#!/bin/bash

if [ -e "serverconf.sh" ]
then
	source "serverconf.sh"
else
	echo No configuration found in PWD. Exiting.
	exit 1
fi

source "backends/tar.sh"
source "backends/bup.sh"
source "backends/borg.sh"

function backup_hook_example {
	bup -d $CUR_BACK_DIR ls -l $BACKUP_NAME/latest/var/minecraft
}

function send_cmd () {
	tmux -S $TMUX_SOCKET send -t $TMUX_WINDOW "$1" enter
}

function assert_running() {
	if server_running; then
		echo "It seems a server is already running. If this is not the case,\
			manually attach to the running screen and close it."
		exit 1
	fi
}

function assert_not_running() {
	if ! server_running; then
		echo "Server not running"
		exit 1
	fi
}

function server_start() {
	assert_running

	if [ ! -f "eula.txt" ]
	then
		echo "eula.txt not found. Creating and accepting EULA."
		echo "eula=true" > "eula.txt"
	fi

	tmux -S $TMUX_SOCKET new-session -s $TMUX_WINDOW -d \
		$JRE_JAVA $JVM_ARGS -jar $JAR $JAR_ARGS
	pid=`tmux -S $TMUX_SOCKET list-panes -t $TMUX_WINDOW -F "#{pane_pid}"`
	echo $pid > $PIDFILE
	echo Started with PID $pid
	exit
}

function server_stop() {
	# Allow success even if server is not running
	#trap "exit 0" EXIT

	assert_not_running
	send_cmd "stop"

	local RET=1
	while [ ! $RET -eq 0 ]
	do
		sleep 1
		ps -p $(cat $PIDFILE) > /dev/null
		RET=$?
	done

	echo "stopped the server"

	rm -f $PIDFILE

	exit
}

function server_attach() {
	assert_not_running
	tmux -S $TMUX_SOCKET attach -t $TMUX_WINDOW
	exit
}

function server_running() {
	if [ -f $PIDFILE ] && [ "$(cat $PIDFILE)" != "" ]; then
		ps -p $(cat $PIDFILE) > /dev/null
		return
	fi

	false
}

function server_status() {
	if server_running
	then
		echo "Server is running"
	else
		echo "Server is not running"
	fi
	exit
}

function players_online() {
	send_cmd "list"
	sleep 1
	while [ $(tail -n 3 "$LOGFILE" | grep -c "There are") -lt 1 ]
	do
		sleep 1
	done

	[ `tail -n 3 "$LOGFILE" | grep -c "There are 0"` -lt 1 ]
}

function init_backup() {
	for BACKUP_DIR in ${BACKUP_DIRS[*]}
	do
		if [[ $BACKUP_DIR == *:* ]]; then
			REMOTE="$(echo "$BACKUP_DIR" | cut -d: -f1)"
			REMOTE_DIR="$(echo "$BACKUP_DIR" | cut -d: -f2)"
			ssh "$REMOTE" "mkdir -p \"$REMOTE_DIR\""
		else
			mkdir -p "$BACKUP_DIR"
		fi
	done

	if [ $BACKUP_BACKEND = "bup" ]; then
		bup_init
	elif [ $BACKUP_BACKEND = "borg" ]; then
		borg_init
	else
		tar_init
	fi
}

function create_backup() {
	init_backup

	if [ $BACKUP_BACKEND = "bup" ]; then
		bup_create_backup
	elif [ $BACKUP_BACKEND = "borg" ]; then
		borg_create_backup
	else
		tar_create_backup
	fi
}

function server_backup_safe() {
	force=$1
	echo "Detected running server. Checking if players online..."
	if [ "$force" != "true" ] && ! players_online; then
		echo "Players are not online. Not backing up."
		return
	fi

	echo "Disabling autosave"
	send_cmd "save-off"
	send_cmd "save-all flush"
	echo "Waiting for save... If froze, run /save-on to re-enable autosave!!"

	sleep 1
	while [ $(tail -n 3 "$LOGFILE" | grep -c "Saved the game") -lt 1 ]
	do
		sleep 1
	done
	sleep 2
	echo "Done! starting backup..."

	create_backup

	local RET=$?

	echo "Re-enabling auto-save"
	send_cmd "save-on"

	if [ $RET -eq 0 ]
	then
		echo Running backup hook
		$BACKUP_HOOK
	fi
}

function server_backup_unsafe() {
	echo "No running server detected. Running Backup"

	create_backup

	if [ $? -eq 0 ]
	then
		echo Running backup hook
		$BACKUP_HOOK
	fi
}

function backup_running() {
	systemctl is-active --quiet mc-backup.service
}

function fbackup_running() {
	systemctl is-active --quiet mc-fbackup.service
}

function server_backup() {
	force=$1

	if [ "$force" = "true" ]; then
		if backup_running; then
			echo "A backup is running. Aborting..."
			return
		fi
	else
		if fbackup_running; then
			echo "A force backup is running. Aborting..."
			return
		fi
	fi

	if server_running; then
		server_backup_safe "$force"
	else
		server_backup_unsafe
	fi

	exit
}

function ls_backups() {
	if [ $BACKUP_BACKEND = "bup" ]; then
		bup_ls_all
	elif [ $BACKUP_BACKEND = "borg" ]; then
		borg_ls_all
	else
		tar_ls_all
	fi
}

function choose_from() {
	local items=("$@")
	select item in "${items[@]}"; do
		echo "$item"
		return
	done
	echo ""
}

function server_restore() {
	echo "Select from where get the snapshot"
	BACKUP_DIR=$(choose_from "${BACKUP_DIRS[@]}")
	if [[ ! ${BACKUP_DIRS[*]} =~ (^|[[:space:]])"$BACKUP_DIR"($|[[:space:]]) ]]; then
		echo "No valid backup directory selected, abort"
		return 1
	fi

	SNAPSHOTS=$(
		if [ $BACKUP_BACKEND = "bup" ]; then
			bup_ls_dir "$BACKUP_DIR"
		elif [ $BACKUP_BACKEND = "borg" ]; then
			borg_ls_dir "$BACKUP_DIR"
		else
			tar_ls_dir "$BACKUP_DIR"
		fi
	)
	if [ -z "$SNAPSHOTS" ]; then
		echo "No snapshots found, abort"
		return 1
	fi
	# convert multiline string to bash array
	SNAPSHOTS=($(echo "$SNAPSHOTS"))
	echo "Select a snapshot to restore"
	SNAPSHOT=$(choose_from "${SNAPSHOTS[@]}")
	if [[ ! ${SNAPSHOTS[*]} =~ (^|[[:space:]])"$SNAPSHOT"($|[[:space:]]) ]]; then
		echo "No valid snapshot selected, abort"
		return 1
	fi

	echo "Restoring snapshot \"$SNAPSHOT\" from \"$BACKUP_DIR\""

	OLDWORLD_NAME=""
	if [[ -d "$WORLD_NAME" ]]; then
		echo "Saving old world, just in case"
		OLDWORLD_NAME="${WORLD_NAME}.old.$(date +'%F_%H-%M-%S')"
		mv -v "$WORLD_NAME" "$OLDWORLD_NAME"
	fi

	if [ $BACKUP_BACKEND = "bup" ]; then
		bup_restore "$BACKUP_DIR" "$SNAPSHOT"
	elif [ $BACKUP_BACKEND = "borg" ]; then
		borg_restore "$BACKUP_DIR" "$SNAPSHOT"
	else
		tar_restore "$BACKUP_DIR" "$SNAPSHOT"
	fi

	if [ ! $? -eq 0 ]; then
		echo "Restore failed, reverting old world back"
		rm -r "$WORLD_NAME"
		mv -v "$OLDWORLD_NAME" "$WORLD_NAME"
	else
		echo "Restore finished"
	fi
}

#cd $(dirname $0)

case $1 in
	"start")
		server_start
		;;
	"stop")
		server_stop
		;;
	"attach")
		server_attach
		;;
	"backup")
		server_backup
		;;
	"restore")
		server_restore
		;;
	"status")
		server_status
		;;
	"fbackup")
		server_backup "true"
		;;
	"ls")
		ls_backups
		;;
	*)
		echo "Usage: $0 start|stop|attach|status|backup"
		;;
esac