#!/bin/sh -e
#
# update-langlist maintains the LANGUAGE priority list. It does so in
# a simplified manner, unlike the UI in language-selector-gnome for
# setting the user language which provides full control.

first_language=$1
homedir=$2
renewed_langlist=

[ -n "$first_language" -a -n "$homedir" ] || exit 1

get_old_langlist() {
if [ -r "$homedir/.pam_environment" ]; then
while read line; do
if [ "${line%=*}" = 'LANGUAGE' ]; then
old_langlist=${line#*=}
break
fi
done < $homedir/.pam_environment
fi
}

old_langlist=
english=true
if [ ${first_language%%[_@]*} != 'en' ]; then
get_old_langlist
english=false
fi

if [ -n "$old_langlist" ] && ! $english; then
if expr $old_langlist : ".*:$first_language:" > /dev/null ; then
renewed_langlist=$( echo $old_langlist | sed -r "s/(.+:)($first_language:)/\2\1/" )
elif [ ${old_langlist%%:*} = $first_language ]; then
# no change
renewed_langlist=$old_langlist
else
renewed_langlist=$first_language:$old_langlist
fi
else
# build fresh list with 'en' as the last element
# no other languages needed if English was selected
renewed_langlist=$first_language
[ $first_language != 'en' ] && renewed_langlist=$renewed_langlist:en
fi

echo $renewed_langlist