library(data.table)
library(magrittr)
library(stringr)

# create a function to delete unnecessary variables from a CAFAS or PECFAS
data set and save the reduced copy

del.items <- function(file)
{
  data <- read.csv(input = paste0("../data/pecfas|cafas/raw",
str_match(pattern = "cafas|pecfas", string = file) %>% tolower, "/raw/",
file), sep = ",", header = TRUE, na.strings = "", stringsAsFactors = FALSE,
skip = 0, colClasses = "character", data.table = FALSE)

  data <- data[-grep(pattern = "^(CA|PEC)FAS_E[0-9]+(T(Initial|[0-
9]+|Exit)|SP[a-z])_(G|S|Item)[0-9]+$", x = names(data))]

  write.csv(data, file = paste0("../data/pecfas|cafas/items-del",
str_match(pattern = "cafas|pecfas", string = file) %>% tolower, "/items-
del/", sub(pattern = "ExportData_", x = file, replacement = "")) %>%
tolower, sep = ",", row.names = FALSE, col.names = TRUE)
}

# delete items from all cafas data sets

cafas.files <- list.files("../data/cafas/raw/", pattern = ".csv")

for (file in cafas.files){
  del.items(file)
}

# delete items from all pecfas data sets

pecfas.files <- list.files("../data/pecfas/raw/", pattern = ".csv")

 for (file in pecfas.files){
  del.items(file)
}