#!/usr/bin/env bash

set_compile_opts() {
	test "$FB_COMPILE_OPTS_SET" == 1 && return 0

	EXPORTED_ENV_NAMES=(
		LDFLAGS
		C_FLAGS
		CXX_FLAGS
		CPP_FLAGS
		RUSTFLAGS
		PKG_CONFIG_PATH
	)
	BUILD_ENV_NAMES=(
		"${EXPORTED_ENV_NAMES[@]}"
		CONFIGURE_FLAGS
		MESON_FLAGS
		CMAKE_FLAGS
		FFMPEG_EXTRA_FLAGS
		CARGO_CINSTALL_FLAGS
		LTO_FLAG
		LIB_SUFF
	)
	unset "${BUILD_ENV_NAMES[@]}"
	export "${EXPORTED_ENV_NAMES[@]}"

	# set job count for all builds
	JOBS="$(nproc)"
	# local vs system prefix
	test "${PREFIX}" == 'local' && PREFIX="${LOCAL_PREFIX}"

	# check if we need to handle PREFIX with sudo
	local testfile=''
	if [[ -d ${PREFIX} ]]; then
		testfile="${PREFIX}/ffmpeg-build-testfile"
	else
		# try creating in parent path
		testfile="$(bash_dirname "${PREFIX}")/ffmpeg-build-testfile"
	fi
	unset SUDO_MODIFY
	if touch "${testfile}" 2>/dev/null; then
		SUDO_MODIFY=''
	else
		SUDO_MODIFY="${SUDO}"
		echo_warn "using ${SUDO}to install"
		${SUDO_MODIFY} mkdir -p "${PREFIX}/bin/" || return 1
	fi
	test -f "${testfile}" && ${SUDO_MODIFY} rm "${testfile}"
	test -d "${PREFIX}" || { ${SUDO_MODIFY} mkdir -p "${PREFIX}" || return 1; }

	# set library/pkgconfig directory
	LIBDIR="${PREFIX}/lib"
	LDFLAGS=("-L${LIBDIR}")

	# HACK rope in libm
	if is_android; then
		test -f "${LIBDIR}/libm.so" || ln -s /system/lib64/libm.so "${LIBDIR}/libm.so"
	fi

	# set prefix flags and basic flags
	CONFIGURE_FLAGS+=(
		"--prefix=${PREFIX}"
		"--libdir=${LIBDIR}"
		"--disable-debug"
	)
	MESON_FLAGS+=(
		"--prefix" "${PREFIX}"
		"--libdir" "lib"
		"--bindir" "bin"
		"--buildtype" "release"
	)
	CMAKE_FLAGS+=(
		"-DCMAKE_PREFIX_PATH=${PREFIX}"
		"-DCMAKE_INSTALL_PREFIX=${PREFIX}"
		"-DCMAKE_INSTALL_LIBDIR=lib"
		"-DCMAKE_BUILD_TYPE=Release"
		"-DCMAKE_C_COMPILER_LAUNCHER=ccache"
		"-DCMAKE_CXX_COMPILER_LAUNCHER=ccache"
	)
	CARGO_CINSTALL_FLAGS=(
		"--release"
		"--prefix" "${PREFIX}"
		"--libdir" "${LIBDIR}"
	)
	PKG_CONFIG_PATH="${LIBDIR}/pkgconfig"

	# add prefix include
	C_FLAGS+=("-I${PREFIX}/include")

	# enabling link-time optimization
	if [[ ${LTO} == 'ON' ]]; then
		LTO_FLAG='-flto'
		C_FLAGS+=("${LTO_FLAG}")
		if ! is_darwin; then
			CONFIGURE_FLAGS+=('--enable-lto')
		fi
		MESON_FLAGS+=("-Db_lto=true")
		RUSTFLAGS+=("-C lto=yes" "-C inline-threshold=1000" "-C codegen-units=1")
	else
		LTO_FLAG=' '
		MESON_FLAGS+=("-Db_lto=false")
		RUSTFLAGS+=("-C lto=no")
	fi

	# setting optimization level
	if [[ ${OPT} == '' ]]; then
		OPT='0'
	fi
	C_FLAGS+=("-O${OPT}")
	RUSTFLAGS+=("-C opt-level=${OPT}")
	MESON_FLAGS+=("--optimization=${OPT}")

	STATIC_LIB_SUFF='a'
	# darwin has different suffix for dynamic libraries
	if is_darwin; then
		SHARED_LIB_SUFF='dylib'
	else
		SHARED_LIB_SUFF='so'
	fi

	# static/shared linking
	if [[ ${STATIC} == 'ON' ]]; then
		CONFIGURE_FLAGS+=(
			'--enable-static'
			'--disable-shared'
		)
		MESON_FLAGS+=('--default-library=static')
		CMAKE_FLAGS+=(
			"-DENABLE_STATIC=${STATIC}"
			"-DENABLE_SHARED=OFF"
			"-DBUILD_SHARED_LIBS=OFF"
		)
		RUSTFLAGS+=("-C target-feature=+crt-static")
		FFMPEG_EXTRA_FLAGS+=("--pkg-config-flags=--static")
		# darwin does not support static linkage
		if ! is_darwin; then
			LDFLAGS+=('-static')
			CMAKE_FLAGS+=("-DCMAKE_EXE_LINKER_FLAGS=-static")
		fi
		FFMPEG_EXTRA_FLAGS+=(--extra-ldflags="${LDFLAGS[*]}")
		# remove shared libraries for static builds
		USE_LIB_SUFF="${STATIC_LIB_SUFF}"
		DEL_LIB_SUFF="${SHARED_LIB_SUFF}"
	else
		FFMPEG_EXTRA_FLAGS+=(--extra-ldflags="${LDFLAGS[*]}")
		LDFLAGS+=("-Wl,-rpath,${LIBDIR}" "-Wl,-rpath-link,${LIBDIR}")
		CONFIGURE_FLAGS+=(
			'--enable-shared'
			'--disable-static'
		)
		CMAKE_FLAGS+=(
			"-DENABLE_STATIC=${STATIC}"
			"-DENABLE_SHARED=ON"
			"-DBUILD_SHARED_LIBS=ON"
			"-DCMAKE_INSTALL_RPATH=${LIBDIR}"
		)
		FFMPEG_EXTRA_FLAGS+=('--enable-rpath')
		# remove static libraries for shared builds
		USE_LIB_SUFF="${SHARED_LIB_SUFF}"
		DEL_LIB_SUFF="${STATIC_LIB_SUFF}"
	fi

	# architecture/cpu compile flags
	# arm prefers -mcpu over -march for native builds
	# https://community.arm.com/arm-community-blogs/b/tools-software-ides-blog/posts/compiler-flags-across-architectures-march-mtune-and-mcpu
	local arch_flags=()
	if [[ ${HOSTTYPE} == "aarch64" && ${ARCH} == 'native' ]]; then
		arch_flags+=("-mcpu=${ARCH}")
	else
		arch_flags+=("-march=${ARCH}")
	fi

	# can fail static builds with -fpic
	# warning: too many GOT entries for -fpic, please recompile with -fPIC
	C_FLAGS+=("${arch_flags[@]}" "-fPIC")
	CXX_FLAGS=("${C_FLAGS[@]}")
	CPP_FLAGS=("${C_FLAGS[@]}")
	RUSTFLAGS+=("-C target-cpu=${ARCH}")
	CMAKE_FLAGS+=("-DCMAKE_C_FLAGS=${C_FLAGS[*]}")
	CMAKE_FLAGS+=("-DCMAKE_CXX_FLAGS=${CXX_FLAGS[*]}")
	MESON_FLAGS+=("-Dc_args=${C_FLAGS[*]}" "-Dcpp_args=${CPP_FLAGS[*]}")
	dump_arr CONFIGURE_FLAGS
	dump_arr C_FLAGS
	dump_arr RUSTFLAGS
	dump_arr CARGO_CINSTALL_FLAGS
	dump_arr CMAKE_FLAGS
	dump_arr MESON_FLAGS
	echo_info "PKG_CONFIG_PATH=${PKG_CONFIG_PATH}"

	# extra ffmpeg flags
	FFMPEG_EXTRA_FLAGS+=(
		--extra-cflags="${C_FLAGS[*]}"
		--extra-cxxflags="${CXX_FLAGS[*]}"
		--pkg-config='pkg-config'
	)
	dump_arr FFMPEG_EXTRA_FLAGS

	# shellcheck disable=SC2178
	RUSTFLAGS="${RUSTFLAGS[*]}"

	FB_COMPILE_OPTS_SET=1
	echo
}

get_remote_head() {
	local url="$1"
	local remoteHEAD=''
	IFS=$' \t' read -r remoteHEAD _ <<< \
		"$(git ls-remote "${url}" HEAD)"
	echo "${remoteHEAD}"
}

get_build_conf() {
	local getBuild="${1}"

	# name version file-extension url dep1,dep2
	# shellcheck disable=SC2016
	local BUILDS_CONF='
ffmpeg			8.0			tar.gz		https://github.com/FFmpeg/FFmpeg/archive/refs/tags/n${ver}.${ext}

libsvtav1_psy	3.0.2-B		tar.gz		https://github.com/BlueSwordM/svt-av1-psyex/archive/refs/tags/v${ver}.${ext} dovi_tool,hdr10plus_tool,cpuinfo
hdr10plus_tool	1.7.1		tar.gz		https://github.com/quietvoid/hdr10plus_tool/archive/refs/tags/${ver}.${ext}
dovi_tool		2.3.1		tar.gz		https://github.com/quietvoid/dovi_tool/archive/refs/tags/${ver}.${ext}
cpuinfo			latest   	git   		https://github.com/pytorch/cpuinfo/

libsvtav1		3.1.2		tar.gz		https://gitlab.com/AOMediaCodec/SVT-AV1/-/archive/v${ver}/SVT-AV1-v${ver}.${ext}
librav1e		0.8.1		tar.gz		https://github.com/xiph/rav1e/archive/refs/tags/v${ver}.${ext}
libaom			3.13.1		tar.gz		https://storage.googleapis.com/aom-releases/libaom-${ver}.${ext}
libvmaf			3.0.0		tar.gz		https://github.com/Netflix/vmaf/archive/refs/tags/v${ver}.${ext}
libopus			1.5.2		tar.gz		https://github.com/xiph/opus/releases/download/v${ver}/opus-${ver}.${ext}
libdav1d		1.5.1		tar.xz		http://downloads.videolan.org/videolan/dav1d/${ver}/dav1d-${ver}.${ext}
libx264			latest   	git   		https://code.videolan.org/videolan/x264.git
libmp3lame		3.100		tar.gz		https://pilotfiber.dl.sourceforge.net/project/lame/lame/${ver}/lame-${ver}.${ext}

libwebp			1.6.0		tar.gz		https://github.com/webmproject/libwebp/archive/refs/tags/v${ver}.${ext} libpng,libjpeg
libjpeg			3.0.3		tar.gz		https://github.com/winlibs/libjpeg/archive/refs/tags/libjpeg-turbo-${ver}.${ext}
libpng			1.6.50		tar.gz		https://github.com/pnggroup/libpng/archive/refs/tags/v${ver}.${ext}	zlib
zlib			1.3.1		tar.gz		https://github.com/madler/zlib/archive/refs/tags/v${ver}.${ext}

libplacebo		7.351.0		tar.gz		https://github.com/haasn/libplacebo/archive/refs/tags/v${ver}.${ext} glslang,vulkan_loader,glad
glslang			16.0.0		tar.gz		https://github.com/KhronosGroup/glslang/archive/refs/tags/${ver}.${ext} spirv_tools
spirv_tools		2025.4		tar.gz		https://github.com/KhronosGroup/SPIRV-Tools/archive/refs/tags/v${ver}.${ext} spirv_headers
spirv_headers	1.4.328.1	tar.gz		https://github.com/KhronosGroup/SPIRV-Headers/archive/refs/tags/vulkan-sdk-${ver}.${ext}
glad			2.0.8		tar.gz		https://github.com/Dav1dde/glad/archive/refs/tags/v${ver}.${ext}

libx265			4.1			tar.gz		https://bitbucket.org/multicoreware/x265_git/downloads/x265_${ver}.${ext} libnuma,cmake3
libnuma			2.0.19		tar.gz		https://github.com/numactl/numactl/archive/refs/tags/v${ver}.${ext}
cmake3			3.31.8		tar.gz		https://github.com/Kitware/CMake/archive/refs/tags/v${ver}.${ext}
'

	local supported_builds=()
	unset ver ext url deps extractedDir
	while read -r line; do
		test "${line}" == '' && continue
		IFS=$' \t' read -r build ver ext url deps <<<"${line}"
		supported_builds+=("${build}")
		if [[ ${getBuild} != "${build}" ]]; then
			build=''
			continue
		fi
		break
	done <<<"${BUILDS_CONF}"

	if [[ ${getBuild} == 'supported' ]]; then
		echo "${supported_builds[@]}"
		return 0
	fi

	if [[ ${build} == '' ]]; then
		echo_fail "build ${getBuild} is not supported"
		return 1
	fi

	# url uses ver and extension
	eval "url=\"$url\""
	# set dependencies array
	# shellcheck disable=SC2206
	deps=(${deps//,/ })
	# set version based off of remote head
	# and set extracted directory
	if [[ ${ext} == 'git' ]]; then
		ver="$(get_remote_head "${url}")"
		extractedDir="${BUILD_DIR}/${build}-${ext}"
	else
		extractedDir="${BUILD_DIR}/${build}-v${ver}"
	fi

	return 0
}

download_release() {
	local basename="$(bash_basename "${extractedDir}")"
	local download="${DL_DIR}/${basename}"

	# remove other versions of a download
	for alreadyDownloaded in "${DL_DIR}/${build}-"*; do
		if line_contains "${alreadyDownloaded}" "${basename}"; then
			continue
		fi
		if [[ ! -d ${alreadyDownloaded} && ! -f ${alreadyDownloaded} ]]; then
			continue
		fi
		echo_warn "removing wrong version: ${alreadyDownloaded}"
		rm -rf "${alreadyDownloaded}"
	done
	# remove other versions of a build
	for alreadyBuilt in "${BUILD_DIR}/${build}-"*; do
		if line_contains "${alreadyBuilt}" "${basename}"; then
			continue
		fi
		test -d "${alreadyBuilt}" || continue
		echo_warn "removing wrong version: ${extractedDir}"
		rm -rf "${alreadyBuilt}"
	done

	# enabling a clean build
	if [[ ${CLEAN} == 'ON' ]]; then
		DO_CLEAN="rm -rf"
	else
		DO_CLEAN='void'
	fi

	# create new build dir for clean builds
	test -d "${extractedDir}" &&
		{ ${DO_CLEAN} "${extractedDir}" || return 1; }

	if test "${ext}" != "git"; then
		wgetOut="${download}.${ext}"

		# download archive if not present
		if ! test -f "${wgetOut}"; then
			echo_info "downloading ${build}"
			echo_if_fail wget "${url}" -O "${wgetOut}"
		fi

		# create new build directory
		test -d "${extractedDir}" ||
			{
				mkdir "${extractedDir}"
				tar -xf "${wgetOut}" \
					--strip-components=1 \
					--no-same-permissions \
					-C "${extractedDir}" || { rm "${wgetOut}" && return 1; }
			}
	else
		# for git downloads
		test -d "${download}" ||
			git clone --recursive "${url}" "${download}" || return 1
		(
			cd "${download}" || exit 1
			local localHEAD remoteHEAD
			localHEAD="$(git rev-parse HEAD)"
			remoteHEAD="$(get_remote_head "$(git config --get remote.origin.url)")"
			if [[ ${localHEAD} != "${remoteHEAD}" ]]; then
				git pull --ff-only
				git submodule update --init --recursive
			fi
			localHEAD="$(git rev-parse HEAD)"
			if [[ ${localHEAD} != "${remoteHEAD}" ]]; then
				echo_exit "could not update git for ${build}"
			fi
		) || return 1

		# create new build directory
		test -d "${extractedDir}" ||
			cp -r "${download}" "${extractedDir}" || return 1
	fi
}

FB_FUNC_NAMES+=('do_build')
# shellcheck disable=SC2034
FB_FUNC_DESCS['do_build']='build a specific project'
# shellcheck disable=SC2034
FB_FUNC_COMPLETION['do_build']="$(get_build_conf supported)"
do_build() {
	local build="${1:-''}"
	get_build_conf "${build}" || return 1
	download_release || return 1

	set_compile_opts || return 1
	for dep in "${deps[@]}"; do
		do_build "${dep}" || return 1
	done
	get_build_conf "${build}" || return 1
	download_release || return 1

	# save the metadata for a build to skip re-building identical builds
	local oldMetadataFile="${TMP_DIR}/${build}-old-metadata"
	local newMetadataFile="${TMP_DIR}/${build}-new-metadata"
	local ffmpegOldMetadataFile="${TMP_DIR}/ffmpeg-old-metadata"

	# add build function, version, url, and top-level env to metadata
	type "build_${build}" >"${newMetadataFile}"
	echo "ver: ${ver}" >>"${newMetadataFile}"
	echo "url: ${url}" >>"${newMetadataFile}"
	for envName in "${BUILD_ENV_NAMES[@]}"; do
		COLOR=OFF dump_arr "${envName}" >>"${newMetadataFile}"
	done

	# only ffmpeg cares about ENABLE and has special function
	if [[ ${build} == 'ffmpeg' ]]; then
		# shellcheck disable=SC2153
		echo "ENABLE=${ENABLE}" >>"${newMetadataFile}"
		type add_project_versioning_to_ffmpeg >>"${newMetadataFile}"
	fi

	# prepare build
	pushd "${extractedDir}" >/dev/null || return 1
	# check for any patches
	for patch in "${PATCHES_DIR}/${build}"/*.patch; do
		test -f "${patch}" || continue
		echo_if_fail patch -p1 -i "${patch}" || return 1
		echo "patch:${patch}" >>"${newMetadataFile}"
	done

	# rebuild if new metadata is different
	local newMetadata="$(<"${newMetadataFile}")"
	local oldMetadata=''
	test -f "${oldMetadataFile}" && oldMetadata="$(<"${oldMetadataFile}")"
	if [[ ${oldMetadata} != "${newMetadata}" || -n ${REQUIRES_REBUILD} ]]; then
		echo_info -n "building ${build} "
		# build in background
		local timeBefore=${EPOCHSECONDS}
		LOGNAME="${build}" echo_if_fail "build_${build}" &
		local buildPid=$!
		# start spinner
		spinner &
		local spinPid=$!
		# get build return code
		wait ${buildPid}
		local retval=$?
		# stop spinner
		kill ${spinPid}
		spinner reset

		popd >/dev/null || return 1
		test ${retval} -eq 0 || return ${retval}
		echo_pass "built ${build} in $((EPOCHSECONDS - timeBefore)) seconds"

		# set new to old for later builds
		cp "${newMetadataFile}" "${oldMetadataFile}"

		# force ffmpeg to rebuild since one of the libraries has changed
		if [[ ${build} != 'ffmpeg' && -f ${ffmpegOldMetadataFile} ]]; then
			rm "${ffmpegOldMetadataFile}"
		fi
		# indicate that build chain will require rebuild
		REQUIRES_REBUILD=1
	else
		popd >/dev/null || return 1
		echo_info "re-using identical previous build for ${build}"
	fi
}

FB_FUNC_NAMES+=('build')
# shellcheck disable=SC2034
FB_FUNC_DESCS['build']='build ffmpeg with the desired configuration'
build() {
	set_compile_opts || return 1

	for build in ${ENABLE}; do
		do_build "${build}" || return 1
		# reset whether build chain requires a rebuild
		unset REQUIRES_REBUILD
	done
	do_build ffmpeg || return 1
	local ffmpegBin="${PREFIX}/bin/ffmpeg"
	# run ffmpeg to show completion
	"${ffmpegBin}" -version

	# suggestion for path
	hash -r
	local ffmpeg="$(command -v ffmpeg 2>/dev/null)"
	if [[ ${ffmpeg} != "${ffmpegBin}" ]]; then
		echo
		echo_warn "ffmpeg in path (${ffmpeg}) is not the built one (${ffmpegBin})"
		echo_info "consider adding ${PREFIX}/bin to \$PATH"
		echo "echo 'export PATH=\"${PREFIX}/bin:\$PATH\"' >> ~/.bashrc"
	fi

	package || return 1

	return 0
}

# make sure the sysroot has the appropriate library type
# darwin will always link dynamically if a dylib is present
# so they must be remove for static builds
sanitize_sysroot_libs() {
	# do nothing for windows
	if is_windows; then return; fi

	local libs=("$@")

	for lib in "${libs[@]}"; do
		local libPath="${LIBDIR}/${lib}"
		local useLib="${libPath}.${USE_LIB_SUFF}"

		if [[ ! -f ${useLib} ]]; then
			echo_fail "could not find ${useLib}, something is wrong"
			return 1
		fi

		${SUDO_MODIFY} rm "${libPath}"*".${DEL_LIB_SUFF}"*
	done

	return 0
}

# cargo cinstall destdir prepends with entire prefix
# this breaks windows with msys path augmentation
# so recurse into directories until PREFIX sysroot
# also windows via msys path resolution breaks sometimes
# for PREFIX installs (C:/ instead of /c/)
install_local_destdir() (
	local destdir="$1"
	test "${destdir}" == '' && return 1
	cd "${destdir}" || return 1
	local sysrootDir="$(bash_basename "${PREFIX}")"
	while ! test -d "${sysrootDir}"; do
		cd ./* || return 1
	done
	# final cd
	cd "${sysrootDir}" || return 1
	${SUDO_MODIFY} cp -r ./* "${PREFIX}/"
)

del_pkgconfig_gcc_s() {
	# HACK PATCH
	# remove '-lgcc_s' from pkgconfig for static builds
	if [[ ${STATIC} == 'ON' ]]; then
		local fname="$1"
		local cfg="${PKG_CONFIG_PATH}/${fname}"
		local newCfg="${TMP_DIR}/${fname}"
		test -f "${cfg}" || return 1
		local del='-lgcc_s'

		test -f "${newCfg}" && rm "${newCfg}"
		while read -r line; do
			if line_contains "${line}" "${del}"; then
				line="${line//${del} /}"
			fi
			echo "${line}" >>"${newCfg}"
		done <"${cfg}"
		# overwrite the pkgconfig
		${SUDO_MODIFY} cp "${newCfg}" "${cfg}"
	fi
}

### RUST ###
cargo_cbuild() {
	local destdir="${PWD}/fb-local-install"
	cargo cinstall \
		--destdir "${destdir}" \
		"${CARGO_CINSTALL_FLAGS[@]}"
	# cargo cinstall destdir prepends with entire prefix
	# this breaks windows with msys path augmentation
	# so recurse into directories until sysroot is there
	install_local_destdir "${destdir}" || return 1
}

build_hdr10plus_tool() {
	# build libhdr10plus
	cd hdr10plus || return 1
	cargo_cbuild || return 1
	sanitize_sysroot_libs libhdr10plus-rs || return 1
}

build_dovi_tool() {
	# build libdovi
	cd dolby_vision || return 1
	cargo_cbuild || return 1
	sanitize_sysroot_libs libdovi || return 1
}

build_librav1e() {
	cargo_cbuild || return 1
	sanitize_sysroot_libs librav1e || return 1
	del_pkgconfig_gcc_s rav1e.pc || return 1
}

### CMAKE ###
cmake_build() {
	local addFlags=("$@")
	# configure
	cmake \
		-B fb-build \
		"${CMAKE_FLAGS[@]}" \
		"${addFlags[@]}" || return 1
	# build
	cmake \
		--build fb-build \
		--config Release \
		-j "${JOBS}" || return 1
	# install
	${SUDO_MODIFY} cmake \
		--install fb-build || return 1
}

build_cpuinfo() {
	cmake_build \
		-DCPUINFO_BUILD_UNIT_TESTS=OFF \
		-DCPUINFO_BUILD_MOCK_TESTS=OFF \
		-DCPUINFO_BUILD_BENCHMARKS=OFF \
		-DUSE_SYSTEM_LIBS=ON || return 1
	sanitize_sysroot_libs libcpuinfo || return 1
}

build_libsvtav1() {
	cmake_build \
		-DENABLE_AVX512=ON \
		-DBUILD_TESTING=OFF \
		-DCOVERAGE=OFF || return 1
	sanitize_sysroot_libs libSvtAv1Enc || return 1
}

build_libsvtav1_psy() {
	cmake_build \
		-DBUILD_TESTING=OFF \
		-DENABLE_AVX512=ON \
		-DCOVERAGE=OFF \
		-DLIBDOVI_FOUND=1 \
		-DLIBHDR10PLUS_RS_FOUND=1 || return 1
	sanitize_sysroot_libs libSvtAv1Enc || return 1
}

build_libaom() {
	cmake_build \
		-DENABLE_TESTS=OFF || return 1
	sanitize_sysroot_libs libaom || return 1
}

build_libopus() {
	cmake_build || return 1
	sanitize_sysroot_libs libopus || return 1
}

build_libwebp() {
	cmake_build || return 1
	sanitize_sysroot_libs libwebp libsharpyuv || return 1
}

build_libjpeg() {
	cmake_build || return 1
	sanitize_sysroot_libs libjpeg libturbojpeg || return 1
}

build_libpng() {
	cmake_build \
		-DPNG_TESTS=OFF \
		-DPNG_TOOLS=OFF || return 1
	sanitize_sysroot_libs libpng || return 1
}

build_zlib() {
	cmake_build \
		-DZLIB_BUILD_EXAMPLES=OFF || return 1
	sanitize_sysroot_libs libz || return 1
}

build_glslang() {
	cmake_build \
		-DALLOW_EXTERNAL_SPIRV_TOOLS=ON || return 1
	sanitize_sysroot_libs libglslang || return 1
}

build_spirv_tools() {
	cmake_build \
		-DSPIRV-Headers_SOURCE_DIR="${PREFIX}" \
		-DSPIRV_WERROR=OFF \
		-DSPIRV_SKIP_TESTS=ON \
		-G Ninja || return 1
}

build_spirv_headers() {
	cmake_build \
		-G Ninja || return 1
}

# libx265 does not support cmake >= 4
build_cmake3() {
	local cmakeVersion verMajor
	# don't need to build if system version is below 4
	IFS=$' \t' read -r _ _ cmakeVersion <<<"$(cmake --version)"
	IFS='.' read -r verMajor _ _ <<<"${cmakeVersion}"
	if [[ ${verMajor} -lt 4 ]]; then
		return 0
	fi

	# don't need to rebuild if already built
	local cmake="${LOCAL_PREFIX}/bin/cmake"
	if [[ -f ${cmake} ]]; then
		IFS=$' \t' read -r _ _ cmakeVersion <<<"$("${cmake}" --version)"
		IFS='.' read -r verMajor _ _ <<<"${cmakeVersion}"
		if [[ ${verMajor} -lt 4 ]]; then
			return 0
		fi
	fi

	local overrideFlags=(
		"-DCMAKE_BUILD_TYPE=Release"
		"-DCMAKE_PREFIX_PATH=${LOCAL_PREFIX}"
		"-DCMAKE_INSTALL_PREFIX=${LOCAL_PREFIX}"
	)
	# reuse variables
	for flag in "${CMAKE_FLAGS[@]}"; do
		if line_contains "${flag}" 'CMAKE_INSTALL_LIBDIR' ||
			line_contains "${flag}" 'COMPILER_LAUNCHER'; then
			overrideFlags+=("${flag}")
		fi
	done
	CMAKE_FLAGS='' cmake_build \
		"${overrideFlags[@]}" || return 1
}

build_libx265() {
	PATH="${LOCAL_PREFIX}/bin:${PATH}" cmake_build \
		-DHIGH_BIT_DEPTH=ON \
		-DENABLE_HDR10_PLUS=OFF \
		-S source || return 1
	sanitize_sysroot_libs libx265 || return 1
	del_pkgconfig_gcc_s x265.pc || return 1
}

### MESON ###
meson_build() {
	local addFlags=("$@")
	meson setup \
		"${MESON_FLAGS[@]}" \
		"${addFlags[@]}" \
		. fb-build || return 1
	meson compile \
		-C fb-build \
		-j "${JOBS}" || return 1
	${SUDO_MODIFY} meson install \
		-C fb-build || return 1
}

build_libdav1d() {
	local enableAsm=true
	# arm64 will fail the build at 0 optimization
	if [[ "${HOSTTYPE}:${OPT}" == "aarch64:0" ]]; then
		enableAsm=false
	fi
	meson_build \
		-D enable_asm=${enableAsm} || return 1
	sanitize_sysroot_libs libdav1d || return 1
}

build_libplacebo() {
	# copy downloaded glad release as "submodule"
	(
		installDir="${PWD}/3rdparty/glad"
		get_build_conf glad
		CLEAN=OFF download_release
		cd "${extractedDir}" || exit 1
		cp -r ./* "${installDir}"
	) || return 1

	meson_build \
		-D tests=false \
		-D demos=false || return 1
	sanitize_sysroot_libs libplacebo || return 1
}

build_libvmaf() {
	cd libvmaf || return 1
	python3 -m virtualenv .venv
	(
		source .venv/bin/activate
		meson_build \
			-D enable_float=true || exit 1
	) || return 1
	sanitize_sysroot_libs libvmaf || return 1

	# HACK PATCH
	# add '-lstdc++' to pkgconfig for static builds
	if [[ ${STATIC} == 'ON' ]]; then
		local fname='libvmaf.pc'
		local cfg="${PKG_CONFIG_PATH}/${fname}"
		local newCfg="${TMP_DIR}/${fname}"
		test -f "${cfg}" || return 1
		local search='Libs: '

		test -f "${newCfg}" && rm "${newCfg}"
		while read -r line; do
			if line_contains "${line}" "${search}"; then
				line+=" -lstdc++"
			fi
			echo "${line}" >>"${newCfg}"
		done <"${cfg}"
		# overwrite the pkgconfig
		${SUDO_MODIFY} cp "${newCfg}" "${cfg}"
	fi
}

### PYTHON ###
build_glad() {
	true
}

### AUTOTOOLS ###
configure_build() {
	local addFlags=("$@")
	local configureFlags=()

	# some builds break with LTO
	if [[ ${LTO} == 'OFF' ]]; then
		for flag in "${CONFIGURE_FLAGS[@]}"; do
			test "${flag}" == '--enable-lto' && continue
			configureFlags+=("${flag}")
		done
	else
		configureFlags+=("${CONFIGURE_FLAGS[@]}")
	fi

	# configure
	./configure \
		"${configureFlags[@]}" \
		"${addFlags[@]}" || return 1
	# build
	ccache make -j"${JOBS}" || return 1
	# install
	local destdir="${PWD}/fb-local-install"
	make -j"${JOBS}" DESTDIR="${destdir}" install || return 1
	install_local_destdir "${destdir}" || return 1
}

build_libx264() {
	# libx264 does not support LTO
	LTO=OFF configure_build \
		--disable-cli || return 1
	sanitize_sysroot_libs libx264 || return 1
}

build_libmp3lame() {
	# https://sourceforge.net/p/lame/mailman/message/36081038/
	if is_darwin; then
		remove_line \
			'include/libmp3lame.sym' \
			'lame_init_old' || return 1
	fi

	configure_build \
		--enable-nasm || return 1
	sanitize_sysroot_libs libmp3lame || return 1
}

build_libnuma() {
	if ! is_linux; then return 0; fi

	./autogen.sh || return 1
	configure_build || return 1
	sanitize_sysroot_libs libnuma || return 1
}

add_project_versioning_to_ffmpeg() {
	# embed this project's enables/versions
	# into ffmpeg with FFMPEG_BUILDER_INFO
	local FFMPEG_BUILDER_INFO=(
		'' # pad with empty line
		"ffmpeg-builder=$(git -C "${REPO_DIR}" rev-parse HEAD)"
	)
	for build in ${ENABLE}; do
		get_build_conf "${build}" || return 1
		# add build configuration info
		FFMPEG_BUILDER_INFO+=("${build}=${ver}")
	done
	# and finally for ffmpeg itself
	get_build_conf ffmpeg || return 1
	FFMPEG_BUILDER_INFO+=("${build}=${ver}")

	local fname='opt_common.c'
	local optFile="fftools/${fname}"
	if [[ ! -f ${optFile} ]]; then
		echo_fail "could not find ${fname} to add project versioning"
	fi

	local searchFor='static void print_all_libs_info'
	local foundUsageStart=0
	local newOptFile="${TMP_DIR}/${fname}"
	test -f "${newOptFile}" && rm "${newOptFile}"
	while read -r line; do
		# if we found the line previously, add the versioning
		if [[ ${foundUsageStart} -eq 1 ]]; then
			if line_starts_with "${line}" '}'; then
				echo_info "found ${line} on ${lineNum}"
				for info in "${FFMPEG_BUILDER_INFO[@]}"; do
					local newline="av_log(NULL, AV_LOG_INFO, \"${info}\n\");"
					echo "${newline}" >>"${newOptFile}"
					lineNum=$((lineNum + 1))
				done
				newline="av_log(NULL, AV_LOG_INFO, \"\n\");"
				echo "${newline}" >>"${newOptFile}"
				foundUsageStart=0
			fi
		fi
		# find the line we are searching for
		if line_contains "${line}" "${searchFor}"; then
			foundUsageStart=1
		fi
		# start building the new file
		echo "${line}" >>"${newOptFile}"
	done <"${optFile}"

	cp "${newOptFile}" "${optFile}" || return 1

	return 0
}
build_ffmpeg() {
	add_project_versioning_to_ffmpeg || return 1

	# libsvtav1_psy real name is libsvtav1
	for enable in ${ENABLE}; do
		test "${enable}" == 'libsvtav1_psy' && enable='libsvtav1'
		CONFIGURE_FLAGS+=("--enable-${enable}")
	done

	local ffmpegFlags=(
		"--enable-gpl"
		"--enable-version3"
		"--disable-htmlpages"
		"--disable-podpages"
		"--disable-txtpages"
		"--disable-ffplay"
		"--disable-autodetect"
		"--extra-version=${ver}"
		"--enable-runtime-cpudetect"
	)

	# lto is broken on darwin for ffmpeg only
	# https://trac.ffmpeg.org/ticket/11479
	if is_darwin; then
		LTO=OFF
		for flag in "${FFMPEG_EXTRA_FLAGS[@]}"; do
			ffmpegFlags+=("${flag// ${LTO_FLAG}/}")
		done
	else
		ffmpegFlags+=("${FFMPEG_EXTRA_FLAGS[@]}")
	fi

	configure_build \
		"${ffmpegFlags[@]}" || return 1
	${SUDO_MODIFY} cp ff*_g "${PREFIX}/bin"
	sanitize_sysroot_libs \
		libavcodec libavdevice libavfilter libswscale \
		libavformat libavutil libswresample || return 1
}