#! /bin/sh
#
# opkhelper
# src/opkbuild
# Build opkg packages.
#
# Copyright (C) 2012 Patrick "P. J." McDermott
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

. @@LIBDIR@@/opkhelper/controlfields
. @@LIBDIR@@/opkhelper/architecture
. @@LIBDIR@@/opkhelper/archive

print_usage()
{
	cat <<EOF
Usage: ${1} [-r assume-uid0-cmd] [-a host-architecture] [-p host-platform] [-d]
EOF
}

print_version()
{
	cat <<EOF
opkbuild (@@PACKAGE@@) @@VERSION@@
Copyright (C) 2012 Patrick "P. J." McDermott
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by P. J. McDermott.
EOF
}

error()
{
	[ ${#} -eq 1 ] && printf 'opkbuild: [%s] Error\n' "${1}" >&2
	if ${dbg}; then
		printf 'opkbuild: Starting debugging shell...\n' >&2
		/bin/sh
	fi
	cd ..
	rm -Rf tmp 2> /dev/null
	exit 1
}

opts=$(getopt -n "${0}" -o 'r:a:p:ds:V' -- "${@}")
if [ ${?} -ne 0 ]; then
	print_usage "${0}" >&2
	exit 1;
fi
eval set -- "${opts}"
while true; do
	case "${1}" in
		-r)
			uid0_cmd=${2}
			shift 2
			;;
		-a)
			host_arch=${2}
			shift 2
			;;
		-p)
			host_platform=${2}
			shift 2
			;;
		-d)
			dbg=true
			shift
			;;
		-s)
			status_override=${2}
			shift 2
			;;
		-V)
			print_version
			exit 0
			;;
		--)
			shift
			break
			;;
		*)
			print_usage "${0}" >&2
			exit 1
			;;
	esac
done

if [ -z "${uid0_cmd}" ]; then
	uid0_cmd=fakeroot
fi
${uid0_cmd} true
if [ ${?} -ne 0 ]; then
	printf 'opkbuild: Error running command to gain UID 0\n' >&2
	exit 1
fi
if [ -z "${dbg}" ]; then
	dbg=false
fi

# Sanity checks.
printf 'opkbuild: Checking for sanity...\n'
if [ ! -f format -o ! -f build -o ! -f control ]; then
	printf 'Error: Current working directory is not a source package.\n' >&2
	exit 1
fi
if [ "$(cat format)" != '1.0' ]; then
	printf 'Error: Source package is of an incompatible version.\n' >&2
	exit 1
fi

# Attempt to detect the build architecture tuple.
build_arch=$(opkg print-architecture | sed -n \
	's/^arch \([^ -][^ -]*-[^ -][^ -]*-[^ -][^ -]*\) [0-9][0-9]*$/\1/p')
if [ -z "${build_arch}" ]; then
	printf 'opkbuild: Error: No installable architecture found\n' >&2
	exit 1
elif [ $(echo "${build_arch}" | wc -l) -gt 1 ]; then
	printf 'opkbuild: Error: Multiple installable architectures found\n' >&2
	exit 1
fi

# If a host architecture is not specified, natively build.
if [ -z "${host_arch}" ]; then
	host_arch="${build_arch}"
fi

# Attempt to detect the host platform.
# If there no config files to copy, build platform-independent packages.
if [ ! -f config ]; then
	host_platform=''
# If a host platform was not specified ...
elif [ -z "${host_platform}" ]; then
	host_platform=$(opkg print-architecture | \
		sed -n 's/^arch \([^ -][^ -]*\) [0-9][0-9]*$/\1/p' | \
		grep -v 'all')
	# ... and there are config files and zero installable platforms, fail.
	if [ -z "${host_platform}" ]; then
		printf 'opkbuild: Error: %s\n' \
			'Building platform-dependent package and no platforms detected' >&2
		exit 1
	# ... and there are config files and multiple installable platforms, request
	# explicit selection.
	elif [ $(echo "${host_platform}" | wc -l) -gt 1 ]; then
		printf 'opkbuild: Error: %s\n' \
			'Multiple platforms found while detecting host' >&2
		exit 1
	fi
	# ... and there are config files and one installable platform, build for it.
fi

# Resolve status override file path.
pkg_dir="${PWD}"
cd "$(dirname "${status_override}")"
status_override="${PWD}/$(basename "${status_override}")"
cd "${pkg_dir}"

# Make work area.
printf 'opkbuild: Making work area...\n'
mkdir tmp
cd tmp

# Get source package name and version.
printf 'opkbuild: Reading source package control fields...\n'
srcpkg=$(oh_get_field Source)
version=$(oh_get_field Version)
export OH_SRCPKG="${srcpkg}"
export OH_PKGVER=${version}

# Set environment variables for the build architecture.
export OH_BUILD_ARCH_DIST="${build_arch}"
IFS=- read OH_BUILD_ARCH_CPU OH_BUILD_ARCH_KERNEL OH_BUILD_ARCH_LIBS <<EOF
${OH_BUILD_ARCH_DIST}
EOF
export OH_BUILD_ARCH_CPU OH_BUILD_ARCH_KERNEL OH_BUILD_ARCH_LIBS

# Set environment variables for the host architecture and platform.
export OH_HOST_ARCH_DIST="${host_arch}"
IFS=- read OH_HOST_ARCH_CPU OH_HOST_ARCH_KERNEL OH_HOST_ARCH_LIBS <<EOF
${OH_HOST_ARCH_DIST}
EOF
export OH_HOST_ARCH_CPU OH_HOST_ARCH_KERNEL OH_HOST_ARCH_LIBS
export OH_HOST_PLATFORM="${host_platform}"

# Make sure the architecture table exists.
if [ ! -f "@@DATADIR@@/opkhelper/archtab" ]; then
	printf 'opkbuild: Error: architecture table not found.\n' >&2
	exit 1
fi

# Look up build GNU architecture name.
export OH_BUILD_ARCH_GNU="$(sed -n \
	"s/^${OH_BUILD_ARCH_DIST}[ \\t][ \\t]*\\(.*\\)$/\\1/p" \
	"@@DATADIR@@/opkhelper/archtab")"
if [ -z "${OH_BUILD_ARCH_GNU}" ]; then
	printf 'opkbuild: Error: "%s" not found in architecture table.\n' \
		"${OH_BUILD_ARCH_DIST}" >&2
	exit 1
fi

# Look up host GNU architecture name.
export OH_HOST_ARCH_GNU="$(sed -n \
	"s/^${OH_HOST_ARCH_DIST}[ \\t][ \\t]*\\(.*\\)$/\\1/p" \
	"@@DATADIR@@/opkhelper/archtab")"
if [ -z "${OH_HOST_ARCH_GNU}" ]; then
	printf 'opkbuild: Error: "%s" not found in architecture table.\n' \
		"${OH_HOST_ARCH_DIST}" >&2
	exit 1
fi

# Detect cross building.
if [ "${OH_BUILD_ARCH_GNU}" != "${OH_HOST_ARCH_GNU}" ]; then
	toolchain_prefix="${OH_HOST_ARCH_GNU}-"
else
	toolchain_prefix=
fi

# Set toolchain environment variables.
# NB: This is written for GNU Binutils and GCC and won't work for, e.g., LLVM.
export AR="${toolchain_prefix}ar"
export AS="${toolchain_prefix}as"
export CC="${toolchain_prefix}gcc"
export CPP="${toolchain_prefix}cpp"
export CXX="${toolchain_prefix}g++"
export LD="${toolchain_prefix}ld"
export NM="${toolchain_prefix}nm"
export OBJCOPY="${toolchain_prefix}objcopy"
export OBJDUMP="${toolchain_prefix}objdump"
export RANLIB="${toolchain_prefix}ranlib"
export READELF="${toolchain_prefix}readelf"
export SIZE="${toolchain_prefix}size"
export STRINGS="${toolchain_prefix}strings"
export STRIP="${toolchain_prefix}strip"

# Set build flags.
if [ -f "@@DATADIR@@/opkhelper/buildflags/${OH_HOST_ARCH_CPU}" ]; then
	. @@DATADIR@@/opkhelper/buildflags/${OH_HOST_ARCH_CPU}
fi

# Check build dependencies.
oh-checkbuilddeps -s "${status_override}" || error "${srcpkg}-src"

printf '\n'

# Build *-src package.
printf 'opkbuild: Attempting to build package "%s"...\n' "${srcpkg}-src"
printf 'opkbuild: Installing files for package "%s"...\n' "${srcpkg}-src"
${uid0_cmd} mkdir -p ${srcpkg}-src.data/usr/src/${srcpkg}_${version} ||
	error "${srcpkg}-src"
for file in ../*; do
	case ${file} in
		../tmp)
			;;
		../*)
			${uid0_cmd} cp -R ${file} \
				${srcpkg}-src.data/usr/src/${srcpkg}_${version} ||
				error "${srcpkg}-src"
			;;
	esac
done
( ${uid0_cmd} oh-gencontrol -s;) || error "${srcpkg}-src"
( ${uid0_cmd} oh-buildopk -s;) || error "${srcpkg}-src"
( ${uid0_cmd} rm -Rf ${srcpkg}-src.data;) || error "${srcpkg}-src"
printf 'opkbuild: Package "%s" complete!\n\n' "${srcpkg}-src"

# Build other binary packages.
for binpkgdir in ../*.pkg/; do
	binpkg=${binpkgdir#'../'}
	binpkg=${binpkg%'.pkg/'}
	export OH_BINPKG="${binpkg}"
	# Check architecture.
	oh_is_buildable "${binpkg}"
	if [ ${?} -eq 0 ]; then
		printf 'opkbuild: Attempting to build package "%s"...\n' "${binpkg}"
		# Copy or extract software sources to src.
		if [ -d ../src ]; then
			printf 'opkbuild: Copying sources into work area...\n'
			cp -Rp ../src src || error "${binpkg}"
		else
			printf 'opkbuild: Extracting sources into work area...\n'
			oh_archive_extract_source
			case ${?} in
				1)
					printf 'opkbuild: Error: No source archive found\n' >&2
					error
					;;
				2)
					printf 'opkbuild: Error: Multiple source archives found\n' \
						>&2
					error
					;;
				3)
					printf 'opkbuild: Error: %s\n' \
						'Unsupported archive compression format detected' >&2
					error
					;;
				4)
					printf 'opkbuild: Error: %s\n' \
						'No directories found in source archive' >&2
					error
					;;
				5)
					printf 'opkbuild: Error: %s\n' \
						'Multiple top-level directories found in source archive' >&2
					error
					;;
				6)
					printf 'opkbuild: Error: %s\n' \
						'Failed to extract source archive' >&2
					error
					;;
				7)
					printf 'opkbuild: Error: %s\n' \
						'Failed to move extracted sources' >&2
					error
					;;
			esac
		fi
		# Make installation directory.
		# TODO: Maybe this should be an FHS-compliant filesystem hierarchy.
		mkdir dest || error "${binpkg}"
		# Apply patches.
		oh-applypatches
		# Copy platform config files.
		oh-copyconfig || error "${binpkg}"
		# Build the package.
		${uid0_cmd} ../build ${binpkg} || error "${binpkg}"
		printf 'opkbuild: Package "%s" complete!\n\n' "${binpkg}"
		# Clean up everything except the build stamps.
		for file in *; do
			case ${file} in
				*.buildstamp)
					;;
				*)
					${uid0_cmd} rm -Rf ${file} || error "${binpkg}"
					;;
			esac
		done
	fi
done

# Clean up tmp.
cd ..
rm -Rf tmp