#! /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

print_usage()
{
	printf 'Usage: [-r assume-uid0-cmd] %s\n' "$1"
}

error()
{
	printf 'opkbuild: [%s] Error\n' "${1}"
	cd ..
	rm -Rf tmp 2> /dev/null
	exit 1
}

opts=$(getopt -n "${0}" -o 'r:p:' -- "${@}")
if [ ${?} -ne 0 ]; then
	print_usage "${0}" >&2
	exit 1;
fi
eval set -- "${opts}"
while true; do
	case "${1}" in
		-r)
			uid0_cmd=${2}
			shift 2
			;;
		-p)
			platform=${2}
			shift 2
			;;
		--)
			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

# 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 target platform.
# If there no config files to copy, build platform-independent packages.
if [ ! -f config ]; then
	platform=''
# If a target platform was not specified ...
elif [ -z "${platform}" ]; then
	platform=$(opkg print-architecture | grep -E '^arch [^ -]+ [0-9]+$')
	# ... and there are config files and zero installable platforms, fail.
	if [ -z "${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 [ $(echo "${platform}" | wc -l) -gt 1 ]; then
		printf 'opkbuild: Error: %s\n' \
			'Multiple platforms found while detecting target' >&2
		exit 1
	fi
	# ... and there are config files and one installable platform, build for it.
fi

# Attempt to detect the target architecture tuple.
# NB: Currently cross-compiling is not supported.
arch=$(opkg print-architecture | grep -E '^arch [^ -]+(-[^ -]+){3} [0-9]+$')
if [ -z "${arch}" ]; then
	printf 'opkbuild: Error: No installable architecture found\n' >&2
elif [ $(echo "${arch}" | wc -l) -gt 1 ]; then
	printf 'opkbuild: Error: Multiple installable architectures found\n' >&2
fi

# 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)

# Set environment variables for the build configuration.
export OH_PLATFORM="${platform}"
export OH_ARCH="${arch}"
echo "${OH_ARCH}" | \
	IFS=- read OH_ARCH_CPU OH_ARCH_VENDOR OH_ARCH_KERNEL OH_ARCH_LIBS
export OH_ARCH_CPU OH_ARCH_VENDOR OH_ARCH_KERNEL OH_ARCH_LIBS
export OH_SRCPKG="${srcpkg}"
export OH_PKGVER="${version%'-'*}"
export OH_PKGREV="${version#*'-'}"

# Check build dependencies.
oh-checkbuilddeps || 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 ${srcpkg}-src;) || error "${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}"
		# Make installation directory.
		# TODO: Maybe this should be an FHS-compliant filesystem hierarchy.
		mkdir dest || error "${binpkg}"
		# Copy or extract software sources to src.
		if [ -d ../src ]; then
			cp -Rp ../src src || error "${binpkg}"
		elif [ -f ../${pkgname}_${pkgver}.tar.gz ]; then
			tar -xzf ../${pkgname}_${pkgver}.tar.gz || error "${binpkg}"
		fi
		# TODO: Other compression formats, putting things in src/, ...
		# Apply patches.
		oh-applypatches
		# Copy platform config files.
		oh-copyconfig || error "${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