#' Data
#'
#' Data encapsulation
#'
#' @field data List of
#' \itemize{
#'   \item time: vector of times
#'   \item serie: centered series
#'   \item level: corresponding levels
#'   \item exo: exogenous variables
#'   \item exo_hat: predicted exogenous variables
#' }
#'
#' @docType class
#' @importFrom R6 R6Class
#'
#' @export
Data = R6Class("Data",
	private = list(
		.data = "list"
	),
	public = list(
		initialize = function(...)
			initialize(self, private, ...)
		,
		getSize = function()
			getSize()
		,
		getStdHorizon = function()
			getStdHorizon(self, private)
		,
		append = function(new_time, new_serie, new_level, new_exo_hat, new_exo)
			append(self, private, 

			data[[length(data)+1]] <<- list("time"=new_time,"serie"=new_serie,"level"=new_level,
				"exo_hat"=new_exo_hat,"exo"=new_exo)
		},
		getTime = function(index)
		{
			"Time values at specified index"

			index = dateIndexToInteger(index, .self)
			data[[index]]$time
		},
		getCenteredSerie = function(index)
		{
			"Serie values (centered) at specified index"

			index = dateIndexToInteger(index, .self)
			data[[index]]$serie
		},
		getLevel = function(index)
		{
			"Level of the serie at specified index"

			index = dateIndexToInteger(index, .self)
			data[[index]]$level
		},
		getSerie = function(index)
		{
			"Serie values (centered+level) at specified index"

			index = dateIndexToInteger(index, .self)
			data[[index]]$serie + data[[index]]$level
		},
		getExoHat = function(index)
		{
			"Exogeous predictions at specified index"

			index = dateIndexToInteger(index, .self)
			data[[index]]$exo_hat
		},
		getExo = function(index)
		{
			"Exogenous measures at specified index"

			index = dateIndexToInteger(index, .self)
			data[[index]]$exo
		}
	)
)

#' Initialize empty Data object
initialize = function(self, private, ...)
{
	invisible(self)
}

#' Number of series in the dataset
getSize = function(self, private)
	length(private$.data)

#' 'Standard' horizon, from t+1 to midnight
getStdHorizon = function(self, private)
	24 - as.POSIXlt( private$.data[[1]]$time[1] )$hour + 1

#' Acquire a new vector of lists (time, centered_serie, level, exo, exo_hat)