#' @title Get and Convert SPSS files to R
#' @author Shea Fyffe email: shea.fyffe@@gmail.com
#' @import haven sjlabelled
#' @family SPSS
get_spss <- function(dir = getwd(), var.pattern = NULL) {
    if (!dir.exists(dir)) {
        stop("Please specify correct directory")
    }
    .file_paths <- list.files(dir, pattern = ".sav", ignore.case = TRUE)
    if (!length(.file_paths)) {
        stop(sprintf("No .sav files found in %s", dir))
    }
    .files <- lapply(.file_paths, haven::read_sav)
    .files <- lapply(.files, haven::zap_formats)
    .files <- lapply(.files, sjlabelled::remove_all_labels)
    .files <- lapply(.files, function(X) as.data.frame(X, stringsAsFactors = FALSE))
    if (!is.null(var.pattern)) {
        .files <- lapply(.files, function(X) get_vars(X, var.pattern))
    }
    names(.files) <- basename(.file_paths)
    if (length(.files) == 1L) {
        return(.files[[1]])
    } else {
        return(.files)
    }
}


#' @title Recode variable values
#' @author Shea Fyffe email: shea.fyffe@@gmail.com
#' @param x Required. Data.frame containing variables to recode
#' @param vars Required. Vector of class character of variable names. May use [GitItSheaGitIt::get_vars()]
#' @param old_values Required. Vector of old values to replace.
#' @param old_values Required. Vector of new values to replace old values.
#' @import plyr
#' @family SPSS
recode_variables <- function(x, vars, old_values = NULL, new_values = NULL) {
    if (!all(is.character(vars))) {
        stop("vars should be of class character")
    }
    if (!all(vars %in% names(x))) {
        stop(sprintf("%s are not all valid columns in x", vars))
    }
    .temp <- unique(unlist(x[, vars]))
    if (!all(.temp %in% old_values)) {
        stop(sprintf("Old values are missing: %s\n", setdiff(.temp, old_values)))
    }
    if (length(vars) > 1) {
        x[, vars] <- apply(x[, vars], 2, function(x) plyr::mapvalues(x, from = old_values,
            to = new_values))
    } else {
        x[, vars] <- plyr::mapvalues(x[, vars], from = old_values, to = new_values)
    }
    return(x)
}


#' @title Create Subscale based on Operation
#' @param x Required. Data.frame containing variables create subscale
#' @param FUNCT Required. A function to be applied
#' @param pattern Optional. Pattern of variable names select for subscale
#'  calculation. May use Regex.
#' @family SPSS
create_subscale <- function(x, FUNCT, pattern = NULL) {
  if (!inherits(x, "data.frame")) {
    stop("x must be a data.frame")
  }
  if(!is.null(pattern)) {
      if(length(pattern) > 1) {
        pattern <- paste0(pattern, collapse = "|")
      }
      x <- x[grep(pattern, names(x))]
    }
  x <- apply(x, 1, FUN = FUNCT)
  return(x)
}
#' @title Identify all variables in a dataframe given a pattern
#' @author Shea Fyffe email: shea.fyffe@@gmail.com
#' @param x Required. Data.frame containing variables to index
#' @param pattern Required. Pattern of variable names to select columns. May use Regex.
#' @param ... Optional. Additional arguments to pass to grepl.
#' @seealso [base::grep()]
#' @family SPSS
#' @export
get_vars <- function(x, pat, ...) {
    .out <- names(x)[grepl(y, names(x), ...)]
    return(.out)
}