open BTree ;; (* Abre o modulo das �rvores *)

(* M�todo indutivo aplicado a strings. A fun��o cut "separa a cabe�a da cauda", numa string. *)
let cut s = (* pre: s <> "" *)
(String.get s 0, String.sub s 1 ((String.length s)-1))
;;
let rec split s = (* parte a string s no primeiro ' ' *)
if s = "" then ("", "") (* caso base *)
else
let (x,xs) = cut s in (* separa cabe�a da cauda *)
if x = ' ' then ("", xs) (* outro caso base *)
else let (a,b) = split xs in (* chamada recursiva para a cauda *)
((Char.escaped x)^a,b)
;;

   (* count -- Displays the number of files contained in the working file system.
    load name -- Loads a new file system and the current path is reset to [].
    show -- Displays the working file system.
    pwd -- Displays the current path, using Unix like notation. For example: /users/jose/documents/lap.
    up -- Changes the current path, moving up one level, if possible.
    down name -- Changes the current path, moving down one level to a specific sub-element, if possible.
    quit -- Exits the command-line interpreter. *)
;;
let z=Dir("root", []);;
let p=[];;

(*working file system is set to Dir("root", []) and the initial current path is set to []*)
let quit () =
exit 0
;;
let show()=
	show z;;
let load(name)=
	p=[];
	z=load name;;
let pwd()=;;
let up()=
	up p;;
let count()=countFiles z;;
let down(name)=
	down p name
	;;

let exec comm filename =
match comm with
"count" -> count()
| "load name" -> (name)
| "show" -> show ()
| "pwd" -> pwd ()
| "up" -> up ()
| "down name"-> down(name)
| "quit" -> quit ()
;;
let error mesg =
output_string stderr mesg ;
output_string stderr "!\n" ;
flush stderr
;;
let rec main ()  =
	let z=Dir("root", []);;
let p=[];;
(try
print_string "> " ;
let line = read_line () in
let (comm, fileName) = split line in
exec comm fileName
with
End_of_file -> quit ()
| Sys_error str -> error str
| _ -> error "Erro") ;
main ()
;;

main () ;; (* Esta linha faz o programa come�ar a correr aqui *)