#!/bin/sh
set -ef

export PYTHONUNBUFFERED=1 PYTHONDONTWRITEBYTECODE=1

prj_dir=$(readlink -f "$(dirname "$0")/../..")
cd "${prj_dir}"

[ -s debian/changelog ]
dpkg-parsechangelog --show-field Source | grep -Eq '^linux'

ch_ver=$(dpkg-parsechangelog --show-field Version)

v=$1
[ -n "$v" ] || v=$(echo "${ch_ver}" | sed -E 's/^\d+://;s/-[^-]+$//')
[ -n "$v" ]

## should be source tree with patches applied
src_dir=$2
[ -n "${src_dir}" ] || src_dir="/tmp/linux-$v"
[ -n "${src_dir}" ]
[ -d "${src_dir}" ]
src_dir=$(readlink -f "${src_dir}")

nproc=$(nproc || printf 2)
case "${nproc}" in
[0-1] ) nproc=2 ;;
[2-9] | 1[0-9] ) ;;
* ) nproc=20 ;;
esac

rm -rf debian/build/
make -f debian/rules debian/control
[ -f debian/rules.gen ]

configs=$(sed -En '\,debian/build/(config\.[^ :]+):$,{s,,\1,p}' debian/rules.gen | sort -uV | tr -s '[:space:]' ' ')
[ -n "${configs}" ]
## produce configs
make -f debian/rules.gen "-j${nproc}" $(printf ' debian/build/%s' ${configs})

## refresh configs
for c in ${configs} ; do
	echo "# refreshing $c" >&2

	f="debian/build/$c"
	cp -f "$f" "${src_dir}/.config"
	env -C "${src_dir}" make "-j${nproc}" olddefconfig
	cp -f "${src_dir}/.config" "$f"
done

## remove build-generated options
find debian/build/ -name 'config.*' -type f -exec \
  sed -i -E \
    -e '/CONFIG_BUILD_SALT/d' \
    -e '/CONFIG_(AS|CC|PAHOLE)_((CAN|HAS)_)/d' \
    -e '/CONFIG_(AS|CLANG|GCC|LD|LLD|PAHOLE)_VERSION/d' \
    -e '/CONFIG_(BINDGEN|CC|RUSTC)_VERSION_TEXT/d' \
    -e '/CONFIG_AS_(AVX512|GFNI|SHA(1|256)_NI|TPAUSE|VAES|VPCLMULQDQ|WRUSS)/d' \
    -e '/CONFIG_CC_(IMPLICIT_FALLTHROUGH)/d' \
    -e '/CONFIG_(CC|GCC10)_NO_ARRAY_BOUNDS/d' \
    -e '/CONFIG_(CC|GCC)_((|NO_)STRINGOP_OVERFLOW)/d' \
  {} +

## prepare configs for splitting
find debian/build/ -name 'config.*' -type f -exec sed -i -En '/CONFIG_/p' {} +

(
	cd debian/build
	mkdir -p split-configs
	cd split-configs
	"${prj_dir}/../kconfigeditor2/split-common.py" $(printf ' ../%s' ${configs})
	find ./ -mindepth 1 -maxdepth 1 -type f -exec sed -i -En '/CONFIG_/p' {} +

	cp -f output-common "${prj_dir}/debian/config/config"
	i=0
	for c in ${configs} ; do
		i=$((i+1))

		## config.amd64_none_cloud -> amd64/config.cloud
		## config.amd64_rt_desktop -> amd64/rt/config.desktop
		read -r arch featureset flavour <<-EOF
		$(printf '%s' "${c#config.}" | tr '_' ' ')
		EOF
		[ -n "${arch}" ]       || continue
		[ -n "${featureset}" ] || continue
		[ -n "${flavour}" ]    || continue
		case "${featureset}" in
		none ) o="${arch}/config.${flavour}" ;;
		* )    o="${arch}/${featureset}/config.${flavour}" ;;
		esac

		cp -f "output-part-$i" "${prj_dir}/debian/config/$o"
	done
)

"${prj_dir}/../kconfigeditor2/process.py" -s "${src_dir}" .