#!/bin/bash
#
# akmodbuild - Helper script for building kernel module SRPMs
# Copyright (c) 2007 Thorsten Leemhuis <fedora@leemhuis.info>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
myprog="akmodsbuild"
myver="0.5.6"

# defaults that might get overwritten by user:
kernels="$(uname -r)"
target="$(uname -m)"
if [[ "${target}" == "armv7l" ]] ; then
	target="armv7hl"
fi
numberofjobs=$(grep -c processor /proc/cpuinfo 2> /dev/null)
verboselevel=2
outputdir="${PWD}"
srpms=

init ()
{
	## startup checks
	# prevent root-usage
	if [[ -w /var ]] ; then
		echo "ERROR: Not to be used as root; start as user or '${myprog}' instead." >&2
		exit 1
	fi

	# do we have everything we need to build for the kernels in question?
	for kernel in ${kernels}; do
		if [[ ! -e /usr/src/kernels/${kernel}/Makefile ]] && [[ ! -e /usr/lib/modules/${kernel}/build/Makefile ]] ; then
			echo "ERROR: Files needed for building modules against kernel" >&2
			echo " ${kernel} could not be found as the following" >&2
			echo " directories are missing:"
			echo " /usr/src/kernels/${kernel}/" >&2
			echo " /usr/lib/modules/${kernel}/build/" >&2
			exit 2
		fi
	done

	if [[ ! "${srpms}" ]] ; then
		echo "ERROR: Please provide a list of SRPM-files to build."
		exit 2
	fi

	# SRPMS available?
	for srpm in ${srpms}; do
		if [[ ! -r ${srpm} ]] ; then
			echo "ERROR: Can't find SRPM ${srpm}"
			exit 1
		fi
	done

	# room to save things
	if [[ ! -d "${outputdir}" ]] ; then
		echo "ERROR: ${outputdir} is not a directory" >&2
		exit 1
	elif [[ ! -w "${outputdir}" ]] ; then
		echo "ERROR: ${outputdir} is not a writable" >&2
		exit 1
	fi


	# make sure this is a number
	if ! (( ${numberofjobs} > 0 )) ; then
		echo "Warning: using hardcoded defaut value for number of jobs"
		numberofjobs=2
	fi

	## preparations
	# tmpdir
	if ! tmpdir="$(mktemp -d -p /tmp ${myprog}.XXXXXXXX)" ; then
		echo "ERROR: Could create tempdir."
		exit 1
	fi

	# buildtreee
	mkdir "${tmpdir}"/{BUILD,SOURCES,SPECS,SRPMS,RPMS,RPMS/"${target}"}

	# logfile
	if [[ ! "${logfile}" ]] ; then
		logfile="${tmpdir}/logfile"
	fi

	if ( [[ -e "${logfile}" ]] && [[ ! -w "${logfile}" ]] ) || ! touch "${logfile}" ; then
		echo "ERROR: Could not write logfile."
		finally
		exit 1
	fi
}


finally()
{
	# kill background jobs if needed
	if [[ "${watch_jobid}" ]] ; then
		kill "${watch_jobid}"
	fi
	if [[ "${rpmbuild_jobid}" ]] ; then
		kill "${rpmbuild_jobid}"
	fi

	# remove tmpfiles
	if [[ -d "${tmpdir}" ]] ; then
		rm -rf "${tmpdir}"
	fi
}
trap "finally" 2


akmods_echo()
{
	# where to output
	local this_fd=${1}
	shift

	# verboselevel
	local this_verbose=${1}
	shift

	if [[ "${1}" == "--not-logfile" ]] ; then
		local notlogfile=true
		shift
	fi

	# output to console
	if (( ${verboselevel} >= ${this_verbose} )) ; then
		echo "$@" >&${this_fd}
	fi

	# global logfile
	if [[ ! ${notlogfile} ]] ; then
		echo "$@" >> "${logfile}"
	fi
}


watch_rpmbuild()
{
	# background function to show rpmbuild progress
	# does't use akmods_echo here; this stage handles the output on its own
	# (seperate process and there is no need to log this)
	if (( ${verboselevel} == 2 )) ; then
		tail --pid ${1} -n +1 -s 0.1 -f ${2} 2>/dev/null | grep --line-buffered -e '%prep' -e '%build' -e '%install' -e '%clean' | while read line ; do
			if [[ "${line}" != "${line##*prep}" ]] ; then
				echo -n "prep "
			elif [[ "${line}" != "${line##*build}" ]] ; then
				echo -n "build "
			elif [[ "${line}" != "${line##*install}" ]] ; then
				echo -n "install "
			elif [[ "${line}" != "${line##*clean}" ]] ; then
				echo -n "clean; "
				# last linefeed is done by the caller
			fi
		done
	elif (( ${verboselevel} > 2 )) ; then
		tail --pid ${1} -n +1 -s 0.1 -f ${2}
	fi
}

process_srpm()
{
	local source_rpm="${1}"

	# status info
	akmods_echo 1 2 -n "* Rebuilding ${source_rpm} for kernel(s) ${kernels}: "

	# kick off rebuild into background
	/usr/bin/time --format='%x' --output="${tmpdir}/.jobexit" rpmbuild \
		--define "_topdir     ${tmpdir}/" \
		--define "_buildtree  ${tmpdir}/BUILD" \
		--define "_specdir    ${tmpdir}/SPECS" \
		--define "_sourcedir  ${tmpdir}/SOURCES" \
		--define "_srcrpmdir  ${tmpdir}/SRPMS" \
		--define "_rpmdir     ${tmpdir}/RPMS" \
		--define "_smp_mflags -j${numberofjobs}" \
		--define "kernels     ${kernels}" \
		--target ${target} \
		--rebuild "${source_rpm}" 2>&1 | tee -a "${logfile}" > "${tmpdir}/.joblog"  &

	local rpmbuild_jobid=$!

	# show progress
	if (( ${verboselevel} >= 2 )) ; then
		watch_rpmbuild ${rpmbuild_jobid} "${tmpdir}/.joblog" 2> /dev/null &
		local watch_jobid=$!
	fi

	# wait for rpmbuild
	wait ${rpmbuild_jobid}
	local rpmbuild_returncode=$(tail -n 1 "${tmpdir}/.jobexit")
	unset rpmbuild_jobid

	# give watch_rpmbuild a moment to catch up; kill it if it does not
	if (( ${verboselevel} >= 2 )) ; then
		sleep 0.5
		kill ${watch_jobid} &> /dev/null
		unset watch_jobid
	fi

	# did rpmbuild succeed?
	if (( ${rpmbuild_returncode} != 0 )) ; then
		# linefeed:
		akmods_echo 1 2 ""

		akmods_echo 2 2 --not-logfile "rpmbuild failed with errorcode ${rpmbuild_returncode}; last 35 Lines of log:"
		akmods_echo 2 2 --not-logfile "--- "
		tail -n 35 "${tmpdir}/.joblog" >&2
		akmods_echo 2 2  --not-logfile "---"
		return ${rpmbuild_returncode}
	fi

	# finish status for watch_rpmbuild
	if (( ${verboselevel} >= 2 )) ; then
		akmods_echo 1 2 -n "Successfull; "
	fi

	local rpms_built="$(cd "${tmpdir}"/RPMS/"${target}" ; echo *)"

	if ! mv "${tmpdir}/RPMS/${target}/"* "${outputdir}" ; then
		# linefeed:
		akmods_echo 1 2 ""

		akmods_echo 2 2 "Failed to move ${tmpdir}/RPMS/${target}/"* "to ${outputdir}"
		return 128
	fi

	if (( ${verboselevel} == 1 )) ; then
		for rpm in ${rpms_built}; do
			echo "${outputdir%%/}/${rpm}"
		done
	elif (( ${verboselevel} >= 2 )) ; then
		akmods_echo 1 2  "Saved ${rpms_built} in ${outputdir%%/}/"
	fi


	# finished
	return 0
}

myprog_help ()
{
	echo "Rebuilds kmod SRPM(s)"
	echo $'\n'"Usage: ${myprog} [OPTIONS] <SRPMS>"
	echo $'\n'"Options:"
	echo " -k, --kernels         -- build for kernel-versions (output from 'uname -r')"
	echo " -l, --logfile <file>  -- save rpmbuild output to <file>"
	echo " -o, --outputdir <dir> -- save rpms and logs here (current directory)"
	echo " -t, --target          -- target-arch (output from 'uname -m')"
	echo " -v, --verbose         -- increase verboseness"
	echo " -q, --quiet           -- be more quiet"
	echo " -h, --help            -- show usage"
	echo " -V, --version         -- show version"
}

while [ "${1}" ] ; do
	case "${1}" in
		-k|--kernels)
			shift
			if [[ ! "${1}" ]] ; then
				echo "ERROR: Please provide kernel-version(s) to build for together with --kernel" >&2
				exit 1
			fi
			kernels="${1}"
			shift
			;;
		-l|--logfile)
			shift
			if [[ ! "${1}" ]] ; then
				echo "ERROR: Please provide a filename together with --logfile" >&2
				exit 1
			fi
			logfile="${1}"
			shift
			;;
		-o|--outputdir)
			shift
			if [[ ! "${1}" ]] ; then
				echo "ERROR: Please provide the output directory together with --outputdir" >&2
				exit 1
			fi
			outputdir="${1}"
			shift
			;;
		-t|--target)
			shift
			if [[ ! "${1}" ]] ; then
				echo "ERROR: Please provide the target-arch together with --target" >&2
				exit 1
			fi
			target="${1}"
			shift
			;;
		-v|--verbose)
			let verboselevel++
			shift
			;;
		-q|--quiet)
			let verboselevel--
			shift
			;;
		-h|--help)
			myprog_help
			exit 0
			;;
		-V|--version)
			echo "${myprog} ${myver}"
			exit 0
			;;
		--*)
			echo "Error: Unknown option '${1}'." >&2
			myprog_help >&2
			exit 2
			;;
		*)
			srpms="${srpms} ${1}"
			shift
			;;
	esac
done

# sanity checks
init

# go
for srpm in ${srpms}; do
	process_srpm ${srpm}
	returncode=$?

	if (( ${returncode} != 0 )) ; then
		finally
		exit ${returncode}
	fi
done

# finished
finally

exit 0