[ "$(readlink -f "$SAFE_ROOT")" != "$(readlink -f "$ROOT")" ]]; then
  rm -f "$SAFE_ROOT"
  ln -sf "$(readlink -f "$ROOT")" "$SAFE_ROOT"
fi
SAFE_THIRD_PARTY="$SAFE_ROOT/third-party"
SAFE_BUILD_NATIVE="$SAFE_ROOT/build/native"

ANDROID_ABI="${1:-arm64-v8a}"

source "$SCRIPT_DIR/android-ndk.sh"
NDK_HOME="$(androidcast_find_ndk_root "$ROOT")"
export ANDROID_NDK_HOME="$NDK_HOME"

case "$ANDROID_ABI" in
  arm64-v8a)   HOST_ARCH="aarch64-linux-android";    API=21 ;;
  armeabi-v7a) HOST_ARCH="armv7a-linux-androideabi"; API=21 ;;
  x86_64)      HOST_ARCH="x86_64-linux-android";     API=21 ;;
  x86)         HOST_ARCH="i686-linux-android";        API=21 ;;
  *) echo "Unsupported ABI: $ANDROID_ABI" >&2; exit 1 ;;
esac

OUT="$BUILD_NATIVE/$ANDROID_ABI"
mkdir -p "$OUT"

# Resolve toolchain
TOOLCHAIN="$NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64"
CC="$TOOLCHAIN/bin/${HOST_ARCH}${API}-clang"
CXX="$TOOLCHAIN/bin/${HOST_ARCH}${API}-clang++"
AR="$TOOLCHAIN/bin/llvm-ar"
RANLIB="$TOOLCHAIN/bin/llvm-ranlib"
STRIP="$TOOLCHAIN/bin/llvm-strip"

if [[ ! -x "$CC" ]]; then
  echo "ERROR: Clang not found at $CC" >&2
  exit 1
fi

LD="$TOOLCHAIN/bin/ld.lld"
[[ -x "$LD" ]] || LD="$TOOLCHAIN/bin/lld"
SYSROOT="$NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/sysroot"

# Export so configure scripts see them
export CC CXX AR RANLIB STRIP LD
export LDFLAGS="--sysroot=$SYSROOT"
export CFLAGS="--sysroot=$SYSROOT"
export CXXFLAGS="--sysroot=$SYSROOT"

echo "==> ABI=$ANDROID_ABI  API=$API  CC=$CC  LD=$LD"

# ─── libvpx ──────────────────────────────────────────────────────────────────
build_libvpx() {
  local src="$SAFE_THIRD_PARTY/libvpx"
  local bld="$SAFE_BUILD_NATIVE/vpx-build-$ANDROID_ABI"
  local lib="$OUT/libvpx.a"

  if [[ -f "$lib" ]]; then
    echo "==> libvpx already built for $ANDROID_ABI ($lib)"
    return 0
  fi

  echo "==> Building libvpx for $ANDROID_ABI..."
  rm -rf "$bld"
  mkdir -p "$bld"

  # Use generic-gnu to avoid Android-specific assembler/linker issues with cross-compilation.
  # The clang compiler provides correct codegen; assembly optimizations are secondary.
  local vpx_target="generic-gnu"

  cd "$bld"
  "$src/configure" \
    --target="$vpx_target" \
    --disable-examples \
    --disable-tools \
    --disable-docs \
    --disable-unit-tests \
    --enable-vp8 \
    --enable-vp9 \
    --enable-static \
    --disable-shared \
    --disable-webm-io \
    --disable-libyuv \
    --extra-cflags="-fPIC --sysroot=$SYSROOT" \
    --prefix="$bld/install" 2>&1 | tail -5

  make -j"$(nproc)" libvpx.a 2>&1 | tail -5
  cp libvpx.a "$lib"
  echo "==> libvpx built: $lib ($(du -sh "$lib" | cut -f1))"
  cd "$ROOT"
}

# ─── libopus ─────────────────────────────────────────────────────────────────
build_libopus() {
  local src="$SAFE_THIRD_PARTY/opus"
  local bld="$SAFE_BUILD_NATIVE/opus-build-$ANDROID_ABI"
  local lib="$OUT/libopus.a"

  if [[ -f "$lib" ]]; then
    echo "==> libopus already built for $ANDROID_ABI ($lib)"
    return 0
  fi

  echo "==> Building libopus for $ANDROID_ABI..."
  rm -rf "$bld"
  mkdir -p "$bld"

  # Run autogen if configure doesn't exist
  if [[ ! -f "$src/configure" ]]; then
    ( cd "$src" && ./autogen.sh 2>&1 | tail -3 )
  fi

  cd "$bld"
  CC="$CC -fPIC" CXX="$CXX -fPIC" AR="$AR" RANLIB="$RANLIB" \
    "$src/configure" \
    --host="$HOST_ARCH" \
    --disable-shared \
    --enable-static \
    --disable-doc \
    --disable-extra-programs \
    --prefix="$bld/install" 2>&1 | tail -5

  make -j"$(nproc)" 2>&1 | tail -5
  cp .libs/libopus.a "$lib" 2>/dev/null || cp src/.libs/libopus.a "$lib" 2>/dev/null || \
    find "$bld" -name 'libopus.a' -exec cp {} "$lib" \;
  # Create opus/ include subdirectory that CMakeLists expects for #include <opus/opus.h>
  mkdir -p "$OUT/include/opus"
  cp "$src/include/"*.h "$OUT/include/opus/" 2>/dev/null || true
  echo "==> libopus built: $lib ($(du -sh "$lib" | cut -f1))"
  cd "$ROOT"
}

# ─── libspeex ────────────────────────────────────────────────────────────────
build_libspeex() {
  local src="$SAFE_THIRD_PARTY/speex"
  local bld="$SAFE_BUILD_NATIVE/speex-build-$ANDROID_ABI"
  local lib="$OUT/libspeex.a"

  if [[ -f "$lib" ]]; then
    echo "==> libspeex already built for $ANDROID_ABI ($lib)"
    return 0
  fi

  echo "==> Building libspeex for $ANDROID_ABI..."
  rm -rf "$bld"
  mkdir -p "$bld"

  if [[ ! -f "$src/configure" ]]; then
    ( cd "$src" && ./autogen.sh 2>&1 | tail -3 )
  fi

  cd "$bld"
  CC="$CC -fPIC" CXX="$CXX -fPIC" AR="$AR" RANLIB="$RANLIB" \
    "$src/configure" \
    --host="$HOST_ARCH" \
    --disable-shared \
    --enable-static \
    --disable-oggtest \
    --prefix="$bld/install" 2>&1 | tail -5

  # Build only the library directory (not speexdec/speexenc tools)
  make -j"$(nproc)" -C libspeex 2>&1 | tail -5
  find "$bld/libspeex" -name 'libspeex.a' | head -1 | xargs -I{} cp {} "$lib"
  [[ -f "$lib" ]] || find "$bld" -name 'libspeex.a' | head -1 | xargs -I{} cp {} "$lib"
  # Copy generated speex_config_types.h which is needed at build time
  if [[ -f "$bld/include/speex/speex_config_types.h" ]]; then
    mkdir -p "$OUT/include/speex"
    cp "$bld/include/speex/speex_config_types.h" "$OUT/include/speex/"
  fi
  echo "==> libspeex built: $lib ($(du -sh "$lib" | cut -f1))"
  cd "$ROOT"
}

build_libvpx
build_libopus
build_libspeex

echo ""
echo "==> Native libs for $ANDROID_ABI:"
ls -lh "$OUT/"*.a 2>/dev/null || echo "  (none)"