R/io.R

In lorenzwalthert/gitsum: Parse and summarize git repositories

#' Manage a gitsum repository
#'
#' A gitsum repository is a git repository with an additional .gitsum folder in
#' the root directory that is mainly used to store a parsed git log as a tibble.
#' @param path The path to the repository to initialize.
#' @param over_write Whether or not an existing directory should be overwritten.
#' @name manage_gitsum
#' @aliases init_gitsum remove_gitsum
NULL

#' @describeIn manage_gitsum Calling this function will parse the available git
#'   history and dump it into the directory .gitsum.
#' @export
init_gitsum <- function(path = ".", over_write = FALSE) {
  check_overwriting_clearance(gitsum_path(path), over_write, dir.exists)
  parse_log_detailed_full_run(path) %>%
    update_dump_from_log(path)
}

#' @describeIn manage_gitsum Removes the gitsum repository, i.e just the folder
#' .gitsum and its contents.
#' @export
remove_gitsum <- function(path = ".") {
  was_gitsum_repo <- is_gitsum_repo(path)
  unlink(gitsum_path(path), recursive = TRUE)
  if (was_gitsum_repo) message(".gitsum removed.")
}

#' Dump a parsed log into .gitsum
#'
#' Store a parsed git log in a gitsum repository.
#' @param log A parsed log as a tibble
#' @param path The path to the root directory of the gitsum repository.
#' @param verbose Whether or not to send informative messages to the console.
#' @inheritParams check_overwriting_clearance
#' @importFrom readr write_rds
#' @keywords internal
dump_parsed_log <- function(log, path = ".", over_write = FALSE, verbose = TRUE) {
  gitsum_path <- ensure_gitsum_repo(path)
  gitsum_path_log <- file.path(gitsum_path, "log.rds")
  check_overwriting_clearance(gitsum_path_log, over_write)
  write_rds(log, gitsum_path_log)
  if (verbose) message("\nLog created at ", gitsum_path_log)
}


#' @describeIn dump_parsed_log Dumps the last commit into .gitsum
#' @importFrom readr write_rds
#' @importFrom dplyr slice arrange desc
#' @keywords internal
dump_last_commit <- function(log, path, verbose = TRUE) {
  gitsum_path_last_commit <- gitsum_path(path, "last_commit.rds")
  last <- log %>%
    arrange(desc(.data$commit_nr)) %>%
    slice(1)
  write_rds(last, gitsum_path_last_commit)
  if (verbose) message("\nlast_commit saved at ", gitsum_path_last_commit)
}

#' Make sure the repository is a gitsum repository and create one if it is not
#' @inheritParams dump_parsed_log
#' @keywords internal
ensure_gitsum_repo <- function(path = ".") {
  if (!is_gitsum_repo(path)) {
    dir.create(gitsum_path(path))
  }
  gitsum_path(path)
}

#' Check whether a file / path exists and return an error when it cannot be
#' overwritten.
#' @inheritParams dump_parsed_log
#' @param over_write Whether or not existing files / directories should be
#'   overwritten.
#' @param fun The function to apply to the path, either file.exists, or
#'   dir.exists.
#' @keywords internal
check_overwriting_clearance <- function(path, over_write, fun = file.exists) {
  if (fun(path)) {
    if (!over_write) {
      stop(
        "Cannot overwrite file / path ", path,
        " since argument overwrite was set to FALSE"
      )
    }
  }
}

#' Read gitsum data into R
#' @inheritParams dump_parsed_log
#' @name read_gitsum
NULL

#' @describeIn read_gitsum Reads a parsed log.
#' @keywords internal
read_log <- function(path = ".") {
  read_gitsum_data(path, "log.rds")
}

#' @describeIn read_gitsum Reads the last parsed commit.
#' @keywords internal
read_last_commit <- function(path = ".") {
  read_gitsum_data(path, "last_commit.rds")
}

#' Find the last commit in a repo
#'
#' Finds the last commit in a repo and optionally updates the dump.
#' @inheritParams parse_log_detailed
#' @export
#' @importFrom dplyr arrange desc slice
find_last_commit <- function(path = ".", update_dump = FALSE) {
  parse_log_detailed(path, update_dump) %>%
    arrange(desc(.data$commit_nr)) %>%
    slice(1)
}

#' @describeIn read_gitsum Reads the last parsed hash.
#' @keywords internal
read_last_hash <- function(path = ".") {
  last_commit <- read_last_commit(path)
  last_commit$hash
}



udpate_dump <- function(path = ".") {
  parse_log_detailed(path, update_dump = TRUE)
  invisible()
}
update_dump_from_log <- function(log, path) {
  dump_parsed_log(log, path, over_write = TRUE, verbose = FALSE)
  dump_last_commit(log, path, verbose = FALSE)
}

#' @importFrom readr read_rds
read_gitsum_data <- function(path, ...) {
  assert_gitsum_repo(path)
  read_rds(gitsum_path(path, ...))
}

is_gitsum_repo <- function(path = ".") {
  dir.exists(gitsum_path(path))
}

gitsum_path <- function(path = ".", ...) {
  file.path(path, ".gitsum", ...)
}
assert_gitsum_repo <- function(path = ".") {
  if (!is_gitsum_repo(path)) init_gitsum(path)
}