#!/usr/bin/env bash
# scripts/build-boringtun.sh
#
# Clones cloudflare/boringtun and compiles it as a static C library.
# The resulting libboringtun.a (macOS) is placed in deps/boringtun/.
#
# Prerequisites:
#   brew install rustup   (or install Rust via https://rustup.rs)
#   rustup target add aarch64-apple-darwin x86_64-apple-darwin
#
# Usage:
#   bash scripts/build-boringtun.sh          # current arch only
#   bash scripts/build-boringtun.sh --universal  # fat binary (arm64 + x86_64)

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(dirname "$SCRIPT_DIR")"
DEPS_DIR="$REPO_ROOT/deps/boringtun"
BT_SRC="$DEPS_DIR/src"
BT_REPO="https://github.com/cloudflare/boringtun.git"
BT_TAG="v0.6.0"   # Update as needed

UNIVERSAL=false
for arg in "$@"; do
    [[ "$arg" == "--universal" ]] && UNIVERSAL=true
done

echo "==> Checking Rust toolchain..."
if ! command -v cargo &>/dev/null; then
    echo "ERROR: cargo not found.  Install Rust: https://rustup.rs"
    exit 1
fi
rustup show active-toolchain || true

echo "==> Cloning boringtun $BT_TAG..."
mkdir -p "$DEPS_DIR"
if [[ ! -d "$BT_SRC/.git" ]]; then
    git clone --depth 1 --branch "$BT_TAG" "$BT_REPO" "$BT_SRC"
else
    echo "    (already cloned, skipping)"
fi

build_for_target() {
    local TARGET="$1"
    echo "==> Building for $TARGET..."
    pushd "$BT_SRC" >/dev/null
    cargo build \
        --release \
        --features ffi \
        --target "$TARGET"
    popd >/dev/null
}

if $UNIVERSAL; then
    rustup target add aarch64-apple-darwin x86_64-apple-darwin
    build_for_target aarch64-apple-darwin
    build_for_target x86_64-apple-darwin

    ARM_LIB="$BT_SRC/target/aarch64-apple-darwin/release/libboringtun.a"
    X86_LIB="$BT_SRC/target/x86_64-apple-darwin/release/libboringtun.a"
    OUT_LIB="$DEPS_DIR/libboringtun.a"

    echo "==> Creating universal (fat) binary..."
    lipo -create "$ARM_LIB" "$X86_LIB" -output "$OUT_LIB"
else
    NATIVE_TARGET="$(rustc -vV | awk '/host:/ { print $2 }')"
    build_for_target "$NATIVE_TARGET"
    OUT_LIB="$DEPS_DIR/libboringtun.a"
    cp "$BT_SRC/target/$NATIVE_TARGET/release/libboringtun.a" "$OUT_LIB"
fi

# Copy the FFI header from boringtun into our source tree.
BT_HEADER="$BT_SRC/boringtun/src/ffi/wireguard_ffi.h"
APP_HEADER="$REPO_ROOT/app/vpn/boringtun_ffi.h"
if [[ -f "$BT_HEADER" ]]; then
    echo "==> Updating boringtun_ffi.h from upstream source..."
    cp "$BT_HEADER" "$APP_HEADER"
else
    echo "    (upstream header not found at expected path — keeping bundled copy)"
fi

echo ""
echo "==> Done!  Library: $OUT_LIB"
echo "    Size:  $(du -sh "$OUT_LIB" | cut -f1)"
echo ""
echo "    Add to your CMakeLists.txt:"
echo "      target_link_libraries(moonlight-qt PRIVATE \"\${CMAKE_SOURCE_DIR}/deps/boringtun/libboringtun.a\")"