#!/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

#
# Functions
#

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 ..."
		;;
	*)
		echo "!!! Please pick a valid choice next time !!!"
		menu1
		;;
	esac
}

#
# 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)
		echo "*** keeping old file ..."
		rm $rm_opts $merged $new
		;;
	3)
		merge_files $old $new
		install_merged_file $old $new
		;;
	4)
		show_diff $old $merged
		install_merged_file $old $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 menu1
#
menu1() {
	echo
	echo
	echo "1) Apply new file"
	echo "2) Keep old file"
	echo "3) Merge files"
	echo "4) Show difference"
	echo "  OR"
	echo "5) Skip (keep both files)"
	echo
	echo -n "Type (1, 2, 3, 4 or 5): "									
}

#
# Show menu2
#
menu2() {
	echo
	echo
	echo "1) Apply merged file"
	echo "2) Keep old file"
	echo "3) Redo merge"
	echo "4) Show difference between old and merged 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): "
}

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

		checklist_old="" # to contain existing files
		checklist_new="" # to contain new files (the ._cfg????_* files)

		#TODO: remove older ._cfg????_* files. i.e. remove ._cfg0000_make.conf
		# if ._cfg0001_make.conf exists

		for new_full_path in ${cfg_files}; do
		    file="${new_full_path##*/}"
		    old_full_path=${new_full_path%/*}/${file:10}
			if [ -z "`diff ${old_full_path} ${new_full_path}`" ]; then
				# new configfile is exactly the same as old
				# configfile. Remove new configfile
				echo "same file: ${old_full_path} and ${new_full_path}"
				rm $rm_opts "${new_full_path}"
			else
				checklist_old="${checklist_old} ${old_full_path}"
				checklist_new="${checklist_new} ${new_full_path}"
			fi
		done

		if [ ! -z "${checklist_old}" ]; then
			echo "Files which need updating:"
			echo "${checklist_old}" |sed -e 's@\ @\n@g'
			echo "Press any key to continue ..."
			read ANYKEY
		fi

		for new_full_path in ${checklist_new}; do
		    file="${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 ..."