#' PostgreSQL - Create 'postgis' database
#' @details Postgis'i andmebaasi loomine.
#' @param host Name or the numeric IPaddress of the host to connect to.
#' @param dbname The database name.
#' @param user PostgreSQL user name to connect as. Defaults to be the same as the operating system name of the user running the application.
#' @param password Password to be used if the server demands password authentication.
#' @param port Port number to connect to at the server host.
#' @return return message.
#' @seealso \code{\link{myPostgresConnect}}, \code{\link{myPostgresDropTable}},
#' \code{\link{myPostgresCreateGisDb}}, \code{\link{myPostgresImprotShp}}
#' @examples \dontrun{
#' con <- myPostgresCreateGisDb(host = '192.168.255.26', port = 5432,
#'        user = 'ardo', password = '247848', dbname = 'xxx')
#'
#' }
#'
#' @export
#'

myPostgresCreateGisDb <- function(host = '192.168.255.26', port = 5432, user = 'ardo', password = '247848', dbname = NULL) {
  if(is.null(dbname)) {message("Palun sisesta andmebaasi nimi!"); return(NULL)}
  system(paste0("export PGPASSWORD='", password, "' && createdb -U ", user, " -h ", host, " -p ", port, " ", dbname, ";"))
  # "psql -U ardo -h 192.168.255.26 -p 5432 -d shp -c 'CREATE EXTENSION hstore; CREATE EXTENSION postgis;'"
  system(paste0("export PGPASSWORD='", password, "' && psql -U ", user, " -d ", dbname, " -h ", host, " -p ", port, "  -c 'CREATE EXTENSION hstore; CREATE EXTENSION postgis;'"))
  message(paste0("Genereeriti postgis'i andmebaas ", dbname, "."))
}