#!/bin/bash -u
#
# Manage kernel config annotations
#
# Supported environment variales:
#   conc_level  : Concurrency level for upstream make (-jX)
#   skip_checks : Skip config checks if set to 'true'
#   gcc         : Default gcc to use (mandatory)
#

function cleanup()
{
	rm -rf build "${TMP_DIR}"
}

# We have to be in the top level Ubuntu kernel source directory
if ! [ -e debian/debian.env ] ; then
	echo "ERROR: This is not an Ubuntu kernel source directory" >&2
	exit 1
fi

if [ -z "${gcc:-}" ] ; then
	echo "ERROR: 'gcc' environment variable must be set" >&2
	exit 1
fi

if [ ${#} -ne 1 ] ; then
	echo "Usage: $0 updateconfigs|defaultconfigs|genconfigs|editconfigs"
	exit 2
fi

mode=${1}

case "${mode}" in
	updateconfigs)  target="syncconfig" ;;
	defaultconfigs) target="olddefconfig" ;;
	genconfigs)     target="oldconfig" ;;
	editconfigs)    ;;  # Target is set later based on user input
	*) echo "ERROR: Invalid mode: ${1}" >&2
	   exit 1 ;;
esac

. debian/debian.env

annotations_file=${DEBIAN}/config/annotations
warning_partial=()

TMP_DIR=$(mktemp -d)
trap cleanup EXIT

# Use annotations to generate configs
FLAVOURS=$(sed -ne 's/^# FLAVOUR: //p' "${annotations_file}")

for arch_flavour in ${FLAVOURS} ; do
	arch=${arch_flavour%%-*}
	flavour=${arch_flavour#*-}
	tmp_conf_file=${TMP_DIR}/${arch}-config.flavour.${flavour}

	# Map debian archs to kernel archs
	case "${arch}" in
		amd64)   kern_arch="x86_64" ;;
		arm64)   kern_arch="arm64" ;;
		armhf)   kern_arch="arm" ;;
		ppc64el) kern_arch="powerpc" ;;
		riscv64) kern_arch="riscv" ;;
		s390x)   kern_arch="s390" ;;
		*)       echo "WARNING: Unsupported architecture: ${arch}"
		         warning_partial+=("${arch}")
		         continue ;;
	esac

	# Determine cross toolchain to use for Kconfig compiler tests
	cross_compile="$(dpkg-architecture -qDEB_HOST_GNU_TYPE -a"${arch}" 2>/dev/null)-"

	# Arch-specific compiler, if any
	arch_gcc=$(cat <<EOF | make -s -f - all
include ${DEBIAN}/rules.d/${arch}.mk
all:
	@echo \$(if \$(gcc),\$(gcc),${gcc})
EOF
			)
	gcc_path=$(which "${cross_compile}${arch_gcc}" || true)
	if [ -z "${gcc_path}" ] ; then
		echo "WARNING: ${cross_compile}${arch_gcc} not installed"
		warning_partial+=("${arch}")
		continue
	fi

	if [ "${mode}" = "editconfigs" ] ; then
		while true ; do
			echo -n "Do you want to edit configs for ${arch}-${flavour}? [Y/n] "
			read -r choice
			case "${choice,,}" in
				y|"") target="menuconfig" ; break ;;
				n)    target="syncconfig" ; break ;;
			esac
		done
	fi

	rm -rf build
	mkdir build

	# Generate .config from annotations
	python3 debian/scripts/misc/annotations -f "${annotations_file}" \
			--arch "${arch}" --flavour "${flavour}" --export > build/.config

	# Environment variables for 'make *config'
	env=(ARCH="${kern_arch}"
		 DEB_ARCH="${arch}"
		 CROSS_COMPILE="${cross_compile}"
		 CC="${gcc_path}")

	# Concurrency level
	if [ -n "${conc_level:-}" ] ; then
		env+=("${conc_level}")
	fi

	# Call config target
	echo
	echo "* Run ${target} on ${arch}/${flavour} ..."
	${kmake} O=build "${env[@]}" "${target}"

	# Move config for further processing
	mv build/.config "${tmp_conf_file}"
done

rc=0

if [ "${skip_checks:-}" = "true" ] ; then
	echo
	echo "Skipping config-check (skip_checks=${skip_checks}) ..."
else
	echo
	echo "Running config-check for all configurations ..."
	fail=0
	for arch_flavour in ${FLAVOURS} ; do
		arch=${arch_flavour%%-*}
		flavour=${arch_flavour#*-}
		tmp_conf_file=${TMP_DIR}/${arch}-config.flavour.${flavour}

		echo
		echo "* Run config-check for ${arch}-${flavour} ..."
		python3 debian/scripts/misc/annotations -f "${annotations_file}" \
				--arch "${arch}" --flavour "${flavour}" --check "${tmp_conf_file}" || \
			fail=$((fail + 1))
	done

	if [ ${fail} -gt 0 ] ; then
		rc=1
		echo "ERROR: ${fail} config-check failures detected" >&2
	fi
fi

if [ ${#warning_partial[@]} -gt 0 ] ; then
	rc=1
	echo "ERROR: Config operation not applied to all architectures (skipped ${warning_partial[*]})" >&2
fi

# Recreate the annotations file
if [ "${mode}" = "genconfigs" ] ; then
	rm -rf CONFIGS
	mv "${TMP_DIR}" CONFIGS
else
	echo
	echo "Importing all configurations ..."
	echo
	for arch_flavour in ${FLAVOURS} ; do
		arch=${arch_flavour%%-*}
		flavour=${arch_flavour#*-}
		tmp_conf_file=${TMP_DIR}/${arch}-config.flavour.${flavour}

		echo "* Import configs for ${arch}-${flavour} ..."
		python3 debian/scripts/misc/annotations -f "${annotations_file}" \
				--arch "${arch}" --flavour "${flavour}" --import "${tmp_conf_file}"
	done
fi

exit "${rc}"