#!/bin/bash
# Copyright 1999-2011 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

# Author Brandon Low <lostlogic@gentoo.org>
#
# Previous version (from which I've borrowed a few bits) by:
# Jochem Kossen <j.kossen@home.nl>
# Leo Lipelis <aeoo@gentoo.org>
# Karl Trygve Kalleberg <karltk@gentoo.org>

cd /

if type -P gsed >/dev/null ; then
	sed() { gsed "$@"; }
fi

get_config() {
	# the sed here does:
	#  - strip off comments
	#  - match lines that set item in question
	#    - delete the "item =" part
	#    - store the actual value into the hold space
	#  - on the last line, restore the hold space and print it
	# If there's more than one of the same configuration item, then
	# the store to the hold space clobbers previous value so the last
	# setting takes precedence.
	local item=$1
	eval echo $(sed -n \
		-e 's:[[:space:]]*#.*$::' \
		-e "/^[[:space:]]*$item[[:space:]]*=/{s:[^=]*=[[:space:]]*\([\"']\{0,1\}\)\(.*\)\1:\2:;h}" \
		-e '${g;p}' \
		"${PORTAGE_CONFIGROOT}"etc/etc-update.conf)
}

cmd_var_is_valid() {
	# return true if the first whitespace-separated token contained
	# in "${1}" is an executable file, false otherwise
	[[ -x $(type -P ${1%%[[:space:]]*}) ]]
}

diff_command() {
	local cmd=${diff_command//%file1/$1}
	${cmd//%file2/$2}
}

scan() {
	echo "Scanning Configuration files..."
	rm -rf ${TMP}/files > /dev/null 2>&1
	mkdir ${TMP}/files || die "Failed mkdir command!" 1
	count=0
	input=0
	local find_opts
	local my_basename

	for path in ${CONFIG_PROTECT} ; do
		path="${ROOT}${path}"
		# Do not traverse hidden directories such as .svn or .git.
		find_opts="-name .* -type d -prune -o -name ._cfg????_*"
		if [ ! -d "${path}" ]; then
			[ ! -f "${path}" ] && continue
			my_basename="${path##*/}"
			path="${path%/*}"
			find_opts="-maxdepth 1 -name ._cfg????_${my_basename}"
		fi

		ofile=""
		# The below set -f turns off file name globbing in the ${find_opts} expansion.
		for file in $(set -f ; find ${path}/ ${find_opts} \
		       ! -name '.*~' ! -iname '.*.bak' -print |
			   sed -e "s:\(^.*/\)\(\._cfg[0-9]*_\)\(.*$\):\1\2\3\%\1%\2\%\3:" |
			   sort -t'%' -k2,2 -k4,4 -k3,3 | LANG=POSIX LC_ALL=POSIX cut -f1 -d'%'); do

			rpath=$(echo "${file/\/\///}" | sed -e "s:/[^/]*$::")
			rfile=$(echo "${file/\/\///}" | sed -e "s:^.*/::")
			for mpath in ${CONFIG_PROTECT_MASK}; do
				mpath="${ROOT}${mpath}"
				mpath=$(echo "${mpath/\/\///}")
				if [[ "${rpath}" == "${mpath}"* ]]; then
					mv ${rpath}/${rfile} ${rpath}/${rfile:10}
					break
				fi
			done
			if [[ ! -f ${file} ]] ; then
				echo "Skipping non-file ${file} ..."
				continue
			fi

			if [[ "${ofile:10}" != "${rfile:10}" ]] ||
			   [[ ${opath} != ${rpath} ]]; then
				MATCHES=0
				if [[ "${EU_AUTOMERGE}" == "yes" ]]; then
					if [ ! -e "${rpath}/${rfile}" ] || [ ! -e "${rpath}/${rfile:10}" ]; then
						MATCHES=0
					else
						diff -Bbua ${rpath}/${rfile} ${rpath}/${rfile:10} | egrep '^[+-]' | egrep -v '^[+-][\t ]*#|^--- |^\+\+\+ ' | egrep -qv '^[-+][\t ]*$'
						MATCHES=$?
					fi
				elif [[ -z $(diff -Nua ${rpath}/${rfile} ${rpath}/${rfile:10}|
							  grep "^[+-][^+-]"|grep -v '# .Header:.*') ]]; then
					MATCHES=1
				fi
				if [[ "${MATCHES}" == "1" ]]; then
					echo "Automerging trivial changes in: ${rpath}/${rfile:10}"
					mv ${rpath}/${rfile} ${rpath}/${rfile:10}
					continue
				else
					count=${count}+1
					echo "${rpath}/${rfile:10}" > ${TMP}/files/${count}
					echo "${rpath}/${rfile}" >> ${TMP}/files/${count}
					ofile="${rfile}"
					opath="${rpath}"
					continue
				fi
			fi

			if [[ -z $(diff -Nua ${rpath}/${rfile} ${rpath}/${ofile}|
					  grep "^[+-][^+-]"|grep -v '# .Header:.*') ]]; then
				mv ${rpath}/${rfile} ${rpath}/${ofile}
				continue
			else
				echo "${rpath}/${rfile}" >> ${TMP}/files/${count}
				ofile="${rfile}"
				opath="${rpath}"
			fi
		done
	done

}

sel_file() {
	local -i isfirst=0
	until [[ -f ${TMP}/files/${input} ]] || \
	      [[ ${input} == -1 ]] || \
	      [[ ${input} == -3 ]]
	do
		local numfiles=$(ls ${TMP}/files|wc -l)
		local numwidth=${#numfiles}
		for file in $(ls ${TMP}/files|sort -n); do
			if [[ ${isfirst} == 0 ]] ; then
				isfirst=${file}
			fi
			numshow=$(printf "%${numwidth}i${PAR} " ${file})
			numupdates=$(( $(wc -l <${TMP}/files/${file}) - 1 ))
			echo -n "${numshow}"
			if [[ ${mode} == 0 ]] ; then
				echo "$(head -n1 ${TMP}/files/${file}) (${numupdates})"
			else
				head -n1 ${TMP}/files/${file}
			fi
		done > ${TMP}/menuitems

		if [ "${OVERWRITE_ALL}" == "yes" ]; then
			input=0
		elif [ "${DELETE_ALL}" == "yes" ]; then
			input=0
		else
			[[ $CLEAR_TERM == yes ]] && clear
			if [[ ${mode} == 0 ]] ; then
				echo "The following is the list of files which need updating, each
configuration file is followed by a list of possible replacement files."
			else
				local my_title="Please select a file to update"
			fi

			if [[ ${mode} == 0 ]] ; then
				cat ${TMP}/menuitems
				echo    "Please select a file to edit by entering the corresponding number."
				echo    "              (don't use -3, -5, -7 or -9 if you're unsure what to do)"
				echo    "              (-1 to exit) (-3 to auto merge all remaining files)"
				echo    "                           (-5 to auto-merge AND not use 'mv -i')"
				echo    "                           (-7 to discard all updates)"
				echo -n "                           (-9 to discard all updates AND not use 'rm -i'): "
				input=$(read_int)
			else
				dialog --title "${title}" --menu "${my_title}" \
					0 0 0 $(echo -e "-1 Exit\n$(<${TMP}/menuitems)") \
					2> ${TMP}/input || die "User termination!" 0
				input=$(<${TMP}/input)
			fi
			if [[ ${input} == -9 ]]; then
				read -p "Are you sure that you want to delete all updates (type YES):" reply
				if [[ ${reply} != "YES" ]]; then
					continue
				else
					input=-7
					export rm_opts=""
				fi
			fi
			if [[ ${input} == -7 ]]; then
				input=0
				export DELETE_ALL="yes"
			fi
			if [[ ${input} == -5 ]] ; then
				input=-3
				export mv_opts=" ${mv_opts} "
				mv_opts="${mv_opts// -i / }"
			fi
			if [[ ${input} == -3 ]] ; then
				input=0
				export OVERWRITE_ALL="yes"
			fi
		fi # -3 automerge
		if [[ -z ${input} ]] || [[ ${input} == 0 ]] ; then
			input=${isfirst}
		fi
	done
}

user_special() {
	if [ -r ${PORTAGE_CONFIGROOT}etc/etc-update.special ]; then
		if [ -z "$1" ]; then
			echo "ERROR: user_special() called without arguments"
			return 1
		fi
		while read -r pat; do
			echo ${1} | grep "${pat}" > /dev/null && return 0
		done < ${PORTAGE_CONFIGROOT}etc/etc-update.special
	fi
	return 1
}

read_int() {
	# Read an integer from stdin.  Continously loops until a valid integer is
	# read.  This is a workaround for odd behavior of bash when an attempt is
	# made to store a value such as "1y" into an integer-only variable.
	local my_input
	while true; do
		read my_input
		# failed integer conversions will break a loop unless they're enclosed
		# in a subshell.
		echo "${my_input}" | ( declare -i x; read x) 2>/dev/null && break
		echo -n "Value '$my_input' is not valid. Please enter an integer value:" >&2
	done
	echo ${my_input}
}

do_file() {
	interactive_echo() { [ "${OVERWRITE_ALL}" != "yes" ] && [ "${DELETE_ALL}" != "yes" ] && echo; }
	interactive_echo
	local -i my_input
	local -i fcount=0
	until (( $(wc -l < ${TMP}/files/${input}) < 2 )); do
		my_input=0
		if (( $(wc -l < ${TMP}/files/${input}) == 2 )); then
			my_input=1
		fi
		until (( ${my_input} > 0 )) && (( ${my_input} < $(wc -l < ${TMP}/files/${input}) )); do
			fcount=0

			if [ "${OVERWRITE_ALL}" == "yes" ]; then
				my_input=0
			elif [ "${DELETE_ALL}" == "yes" ]; then
				my_input=0
			else
				for line in $(<${TMP}/files/${input}); do
					if (( ${fcount} > 0 )); then
						echo -n "${fcount}${PAR} "
						echo "${line}"
					else
						if [[ ${mode} == 0 ]] ; then
							echo "Below are the new config files for ${line}:"
						else
							local my_title="Please select a file to process for ${line}"
						fi
					fi
					fcount=${fcount}+1
				done > ${TMP}/menuitems

				if [[ ${mode} == 0 ]] ; then
					cat ${TMP}/menuitems
					echo -n "Please select a file to process (-1 to exit this file): "
					my_input=$(read_int)
				else
					dialog --title "${title}" --menu "${my_title}" \
						0 0 0 $(echo -e "$(<${TMP}/menuitems)\n${fcount} Exit") \
						2> ${TMP}/input || die "User termination!" 0
					my_input=$(<${TMP}/input)
				fi
			fi # OVERWRITE_ALL

			if [[ ${my_input} == 0 ]] ; then
				my_input=1
			elif [[ ${my_input} == -1 ]] ; then
				input=0
				return
			elif [[ ${my_input} == ${fcount} ]] ; then
				break
			fi
		done
		if [[ ${my_input} == ${fcount} ]] ; then
			break
		fi

		fcount=${my_input}+1

		file=$(sed -e "${fcount}p;d" ${TMP}/files/${input})
		ofile=$(head -n1 ${TMP}/files/${input})

		do_cfg "${file}" "${ofile}"

		sed -e "${fcount}!p;d" ${TMP}/files/${input} > ${TMP}/files/sed
		mv ${TMP}/files/sed ${TMP}/files/${input}

		if [[ ${my_input} == -1 ]] ; then
			break
		fi
	done
	interactive_echo
	rm ${TMP}/files/${input}
	count=${count}-1
}

do_cfg() {

	local file="${1}"
	local ofile="${2}"
	local -i my_input=0

	until (( ${my_input} == -1 )) || [ ! -f ${file} ]; do
		if [[ "${OVERWRITE_ALL}" == "yes" ]] && ! user_special "${ofile}"; then
			my_input=1
		elif [[ "${DELETE_ALL}" == "yes" ]] && ! user_special "${ofile}"; then
			my_input=2
		else
			[[ $CLEAR_TERM == yes ]] && clear
			if [ "${using_editor}" == 0 ]; then
				(
					echo "Showing differences between ${ofile} and ${file}"
					diff_command "${ofile}" "${file}"
				) | ${pager}
			else
				echo "Beginning of differences between ${ofile} and ${file}"
				diff_command "${ofile}" "${file}"
				echo "End of differences between ${ofile} and ${file}"
			fi
			if [ -L "${file}" ]; then
				echo
				echo "-------------------------------------------------------------"
				echo "NOTE: File is a symlink to another file. REPLACE recommended."
				echo "      The original file may simply have moved. Please review."
				echo "-------------------------------------------------------------"
				echo
			fi
			echo -n "File: ${file}
1) Replace original with update
2) Delete update, keeping original as is
3) Interactively merge original with update
4) Show differences again
5) Save update as example config
Please select from the menu above (-1 to ignore this update): "
			my_input=$(read_int)
		fi

		case ${my_input} in
			1) echo "Replacing ${ofile} with ${file}"
			   mv ${mv_opts} ${file} ${ofile}
			   [ -n "${OVERWRITE_ALL}" ] && my_input=-1
			   continue
			   ;;
			2) echo "Deleting ${file}"
			   rm ${rm_opts} ${file}
			   [ -n "${DELETE_ALL}" ] && my_input=-1
			   continue
			   ;;
			3) do_merge "${file}" "${ofile}"
			   my_input=${?}
#			   [ ${my_input} == 255 ] && my_input=-1
			   continue
			   ;;
			4) continue
			   ;;
			5) do_distconf "${file}" "${ofile}"
			   ;;
			*) continue
			   ;;
		esac
	done
}

do_merge() {
	# make sure we keep the merged file in the secure tempdir
	# so we dont leak any information contained in said file
	# (think of case where the file has 0600 perms; during the
	# merging process, the temp file gets umask perms!)

	local file="${1}"
	local ofile="${2}"
	local mfile="${TMP}/${2}.merged"
	local -i my_input=0
	echo "${file} ${ofile} ${mfile}"

	if [[ -e ${mfile} ]] ; then
		echo "A previous version of the merged file exists, cleaning..."
		rm ${rm_opts} "${mfile}"
	fi

	# since mfile will be like $TMP/path/to/original-file.merged, we
	# need to make sure the full /path/to/ exists ahead of time
	mkdir -p "${mfile%/*}"

	until (( ${my_input} == -1 )); do
		echo "Merging ${file} and ${ofile}"
		$(echo "${merge_command}" |
		 sed -e "s:%merged:${mfile}:g" \
		 	 -e "s:%orig:${ofile}:g" \
			 -e "s:%new:${file}:g")
		until (( ${my_input} == -1 )); do
			echo -n "1) Replace ${ofile} with merged file
2) Show differences between merged file and original
3) Remerge original with update
4) Edit merged file
5) Return to the previous menu
Please select from the menu above (-1 to exit, losing this merge): "
			my_input=$(read_int)
			case ${my_input} in
				1) echo "Replacing ${ofile} with ${mfile}"
				   if  [[ ${USERLAND} == BSD ]] ; then
				       chown "$(stat -f %Su:%Sg "${ofile}")" "${mfile}"
				       chmod $(stat -f %Mp%Lp "${ofile}") "${mfile}"
				   else
				       chown --reference="${ofile}" "${mfile}"
				       chmod --reference="${ofile}" "${mfile}"
				   fi
				   mv ${mv_opts} "${mfile}" "${ofile}"
				   rm ${rm_opts} "${file}"
				   return 255
				   ;;
				2)
					[[ $CLEAR_TERM == yes ]] && clear
					if [ "${using_editor}" == 0 ]; then
						(
							echo "Showing differences between ${ofile} and ${mfile}"
							diff_command "${ofile}" "${mfile}"
						) | ${pager}
					else
						echo "Beginning of differences between ${ofile} and ${mfile}"
						diff_command "${ofile}" "${mfile}"
						echo "End of differences between ${ofile} and ${mfile}"
					fi
				   continue
				   ;;
				3) break
				   ;;
				4) ${EDITOR:-nano -w} "${mfile}"
				   continue
					 ;;
				5) rm ${rm_opts} "${mfile}"
				   return 0
				   ;;
				*) continue
				   ;;
			esac
		done
	done
	rm ${rm_opts} "${mfile}"
	return 255
}

do_distconf() {
	# search for any previously saved distribution config
	# files and number the current one accordingly

	local file="${1}"
	local ofile="${2}"
	local -i count
	local -i fill
	local suffix
	local efile

	for ((count = 0; count <= 9999; count++)); do
		suffix=".dist_"
		for ((fill = 4 - ${#count}; fill > 0; fill--)); do
			suffix+="0"
		done
		suffix+="${count}"
		efile="${ofile}${suffix}"
		if [[ ! -f ${efile} ]]; then
			mv ${mv_opts} "${file}" "${efile}"
			break
		elif diff_command "${file}" "${efile}" &> /dev/null; then
			# replace identical copy
			mv "${file}" "${efile}"
			break
		fi
	done
}

die() {
	trap SIGTERM
	trap SIGINT

	if [ "$2" -eq 0 ]; then
		echo "Exiting: ${1}"
		scan > /dev/null
		[ ${count} -gt 0 ] && echo "NOTE: ${count} updates remaining"
	else
		echo "ERROR: ${1}"
	fi

	rm -rf "${TMP}"
	exit ${2}
}

usage() {
	cat <<-EOF
	etc-update: Handle configuration file updates

	Usage: etc-update [options]

	Options:
	  -d, --debug    Enable shell debugging
	  -h, --help     Show help and run away
	  -V, --version  Show version and trundle away
	EOF

	[[ -n ${*:2} ]] && printf "\nError: %s\n" "${*:2}" 1>&2

	exit ${1:-0}
}

#
# Run the script
#

SET_X=false
while [[ -n $1 ]] ; do
	case $1 in
		-d|--debug)   SET_X=true;;
		-h|--help)    usage;;
		-V|--version) emerge --version ; exit 0;;
		*)            usage 1 "Invalid option '$1'";;
	esac
	shift
done
${SET_X} && set -x

type portageq > /dev/null || exit $?
eval $(portageq envvar -v CONFIG_PROTECT \
	CONFIG_PROTECT_MASK PORTAGE_CONFIGROOT PORTAGE_TMPDIR ROOT USERLAND)
export PORTAGE_TMPDIR

TMP="${PORTAGE_TMPDIR}/etc-update-$$"
trap "die terminated 1" SIGTERM
trap "die interrupted 1" SIGINT

[ -w ${PORTAGE_CONFIGROOT}etc ] || die "Need write access to ${PORTAGE_CONFIGROOT}etc" 1
#echo $PORTAGE_TMPDIR
#echo $CONFIG_PROTECT
#echo $CONFIG_PROTECT_MASK
#export PORTAGE_TMPDIR=$(/usr/lib/portage/bin/portageq envvar PORTAGE_TMPDIR)

rm -rf "${TMP}" 2> /dev/null
mkdir "${TMP}" || die "failed to create temp dir" 1
# make sure we have a secure directory to work in
chmod 0700 "${TMP}" || die "failed to set perms on temp dir" 1
chown ${UID:-0}:${GID:-0} "${TMP}" || die "failed to set ownership on temp dir" 1

# I need the CONFIG_PROTECT value
#CONFIG_PROTECT=$(/usr/lib/portage/bin/portageq envvar CONFIG_PROTECT)
#CONFIG_PROTECT_MASK=$(/usr/lib/portage/bin/portageq envvar CONFIG_PROTECT_MASK)

# load etc-config's configuration
CLEAR_TERM=$(get_config clear_term)
EU_AUTOMERGE=$(get_config eu_automerge)
rm_opts=$(get_config rm_opts)
mv_opts=$(get_config mv_opts)
cp_opts=$(get_config cp_opts)
pager=$(get_config pager)
diff_command=$(get_config diff_command)
using_editor=$(get_config using_editor)
merge_command=$(get_config merge_command)
declare -i mode=$(get_config mode)
[[ -z ${mode} ]] && mode=0
if ! cmd_var_is_valid "${pager}" ; then
	pager=${PAGER}
	cmd_var_is_valid "${pager}" || pager=cat
fi

if [ "${using_editor}" == 0 ]; then
	# Sanity check to make sure diff exists and works
	echo > "${TMP}"/.diff-test-1
	echo > "${TMP}"/.diff-test-2
	
	if ! diff_command "${TMP}"/.diff-test-1 "${TMP}"/.diff-test-2 ; then
		die "'${diff_command}' does not seem to work, aborting" 1
	fi
else
	if ! type ${diff_command%% *} >/dev/null; then
		die "'${diff_command}' does not seem to work, aborting" 1
	fi
fi

if [[ ${mode} == "1" ]] ; then
	if ! type dialog >/dev/null || ! dialog --help >/dev/null ; then
		die "mode=1 and 'dialog' not found or not executable, aborting" 1
	fi
fi

#echo "rm_opts: $rm_opts, mv_opts: $mv_opts, cp_opts: $cp_opts"
#echo "pager: $pager, diff_command: $diff_command, merge_command: $merge_command"

if (( ${mode} == 0 )); then
	PAR=")"
else
	PAR=""
fi

declare -i count=0
declare input=0
declare title="Gentoo's etc-update tool!"

scan

until (( ${input} == -1 )); do
	if (( ${count} == 0 )); then
		die "Nothing left to do; exiting. :)" 0
	fi
	sel_file
	if (( ${input} != -1 )); then
		do_file
	fi
done

die "User termination!" 0