#!/bin/sh
# Build the rsh SSH transport for each Android ABI as a Bionic PIE executable
# named lib*.so (packaged inside the APK and exec'd from nativeLibraryDir),
# using the Android NDK. Also build a plain host binary for tests and manual
# debugging.
#
# Android needs PIE and the Bionic dynamic linker (/system/bin/linker64), so
# the on-device build is GOOS=android with cgo and the NDK clang. A GOOS=linux
# build targets glibc's linker and will not exec on a phone.
set -eu

root=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
. "$root/versions"

# Locate the NDK toolchain.
ndk=${ANDROID_NDK_HOME:-${ANDROID_NDK_ROOT:-}}
if [ -z "$ndk" ] && [ -n "${ANDROID_HOME:-}" ]; then
	ndk="$ANDROID_HOME/ndk/$ANDROID_NDK"
fi
if [ -z "$ndk" ] || [ ! -d "$ndk" ]; then
	echo "rsh: Android NDK not found; set ANDROID_NDK_HOME" >&2
	exit 1
fi
tc="$ndk/toolchains/llvm/prebuilt/linux-x86_64/bin"

ldflags="-s -w -buildid="

cd "$root/rsh"

for abi in $ABIS; do
	case "$abi" in
	arm64-v8a)   goarch=arm64 goarm= cc="aarch64-linux-android${ANDROID_MIN_SDK}-clang" ;;
	armeabi-v7a) goarch=arm   goarm=7 cc="armv7a-linux-androideabi${ANDROID_MIN_SDK}-clang" ;;
	x86_64)      goarch=amd64 goarm= cc="x86_64-linux-android${ANDROID_MIN_SDK}-clang" ;;
	x86)         goarch=386   goarm= cc="i686-linux-android${ANDROID_MIN_SDK}-clang" ;;
	*) echo "rsh: unknown ABI $abi" >&2; exit 1 ;;
	esac
	dest="$root/app/src/main/jniLibs/$abi"
	mkdir -p "$dest"
	echo "rsh: building $abi (android/$goarch)"
	CGO_ENABLED=1 GOOS=android GOARCH="$goarch" GOARM="$goarm" \
		CC="$tc/$cc" GOFLAGS=-trimpath CGO_CFLAGS="-ffile-prefix-map=$root=." \
		go build -buildmode=pie -ldflags "$ldflags" -o "$dest/libxrsh.so" .
done

# Host binary (no NDK, cgo off) for tests and manual debugging.
mkdir -p "$root/out"
echo "rsh: building host binary -> out/rsh"
CGO_ENABLED=0 GOFLAGS=-trimpath go build -ldflags "$ldflags" -o "$root/out/rsh" .
