#!/usr/bin/env bash

TARGET="x86_64-elf"
NASM_VERSION="2.13.03"
BINUTILS_VERSION="2.31.1"

TOOLS="clang" # lld libunwind libcxxabi libcxx"
PROJECTS="compiler-rt libcxxabi libcxx libunwind"
#RUNTIMES="compiler-rt libcxxabi libcxx libunwind"

set -e

SYSROOT=$(realpath "$(dirname $0)/../sysroot")
WORK=$(realpath "$(dirname $0)/sysroot")
mkdir -p "${SYSROOT}"
mkdir -p "${WORK}"

export CC=clang
export CXX=clang++

function build_nasm() {
	if [[ ! -d "${WORK}/nasm-${NASM_VERSION}" ]]; then
		echo "Downloading NASM..."
		tarball="nasm-${NASM_VERSION}.tar.gz"
		curl -sSOL "https://www.nasm.us/pub/nasm/releasebuilds/${NASM_VERSION}/${tarball}"
		tar xzf "${tarball}" -C "${WORK}" && rm "${tarball}"
	fi

	mkdir -p "${WORK}/build/nasm"
	pushd "${WORK}/build/nasm"

	if [[ ! -f "${WORK}/build/nasm/config.cache" ]]; then
		echo "Configuring NASM..."
		"${WORK}/nasm-${NASM_VERSION}/configure" \
			--quiet \
			--config-cache \
			--disable-werror \
			--prefix="${SYSROOT}" \
			--srcdir="${WORK}/nasm-${NASM_VERSION}"
	fi

	echo "Building NASM..."
	(make -j && make install) > "${WORK}/build/nasm_build.log"
	popd
}

function build_binutils() {
	if [[ ! -d "${WORK}/binutils-${BINUTILS_VERSION}" ]]; then
		echo "Downloading binutils..."
		tarball="binutils-${BINUTILS_VERSION}.tar.gz"
		curl -sSOL "https://ftp.gnu.org/gnu/binutils/${tarball}"
		tar xzf "${tarball}" -C "${WORK}" && rm "${tarball}"
	fi

	mkdir -p "${WORK}/build/binutils"
	pushd "${WORK}/build/binutils"

	if [[ ! -f "${WORK}/build/binutils/config.cache" ]]; then
		echo "Configuring binutils..."
		"${WORK}/binutils-${BINUTILS_VERSION}/configure" \
			--quiet \
			--config-cache \
			--target="${TARGET}" \
			--prefix="${SYSROOT}" \
			--with-sysroot="${SYSROOT}" \
			--with-lib-path="${SYSROOT}/lib" \
			--disable-nls \
			--disable-werror
	fi

	echo "Building binutils..."
	(make -j && make install) > "${WORK}/build/binutils_build.log"
	popd
}

function build_llvm() {
	if [[ ! -d "${WORK}/llvm" ]]; then
		echo "Downloading LLVM..."
		git clone -q \
			--branch release_70 \
			--depth 1 \
			"https://git.llvm.org/git/llvm.git" "${WORK}/llvm"
	fi

	for tool in ${TOOLS}; do
		if [[ ! -d "${WORK}/llvm/tools/${tool}" ]]; then
			echo "Downloading ${tool}..."
			git clone -q \
				--branch release_70 \
				--depth 1 \
				"https://git.llvm.org/git/${tool}.git" "${WORK}/llvm/tools/${tool}"
		fi
	done

	if [[ ! -d "${WORK}/llvm/tools/clang/tools/extra" ]]; then
		echo "Downloading clang-tools-extra..."
		git clone -q \
			--branch release_70 \
			--depth 1 \
			"https://git.llvm.org/git/clang-tools-extra.git" "${WORK}/llvm/tools/clang/tools/extra"
	fi

	for proj in ${PROJECTS}; do
		if [[ ! -d "${WORK}/llvm/projects/${proj}" ]]; then
			echo "Downloading ${proj}..."
			git clone -q \
				--branch release_70 \
				--depth 1 \
				"https://git.llvm.org/git/${proj}.git" "${WORK}/llvm/projects/${proj}"
		fi
	done

	for proj in ${RUNTIMES}; do
		if [[ ! -d "${WORK}/llvm/runtimes/${proj}" ]]; then
			echo "Downloading ${proj}..."
			git clone -q \
				--branch release_70 \
				--depth 1 \
				"https://git.llvm.org/git/${proj}.git" "${WORK}/llvm/runtime/${proj}"
		fi
	done

	mkdir -p "${WORK}/build/llvm"
	pushd "${WORK}/build/llvm"

	echo "Configuring LLVM..."

	cmake -G Ninja \
		-DCLANG_DEFAULT_RTLIB=compiler-rt \
		-DCLANG_DEFAULT_STD_C=c11 \
		-DCLANG_DEFAULT_STD_CXX=cxx14 \
		-DCMAKE_BUILD_TYPE=Release \
		-DCMAKE_C_COMPILER="clang" \
		-DCMAKE_CXX_COMPILER="clang++" \
		-DCMAKE_CXX_FLAGS="-Wno-unused-parameter -D_LIBCPP_HAS_NO_ALIGNED_ALLOCATION -D_LIBUNWIND_IS_BAREMETAL=1 -U_LIBUNWIND_SUPPORT_DWARF_UNWIND" \
		-DCMAKE_INSTALL_PREFIX="${SYSROOT}" \
		-DCMAKE_MAKE_PROGRAM=`which ninja` \
		-DDEFAULT_SYSROOT="${SYSROOT}" \
		-DLIBCXX_CXX_ABI=libcxxabi \
		-DLIBCXX_CXX_ABI_INCLUDE_PATHS="${WORK}/llvm/projects/libcxxabi/include" \
		-DLIBCXX_CXX_ABI_LIBRARY_PATH=lib \
		-DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=OFF \
		-DLIBCXX_ENABLE_NEW_DELETE_DEFINITIONS=ON \
		-DLIBCXX_ENABLE_SHARED=OFF \
		-DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON \
		-DLIBCXX_ENABLE_THREADS=OFF \
		-DLIBCXX_INCLUDE_BENCHMARKS=OFF \
		-DLIBCXX_USE_COMPILER_RT=ON \
		-DLIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS=OFF \
		-DLIBCXXABI_ENABLE_SHARED=OFF \
		-DLIBCXXABI_ENABLE_STATIC_UNWINDER=ON \
		-DLIBCXXABI_ENABLE_THREADS=OFF \
		-DLIBCXXABI_LIBCXX_PATH="${WORK}/llvm/projects/libcxx" \
		-DLIBCXXABI_USE_COMPILER_RT=ON \
		-DLIBCXXABI_USE_LLVM_UNWINDER=ON \
		-DLIBUNWIND_ENABLE_SHARED=OFF \
		-DLIBUNWIND_ENABLE_THREADS=OFF \
		-DLIBUNWIND_USE_COMPILER_RT=ON \
		-DLLVM_CONFIG_PATH="${SYSROOT}/bin/llvm-config" \
		-DLLVM_DEFAULT_TARGET_TRIPLE="x86_64-unknown-elf" \
		-DLLVM_ENABLE_LIBCXX=ON \
		-DLLVM_ENABLE_PIC=OFF \
		-DLLVM_ENABLE_THREADS=OFF \
		-DLLVM_INSTALL_BINUTILS_SYMLINKS=ON \
		-DLLVM_TARGETS_TO_BUILD="X86" \
		${WORK}/llvm > cmake_configure.log

	#  -DCMAKE_ASM_COMPILER=nasm \
	#  -DCMAKE_LINKER="${SYSROOT}/bin/ld.lld" \
	#  -DCOMPILER_RT_ENABLE_LLD=ON \
	#  -DLIBCXX_ENABLE_LLD=ON \
	#  -DLIBCXX_ENABLE_STATIC_UNWINDER=ON \
	#  -DLIBCXXABI_ENABLE_LLD=ON \
	#  -DLIBUNWIND_ENABLE_LLD=ON \
	#  -DLLVM_ENABLE_LLD=ON \
	#  -DLLVM_ENABLE_PROJECTS="libcxx;libcxxabi;libunwind;compiler-rt" \
	#  -DCOMPILER_RT_BAREMETAL_BUILD=ON \
	#  -DLIBCXXABI_BAREMETAL=ON \

	echo "Building LLVM..."
	ninja && ninja install
	ninja cxx cxxabi compiler-rt
	ninja install-compiler-rt install-cxx install-cxxabi
	popd
}

function build_libc() {
	if [[ ! -d "${WORK}/poplibc" ]]; then
		echo "Downloading poplibc..."
		git clone \
			"https://github.com/justinian/poplibc.git" \
			"${WORK}/poplibc"
	else
		echo "Updating poplibc..."
		git -C "${WORK}/poplibc" pull
	fi

	pushd "${WORK}/poplibc"
	echo "Building poplibc..."
	make install PREFIX="${SYSROOT}"
	popd
}

function update_links() {
	for exe in `ls "${SYSROOT}/bin/${TARGET}-"*`; do
		base=$(echo "$exe" | sed -e "s/${TARGET}-//")
		ln -fs "${exe}" "${base}"
	done
}

build_nasm
build_binutils
build_libc
build_llvm
update_links

export CC="${SYSROOT}/bin/clang"
export CXX="${SYSROOT}/bin/clang++"
export LD="${SYSROOT}/bin/ld"
build_libc