#!/bin/bash
# Backup Nextcloud database in a Kubernetes environment.
# Usage: backup-database <destination>

usage() {
    >&2 printf "Usage: %s <destination>\n" "${0}"
    exit "${1:-1}"
}

# Get options

while getopts ":e:" option; do
    case "${option}" in
        e)
            if ! [ -f "${OPTARG}" ]; then
                >&2 printf "Error: Specified environment file does not exist: '%s'.\n" "${OPTARG}"
            elif ! [ -r "${OPTARG}" ]; then
                >&2 printf "Error: Specified environment file is not readable: '%s'.\n" "${OPTARG}"
            fi
            env_file="${OPTARG}"
            ;;
        *)
            >&2 printf "Error: Invalid option: '%s'.\n" "${option}"
            usage
            ;;
    esac
done
shift $(( OPTIND - 1 ))

# Check arguments.

if [ $# -ne 1 ]; then
    >&2 printf "Error: You need to specify a destination.\n"
    usage
elif ! [ -d "${1}" ]; then
    >&2 printf "Error: Specified destination does not exist or is not readable : '%s'.\n" "${1}"
    usage
else
    destination="${1}"
fi

# Filename for database backup
database_backupfile="nextcloud-sqlbkp_$(date +'%Y%m%d').bak"

# Retrieve container names
base_container="$( docker ps --format '{{.Names}}' | grep -E 'nextcloud-2_nextcloud-2-[0-9a-z]{10}-[0-9a-z]{5}' )"
database_container="$( docker ps --format '{{.Names}}' | grep postgres_nextcloud-2-cnpg-main-1 )"

if ! [[ -n "${base_container}" && -n "${database_container}" ]]; then
    >&2 printf "Error: Not all containers could be found.\n"
    exit 2
fi

# Abort entire script if any command fails
set -e

# Turn on maintenance mode
docker exec "${base_container}" php occ maintenance:mode --on

# Database backup
echo 'Backing up database'
host_database_backupfile="${destination}/${database_backupfile}"
docker exec --env-file "${env_file:=.env}" "${database_container}" pg_dump 'nextcloud' -cwv -h 'localhost' -U 'nextcloud' > "${host_database_backupfile}"

# Files backup
for file in 'config' 'themes'; do
    printf "Copying %s\n" "${file}"
    docker cp -a "${base_container}":"/var/www/html/${file}" "${destination}"
done

# Turn off maintenance mode
docker exec "${base_container}" php occ maintenance:mode --off

# Backup cleanup
# Only keep 30 days of backups
printf "Clean up old database backups.\n"
find "${destination}" -name '*sqlbkp*' -type f -mtime +30 -print -delete

printf "Done\n"