@hook 'upgrade-charm'
function check_fixpack(){
        # The upgrade-charm hook will fire when a new resource is pushed for this
        # charm. This is a good time to determine if we need to deal with a new
        # fixpack.
        if ! charms.reactive is_state 'ibm-was-base.updated'; then
                # If there is no prior fixpack installed (because ibm-was-base.updated is not
                # set), do nothing since install_was_base_fixpack will handle that case.
                juju-log "IBM WAS Base: no fixpack has been installed; nothing to upgrade."
                exit 0
        else
                # If we have a fixpack packges already (because ibm-was-base.updated is set),
                # we should fetch the latest fixpack packages and determine if it is new.
                #  - If it is new, set our states so install_was_base_fixpack is called again
                #  - If it is not new, do nothing
                juju-log "IBM WAS Base: scanning for new fixpacks to install"
                WAS_FP1_DIR="$CHARM_DIR/../resources/ibm_was_base_fp1"
                WAS_FP2_DIR="$CHARM_DIR/../resources/ibm_was_base_fp2"
                CUR_FP1="$WAS_FP1_DIR/ibm_was_base_fp1.zip"
                CUR_FP2="$WAS_FP2_DIR/ibm_was_base_fp2.zip"
                if [ -f $CUR_FP1 -a -f  $CUR_FP2 ]; then
                        CUR_FP1_MD5=`md5sum "$CUR_FP1" | awk '{print $1}'`
                        CUR_FP2_MD5=`md5sum "$CUR_FP2" | awk '{print $1}'`
                fi
                NEW_FP1=`resource-get 'ibm_was_base_fp1' || echo unavailable`
                NEW_FP2=`resource-get 'ibm_was_base_fp2' || echo unavailable`

                if [ "$NEW_FP1" = "unavailable" -a "$NEW_FP2" = "unavailable" ]; then
                        juju-log "IBM WAS Base: no fixpacks to install"
                elif [ -f $NEW_FP1 -a -f  $NEW_FP2 ]; then
                        NEW_FP1_MD5=`md5sum "$NEW_FP1" | awk '{print $1}'`
                        NEW_FP2_MD5=`md5sum "$NEW_FP2" | awk '{print $1}'`
                fi

                if [ "$CUR_FP1_MD5" != "$NEW_FP1_MD5" -a "$CUR_FP2_MD5" != "$NEW_FP2_MD5" ]; then
                        juju-log "IBM WAS Base: new fixpack detected ($CUR_FP1 with $CUR_FP1_MD5 versus $NEW_FP1 with $NEW_FP1_MD5 and $CUR_FP2 with $CUR_FP2_MD5 versus $NEW_FP2 with $NEW_FP2_MD5)"
                        rm -rf $CHARM_DIR/../resources/WAS_BASE/FP
                        remove_state 'ibm-was-base.updated'
                else
                        juju-log "IBM WAS Base: no new fixpack to install"
                fi
        fi
}