#!/bin/bash

# Backup one directory
function backup_dir {
	# Check if the dir to backup is mounted as a subdirectory of /root inside this container
	if [ "$1" = "" ]; then
		echo "[ERROR] Cannot backup the root directory. Have you correctly configured the volumes to backup for this container ?"
		return -1
	elif [ -d "/root_fs$1" ]; then
		restic backup -q $RESTIC_BACKUP_FLAGS /root_fs$1
		return $?
	else
		echo "[ERROR] Directory $1 not found. Have you mounted the root fs from your host with the following option : '-v /:/root_fs:ro' ?"
		return -1
	fi
}

function backup_local_dir {
	if [ "$1" = "" ]; then
		echo "[ERROR] Cannot backup the root directory. Have you correctly configured the volumes to backup for this container ?"
		return -1
	elif [ -d "$1" ]; then
		restic backup -q $RESTIC_BACKUP_FLAGS $1
		return $?
	else
		echo "[ERROR] Directory $1 not found."
		return -1
	fi
}

# Backup one file
function backup_file {
	cat $1 | restic backup -q $RESTIC_BACKUP_FLAGS --stdin --stdin-filename $2
	return $?
}

# Firt, check the repository is unlocked and try to unlock it
if [ "$(restic --no-lock list locks -q)" != "" ]; then
	echo -n "[INFO] Repository locked, trying to unlock ... "
	restic unlock
	if [ $? -ne 0 ]; then
		echo "[ERROR] Could not unlock repository"
		return -1
	else
		echo "done."
	fi
fi

count_success=0
count_failure=0

# List all the containers
for container_id in $(docker ps -aq) ; do
	container_json=$(docker inspect $container_id)
	# Get the name and namespace (in case of a container run in a swarm stack)
	container_name=$(echo $container_json | jq -r '.[].Name' | cut -d'/' -f2)

	# Ignore containers listed in env variable BACKUP_EXCLUDES
	if [[ ${BACKUP_EXCLUDES} =~ (^|[[:space:]])${container_name}($|[[:space:]]) ]] ; then
		continue
	fi

	# Ignore containers not listed in env variable BACKUP_INCLUDES, if it is set
	if [[ ! -z ${BACKUP_INCLUDES} && ! ${BACKUP_INCLUDES} =~ (^|[[:space:]])${container_name}($|[[:space:]]) ]] ; then
		continue
	fi

	# Backup the dirs labelled with "napnap75.backup.dirs"
	backup_dirs=$(echo $container_json | jq -r '.[].Config.Labels."napnap75.backup.dirs"')
	if [ "$backup_dirs" != "null" ] ; then
		for dir_name in $backup_dirs ; do
			echo -n "[INFO] Backing up dir" $dir_name "for container" $container_name " ... "
			backup_dir $dir_name
			if [ $? -ne 0 ]; then
				((++count_failure))
			else
				echo "done."
				((++count_success))
			fi
		done
	fi

	# Backup the dirs (inside container) labelled with "napnap75.backup.local-dirs"
	backup_dirs=$(echo $container_json | jq -r '.[].Config.Labels."napnap75.backup.local-dirs"')
	if [ "$backup_dirs" != "null" ] ; then
		if [[ "$(echo $container_json | jq -r '.[].Config.Image')" == "napnap75/restic-auto"* ]] ; then
			for dir_name in $backup_dirs ; do
				echo -n "[INFO] Backing up local dir" $dir_name "for container" $container_name " ... "
				backup_local_dir $dir_name
				if [ $? -ne 0 ]; then
					((++count_failure))
				else
					echo "done."
					((++count_success))
				fi
			done
		else
			echo "[ERROR] Could not use \"napnap75.backup.local-dirs\" on another container that the one running restic"
		fi
	fi

	# Backup the volumes labelled with "napnap75.backup.volumes"
	backup_volumes=$(echo $container_json | jq -r '.[].Config.Labels."napnap75.backup.volumes"')
	if [ "$backup_volumes" != "null" ] ; then
		for volume_name in $backup_volumes ; do
			volume_mount=$(echo $container_json | jq -r ".[].Mounts[] | select(.Name==\"$volume_name\") | .Source")
			echo -n "[INFO] Backing up volume" $volume_name "with mount" $volume_mount "for container" $container_name " ... "
			backup_dir $volume_mount
			if [ $? -ne 0 ]; then
				((++count_failure))
			else
				echo "done."
				((++count_success))
			fi
		done
	fi

	# Backup the databases labelled with "napnap75.backup.databases"
	backup_databases=$(echo $container_json | jq -r '.[].Config.Labels."napnap75.backup.databases"')
	if [ "$backup_databases" != "null" ] ; then
		for database_name in $backup_databases ; do
			echo -n "[INFO] Backing up database" $database_name "for container" $container_name " ... "
			docker exec $container_id bash -c "/usr/bin/mariadb-dump --databases $database_name | gzip -c > /tmp/database_backup.sql.gz"
			if [ $? -ne 0 ]; then
				echo "[ERROR] Unable to backup database $database_name from container $container_name"
				((++count_failure))
			else
				container_overlay=$(echo $container_json | jq -r '.[].GraphDriver.Data.MergedDir')
				backup_file /root_fs${container_overlay}/tmp/database_backup.sql.gz ${container_name}—${database_name}.sql.gz
				if [ $? -ne 0 ]; then
					((++count_failure))
				else
					echo "done."
					((++count_success))
				fi
			fi
			docker exec $container_id bash -c "rm /tmp/database_backup.sql.gz"
		done
	fi
done

# Send a notification to Slack
if [[ "$SLACK_URL" != "" ]] ; then
	curl -o /dev/null -s -m 10 --retry 5 -X POST --data-urlencode "payload={\"username\": \"rpi-docker-backup\", \"icon_emoji\": \":dvd:\", \"text\": \"Backup finished on host $HOSTNAME : $count_success succeeded, $count_failure failed\"}" $SLACK_URL
fi

# Send a notification to Gotify
if [[ "$GOTIFY_URL" != "" ]] ; then
	curl -o /dev/null -s -m 10 --retry 5 -X POST -H "accept: application/json" -H "Content-Type: application/json" -d "{\"priority\": 5, \"title\": \"Backup finished on host $HOSTNAME\", \"message\": \"Backup finished on host $HOSTNAME : $count_success succeeded, $count_failure failed\"}" $GOTIFY_URL
fi

# Return a non zero exit code if an error happened
if [ $count_failure -ne 0 ]; then
	exit -1
fi
