
enc2path <- function(x) {
  if (is_windows()) {
    enc2utf8(x)
  } else {
    enc2native(x)
  }
}

`%||%` <- function(l, r) if (is.null(l)) r else l

os_type <- function() {
  .Platform$OS.type
}

is_windows <- function() {
  .Platform$OS.type == "windows"
}

is_linux <- function() {
  identical(tolower(Sys.info()[["sysname"]]), "linux")
}

last_char <- function(x) {
  nc <- nchar(x)
  substring(x, nc, nc)
}

# Given a filename, return an absolute path to that file. This has two important
# differences from normalizePath(). (1) The file does not need to exist, and (2)
# the path is merely absolute, whereas normalizePath() returns a canonical path,
# which resolves symbolic links, gives canonical case, and, on Windows, may give
# short names.
#
# On Windows, the returned path includes the drive ("C:") or network server
# ("//myserver").
full_path <- function(path) {
  assert_that(is_string(path))

  # Try expanding "~"
  path <- path.expand(path)

  # If relative path, prepend current dir. On Windows, also record current
  # drive.
  if (is_windows()) {
    path <- gsub("\\", "/", path, fixed = TRUE)

    if (grepl("^[a-zA-Z]:", path)) {
      drive <- substring(path, 1, 2)
      path <- substring(path, 3)

    } else if (substring(path, 1, 2) == "//") {
      # Extract server name, like "//server", and use as drive.
      pos <- regexec("^(//[^/]*)(.*)", path)[[1]]
      drive <- substring(path, pos[2], attr(pos, "match.length", exact = TRUE)[2])
      path <- substring(path, pos[3])

      # Must have a name, like "//server"
      if (drive == "//")
        throw(new_error("Server name not found in network path."))

    } else {
      drive <- substring(getwd(), 1, 2)

      if (substr(path, 1, 1) != "/")
        path <- substring(file.path(getwd(), path), 3)
    }

  } else {
    if (substr(path, 1, 1) != "/")
      path <- file.path(getwd(), path)
  }

  parts <- strsplit(path, "/")[[1]]

  # Collapse any "..", ".", and "" in path.
  i <- 2
  while (i <= length(parts)) {
    if (parts[i] == "." || parts[i] == "") {
      parts <- parts[-i]

    } else if (parts[i] == "..") {
      if (i == 2) {
        parts <- parts[-i]
      } else {
        parts <- parts[-c(i-1, i)]
        i <- i-1
      }
    } else {
      i <- i+1
    }
  }

  new_path <- paste(parts, collapse = "/")
  if (new_path == "")
    new_path <- "/"

  if (is_windows())
    new_path <- paste0(drive, new_path)

  new_path
}

vcapply <- function (X, FUN, ..., USE.NAMES = TRUE) {
  vapply(X, FUN, FUN.VALUE = character(1), ..., USE.NAMES = USE.NAMES)
}

do_echo_cmd <- function(command, args) {
  quoted <- sh_quote_smart(c("Running", command, args))

  out <- str_wrap_words(quoted, width = getOption("width") - 3)

  if ((len <- length(out)) > 1) {
    out[1:(len - 1)] <- paste0(out[1:(len - 1)], " \\")
  }
  cat(out, sep = "\n")
}

sh_quote_smart <- function(x) {
  if (!length(x)) return(x)
  ifelse(grepl("^[-a-zA-Z0-9/_\\.]*$", x), x, shQuote(x))
}

strrep <- function(x, times) {
  x <- as.character(x)
  if (length(x) == 0L) return(x)
  r <- .mapply(
    function(x, times) {
      if (is.na(x) || is.na(times)) return(NA_character_)
      if (times <= 0L) return("")
      paste0(replicate(times, x), collapse = "")
    },
    list(x = x, times = times),
    MoreArgs = list()
  )

  unlist(r, use.names = FALSE)
}

str_wrap_words <- function(words, width, indent = 0, exdent = 2) {
  word_widths <- nchar(words, type = "width")
  out <- character()

  current_width <- indent
  current_line <- strrep(" ", indent)
  first_word <- TRUE

  i <- 1
  while (i <= length(words)) {
    if (first_word) {
      current_width <- current_width + word_widths[i]
      current_line <- paste0(current_line, words[i])
      first_word <- FALSE
      i <- i + 1

    } else if (current_width + 1 + word_widths[i] <= width) {
      current_width <- current_width + word_widths[i] + 1
      current_line <- paste0(current_line, " ", words[i])
      i <- i + 1

    } else {
      out <- c(out, current_line)
      current_width <- exdent
      current_line <- strrep(" ", exdent)
      first_word <- TRUE
    }
  }

  if (!first_word) out <- c(out, current_line)

  out
}

set_names <- function(x, n) {
  names(x) <- n
  x
}

get_private <- function(x) {
  x$.__enclos_env__$private
}

get_tool <- function(prog) {
  if (os_type() == "windows") prog <- paste0(prog, ".exe")
  exe <- system.file(package = "processx", "bin", .Platform$r_arch, prog)
  if (exe == "") {
    pkgpath <- system.file(package = "processx")
    if (basename(pkgpath) == "inst") pkgpath <- dirname(pkgpath)
    exe <- file.path(pkgpath, "src", "tools", prog)
    if (!file.exists(exe)) return("")
  }
  exe
}

get_id <- function() {
  paste0(
    "PS",
    paste(sample(c(LETTERS, 0:9), 10, replace = TRUE), collapse = ""),
    "_", as.integer(asNamespace("base")$.Internal(Sys.time()))
  )
}

format_unix_time <- function(z) {
  structure(z, class = c("POSIXct", "POSIXt"), tzone = "GMT")
}

file_size <- function(x) {
  if (getRversion() >= "3.2.0") {
    file.info(x, extra_cols = FALSE)$size
  } else {
    file.info(x)$size
  }
}

disable_crash_dialog <- function() {
  chain_call(c_processx_disable_crash_dialog)
}

has_package <- function(pkg) {
  requireNamespace(pkg, quietly = TRUE)
}

tty_echo_off <- function() {
  chain_call(c_processx__echo_off)
}

tty_echo_on <- function() {
  chain_call(c_processx__echo_on)
}

str_trim <- function(x) {
  sub("^\\s+", "", sub("\\s+$", "", x))
}

new_not_implemented_error <- function(message, call) {
  add_class(new_error(message, call. = call),
            c("not_implemented_error", "not_implemented"))
}

add_class <- function(obj, class) {
  class(obj) <- c(class, class(obj))
  obj
}

is_interactive <- function() {
  opt <- getOption("rlib_interactive")
  if (isTRUE(opt)) {
    TRUE
  } else if (identical(opt, FALSE)) {
    FALSE
  } else if (tolower(getOption("knitr.in.progress", "false")) == "true") {
    FALSE
  } else if (tolower(getOption("rstudio.notebook.executing", "false")) == "true") {
    FALSE
  } else if (identical(Sys.getenv("TESTTHAT"), "true")) {
    FALSE
  } else {
    interactive()
  }
}

make_buffer <- function() {
  con <- file(open = "w+b")
  size <- 0L
  list(
    push = function(text) {
      size <<- size + nchar(text, type = "bytes")
      cat(text, file = con)
    },
    read = function() {
      readChar(con, size, useBytes = TRUE)
    },
    done = function() {
      close(con)
    }
  )
}

update_vector <- function(x, y = NULL) {
  if (length(y) == 0L) return(x)
  c(x[!(names(x) %in% names(y))], y)
}

process_env <- function(env) {
  current <- env == "current" & names(env) == ""
  if (any(current)) env <- update_vector(Sys.getenv(), env[!current])
  enc2path(paste(names(env), sep = "=", env))
}

starts_with <- function(x, pre) {
  substr(x, 1, nchar(pre)) == pre
}

ends_with <- function(x, post) {
  l <- nchar(post)
  substr(x, nchar(x) - l + 1, nchar(x)) == post
}
