###################################################################

folder_path <- "diamond csv storage"

csv_file_path <- paste0(folder_path, "/diamonds.csv")

xlsx_file_path <- paste0(folder_path, "/diamonds.xlsx")


###################################################################

# running for the first time, this section creates the csv + excel files

if (FALSE) {
  
  library(tidyverse)
  
  if (!dir.exists(folder_path)) {dir.create(folder_path)}
  
  diamonds %>% 
    write_csv(csv_file_path)
  
  diamonds %>% 
    openxlsx::write.xlsx(xlsx_file_path, asTable = T)
  
  
}


###################################################################

# from:
# https://www.jottr.org/2023/01/10/progressr-0.13.0/

progressr::handlers(global = TRUE)
options(cli.progress_handlers = "progressr")


###################################################################

# for 300 files 13.64 sec elapsed

if (FALSE) {
  
  library(tidyverse)
  
  how_many_files <- 300
  
  
  tictoc::tic()
  
  import_of_files <-
    tibble(row_id = 1:how_many_files, file_path = csv_file_path) %>% 
    mutate(imported_data = map(file_path, ~.x %>% read_csv(show_col_types = F, progress = FALSE), .progress = TRUE))
  
  tictoc::toc()
  
  
  
}




###################################################################


# for 300 files 4.96 sec elapsed

if (FALSE) {
  
  library(tidyverse)
  
  how_many_files <- 300
  
  tictoc::tic()
  
  import_of_files <-
    tibble(row_id = 1:how_many_files, file_path = csv_file_path) %>% 
    mutate(imported_data = map(file_path, ~.x %>% vroom::vroom(show_col_types = F, progress = FALSE), .progress = TRUE))
  
  tictoc::toc()
  
  
  
}

###################################################################



# for 100 files 61.35 sec elapsed

if (FALSE) {
  
  library(tidyverse)
  
  how_many_files <- 100
  
  tictoc::tic()
  
  import_of_files <-
    tibble(row_id = 1:how_many_files, file_path = xlsx_file_path) %>% 
    mutate(imported_data = map(file_path, ~.x %>% readxl::read_excel(), .progress = TRUE))
  
  tictoc::toc()
  
  
  
}

###################################################################

# with future map
# for 100 files 19.87 sec elapsed


if (FALSE) {
  
  library(tidyverse)
  library(furrr) 
  
  
  # this also loads the future package
  
  all_cores <- parallelly::availableCores()  # what's the difference to?  all_cores <- parallelly::availableCores(logical = FALSE)  -is this line even required?
  future::plan(multisession, workers = all_cores)
  
  
  how_many_files <- 100
  
  tictoc::tic()
  
  import_of_files <-
    tibble(row_id = 1:how_many_files, file_path = xlsx_file_path) %>% 
    mutate(imported_data = future_map(file_path, ~.x %>% readxl::read_excel(progress = FALSE), .progress = TRUE))
  
  tictoc::toc()
  
  
}




###################################################################



# for 100 files 20.33 sec elapsed

if (FALSE) {
  
  library(tidyverse)
  library(doSNOW)
  library(doParallel)
  
  
  
  # all_cores <- parallel::detectCores(logical = FALSE)
  all_cores <- parallel::detectCores()
  cl <- parallel::makePSOCKcluster(all_cores)
  doSNOW::registerDoSNOW(cl)
  
  
  how_many_files <- 100
  
  
  pb <- txtProgressBar(max = how_many_files, style = 3)
  progress <- function(n) setTxtProgressBar(pb, n)
  opts <- list(progress = progress)
  
  
  tictoc::tic()
  
  result_of_loop <- 
    foreach(file_id=1:how_many_files, .options.snow = opts, .packages = c("tidyverse")) %dopar% {
      
      readxl::read_excel(xlsx_file_path, progress = FALSE)
      
    }
  
  
  import_of_files <- result_of_loop %>% list_rbind()
  
  tictoc::toc()
  
  
  stopCluster(cl)
  close(pb)
  
}




###################################################################


# for 100 files 18.78 sec elapsed

if (FALSE) {
  
  library(tidyverse)
  library(doFuture)
  
  doFuture::registerDoFuture()
  plan(multisession)
  
  
  how_many_files <- 100
  
  tictoc::tic()
  
  result_of_loop <- 
    foreach(file_id=1:how_many_files) %dopar% {
      
      readxl::read_excel(xlsx_file_path, progress = FALSE)
      
    }
  
  
  import_of_files <- result_of_loop %>% list_rbind()
  
  tictoc::toc()
  
  
}