(* mclu: Mini Cloud
 * Copyright (C) 2014-2015 Red Hat Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *)

(* Miscellaneous utility functions. *)

open Scanf
open Printf

module D = Libvirt.Domain

let (//) = Filename.concat
let quote = Filename.quote

let ( +^ ) = Int64.add
let ( -^ ) = Int64.sub
let ( *^ ) = Int64.mul
let ( /^ ) = Int64.div
let ( &^ ) = Int64.logand
let ( ~^ ) = Int64.lognot

let human_size i =
  let sign, i = if i < 0L then "-", Int64.neg i else "", i in

  if i < 1024L then
    sprintf "%s%Ld" sign i
  else (
    let f = Int64.to_float i /. 1024. in
    let i = i /^ 1024L in
    if i < 1024L then
      sprintf "%s%.1fK" sign f
    else (
      let f = Int64.to_float i /. 1024. in
      let i = i /^ 1024L in
      if i < 1024L then
        sprintf "%s%.1fM" sign f
      else (
        let f = Int64.to_float i /. 1024. in
        (*let i = i /^ 1024L in*)
        sprintf "%s%.1fG" sign f
      )
    )
  )

let bytes_of_human_size s =
  try sscanf s "%Ld%[Gg]" (fun b _ -> b *^ 1024L *^ 1024L *^ 1024L)
  with Scan_failure _ ->
    try sscanf s "%Ld%[Mm]" (fun b _ -> b *^ 1024L *^ 1024L)
    with Scan_failure _ ->
      try sscanf s "%Ld%[Kk]" (fun b _ -> b *^ 1024L)
      with Scan_failure _ ->
        try sscanf s "%Ld%[Bb]" (fun b _ -> b)
        with Scan_failure _ ->
          raise Not_found

let string_of_dom_state = function
  | D.InfoNoState -> "unknown"
  | D.InfoRunning -> "running"
  | D.InfoBlocked -> "blocked"
  | D.InfoPaused -> "paused"
  | D.InfoShutdown -> "shutdown"
  | D.InfoShutoff -> "shutoff"
  | D.InfoCrashed -> "crashed"

let regexp_of_glob s =
  let len = String.length s in
  let buf = Buffer.create len in
  Buffer.add_char buf '^';
  for i = 0 to len-1 do
    match String.unsafe_get s i with
    (* Wildcard characters converted to regular expressions. *)
    | '?' -> Buffer.add_char buf '.'
    | '*' -> Buffer.add_string buf ".*"
    (* Must escape any character which is special for PCRE - see
     * pcrepattern(3).  However ignore [..] because they are
     * (approximately) the same for globs and regexps.
     *)
    | ('\\' | '^' | '$' | '.' | '|' | '(' | ')'
          | '+' | '{') as c ->
      Buffer.add_char buf '\\'; Buffer.add_char buf c
    | c -> Buffer.add_char buf c
  done;
  Buffer.add_char buf '$';
  Buffer.contents buf

let string_random8 =
  let chars = "abcdefghijklmnopqrstuvwxyz0123456789" in
  fun () ->
    String.concat "" (
      List.map (
        fun _ ->
          let c = Random.int 36 in
          let c = chars.[c] in
          String.make 1 c
      ) [1;2;3;4;5;6;7;8]
    )

let name_parse name =
  let i = try Some (String.index name ':') with Not_found -> None in
  match i with
  | None -> None, name
  | Some i ->
    Some (String.sub name 0 i),
    String.sub name (i+1) (String.length name - i - 1)