#
#  Copyright (c) 2005 Canonical LTD
#
#  Author: Matt Zimmerman <mdz@canonical.com>
#
#  2006, Oliver Grawert <ogra@canonical.com>
#        Vagrant Cascadian <vagrant@freegeek.org>
#  2007, Scott Balneaves <sbalneav@ltsp.org>
#        Oliver Grawert <ogra@canonical.com>
#  2008, Vagrant Cascadian <vagrant@freegeek.org>
#        Oliver Grawert <ogra@canonical.com>
#        Warren Togami <wtogami@redhat.com>
#        Gideon Romm <ltsp@symbio-technologies.com>
#  2011, Gideon Romm <ltsp@symbio-technologies.com>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, you can find it on the World Wide
#  Web at http://www.gnu.org/copyleft/gpl.html, or write to the Free
#  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#

#
# ltsp_config: This should be sourced by most scripts within an ltsp
# environment.  Ensures that LTSP5 defaults are set up
#
#

# Source ltsp-client-functions if we have not already (needed in some functions)
# We set PATH to empty string here (in the subshell), because shell will look
# for boolean_is_true in PATH if it doesn't find it as a built-in function
# That search is a waste of time and so, we avoid it by not giving a PATH.
#
# Also, let's call this at the very beginning to make absolutely sure that 
# anything that calls ltsp_config will have ltsp-client-functions sourced
(PATH="" boolean_is_true True 2>/dev/null) || . /usr/share/ltsp/ltsp-client-functions || true

# Once lts.conf params are processed, they should all be stored
# in a quickly source-able file: /var/cache/ltsp/ltsp_config_env
# If this file does not exist, it means we need to process lts.conf
# If it does exist, we can either just source it, OR if we are asked
# to process lts.conf again, we should read in all the environemnt
# variables that were set last time and unset them before processing the
# lts.conf again
ltsp_config_env=/var/cache/ltsp/ltsp_config_env

# Make sure cache dir exists
mkdir -p /var/cache/ltsp

# This function will set the lts.conf var and will be used by ltsp_config.d/
# scripts
set_lts_var() {
    var=$1
    val=$2
    [ -z "$var" ] && return
    sed -i -e "/$var=/d" ${ltsp_config_env}
    if [ -n "$val" ]; then
        export "$var"="$val"
        echo "$var=\"$val\"" >> ${ltsp_config_env}
    else
        unset $var
    fi    
}

# This function will reset the lts.conf params that were previously set
reset_lts_env() {
    [ -r "${ltsp_config_env}" ] || return
    oldifs="${IFS-not set}"
    IFS='='
    while read var val; do
        unset $var
        export $var
    done < ${ltsp_config_env}
    test "$oldifs" = "not set" && unset IFS || IFS="$oldifs"
    rm -f ${ltsp_config_env} 2>/dev/null
    return 0
}

# This function sets all vars from cache
set_lts_from_cache() {
    [ -r "${ltsp_config_env}" ] || return
    # Make all vars we are about to set exported
    set -a
    . ${ltsp_config_env}
    set +a
}

# This function will process the lts.conf params
process_lts_conf() {
    set -f 
    if [ -d /usr/share/ltsp/ltsp_config.d ]; then
        for script in $(run_parts_list /usr/share/ltsp/ltsp_config.d) ; do
            . $script        
        done
    fi
    set +f
}

if [ ! -r "${ltsp_config_env}" ]; then
    process_lts_conf
else 
    if boolean_is_true "${PROCESS_LTS_CONF}"; then
        reset_lts_env
        process_lts_conf
    else
        set_lts_from_cache
    fi
fi