#!/bin/sh

function usage {
    echo "Usage: $(basename $0) [-p] WikiUsername"
    exit 1
}

function user_mentioned {
    RETURN=1
    # Argument list too long: grep -q $USER $TWIKI_DATA/*/*txt
    for FILE in $(find $TWIKI_DATA -name \*.txt -maxdepth 2 -mindepth 2); do
	grep -l $1 $FILE && RETURN=0
    done
    return $RETURN
}

set -e

WIKI_BASE=/var/lib/twiki
APACHE_USER=www-data
PURGE=

[ $TMP ] || TMP=/tmp

# commandline opts only work for one package ...
while getopts "s:p" OPTION; do
    case $OPTION in
	p) PURGE="yes" ;;
	*) echo "Unknown argument -$OPTION" >&2 ;;
    esac
done

shift $(($OPTIND - 1))

[ "$1" ] || usage

TWIKI_DATA=$WIKI_BASE/data

for USER in $@; do
    
    TMPFILE=$(mktemp -t)
    
    # remove the user from the password file
    grep -v "^$USER:" $TWIKI_DATA/.htpasswd > $TMPFILE
    chown --reference=$TWIKI_DATA/.htpasswd $TMPFILE
    mv -b $TMPFILE $TWIKI_DATA/.htpasswd
    
    # remove the user from TWikiUsers
    grep -v "* $USER -" $TWIKI_DATA/Main/TWikiUsers.txt > $TMPFILE
    chown --reference=$TWIKI_DATA/Main/TWikiUsers.txt  $TMPFILE
    mv $TMPFILE $TWIKI_DATA/Main/TWikiUsers.txt
    su - $APACHE_USER -c "ci -l -m'Removed $USER' $TWIKI_DATA/Main/TWikiUsers.txt"
    
    # remove the user from all groups he is in:
    for GROUP in $(grep -l "Set GROUP =.*$USER" /var/lib/twiki/data/Main/*Group.txt); do
	sed -e "s/^\(.*Set GROUP =.*\) *$USER,\? *\(.*\)$/\1\2/" $GROUP > $TMPFILE
	chown --reference=$GROUP $TMPFILE
	mv $TMPFILE $GROUP
	su - $APACHE_USER -c "ci -l -m'Removed $USER' $GROUP"
    done
    
    if [ "$PURGE" ]; then
	mv $TWIKI_DATA/Main/$USER.txt* $TMP
        # remove the user completly only if he's mentioned nowhere
	
	TMPFILE=$(mktemp)
	if user_mentioned $USER > $TMPFILE; then
	    echo "User $USER not purged since still mentioned in these topics:"
	    cat $TMPFILE
	    mv $TMP/$USER.txt* $TWIKI_DATA/Main/
	else
	    rm $TMP/$USER.txt*
	fi
	rm $TMPFILE
    else
        # don't remove the user topic
        # but remove email address and set a "retired" comment
	sed -e "s/\(.*\* Email:\).*/\1/;s/\(.*\* Comment:\).*/\1 Retired User/" $TWIKI_DATA/Main/$USER.txt > $TMPFILE
	chown --reference=$TWIKI_DATA/Main/$USER.txt $TMPFILE
	mv $TMPFILE $TWIKI_DATA/Main/$USER.txt
	su - $APACHE_USER -c "ci -l -m'Retired $USER' $TWIKI_DATA/Main/$USER.txt"
    fi
done