#!/bin/bash
#
# This script should be run inside the tsl0922/musl-cross docker image
#
set -eo pipefail

CROSS_ROOT="${CROSS_ROOT:-/opt/cross}"
STAGE_ROOT="${STAGE_ROOT:-/opt/stage}"
BUILD_ROOT="${BUILD_ROOT:-/opt/build}"

ZLIB_VERSION="${ZLIB_VERSION:-1.2.11}"
JSON_C_VERSION="${JSON_C_VERSION:-0.13.1}"
OPENSSL_VERSION="${OPENSSL_VERSION:-1.0.2p}"
LIBWEBSOCKETS_VERSION="${LIBWEBSOCKETS_VERSION:-3.1.0}"
TTYD_VERSION="${TTYD_VERSION:-1.5.1}"

build_zlib() {
	echo "=== Building zlib ($TARGET)..."
	curl -sLo- https://zlib.net/zlib-$ZLIB_VERSION.tar.gz | tar xz -C $BUILD_DIR
	pushd $BUILD_DIR/zlib-$ZLIB_VERSION
		env CHOST=$TARGET ./configure --static --archs="-fPIC" --prefix=$STAGE_DIR
		make install
	popd
}

build_json-c() {
	echo "=== Building json-c ($TARGET)..."
	curl -sLo- https://s3.amazonaws.com/json-c_releases/releases/json-c-$JSON_C_VERSION.tar.gz | tar xz -C $BUILD_DIR
	pushd $BUILD_DIR/json-c-$JSON_C_VERSION
		env CFLAGS=-fPIC ./configure --prefix=$STAGE_DIR --host $TARGET
		make install
	popd
}

build_openssl() {
	echo "=== Building openssl ($TARGET)..."
	curl -sLo- https://www.openssl.org/source/openssl-$OPENSSL_VERSION.tar.gz | tar xz -C $BUILD_DIR
	pushd $BUILD_DIR/openssl-$OPENSSL_VERSION
		env CC=$TARGET-gcc AR=$TARGET-ar RANLIB=$TARGET-ranlib C_INCLUDE_PATH=$STAGE_DIR/include \
			./Configure dist -fPIC --prefix=/ --install_prefix=$STAGE_DIR
		make > /dev/null
		make install_sw
	popd
}

install_sys_queue_h() {
	curl -sLo $CROSS_ROOT/$TARGET/include/sys/queue.h "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=misc/sys/queue.h;hb=HEAD"
}

install_cmake_cross_file() {
	cat << EOF > $BUILD_DIR/cross-$TARGET.cmake
set(CMAKE_SYSTEM_NAME Linux)

set(CMAKE_C_COMPILER "$TARGET-gcc")
set(CMAKE_CXX_COMPILER "$TARGET-g++")

set(CMAKE_FIND_ROOT_PATH "$STAGE_DIR")
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
EOF
}

build_libwebsockets() {
	echo "=== Building libwebsockets ($TARGET)..."
	curl -sLo- https://github.com/warmcat/libwebsockets/archive/v$LIBWEBSOCKETS_VERSION.tar.gz | tar xz -C $BUILD_DIR
	pushd $BUILD_DIR/libwebsockets-$LIBWEBSOCKETS_VERSION
		sed -i '13s;^;\nSET(CMAKE_FIND_LIBRARY_SUFFIXES ".a")\nSET(CMAKE_EXE_LINKER_FLAGS "-static")\n;' CMakeLists.txt
		sed -i 's/ websockets_shared//g' cmake/LibwebsocketsConfig.cmake.in
		mkdir build && cd build
		cmake -DLWS_WITHOUT_TESTAPPS=ON \
		    -DLWS_STATIC_PIC=ON \
		    -DLWS_WITH_SHARED=OFF \
		    -DLWS_UNIX_SOCK=ON \
		    -DLWS_IPV6=ON \
		    -DCMAKE_TOOLCHAIN_FILE=../../cross-$TARGET.cmake \
		    -DCMAKE_INSTALL_PREFIX=$STAGE_DIR \
		    ..
		make install
	popd
}

build_ttyd() {
	echo "=== Building ttyd ($TARGET)..."
	curl -sLo- https://github.com/tsl0922/ttyd/archive/$TTYD_VERSION.tar.gz | tar xz -C $BUILD_DIR
	pushd $BUILD_DIR/ttyd-$TTYD_VERSION
		sed -i '5s;^;\nSET(CMAKE_FIND_LIBRARY_SUFFIXES ".a")\nSET(CMAKE_EXE_LINKER_FLAGS "-static -no-pie -s")\n;' CMakeLists.txt
		mkdir build && cd build
		cmake -DCMAKE_TOOLCHAIN_FILE=../../cross-$TARGET.cmake \
		    -DCMAKE_BUILD_TYPE=RELEASE \
		    ..
		make
	popd
	cp $BUILD_DIR/ttyd-$TTYD_VERSION/build/ttyd bin/ttyd_linux.$ALIAS
}

build() {
	TARGET="$1"
	ALIAS="$2"
	STAGE_DIR="$STAGE_ROOT/$TARGET"
	BUILD_DIR="$BUILD_ROOT/$TARGET"

	echo "=== Building target $ALIAS ($TARGET)..."

	mkdir -p $STAGE_DIR $BUILD_DIR
	export PKG_CONFIG_PATH="$STAGE_DIR/lib/pkgconfig"

	install_cmake_cross_file
	install_sys_queue_h

	build_zlib
	build_json-c
	build_openssl
	build_libwebsockets
	build_ttyd
}

TARGETS=(
	i386    i386-linux-musl
	x86_64  x86_64-linux-musl
	arm     arm-linux-musleabi
	armhf   arm-linux-musleabihf
	aarch64 aarch64-linux-musl
	mips    mips-linux-musl
	mipsel  mipsel-linux-musl
)

rm -rf bin && mkdir bin
rm -rf $STAGE_ROOT $BUILD_ROOT

for ((i=0; i<${#TARGETS[@]}; i+=2)); do
	build "${TARGETS[$i+1]}" "${TARGETS[$i]}"
done

echo "=== Archiving bin to a tarball..."
pushd bin
	sha256sum ttyd_linux.* > SHA256SUMS
	tar czvf ../ttyd_${TTYD_VERSION}_linux.tar.gz ttyd_linux.* SHA256SUMS
popd