#!/bin/bash
VIRTUAL_USERS_DIR=${VIRTUAL_USERS_DIR:-/ftp_users}
DISKS_DIR=${DISKS_DIR:-/ftp_disks}
ROOT_DIR=${ROOT_DIR:-/ftp_mountpoints}
USER_QUOTA=${USER_QUOTA:-100MB}

DEFAULT_FTP_USER_ID=${DEFAULT_FTP_USER_ID:-14}
DEFAULT_FTP_GROUP_ID=${DEFAULT_FTP_GROUP_ID:-50}
CHMOD=${CHMOD:-0777}


OWN_USER=$(id -u ftp 2>/dev/null)
OWN_GROUP=$(id -g ftp  2>/dev/null)
OWN_USER=${OWN_USER:-$DEFAULT_FTP_USER_ID}
OWN_GROUP=${OWN_GROUP:-$DEFAULT_FTP_GROUP_ID}


VUSER_TXT="${VIRTUAL_USERS_DIR}/virtual_users.txt"
VUSER_DB="${VIRTUAL_USERS_DIR}/virtual_users.db"

function vsftpduser_add()
{
	USER=$1
	PASSWORD=$2

	if [ "$USER" == "" ]; then
		echo "error: missing user parameter"
		exit 1
	fi

	if [ "$PASSWORD" == "" ]; then
		echo "error: password can not be empty"
		exit 1
	fi

	find_user $USER
	if [ $? = 0 ]; then
		echo "adding $USER to virtual users registry"
		echo -e "${USER}\n${PASSWORD}" >> $VUSER_TXT
		make_db
	else
		echo "user: $USER already exists in registry"
	fi

	make_user_disk $USER
	make_user_dir $USER
	mount_user_disk $USER
	echo "new user $USER created"
}

function vsftpduser_del()
{
	USER=$1

	if [ "$USER" == "" ]; then
		echo "error: missing user parameter"
		exit 1
	fi


	find_user $USER
	if [ $? = 1 ]
	then
		echo "removing $USER from virtual users registry"
		sed -i '/\<'$USER'\>/{N;d}' $VUSER_TXT > /dev/null
		make_db
	else
		echo "user: $USER does not exists in registry"
	fi

	remove_user_storage $USER
}

function vsftpduser_passwd()
{
	USER=$1
	PASSWORD=$2

	if [ "$USER" == "" ]; then
		echo "error: missing user parameter"
		exit 1
	fi

	if [ "$PASSWORD" == "" ]; then
		echo "error: password can not be empty"
		exit 1
	fi

	find_user $USER
	if [ $? = 1 ]; then
		sed -i '/\<'$USER'\>/{n;d}' $VUSER_TXT > /dev/null
		sed -i '/\<'$USER'\>/a\'$PASSWORD'' $VUSER_TXT > /dev/null
		echo "password for user ${USER} has been modified"
		make_db
	else
		echo "user: $USER does not exists in registry"
		return 1
	fi
}

function vsftpduser_ls()
{
	echo $(sed -n '1~2p' $VUSER_TXT) | tr " " "\n"
}

function vsftpduser_rebuild()
{

	FORCE="NO"
	POSITIONAL=()
	while [[ $# -gt 0 ]]
		do
		key="$1"
		case $key in
			-f|--force)
			FORCE="YES"
			shift
			;;
			*)
			POSITIONAL+=("$1")
			shift
			;;
		esac
	done
	set -- "${POSITIONAL[@]}" # restore positional parameters

	if [ "$1" == "" ]; then
		rebuild_all $FORCE $@
	else
		USER=$1
		shift
		need_user $USER
		rebuild_user $USER $FORCE $@
	fi
}

function vsftpduser_mount()
{
	if [ "$1" == "" ]; then
		mount_all $@
	else
		USER=$1
		shift
		need_user $USER
		mount_user_disk $USER
	fi
}

function vsftpduser_umount()
{
	if [ "$1" == "" ]; then
		umount_all $@
	else
		USER=$1
		shift
		need_user $USER
		umount_user_disk $USER
	fi
}

function vsftpduser_remount()
{
	vsftpduser_umount $@
	vsftpduser_mount $@
}

function rebuild_user()
{
	USER=$1
	FORCE=$2
	echo "rebuilding user $USER"
	if [ "$FORCE" == "YES" ]; then
		remove_user_storage $USER
	fi
	make_user_disk $USER
	make_user_dir $USER
	mount_user_disk $USER
}
function rebuild_all()
{
	FORCE=$1
	USER_LIST_ARRAY=($(sed -n '1~2p' $VUSER_TXT))
	for USER in "${USER_LIST_ARRAY[@]}" ; do
		rebuild_user $USER $FORCE
	done
}

function mount_all()
{
	USER_LIST_ARRAY=($(sed -n '1~2p' $VUSER_TXT))
	for USER in "${USER_LIST_ARRAY[@]}" ; do
		mount_user_disk $USER
	done
}

function umount_all()
{
	USER_LIST_ARRAY=($(sed -n '1~2p' $VUSER_TXT))
	for USER in "${USER_LIST_ARRAY[@]}" ; do
		umount_user_disk $USER
	done
}

function need_user(){
	USER=$1
	find_user $USER
	if [ $? = 0 ]; then
		echo "user: $USER does not exists in registry"
		exit 1
	fi
}

function find_user()
{
	if [ -f $VUSER_TXT ];then
    ACCOUNTDB_TOTALLINES=`grep '.' -c $VUSER_TXT`
	else
		ACCOUNTDB_TOTALLINES=0
	fi
	C=1;
	if [ "$ACCOUNTDB_TOTALLINES" != "0" ]; then
		while [ $C -lt $ACCOUNTDB_TOTALLINES ]; do
			VALIDUSER=`sed -n -e "$C p" $VUSER_TXT`
			if [ "$1" == "$VALIDUSER" ];then
					USERNAMEOK=1
					break;
			else
				USERNAMEOK=0
			fi
			let C=$C+2;
		done
	fi
	return $USERNAMEOK
}

function make_db()
{
	db_load -T -t hash -f $VUSER_TXT $VUSER_DB
}

function make_user_disk()
{
	USER=$1
	USER_DISK="${DISKS_DIR}/${USER}.ext3"
	if [ ! -f "$USER_DISK" ]
	then
		echo "creating ${USER_DISK}"
		touch "${USER_DISK}"
		dd if=/dev/zero of="${USER_DISK}" bs="${USER_QUOTA}" count=1
		/sbin/mkfs --type=ext3 -F "${USER_DISK}"
	else
		echo "disk allready exists ${USER_DISK}"
	fi
}
function make_user_dir()
{
	USER_DIR="$ROOT_DIR/$1"
	if [ ! -d "$USER_DIR" ]
	then
		echo "creating ${USER_DIR}"
		mkdir -p "${USER_DIR}"
		chown $OWN_USER:$OWN_GROUP "${USER_DIR}"
		chmod $CHMOD "${USER_DIR}"
	else
		echo "directory already exists ${USER_DIR}"
	fi
}
function mount_user_disk()
{
	USER=$1
	USER_DISK="${DISKS_DIR}/${USER}.ext3"
	USER_DIR="$ROOT_DIR/$1"
	if mount | grep $USER_DIR > /dev/null; then
		echo "mountpoint allready mounted ${USER_DIR}"
	elif [ ! -f "$USER_DISK" ]; then
		echo "missing disk file ${USER_DISK} for user ${USER}"
	else
		echo "mounting ${USER_DISK} in ${USER_DIR}"
		mount -o loop,rw "${USER_DISK}" "${USER_DIR}"
		chmod $CHMOD "${USER_DIR}"
		if [ -d "${USER_DIR}/lost+found" ]; then
			if [ -z "$(ls -A ${USER_DIR}/lost+found)" ]; then
				rm -r "${USER_DIR}/lost+found"
			fi
		fi
	fi
}

function remove_user_storage()
{
	USER=$1
	USER_DIR="${ROOT_DIR}/${USER}"
	USER_DISK="${DISKS_DIR}/${USER}.ext3"
	umount_user_disk $USER

	if [ -d "$USER_DIR" ]; then
		echo "removing $USER_DIR"
		rm -r "$USER_DIR"
	fi

	if [ -f "$USER_DISK" ]; then
		echo "removing $USER_DISK"
		unlink "$USER_DISK"
	fi
}

function umount_user_disk(){
	USER=$1
	USER_DIR="${ROOT_DIR}/${USER}"
	if mount | grep $USER_DIR > /dev/null; then
		echo "unmounting $USER_DIR"
		umount "$USER_DIR"
	fi
}

function main()
{
	if [ $# -lt 1 ];
	then
		echo "usage: vsftpduser add | del | passwd | ls | rebuild | mount | umount | remount"
		exit 1
	fi

	CMD=$1
	shift

	if [ $CMD = "add" ]; then
		vsftpduser_add $@
	elif [ $CMD = "del" ]; then
		vsftpduser_del $@
	elif [ $CMD = "passwd" ]; then
		vsftpduser_passwd $@
	elif [ $CMD = "ls" ]; then
		vsftpduser_ls $@
	elif [ $CMD = "rebuild" ]; then
		vsftpduser_rebuild $@
	elif [ $CMD = "mount" ]; then
		vsftpduser_mount $@
	elif [ $CMD = "umount" ]; then
		vsftpduser_umount $@
	elif [ $CMD = "remount" ]; then
		vsftpduser_remount $@
	else
		echo [$CMD] a bad argument.
	fi
}

main $@