#!/bin/sh
#
# Initial port bootstrap scripts
# bootstrap-prepare.sh
# Downloads, configures, and patches packages to be built.
#
# Copyright (C) 2013  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 2 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/>.

set -e

IDX_SHA256SUM='1df55a00659f82da3a595c154ce2fbfb4b9ca355b5bc6edceb34076536d7f09d'
SCRIPT_DIR=
ARCH=
PLAT=

main()
{
	SCRIPT_DIR="$(cd "${0%/*}" && pwd)"
	ARCH="$(cat /etc/proteanos_arch)"
	PLAT="$(cat /etc/proteanos_plat)"

	cat <<-EOF

		Preparing packages for bootstrap...
		===================================
		EOF

	prepare_file_system_fake
	prepare_packages_from_git
	prepare_packages
	prepare_file_system
}

log()
{
	local msg i

	msg="$(printf "${@}")"
	printf '\n%s\n' "${msg}"
	i=0
	while [ ${i} -lt ${#msg} ]; do
		printf '-'
		i=$(($i + 1))
	done
	printf '\n\n'
}

prepare_file_system_fake()
{
	# ob-platconf needs to find this file.  Otherwise, opkbuild fails to
	# build busybox.  config-dev provides this, but that isn't fetched until
	# after busybox is built.
	sudo mkdir -p "/usr/local/share/platconf/${PLAT}/busybox"
	sudo touch "/usr/local/share/platconf/${PLAT}/busybox/busybox.config"

	# opkhelper installs an opkbuild helper configuration script named
	# "opkhelper".  ProteanOS packages depend on "opkhelper-3.0".
	sudo ln -sf opkhelper /usr/local/share/opkbuild/helpers/opkhelper-3.0
}

prepare_packages_from_git()
{
	local pkgs_list repo branch patch

	if [ -e "${SCRIPT_DIR}/bootstrap-pkgs-git_${ARCH}.txt" ]; then
		pkgs_list="${SCRIPT_DIR}/bootstrap-pkgs-git_${ARCH}.txt"
	elif [ -e "${SCRIPT_DIR}/bootstrap-pkgs-git.txt" ]; then
		pkgs_list="${SCRIPT_DIR}/bootstrap-pkgs-git.txt"
	else
		return 0
	fi

	[ -d pkg ] || mkdir pkg
	cd pkg

	while read repo branch; do
		if [ -f "${repo##*/}_"*'_src_all.changes' ]; then
			continue
		fi
		log 'Preparing package %s...' "${repo##*/}"
		if [ ! -d "${repo##*/}/.git" ]; then
			git clone --depth 1 --branch "${branch}" \
				"git://git.proteanos.com/pkg/${repo}.git"
		fi
		cd "${repo##*/}"
		git pull origin "${branch}"
		if [ -d "${SCRIPT_DIR}/patches/${repo##*/}" ]; then
			printf 'Patching package %s...\n' "${repo##*/%/}"
			for patch in "${SCRIPT_DIR}/patches/${repo##*/}/"*; do
				patch -N -p 1 -u -i "${patch}" || \
					true
			done
		fi
		if [ -x config ]; then
			./config clean
			./config
		fi
		rm -f local.mk
		if [ -f source.mk -a ! -f "${repo##*/}"*.orig.tar* ]; then
			if [ -f "../.cache/${repo##*/}"*.orig.tar* ]; then
				mv "../.cache/${repo##*/}"*.orig.tar* .
			else
				opkbuild -bCT source
				rm -Rf tmp
			fi
		fi
		opkbuild -SC
		rm -Rf tmp
		cd ..
	done <"${pkgs_list}"

	cd ..
}

: <<'EOF'
prepare_packages_from_ftp()
{
	local pkg src_opk path

	cd pkg

	for pkg in ; do
		log 'Preparing package %s...' "${pkg}"
		if [ ! -d "${pkg}" ]; then
			src_opk="src-${pkg}_*_src_all.opk"
			path="pub/pkg/${pkg}/${src_opk}"
			wget "ftp://files.proteanos.com/${path}"
			tar -xzOf ${src_opk} data.tar.gz | tar -xz
			mv "usr/src/${pkg}_"* "${pkg}"
		fi
	done
	[ -d usr/src ] && rmdir usr/src
	[ -d usr ] && rmdir usr

	cd ..
}
EOF

prepare_packages()
{
	local mirror rand line filename sha256sum

	log 'Selecting package archive mirror...'
	if [ -r "${SCRIPT_DIR}/mirror" ]; then
		mirror="$(cat "${SCRIPT_DIR}/mirror")"
	else
		rand=$(date '+%S')
		rand=$(($rand % 2))
		case ${rand} in
			0)
				mirror='http://mirror.gnu.dk/pub/proteanos'
				;;
			1)
				mirror='http://mirror.oss.maxcdn.com/proteanos'
				;;
		esac
	fi

	log 'Downloading Packages index file...'
	wget -O Packages "${mirror}/feeds/dev/trunk/src/all/base/Packages"
	if ! printf '%s  Packages\n' "${IDX_SHA256SUM}" | sha256sum -c -; then
		printf 'ERROR: Checksum of Packages index file failed!\n' >&2
		exit 1
	fi

	log 'Downloading source packages...'
	while IFS='' read -r line; do
		if [ "x${line%: *}" = 'xFilename' ]; then
			filename="${line}"
			filename="${filename#Filename: }"
		elif [ "x${line%: *}" = 'xSHA256sum' ]; then
			sha256sum="${line}"
			sha256sum="${sha256sum#SHA256sum: }"
			get_pkg "${mirror}" "${filename}" "${sha256sum}"
		fi
	done <Packages
}

get_pkg()
{
	local mirror="${1}"
	local filename="${2}"
	local sha256sum="${3}"
	local pkg_ver

	pkg_ver="${filename##*/src-}"
	pkg_ver="${pkg_ver%_src_all.opk}"
	[ -d "pkg/${pkg_ver%_*}" ] && return

	[ -d pkg ] || mkdir pkg
	cd pkg

	wget -O "${filename##*/}" \
		"${mirror}/feeds/dev/trunk/src/all/base/${filename}"

	filename="${filename##*/}"

	if ! printf '%s  %s\n' "${sha256sum}" "${filename}" | sha256sum -c; then
		printf 'ERROR: Checksum of source package file failed!\n' >&2
		exit 1
	fi

	tar -xzOf "${filename}" data.tar.gz | tar -xz
	mv "usr/src/${pkg_ver}" "${pkg_ver%_*}"
	rmdir usr/src usr

	cd ..
}

prepare_file_system()
{
	local ma dir bb_ver

	if ma=$(dpkg-architecture -qDEB_HOST_MULTIARCH 2>/dev/null); then
		log 'Making multiarch directory links...'
		for dir in /lib /usr/lib /usr/include; do
			if [ ! -e "${dir}/${ARCH}" ]; then
				printf '%s/%s -> %s\n' \
					"${dir}" "${ARCH}" "${ma}"
				sudo ln -s "${ma}" "${dir}/${ARCH}"
			fi
		done
		printf '\n'
		log 'Overriding elf_interp macro in gcc-4.7 source package...'
		case "${ma}" in
			'x86_64-linux-gnu')
				interp='ld-linux-x86-64.so.2'
				;;
			'i386-linux-gnu')
				interp='ld-linux.so.2'
				;;
			'arm-linux-gnueabihf')
				interp='ld-linux-armhf.so.3'
				;;
		esac
		printf 'Using %s...\n\n' /lib/${ARCH}/${interp:-ld-*.so.*}
		printf 'elf_interp = %s\n' /lib/${ARCH}/${interp:-ld-*.so.*} \
			>pkg/gcc-4.7/local.mk
	fi

	bb_ver="$(sed 's/^busybox (\(.*\)-.*) .*$/\1/; q;' \
		pkg/busybox/changelog)"
	sudo cp -p "pkg/config-${PLAT}/src/build/busybox/${bb_ver}/busybox.config" \
		"/usr/local/share/platconf/${PLAT}/busybox/busybox.config"
	sudo cp -p "pkg/config-${PLAT}/src/build/busybox/${bb_ver}/inittab" \
		"/usr/local/share/platconf/${PLAT}/busybox/inittab"
}

main "${@}"