#!/bin/dash

#############################################################################
#            Everything below this line is seen by buildfiles and           #
#                   can be overriden unless readonly is used.               #
#############################################################################

download() {
	# $1 = URL, $2 => if defined, store in distfiles only
	cd "${tmpdir}" || _xfailedbye "cd failed"
	srcbname="$( basename "${1}" )"
	srcfile="${distdir}/${srcbname}"
	cksum="${swirldir}/checksum"
	echo "===> Downloading ${1}"
	if test ! -e "${srcfile}"; then
		curl -L# "${1}" -o "${srcfile}" ||\
			_xfailedbye "Download failed"
	else
		echo "===> Found a local distfile for ${1}"
	fi
	# Do not extract if we are just creating checksums
	if test -z "${2}" -a -z "${dochecksum}"; then
		echo "===> Extracting ${srcfile}"
		bsdtar -xf "${srcfile}" || _xfailedbye "Extraction failed"
	else
		echo "===> Extra distfile stored at ${srcfile}"
	fi
}
# other public hooks
prebuild() { :; }
postbuild() { :; }

# Provide defaults for some buildfile shell variables
# Some are voluntarily undocumented, they are maybe for future use.
test -z "${MAKE_JOBS}" && MAKE_JOBS="$(nproc)"

ARCH="$(dpkg-architecture -q DEB_BUILD_ARCH)"
if test -z "${ARCH}"; then
	echo "FATAL: unable to determine current architecture"
	exit 1
fi
readonly ARCH

buildswirl_is_at="$(realpath "$(dirname "${0}")")"
if test -z "${buildswirl_is_at}"; then
	echo "FATAL: unable to find where the swirlbuild tree is"
	exit 1
fi
readonly buildswirl_is_at

# Try hard to make the buildfile location is properly found when
# using ../../buildswirl $PWD
buildfile="${buildswirl_is_at}/${1}/build"
test ! -e "${buildfile}" && buildfile="${1}/build"
if test ! -e "${buildfile}"; then
	echo "FATAL: unable to get the buildfile location"
	exit 1
fi
readonly buildfile

swirldir="$( dirname "$( realpath "${buildfile}" )" )"
if test ! -e "${swirldir}"; then
	echo "FATAL: unable to get the swirl directory"
	exit 1
fi
readonly swirldir

cd "${buildswirl_is_at}" || exit 1
. "${buildfile}"

#############################################################################
#           Everything below this line is NOT seen by buildfiles            #
#                	BUT can be seen by hooks             		    #
#############################################################################

_checkchecksum() {
	cksum="${swirldir}/checksum"
	if test -e "${cksum}"; then
		echo "===> Computing checksum of the distfiles"
		cd "${distdir}" || _xfailedbye "cd failed"
		sha512sum -c "${cksum}"
		if test $? -ne 0; then
			echo "===> Checksum failed, will bail out."
			# kill all the files, so the next invocation can try to
			# download again.
			rm -f "${distdir}"/*
			echo "===> Deleted distfiles in ${distdir}, please try again."
			_xfailedbye "FATAL: Checksum failed"
		fi
	else
		echo "===> No checksum to compute, no checksum file found"
	fi
}


_checksumandquit() {
	echo "===> Creating checksum file"
	if test ! -d "${distdir}"; then
		echo "Cannot do any checksum: ${distdir} does not exist. It is"
		echo "normal if you have no SOURCE or EXTRA_SOURCES in your"
		echo "buildfile."
		exit 1
	fi
	cd "${distdir}" || exit 1
	sha512sum --tag -- * > "${swirldir}/checksum"
	if test $? -ne 0; then
		echo "===> Computing the checksums failed. Bailing out."
		exit 1
	fi
	echo "===> Finished. Result:"
	cat "${swirldir}/checksum"
	exit
}

_formatdepends() {
	# make debian/control compatible depend lines
	echo "${1}" | awk '
		! $1 { next } # empty line
		{
			# trim() :)
			gsub(/(^[[:space:]]+|[[:space:]]+$)/, "")
			printf(" %s,\n", $0)
		}
	'
}

_formatdescription() {
	echo "${DESCRIPTION}" | awk '
		{ gsub(/(^[[:space:]]+|[[:space:]]+$)/, "") }
		# empty line and we are not in the long description
		! $1 && output == "" { next }
		# empty line, but this the long description, put dot
		! $1 && output != "" { output = sprintf("%s\n .", output); next }
		# real first line => short description
		output == "" { output = $0; next }
		# long description
		output != "" { output = sprintf("%s\n %s", output, $0) }
		END { print output }
	'
}

_flatten4for() {
	# transform a multiline string to something that for can iterate on
	# the first item of each line
	echo "${1}" | awk '
		! $1 { next } # empty line
		{ print $1 }
	'
}

_changecontrol() {
	awk 	-v BD="$( _formatdepends "${BUILD_DEPENDS}" )" \
		-v RD="$( _formatdepends "${RUN_DEPENDS}" )" \
		-v C="$( _formatdepends "${CONFLICTS}" )" \
		-v BR="$( _formatdepends "${BREAKS}" )" \
		-v REP="$( _formatdepends "${REPLACES}" )" \
		-v PR="$( _formatdepends "${PROVIDES}" )" \
		-v H="${HOMEPAGE}" \
		-v D="$( _formatdescription "${DESCRIPTION}" )"\
		-v GIP="${GO_IMPORT_PATH}" \
		'
		/^ <Insert long description, indented with spaces.>/ { next }
	       	/^Build-Depends:/ && BD != "" { printf("%s\n%s\n", $0, BD); next }
	       	/^Depends:/ && RD != "" { printf("%s\n%s\n", $0, RD); next }
		/^Homepage:/ && GIP != "" { printf("XS-Go-Import-Path: %s\n", GIP) }
	       	/^Homepage:/ && H != "" { printf("Homepage: %s\n", H); next }
		/^Description:/ && D != "" { printf("Description: %s\n", D); next }
	       	{ print }
		END {
			if (C != "") printf("Conflicts: %s\n", C)
			if (BR != "") printf("Breaks: %s\n", BR)
			if (REP != "") printf("Replaces: %s\n", REP)
			if (PR != "") printf("Provides: %s\n", PR)
		}' "${srcdir}/debian/control"
}

_xfailedbye() {
	echo "FATAL: $*!"
	_clean
	exit 1
}

_dhmake() {
	cd "${srcdir}" || _xfailedbye "cd failed"
	# ditch upstream debianization
	if test -e "./debian"; then
		echo "===> Moving upstream debian directory to debian.upstream"
		mv debian debian.upstream
	fi
	echo "===> Running dh_make"
	test -e "${swirldir}/debian" && debiantemplate=-t"${swirldir}/debian"
	# XXX Cannot quote $debiantemplate because it fails if no debian/
	#     directory exist
	dh_make \
		-yns ${debiantemplate} \
		-p "${PKGNAME}_${VERSION}" || _xfailedbye "dh_make failed"
	if test ! -z "${EPOCH}"; then
		echo "===> Applying EPOCH to debian/control as requested"
		EPOCH="${EPOCH}:"
		# XXX should use dch(1), but it pulls devscript
		chglog="${PKGNAME} (${EPOCH}${VERSION}) UNRELEASED; urgency=medium"
		sed -i '1s/^.*$/'"${chglog}"'/' debian/changelog
	fi
}

_applycopyright() {
	echo "===> Applying LICENSE to debian/copyright"
	test -z "${LICENSE}" && _xfailedbye "The LICENSE file(s) must be specified"
	# Display an empty line between license files
	printf "Source downloaded from %s or from local files\n\n" "${SOURCE}" \
		> "${srcdir}"/debian/copyright
	tail -n+1 $( echo "${LICENSE}" | xargs ) >>  "${srcdir}"/debian/copyright
	test $? -ne 0 && _xfailedbye "The mandatory LICENSE file(s) cannot be found"
}

_createsourcepkg() {
	echo "===> Creating source package"
	cd "${srcdir}" || _xfailedbye "cd failed"
	dpkg-source --build . || \
		_xfailedbye "Error during source package creation. Check your swirl"
}

_pbuilder() {
	cd "${tmpdir}" || _xfailedbye "cd failed"
	mkdir -p "${buildswirl_is_at}"/logs || _xfailedbye "mkdir failed"
	echo "===> Launching pbuilder, need root!"
	sudo pbuilder update
	debline="deb [trusted=yes] file:${repodir} ./"
	sudo pbuilder build --override-config \
		--hookdir "${buildswirl_is_at}/infrastructure/pbuilder/hooks" \
		--distribution stable \
		--components "main contrib non-free" \
		--bindmounts "${buildswirl_is_at}" \
		--othermirror "${debline}" \
		--debbuildopts "-j${MAKE_JOBS} --build=binary" \
		--logfile "${buildswirl_is_at}/logs/${PKGNAME}_${VERSION}_${ARCH}.log" \
	 	--use-network yes \
		./*.dsc
	test $? -ne 0 && _xfailedbye "Building failed"
}

_clean() {
	echo "===> Cleaning the temporary source directory"
	rm -rf "${tmpdir}" || exit 1
}

_torepo() {
	echo "===> Moving package(s) to the repository"
	mkdir -p "${repodir}"
	# Avoid getcwd() warning after _clean
	cd "${repodir}" || _xfailedbye "cd failed"
	cp "/var/cache/pbuilder/result/${PKGNAME}_${VERSION}_${ARCH}.deb" "${repodir}"
	# dbgsym packages are not always built
	cp "/var/cache/pbuilder/result/${PKGNAME}-dbgsym_${VERSION}_${ARCH}.deb" \
	   "${repodir}" 2> /dev/null
	_clean
	"${buildswirl_is_at}"/infrastructure/bin/repoupdate "${repodir}"
	echo "Finished. Don't forget to 'apt update' before trying to install!"
}

_debugsource() {
	echo "Here is your source debug shell."
	echo "You can use the SWIRLDIR shell variable to refer to the swirl"
	echo "directory."
	echo "Note that leaving the shell will destroy the source directory."
	cd "${tmpdir}" || _xfailedbye "FATAL: unable to enter ${tmpdir}"
	env SWIRLDIR="${swirldir}" "${SHELL}"
	rm -rf "${tmpdir}"
	env -u SWIRLDIR > /dev/null
	exit 1
}

_applypatches() {
	echo "===> Patching"
	patchdir="${swirldir}/patches"
	test ! -d "${patchdir}" && return
	cd "${srcdir}" || _xfailedbye "cd failed"
	for patch in "${patchdir}"/*.patch; do
		# empty or patches-disabled patches/ directory
		test -e "${patch}" || continue
		patch -b -Ep0 < "${patch}"
		if test $? -ne 0; then
			echo "ALERT: Patching Failed, activating DEBUG_SOURCE=1"
			_debugsource
		fi
	done
}

readonly distdir="${buildswirl_is_at}/distfiles/${PKGNAME}-${VERSION}"
mkdir -p "${distdir}" || { echo "FATAL: Unable to store distfiles!"; exit 1; }

if test ! -d "${1}"; then
	echo "Usage: buildswirl <directory> [checksum]"
	exit 1
fi

if test "${2}" = "checksum"; then
	readonly dochecksum=Yes
	if test -e "${swirldir}/checksum"; then
		echo "FATAL: checksum file already existing! Please remove it first."
		exit 1
	fi
fi

# Don't create stuff we do not need, we just want checksums
if test -z "${dochecksum}"; then
	readonly repodir="${buildswirl_is_at}/repository"
	readonly localversion="${VERSION}+swirl${REVISION}"
	if test -e "${repodir}/${PKGNAME}_${localversion}_${ARCH}.deb"; then
		echo "Package '${PKGNAME}-${localversion}' already built!"
		test -z "${DEBUG_RMPKG}" && exit 1
	fi

	tmpdir="$( mktemp -d )"
	if test -z "${tmpdir}"; then
		echo "FATAL: unable to create the temporary root source directory"
		exit 1
	fi
	readonly tmpdir

	if test -z "${OVERRIDE_SRCDIR}"; then
		readonly srcdir="${tmpdir}/${PKGNAME}-${VERSION}"
	else
		readonly srcdir="${tmpdir}/${OVERRIDE_SRCDIR}"
	fi
fi

download "${SOURCE}"
for extrasrc in $( _flatten4for "${EXTRA_SOURCES}" ); do
	download "${extrasrc}" extra
done
test ! -z "${dochecksum}" && _checksumandquit
test ! -z "${SOURCE}" && _checkchecksum
for swirldep in $( _flatten4for "${SWIRL_DEPENDS}" ); do
	echo "===> Building dependency \"${swirldep}\""
	"${buildswirl_is_at}/buildswirl" "${swirldep}"
	if test $? -ne 0; then
		echo "===> Building \"${swirldep}\" failed, or is already built."
		# XXX Cannot exit 1 on fail in case the package has already been built
	fi
done

VERSION="${localversion}"
_dhmake
echo "$( _changecontrol )" > "${srcdir}/debian/control"
_applypatches
prebuild
_applycopyright
_createsourcepkg
test ! -z "${DEBUG_SOURCE}" && _debugsource
_pbuilder
_torepo
postbuild