#' Forecast
#'
#' Forecast encapsulation
#'
#' @field pred List with
#' \itemize{
#'   \item serie: forecasted serie
#'   \item params: corresponding list of parameters (weights, neighbors...)
#'   \item index: corresponding index in data object
#' }
#'
#' @docType class
#' @importFrom R6 R6Class
#'
#' @export
Forecast = R6::R6Class("Forecast",
	private = list(
		.pred = "list",
		.dates = "Date"
	),
	public = list(
		initialize = function(dates)
			initialize(self, private, dates)
		,
		getSize = function()
			getSize(private)
		,
		append = function(new_serie, new_params, new_index)
			append(private, new_serie, new_params, new_index)
		,
		getDates = function()
			getDates(private)
		,
		getSerie = function(index)
			getSerie(private, index)
		,
		getParams = function(index)
			getParams(private, index)
		,
		getIndexInData = function(index)
			getIndexInData(private, index)
	)
)

#' Initialize empty Forecast object
#'
#' @param o Object of class Forecast
#' @param private List of private members in o
#' @param dates vector of dates where forecast occurs
initialize = function(o, private, dates)
{
	private$.dates <<- dates
	private$.pred <<- list()
	invisible(o)
}

#' Number of individual forecasts"
#'
#' @inheritParams initialize
getSize = function(private)
	length(private$.pred)

#' Obtain a new pair (serie, params)"
#'
#' @inheritParams initialize
append = function(new_serie, new_params, new_index_in_data)
{
	private$.pred[[length(private$.pred)+1]] <<-
		list("serie"=new_serie, "params"=new_params, "index_in_data"=new_index_in_data)
}

#' Dates where prediction occurs
#'
#' inheritParams initialize
getDates = function(private)
	private$.dates

#' Serie values at specified index"
#'
#' @inheritParams initialize
#' @param index Return value at this index
getSerie = function(index)
{
	if (is(index,"Date"))
		index = match(index, private$.dates)
	private$.pred[[index]]$serie
}

#' Params at specified index"
#'
#' @inheritParams getSerie
getParams = function(index)
{
	if (is(index,"Date"))
		index = match(index, private$.dates)
	private$.pred[[index]]$params
}

#' (day) Index in data where prediction took place"
#'
#' @inheritParams getSerie
getIndexInData = function(index)
{
	if (is(index,"Date"))
		index = match(index, private$.dates)
	private$.pred[[index]]$index_in_data
}