#! /bin/sh

REPOS="$1"
DUMP="$2"
OWNER="$3"
if [ -z "$REPOS" ] || [ -z "$DUMP" ]; then
    echo "Usage: $0 repository dump-prefix [repository-owner]" >&2
    exit 1
fi

if [ -n "$OWNER" ]; then
    SVNADMIN="sudo -u $OWNER svnadmin"
    SVNLOOK="sudo -u $OWNER svnlook"
else
    SVNADMIN=svnadmin
    SVNLOOK=svnlook
fi

REV=`$SVNLOOK youngest "$REPOS"`
if [ "`expr "$REV" : '[0-9]\+'`" -eq 0 ]; then
    echo "$0: svnlook youngest failed" >&2
    exit 1
fi

if [ -f "$DUMP.$REV" ] || [ -f "$DUMP.$REV.bz2" ]; then
    exit 0
else
    $SVNADMIN dump --quiet "$REPOS" -r 0:"$REV" > "$DUMP.$REV"
    bzip2 "$DUMP.$REV"
fi

exit 0