(************************************************************
   ftp.ml		Created      : Thu Oct  2 00:26:01 2003
  			Last modified: Tue Oct 07 13:36:41 2003
  Compile: ocamlc -g unix.cma str.cma mytcp.ml ftp.ml -o ftp #
  FTP Directory: sources/ocaml #
************************************************************)
(**

  @author Takashi Masuyama <mamewo@dk9.so-net.ne.jp>

ftp://ftp.turbolinux.co.jp/pub/TurboLinux/stable/tested/Workstation/7/i586

  サーバーからの返答は 数字,スペースまたは-,メッセージ  からなる。
   数字のあとが - のときは返答が複数行にわたることを意味する。
   メッセージは同じ数字から始まり、数字のあとがスペースで
  ある行で終る
*)

open Mytcp

let hostname = "ftp.turbolinux.co.jp"
let dir = "/pub/TurboLinux/stable/tested/Workstation/7/i586"
let port = 21
let ack_regexp = Str.regexp ".*logged in."
let passive_regexp = Str.regexp "\\([0-9]+\\),\\([0-9]+\\),\\([0-9]+\\),\\([0-9]+\\),\\([0-9]+\\),\\([0-9]+\\)"


let end_line_regexp = Str.regexp "^[0-9]+ "

let receive_ftp_message socket =
  let rec iter m = 
    let line = receive_one_line socket in
    if Str.string_match end_line_regexp line 0 then
      m^line
    else
      iter (m^line) in
  iter ""
;;
	
let login ~user ~password ~cmdsocket =
  let user_message = "USER " ^ user ^ "\r\n" in
  let password_message = "PASS " ^ password ^ "\r\n" in
  begin
    ignore (receive_ftp_message cmdsocket);
    ignore (send_string cmdsocket user_message);
    ignore (receive_ftp_message cmdsocket);
    ignore (send_string cmdsocket password_message);
    let ack = receive_ftp_message cmdsocket in
    Str.string_match ack_regexp ack 0
  end
;;

open Unix

let get_passive_connection ~cmdsocket =
  begin
    ignore (send_string cmdsocket "PASV\n\r");
    let target = receive_one_line cmdsocket in
    ignore (Str.search_forward passive_regexp target 0);
    let ipstr = (Str.matched_group 1 target)^"."^(Str.matched_group 2 target)
     ^"."^(Str.matched_group 3 target)^"."^(Str.matched_group 4 target) in
    let fst = Str.matched_group 5 target in
    let snd = Str.matched_group 6 target in
    let port = ((int_of_string fst) * 256) + (int_of_string snd) in
    let addr = inet_addr_of_string ipstr in
    try 
      let resultsock = Unix.socket PF_INET SOCK_STREAM 0 in
      Unix.connect resultsock (ADDR_INET(addr, port));
      resultsock
    with
      Unix.Unix_error (m, _, _) ->
	print_endline (Unix.error_message m); exit 1
  end
;;

let list_passive ~directory ~cmdsocket =
  let datasocket = get_passive_connection cmdsocket in
  ignore (send_string cmdsocket ("LIST "^directory^"\r\n"));
  receive_all datasocket
;;  

let quit ~cmdsocket =
  ignore (send_string cmdsocket "QUIT\r\n")
;;

(*let _ = *)
(*  let user = "anonymous" in*)
(*  let password = "mamewo@dk9.so-net.ne.jp" in*)
(*  let cmdsocket = Mytcp.connect hostname port in*)
(*  begin*)
(*    ignore (login ~user ~password ~cmdsocket);*)
(*    print_endline (list_passive ~directory:dir ~cmdsocket)*)
(*(*    else*)*)
(*(*      print_endline "failed"*)*)
(*  end*)