(*
    Ocaml - proxy - media files downloader
    Copyright (C) 2009  BODIN Antoine <antoinexp@gmail.com>

    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 3 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, see <http://www.gnu.org/licenses/>.

  $ ocaml unix.cma str.cma proxy.ml
*)


open Unix
open Str


let proxy sin sout =
  let url = split_delim (regexp " ") (input_line sin) in
  let uri = "/"^
    (List.nth
       (split_delim 
	  (regexp "http://[A-Za-z0-9._-]*\\(/\\|\\)") 
	  (List.nth url 1)) 1) in
  let domain = 
    List.nth 
      (split_delim 
	 (regexp "http://\\|/.*") 
	 (List.nth url 1)) 1 in
  let cin,cout = 
    open_connection 
      (ADDR_INET (
	 (gethostbyname domain).h_addr_list.(0),
	 80)) in
  let scan sockin sockout = 
    let l = ref 0 in
      (try while true do
	 match input_line sockin with
	     "\r" -> output_string sockout "\r\n"; failwith "end"
	   | c when 
	       string_match 
		 (regexp "Content-Length: [0-9]*\r") 
		 c 0 ->
	       Scanf.sscanf c "Content-Length: %u" (fun x->l:=x);
		   output_string sockout (c^"\n")
	   | c -> output_string sockout (c^"\n")
       done with _ -> ()); !l
  in
    output_string cout ((List.nth url 0)^" "^uri^" "^(List.nth url 2)^"\n");  
    for i=1 to (scan sin cout) do output_byte cout (input_byte sin) done;
    flush cout;
    
    begin match scan cin sout with
	0 -> (try while true do output_byte sout (input_byte cin) done with _ -> ())
      | l -> 
	  match 
	    (let ty = String.make 3 ' ' in
	       match (really_input cin ty 0 3; 
		      output sout ty 0 3; ty) 
	       with 
		   "FLV" | "ID3" -> 
		     (match (Printf.printf 
			       "# %s Media of %u bytes spoted, save ? [y/n]\n" ty l; 
			     read_line ()) with
			  "y" -> ty | "n" -> "" | _ -> print_endline "# error : unbound command"; "")
		 | _ -> "")
	  with
	      "" -> for i=1 to l-3 do output_byte sout (input_byte cin) done;
	    | ty -> 
		(let file = open_out (print_endline "# File name :"; read_line ()) in
		 let percent = ref 0 in 
		   output file ty 0 3;
		   for i=1 to l-3 do 
		     let b = (input_byte cin) in
		       (match (100*((i+3)/100)/(l/100)) with
			    n when n=(!percent) -> ()
			  | n -> (percent := n;
				  Printf.printf "\r> downloading : %d %%  %u / %u" n (i+3) l;
				  flush Pervasives.stdout));
		       output_byte file b;
		       output_byte sout b;
		      done;
		   print_endline "\n# saved";
		   close_out file)
    end;
    flush sout;
    shutdown_connection cin
      


let _ = 
  let inetaddr = ADDR_INET 
    (inet_addr_any, 
     match Array.length Sys.argv with
	 2 -> int_of_string Sys.argv.(1)
       | _ -> print_endline "using default port 9999";
	   9999
    ) in establish_server proxy inetaddr