#!/bin/sh

set -e

ZPMSPOOL=${ZPMSPOOL:-/var/lib/admin/notes}
DB=$ZPMSPOOL/.sequence.db
SQL="zpm shell -bail $DB"

#rm -f $DB
test -f $DB || {
zpm shell $DB <<EOS
create table sequence ( sequence text not null primary key, val integer not null default 0);
insert into sequence (sequence) values ('default');
EOS
}

# -c create named sequence
# -d delete named sequence
# -v current value
# -l list all
# -s set value
# -n next (optional)
# -p prepare db, but do nothing
case $1 in
	-c)
		$SQL "insert into sequence (sequence) values ('${2:-default}')"
		exit 0
		;;
	-d)
		$SQL "delete from sequence where sequence = '${2:-default}'"
		exit 0
		;;
	-v)
		val=$($SQL "select val from sequence where sequence = '${2:-default}'")
		echo $val
		exit 0
		;;
	-l)
		$SQL 'select * from sequence'
		exit 0
		;;
	-s)
		$SQL "begin;update sequence set val = $2 where sequence = '${3:-default}'; commit;"
		exit 0
		;;
	-n)
		shift
		;;
	-p)
		exit 0
		;;
esac

seq=${1:-default}

num=$(zpm shell $DB "begin; update sequence set val = val + 1 where sequence = '$seq'; commit;select val from sequence where sequence = '$seq';")

echo $num