#!/bin/bash
# Copyright 2002 Gentoo Technologies, Inc.
# Distributed under the terms of the GNU General Public License, v2 or later
# Author: Jochem Kossen <j.kossen@home.nl>, (c) 2002
# Author: Leo Lipelis <aeoo@gentoo.org>, (c) 2002
# Author: Karl Trygve Kalleberg <karltk@gentoo.org>, (c) 2002

get_config() {
    item=$1

    # First strip off comment lines, then grab the configuration
    # item. If there's more than one of the same configuration item,
    # then allow the last setting to take precedence.
    cut -d'#' -f1-1 /etc/etc-update.conf | \
        sed -ne "s/^\ *$item\ *=\ *\"\(.*\)\"/\1/p" | tail -1
}

#
# Ask which one of the given two files to install
#
rm_extra_file() {
	old=$1
	new=$2
	
	show_diff $old $new
	menu1
	
	# read and echo 1 char from stdin
	read input
	echo
	case $input in
	1)
		echo "*** upgrading to $new ..."
		mv $mv_opts $new $old
		;;
	2)
		echo "*** keeping $old ..."
		rm $rm_opts $new
		;;
	3)
		merge_files $old $new
		install_merged_file $old $new
		;;
	4)
		rm_extra_file $old $new
		;;
	5)
		echo "*** skipping ..."
		exit
		;;
	*)
		echo "!!! Please pick a valid choice next time !!!"
		menu1
		;;
	esac
}

#
# Show menu1
#
menu1() {
echo
echo
echo "1) Upgrade to new $new"
echo "2) Keep existing $old"
echo "3) Merge the two files"
echo "4) Show the difference between the two files again"
echo "  OR"
echo "5) Skip (keep all files)"
echo
echo -n "Type (1, 2, 3, 4 or 5): "									
}

#
# Show menu2
#
menu2() {
echo
echo
echo "1) Upgrade to merged file"
echo "2) Show the difference between original and merged file"
echo "3) Redo the merge"
echo "4) Keep original file"
echo "5) Skip (keep all files)"
echo "  OR"
echo "6) Back to previous menu"
echo
echo -n "Type (1, 2, 3, 4, 5 or 6): "
}

#
# Install merged file
#
install_merged_file() {
	old=$1
	merged=$1.merged
	new=$2

	menu2
	# read and echo 1 char from stdin
	read input
	echo
	case $input in
	1)
		echo "*** upgrading to $merged ..."
		mv $mv_opts $merged $old
		rm $rm_opts $new
		;;
	2)
		show_diff $old $merged
		install_merged_file $old $new
		;;
	3)
		merge_files $old $new
		install_merged_file $old $new
		;;
	4)
		echo "*** keeping original file ..."
		rm $rm_opts $merged $new
		;;
	5)
		echo "*** skipping ..."
		;;
	6)
		echo "*** going back to previous menu ..."
		echo
		if [ -e $merged ]; then
			echo "*** an (old?) merged file exists. It will be removed ..."
			rm $rm_opts $merged
		fi
		rm_extra_file $old $new
		;;
	*)
		echo "!!! Please pick a valid choice next time !!!"
		menu2
		;;
	esac
}

#
# Show the difference between two files
#
show_diff() {
	echo
	if [ "`echo $pager`" ]; then
		(echo "*** showing difference between $1 and $2" && echo && \
		`echo $diff_command | sed \
		-e s@%file1@$1@g \
		-e s@%file2@$2@g` ) | $pager
	else
		echo "*** showing difference between $1 and $2" && echo
		`echo $diff_command | sed \
		-e s@%file1@$1@g \
		-e s@%file2@$2@g`
	fi
}

#
# Merge two files
#
merge_files() {
	old=$1
	merged=$1.merged
	new=$2

	echo
	echo "*** merging $old with $new ..."

	if [ -e $merged ]; then
		echo
		echo "*** an (old?) merged file already exists. It will be removed ..."
		echo
		rm $rm_opts $merged
	fi
	
	# execute the merge command
	`echo $merge_command |sed \
	-e s@%merged@$merged@g \
	-e s@%orig@$old@g \
	-e s@%new@$new@g`
}

#
# Run the script
#
scriptname=`basename $0`

# I need the CONFIG_PROTECT value
source /etc/make.globals

# load etc-config's configuration
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`
merge_command=`get_config merge_command`

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

#
# Find all "new" configuration files, sort, so that ._cfg_0000 is presented
# before ._cfg_0001
#
#set -o xtrace
for cfg_dir in $CONFIG_PROTECT; do
    if [ -d "$cfg_dir" ] ; then
	cfg_files=`find $cfg_dir -iname '._cfg????_*' | sort`

	if [ -z "$cfg_files" ] ; then
	    echo "!!! No config files to update in $cfg_dir"
	fi
	for new_full_path in $cfg_files; do
	    file=${new_full_path##*/}
	    old_full_path=${new_full_path%/*}/${file:10}

	    rm_extra_file ${old_full_path} ${new_full_path}
	done
    else
	echo "!!! Skipping non-existant directory $cfg_dir"
    fi
done
echo "*** script finished ..."