#' @include Forecaster.R
#'
#' @title Level Forecaster
#'
#' @description Return flat serie of last observed level (on similar day).
#'   Inherits \code{\link{ShapeForecaster}}
LevelForecaster = setRefClass(
	Class = "LevelForecaster",
	contains = "Forecaster",

	methods = list(
		initialize = function(...)
		{
			callSuper(...)
		},
		predict = function(today, memory, horizon, all_memory=TRUE, ...)
		{
			#return last (similar) day level, or on all memory if all_memory==TRUE
			first_day = max(1, today-memory)
			index = today-7 + 1
			if (all_memory)
			{
				sum_level = 0.
				nb_series = 0
			}
			repeat
			{
				{
					last_similar_serie = data$getSerie(index)[1:horizon]
					index = index - 7
				};
				#TODO: next test is too strict
				if (!any(is.na(last_similar_serie)))
				{
					if (all_memory)
					{
						sum_level = sum_level + mean(last_similar_serie)
						nb_series = nb_series + 1
					}
					else
						return (rep(mean(last_similar_serie), horizon))
				};
				if (index < first_day)
				{
					if (all_memory)
						return (rep(sum_level / nb_series, horizon))
					return (NA)
				}
			}
		}
	)
)