mip: Comparison of multi-model runs

#' Adds plot styles locally to plotstyle.csv
#' 
#' Adds plot styles locally to plotstyle object and returns a dataframe with all plotstyles including the added data. However, it does NOT change the "./inst/extdata/plotstyle.csv".
#' To add new entities to "./inst/extdata/plotstyle.csv" please open the file in your editor and add or change values by hand.
#' By default plotstyles of already existing entities will not be changed. Only new entities will be added. Use the \code{replace} switch to replace existing styles. 
#' If you want to keep the legend text or the color of an already existing entity and only replace one of the two values, use the string "keep" for the value you want to keep.
#' 
#' @param entity Vector of strings with names of entities (regions, variable names, etc.)
#' @param legend Vector of strings with legend names of entities.
#' @param color Vector of strings containing hexadecimal color codes.
#' @param marker optional Vector of strings with marker codes.
#' @param linestyle optional Vector of strings containing linestyle codes .
#' @param replace Logical (default FALSE) indicating whether existing data should be replaced with new data.
#' @author David Klein, Jan Philipp Dietrich
#' @seealso \code{\link{plotstyle}}
#' @examples
#' \dontrun{plotstyle.add("AFR","Africa","#000000")}
#' \dontrun{plotstyle.add("AFR","keep","#FFFFFF")}
#' \dontrun{plotstyle.add("AFR","keep","keep",marker=20,replace=TRUE)}
#' @importFrom utils read.csv2 write.csv2
#' @export
plotstyle.add <- function (entity, legend, color, marker=NULL, linestyle=NULL, replace=FALSE) {
  
  # in no data is given for marker and linestyle fill with NA
  if (is.null(marker))    marker    <- rep(NA,time=length(entity))
  if (is.null(linestyle)) linestyle <- rep(NA,time=length(entity))
  
  # Check if all parameters are of the same length
  a <- diff(range(c(length(entity),length(legend),length(color),length(marker),length(linestyle))))
  if (a > .Machine$double.eps ^ 0.5) {
    stop("Entities, legend names, and colors have to be of the same length.")
  }

  plotstyles <- read.csv2(system.file("extdata","plotstyle.csv",package = "mip"),stringsAsFactors = F,row.names=1)
  class(plotstyles) <- "data.frame"
  
  # find existing entries
  dup <- which(entity %in% rownames(plotstyles))
  
  # create data.frame with new data
  newdata <- data.frame(row.names=entity,legend=legend,color=color,marker=marker,linestyle=linestyle,stringsAsFactors=FALSE)
  
  # add new data to existing data and replace if wanted
  if (length(dup)==0) {
    # if no duplicates are found between old and new data append new data
    plotstyles <- rbind(plotstyles,newdata)
  } else if (replace) {
    # add new data and replace existing data
    # keep existing data where new data contains "keep"
    # keep legend
    i <- rownames(subset(newdata,legend=="keep"))
    newdata[i,]$legend <- plotstyles[i,]$legend
    # keep color
    i <- rownames(subset(newdata,color=="keep"))
    newdata[i,]$color <- plotstyles[i,]$color
    # keep marker
    i <- rownames(subset(newdata,marker=="keep"))
    newdata[i,]$marker <- plotstyles[i,]$marker
    # keep linestyle
    i <- rownames(subset(newdata,linestyle=="keep"))
    newdata[i,]$linestyle <- plotstyles[i,]$linestyle

    plotstyles[entity,] <- newdata
  } else {
    # append new data without replacing duplicates in existing data
    cat("Element",entity[dup],"already exist. It has not been added. Please use replace=TRUE to replace it. All other data has been added\n")
    plotstyles <- rbind(plotstyles,newdata[-dup,])
  }

  cat("\nNOTE: This function adds new elements to inst/extdata/plotstyle_new.csv locally only! 
      To make it available for everyone please rebuild the library after adding entities, commit your changes and install it on the cluster.
      Here you find the how-to: https://redmine.pik-potsdam.de/projects/mo/wiki/R_-_Libraries_-_Installation_Updating_and_Commiting\n")
  
  write.csv2(plotstyles,file=system.file("extdata","plotstyle.csv",package = "mip"),quote=FALSE)
  return(plotstyles)
}