#!/usr/bin/env bash
#
# Copyright (c) 2024 YunoHost Contributors
#
# This file is part of YunoHost (see https://yunohost.org)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#

# get the first available redis database
#
# usage: ynh_redis_get_free_db
# | returns: the database number to use
ynh_redis_get_free_db() {
    local result max db
    result=$(redis-cli INFO keyspace)

    # get the num
    max=$(cat /etc/redis/redis.conf | grep ^databases | grep -Eow "[0-9]+")

    db=0
    # default Debian setting is 15 databases
    for i in $(seq 0 "$max"); do
        if ! echo "$result" | grep -q "db$i"; then
            db=$i
            break 1
        fi
        db=-1
    done

    test "$db" -eq -1 && ynh_die "No available Redis databases..."

    echo "$db"
}

# Erase a redis database so it can be reused by other apps.
#
# usage: ynh_redis_remove_db database
# | arg: database - the database to erase
ynh_redis_remove_db() {
    local db=$1
    redis-cli -n "$db" flushdb
}