open Location
exception Usage

let () =
  List.iter 
    (fun (n,t) -> Typer.register_global_types [n, mk noloc (Ast.Internal t)])
    Builtin.types


let (source,input_channel) = 
  match Array.length Sys.argv with
    | 1 -> ("",stdin)
    | 2 -> let s = Sys.argv.(1) in (s, open_in s)
    | _ -> raise Usage

let input = Stream.of_channel input_channel

let ppf = Format.std_formatter
let prog () = 
  try Parser.prog input
  with
    | Stdpp.Exc_located (loc, e) -> raise (Location (loc, e))

let rec print_exn ppf = function
  | Location ((i,j), exn) ->
      if source = "" then
	Format.fprintf ppf "Error at chars %i-%i@\n" i j
      else (
	let (l1,c1) = Location.get_line_number source i
	and (l2,c2) = Location.get_line_number source j in
	if l1 = l2 then
	  Format.fprintf ppf "Error at line %i (chars %i-%i)@\n"
	    l1 c1 c2
	else
	  Format.fprintf ppf "Error at lines %i (char %i) - %i (char %i)@\n"
	    l1 c1 l2 c2
      );
      print_exn ppf exn
  | Typer.WrongLabel (t,l) ->
      Format.fprintf ppf "Wrong record selection: the label %s@\n" 
        (Types.label_name l);
(*      Format.fprintf ppf "applied to an expression of type %a@\n"
        (Types.Print.print_descr t)  *)
  | Typer.ShouldHave (t,msg) ->
      Format.fprintf ppf "This expression should have type %a@\n%s@\n" 
        Types.Print.print_descr t
      msg
  | Typer.Constraint (s,t,msg) ->
      Format.fprintf ppf "This expression should have type %a@\n" 
        Types.Print.print_descr t;
      Format.fprintf ppf "but its infered type is: %a@\n" 
        Types.Print.print_descr s;
      Format.fprintf ppf "which is not a subtype, as shown by the value %a@\n" 
	Types.Print.print_sample (Types.Sample.get (Types.diff s t));
      Format.fprintf ppf "%s@\n" msg
  | Typer.NonExhaustive t ->
      Format.fprintf ppf "This pattern matching is not exhaustive@\n";
      Format.fprintf ppf "Residual type: %a@\n"
	Types.Print.print_descr t;
      Format.fprintf ppf "Sample value: %a@\n" 
	Types.Print.print_sample (Types.Sample.get t)
  | exn ->
      Format.fprintf ppf "%s@\n" (Printexc.to_string exn)

let phrase ph =
  match ph.descr with
    | Ast.EvalStatement e ->
	let (fv,e) = Typer.expr e in
	let t = Typer.type_check Typer.Env.empty e Types.any true in
	Format.fprintf ppf "%a@\n" Types.Print.print_descr t
    | Ast.TypeDecl _ -> ()
    | _ -> assert false

let () = 
  try 
    let p = prog () in
    let type_decls = 
      List.fold_left
	(fun accu ph -> match ph.descr with
	   | Ast.TypeDecl (x,t) -> (x,t) :: accu
	   | _ -> accu
	) [] p in
    Typer.register_global_types type_decls;
    List.iter phrase p
  with  (Failure _) as e -> raise e
       | exn -> print_exn ppf exn