#!/bin/sh

BASH_VER=4.3
PYTHON_VER=2.7.10
PORTAGE_VER=2.2.8

usage() {
	exec cat <<EOF
Usage: bootstrap-portage

Small script to download & build & install the minimal packages for portage.
The intention is to be run inside an existing (non-Gentoo) distro that lacks
the packages already.

Those packages are:
 Bash ${BASH_VER}
 Python ${PYTHON_VER}
 Portage ${PORTAGE_VER}

A summary of the work/paths will be shown before any changes are made.
EOF
}

env_init() {
	# Locate env vars that we'll want later on.
	CRITICAL_VARS="ARCH CHOST CFLAGS"
	ALL_VARS="${CRITICAL_VARS} MAKEFLAGS PORTDIR DISTDIR PORTAGE_TMPDIR"
	echo "Setting up initial environment"

	eval $(portageq envvar -v ${ALL_VARS} 2>/dev/null)

	v() { eval echo \"\$$1\" ; }
	for v in ${ALL_VARS} ; do
		# See if the var has been set yet.
		if [ -n "$(v ${v})" ] ; then
			continue
		fi

		# Try to read it ourselves.
		for f in /etc/portage/make.conf /etc/make.conf ; do
			[ -e ${f} ] || continue
			eval ${v}=\"$(. "${f}" 2>/dev/null ; v ${v})\"
		done
	done
	for v in ${CRITICAL_VARS} ; do
		if [ -z "$(v ${v})" ] ; then
			echo "Please set ${v}"
			exit 1
		fi
	done
	: ${MAKEOPTS:=${MAKEFLAGS:--j$(getconf _NPROCESSORS_ONLN 2>/dev/null)}}
	: ${PORTDIR:=/usr/portage}
	: ${DISTDIR:=${PORTDIR}/distfiles}
	: ${PORTAGE_TMPDIR:=/var/tmp}
	export ${ALL_VARS}
}

die() {
	[ $# -gt 0 ] && cat "$1"
	exit 1
}
econf() {
	set -- \
	"${ECONF_SOURCE:-.}/configure" \
		--prefix=/usr \
		--build=${CHOST} \
		--host=${CHOST} \
		--mandir=/usr/share/man \
		--infodir=/usr/share/info \
		--datadir=/usr/share \
		--sysconfdir=/etc \
		--infodir='${prefix}'/share/info \
		--mandir='${prefix}'/share/man \
		--localstatedir=/var/lib \
		"$@"
	echo "$@"
	"$@" >.config.log 2>&1 || die .config.log
}
emake() {
	set -- make ${MAKEOPTS} "$@"
	echo "$@"
	"$@" >.build.log 2>&1 || die .build.log
}
src_fetch() {
	PN=$1
	PV=$2
	P="${PN}-${PV}"
	# The output might have $PV in it.
	eval A=\""$3"\"
	echo
	echo "bootstrapping ${P}"

	if [ ! -e "${DISTDIR}/${A}" ] ; then
		# The URL might have $PV in it.
		eval wget -P \'"${DISTDIR}"\' \""$4/${A}"\"
	fi
}
src_unpack() {
	export S="${PORTAGE_TMPDIR}/${P}"

	rm -rf "${S}"
	mkdir -p "${S}"
	cd "${S}"
	case ${A} in
	*bz2) tar -jxf "${DISTDIR}"/${A} || die ;;
	*gz)  tar -zxf "${DISTDIR}"/${A} || die ;;
	*)    die ;;
	esac

	cd "${S}"/*/
	S=${PWD}
}

######################
# bootstrap bash
######################
bootstrap_bash() {
	V=$(bash -c 'echo ${BASH_VERSINFO[0]}' 2>/dev/null)
	if [ "${V}" -ge 4 ] ; then
		echo
		echo "bash seems to be up-to-date; skipping"
		return 0
	fi

	src_fetch bash ${BASH_VER} '${P}.tar.gz' http://ftp.gnu.org/gnu/bash
	src_unpack

	econf
	emake
	# Make sure it's an "atomic" update otherwise we'll get ETXTBSY.
	cp -a bash /bin/.bash
	mv /bin/.bash /bin/bash
}

######################
# bootstrap python
######################
bootstrap_python() {
	if [ -x /usr/bin/python ] ; then
		echo
		echo "python seems to be up-to-date; skipping"
		echo "rm /usr/bin/python to force"
		return 0
	fi

	src_fetch python ${PYTHON_VER} 'Python-${PV}.tgz' 'http://www.python.org/ftp/python/${PV%_*}'
	src_unpack

	export PYTHON_DISABLE_MODULES="readline pyexpat dbm gdbm bsddb _curses _curses_panel _tkinter"
	export PYTHON_DISABLE_SSL=1
	export OPT="${CFLAGS}"

	econf \
		--enable-unicode=ucs4 \
		--with-fpectl \
		--enable-shared \
		--disable-ipv6 \
		--with-threads \
		--with-cxx=no
	emake
	emake altinstall
	ln -s python`expr substr ${PV} 1 3` /usr/bin/python
}

######################
# bootstrap portage
######################
bootstrap_portage() {
	if [ -x /usr/bin/emerge ] ; then
		echo
		echo "emerge seems to be up-to-date; skipping"
		echo "rm /usr/bin/emerge to force"
		return 0
	fi

	src_fetch portage ${PORTAGE_VER} '${P}.tar.bz2' http://distfiles.gentoo.org/distfiles
	src_unpack

	dodir() { mkdir -p "$@" ; }
	keepdir() { dodir "$@" ; }
	insinto() { INSDESTTREE=$1 ; }
	doins() { cp -a "$@" "$INSDESTTREE/" || die ; }
	newins() { cp -a "$1" "$INSDESTTREE/$2" || die ; }
	exeinto() { EXEDESTTREE=$1 ; }
	doexe() { install -m 755 "$@" "$EXEDESTTREE/" ; }
	get_libdir() { echo lib ; }
	dosym() { ln -sf "$@" || die ; }
	dodoc() { :; }
src_install() {
	local libdir=$(get_libdir)
	local portage_base="/usr/${libdir}/portage"
	local portage_share_config=/usr/share/portage/config

	cd "${S}"/cnf
	insinto /etc
	doins etc-update.conf dispatch-conf.conf || die

	insinto "$portage_share_config"
	doins "$S/cnf/make.globals" || die
	if [ -f "make.conf.${ARCH}".diff ]; then
		patch make.conf "make.conf.${ARCH}".diff || \
			die "Failed to patch make.conf.example"
		newins make.conf make.conf.example || die
	else
		eerror ""
		eerror "Portage does not have an arch-specific configuration for this arch."
		eerror "Please notify the arch maintainer about this issue. Using generic."
		eerror ""
		newins make.conf make.conf.example || die
	fi

	dosym ..${portage_share_config}/make.globals /etc/make.globals

	insinto /etc/logrotate.d
	doins "${S}"/cnf/logrotate.d/elog-save-summary || die

	# BSD and OSX need a sed wrapper so that find/xargs work properly
	if use userland_GNU; then
		rm "${S}"/bin/ebuild-helpers/sed || die "Failed to remove sed wrapper"
	fi

	local x symlinks files

	cd "$S" || die "cd failed"
	for x in $(find bin -type d) ; do
		exeinto $portage_base/$x || die "exeinto failed"
		cd "$S"/$x || die "cd failed"
		files=$(find . -mindepth 1 -maxdepth 1 -type f ! -type l)
		if [ -n "$files" ] ; then
			doexe $files || die "doexe failed"
		fi
		symlinks=$(find . -mindepth 1 -maxdepth 1 -type l)
		if [ -n "$symlinks" ] ; then
			cp -P $symlinks "$D$portage_base/$x" || die "cp failed"
		fi
	done

	cd "$S" || die "cd failed"
	for x in $(find pym/* -type d ! -path "pym/portage/tests*") ; do
		insinto $portage_base/$x || die "insinto failed"
		cd "$S"/$x || die "cd failed"
		# __pycache__ directories contain no py files
		[[ "*.py" != $(echo *.py) ]] || continue
		doins *.py || die "doins failed"
		symlinks=$(find . -mindepth 1 -maxdepth 1 -type l)
		if [ -n "$symlinks" ] ; then
			cp -P $symlinks "$D$portage_base/$x" || die "cp failed"
		fi
	done

	# We install some minimal tests for use as a preinst sanity check.
	# These tests must be able to run without a full source tree and
	# without relying on a previous portage instance being installed.
	cd "$S" || die "cd failed"
	exeinto $portage_base/pym/portage/tests || die
	doexe pym/portage/tests/runTests || die
	insinto $portage_base/pym/portage/tests || die
	doins pym/portage/tests/*.py || die
	insinto $portage_base/pym/portage/tests/lint || die
	doins pym/portage/tests/lint/*.py || die
	doins pym/portage/tests/lint/__test__ || die

	# Symlinks to directories cause up/downgrade issues and the use of these
	# modules outside of portage is probably negligible.
	for x in "${D}${portage_base}/pym/"{cache,elog_modules} ; do
		[ ! -L "${x}" ] && continue
		die "symlink to directory will cause upgrade/downgrade issues: '${x}'"
	done

	doman "${S}"/man/*.[0-9]
	if use linguas_pl; then
		doman -i18n=pl "${S_PL}"/man/pl/*.[0-9]
		doman -i18n=pl_PL.UTF-8 "${S_PL}"/man/pl_PL.UTF-8/*.[0-9]
	fi

	dodoc "${S}"/{ChangeLog,NEWS,RELEASE-NOTES}
	use doc && dohtml -r "${S}"/doc/*
	use epydoc && dohtml -r "${WORKDIR}"/api

	dodir /usr/bin
	for x in ebuild egencache emerge portageq quickpkg repoman ; do
		dosym ../${libdir}/portage/bin/${x} /usr/bin/${x}
	done

	dodir /usr/sbin
	local my_syms="archive-conf
		dispatch-conf
		emaint
		emerge-webrsync
		env-update
		etc-update
		fixpackages
		regenworld"
	local x
	for x in ${my_syms}; do
		dosym ../${libdir}/portage/bin/${x} /usr/sbin/${x}
	done
	dosym env-update /usr/sbin/update-env
	dosym etc-update /usr/sbin/update-etc

	dodir /etc/portage
	keepdir /etc/portage
}
	set -x
	src_install
	set +x
}

######################
# setup misc configs
######################
acct_setup() {
	grep -qs ^wheel: /etc/group    || echo "wheel::10:root" >> /etc/group
	grep -qs ^portage: /etc/group  || echo "portage::250:portage" >> /etc/group
	grep -qs ^portage: /etc/passwd || echo "portage:x:250:250:portage:/var/tmp/portage:/bin/false" >> /etc/passwd
}

main() {
	if [ $# -ne 0 ] ; then
		usage
	fi

	env_init

	echo
	for v in ${ALL_VARS} ; do
		printf "%-20s = %s\n" "${v}" "$(v ${v})"
	done
	echo
	echo "Going to try to boostrap bash / python / portage if needed."
	echo "Bash ${BASH_VER}"
	echo "Python ${PYTHON_VER}"
	echo "Portage ${PORTAGE_VER}"
	echo
	echo "Press return to continue or CTRL+C to abort ..."
	read reply

	mkdir -p "${DISTDIR}"

	bootstrap_bash
	bootstrap_python
	bootstrap_portage
	acct_setup
}
main "$@"