open Location
open Ident

let quiet = ref false
let toplevel = ref false

let typing_env = State.ref "Cduce.typing_env" Env.empty

let eval_env = State.ref "Cduce.eval_env" Env.empty

let enter_global_value x v t =
  eval_env := Env.add x v !eval_env;
  typing_env := Env.add x t !typing_env

let rec is_abstraction = function
  | Ast.Abstraction _ -> true
  | Ast.LocatedExpr (_,e) -> is_abstraction e
  | _ -> false

let print_norm ppf d = 
  Location.protect ppf 
    (fun ppf -> Types.Print.print ppf ((*Types.normalize*) d))

let print_sample ppf s =
  Location.protect ppf
    (fun ppf -> Sample.print ppf s)


let print_value ppf v =
  Location.protect ppf (fun ppf -> Value.print ppf v)

let dump_env ppf =
  Format.fprintf ppf "Global types:";
  Typer.dump_global_types ppf;
  Format.fprintf ppf ".@.";
  Env.iter 
    (fun x v ->
       let t = Env.find x !typing_env in
       Format.fprintf ppf "@[val %a : @[%a = %a@]@]@."
	 U.print (Id.value x) print_norm t print_value v
    )
    !eval_env;
  Format.fprintf ppf "Namespaces:@.";
  Atoms.Ns.dump_prefix_table ppf


let rec print_exn ppf = function
  | Location (loc, w, exn) ->
      Format.fprintf ppf "Error %a:@." Location.print_loc (loc,w);
      Format.fprintf ppf "%a" Location.html_hilight (loc,w);
      print_exn ppf exn
  | Value.CDuceExn v ->
      Format.fprintf ppf "Uncaught CDuce exception: @[%a@]@."
        print_value v
  | Eval.MultipleDeclaration v ->
      Format.fprintf ppf "Multiple declaration for global value %a@." 
        U.print (Id.value v)
  | Typer.WrongLabel (t,l) ->
      Format.fprintf ppf "Wrong record selection; field %a " 
        U.print (LabelPool.value l);
      Format.fprintf ppf "not present in an expression of type:@.%a@."
        print_norm t
  | Typer.ShouldHave (t,msg) ->
      Format.fprintf ppf "This expression should have type:@.%a@.%s@." 
        print_norm t
        msg
  | Typer.ShouldHave2 (t1,msg,t2) ->
      Format.fprintf ppf "This expression should have type:@.%a@.%s %a@." 
        print_norm t1
        msg
        print_norm t2
  | Typer.Error s ->
      Format.fprintf ppf "%s@." s
  | Typer.Constraint (s,t) ->
      Format.fprintf ppf "This expression should have type:@.%a@." 
        print_norm t;
      Format.fprintf ppf "but its inferred type is:@.%a@." 
        print_norm s;
      Format.fprintf ppf "which is not a subtype, as shown by the sample:@.%a@." 
	print_sample (Sample.get (Types.diff s t))
  | Typer.NonExhaustive t ->
      Format.fprintf ppf "This pattern matching is not exhaustive@.";
      Format.fprintf ppf "Residual type:@.%a@."
	print_norm t;
      Format.fprintf ppf "Sample:@.%a@." print_sample (Sample.get t)
  | Typer.UnboundId x ->
      Format.fprintf ppf "Unbound identifier %a@." U.print (Id.value x)
  | Wlexer.Illegal_character c ->
      Format.fprintf ppf "Illegal character (%s)@." (Char.escaped c)
  | Wlexer.Unterminated_comment ->
      Format.fprintf ppf "Comment not terminated@."
  | Wlexer.Unterminated_string ->
      Format.fprintf ppf "String literal not terminated@."
  | Wlexer.Unterminated_string_in_comment ->
      Format.fprintf ppf "This comment contains an unterminated string literal@."
  | Parser.Error s | Stream.Error s -> 
      Format.fprintf ppf "Parsing error: %s@." s
  | Location.Generic s ->
      Format.fprintf ppf "%s@." s
  | exn ->
(*      raise exn *)
      Format.fprintf ppf "%s@." (Printexc.to_string exn)

let debug ppf = function
  | `Subtype (t1,t2) ->
      Format.fprintf ppf "[DEBUG:subtype]@.";
      let t1 = Types.descr (Typer.typ t1)
      and t2 = Types.descr (Typer.typ t2) in
      Format.fprintf ppf "%a <= %a : %b@." print_norm t1 print_norm t2
	(Types.subtype t1 t2)
  | `Sample t ->
      Format.fprintf ppf "[DEBUG:sample]@.";
      (try
	 let t = Types.descr (Typer.typ t) in
	 Format.fprintf ppf "%a@." print_sample (Sample.get t)
       with Not_found ->
	 Format.fprintf ppf "Empty type : no sample !@.")
  | `Filter (t,p) -> 
      Format.fprintf ppf "[DEBUG:filter]@.";
      let t = Typer.typ t
      and p = Typer.pat p in
      let f = Patterns.filter (Types.descr t) p in
      List.iter (fun (x,t) ->
		   Format.fprintf ppf " %a:%a@." U.print (Id.value x)
		     print_norm (Types.descr t)) f
  | `Accept p ->
      Format.fprintf ppf "[DEBUG:accept]@.";
      let p = Typer.pat p in
      let t = Patterns.accept p in
      Format.fprintf ppf " %a@." Types.Print.print (Types.descr t)
  | `Compile (t,pl) ->
      Format.fprintf ppf "[DEBUG:compile]@.";
      let t = Typer.typ t
      and pl = List.map Typer.pat pl in
      Patterns.Compile.debug_compile ppf t pl

let insert_bindings ppf =
  List.iter2 
    (fun (x,t) (y,v) ->
       assert (x = y);
       typing_env := Env.add x t !typing_env;
       eval_env := Env.add x v !eval_env;
       if not !quiet then
	 Format.fprintf ppf "val %a : @[@[%a@] =@ @[%a@]@]@." 
	   U.print (Id.value x) print_norm t print_value v)
  
let rec collect_funs ppf accu = function
  | { descr = Ast.FunDecl e } :: rest -> 
      let (_,e) = Typer.expr e in
      collect_funs ppf (e::accu) rest
  | rest ->
      let typs = Typer.type_rec_funs !typing_env accu in
      Typer.report_unused_branches ();
      let vals = Eval.eval_rec_funs !eval_env accu in
      insert_bindings ppf typs vals;
      rest

let rec collect_types ppf accu = function
  | { descr = Ast.TypeDecl (x,t) } :: rest -> 
      collect_types ppf ((x,t) :: accu) rest
  | rest ->
      Typer.register_global_types accu;
      rest

let rec phrases ppf phs = match phs with
  | { descr = Ast.FunDecl _ } :: _ -> 
      phrases ppf (collect_funs ppf [] phs)
  | { descr = Ast.TypeDecl (_,_) } :: _ ->
      phrases ppf (collect_types ppf [] phs)
  | { descr = Ast.SchemaDecl (name, schema) } :: rest ->
      Typer.register_schema name schema;
      phrases ppf rest
  | { descr = Ast.Namespace (pr,ns) } :: rest ->
      Typer.register_ns_prefix pr ns;
      phrases ppf rest
  | { descr = Ast.EvalStatement e } :: rest ->
      let (fv,e) = Typer.expr e in
      let t = Typer.type_check !typing_env e Types.any true in
      Typer.report_unused_branches ();
      if not !quiet then
	Location.dump_loc ppf (e.Typed.exp_loc,`Full);
      let v = Eval.eval !eval_env e in
      if not !quiet then
	Format.fprintf ppf "- : @[@[%a@] =@ @[%a@]@]@." print_norm t print_value v;
      phrases ppf rest
  | { descr = Ast.LetDecl (p,e) } :: rest ->
      let decl = Typer.let_decl p e in
      let typs = Typer.type_let_decl !typing_env decl in
      Typer.report_unused_branches ();
      let vals = Eval.eval_let_decl !eval_env decl in
      insert_bindings ppf typs vals;
      phrases ppf rest
  | { descr = Ast.Debug l } :: rest -> 
      debug ppf l;
      phrases ppf rest
  | { descr = Ast.Directive `Quit } :: rest ->
      if !toplevel then raise End_of_file;
      phrases ppf rest
  | { descr = Ast.Directive `Env } :: rest ->
      dump_env ppf;
      phrases ppf rest
  | [] -> ()

let run rule ppf ppf_err input =
  try 
    let p = 
      try rule input
      with
	| Stdpp.Exc_located (_, (Location _ as e)) ->
	    Parser.sync (); raise e
	| Stdpp.Exc_located ((i,j), e) -> 
	    Parser.sync (); raise_loc i j e
    in
    phrases ppf p;
    true
  with 
    | (End_of_file | Failure _ | Not_found | Invalid_argument _ | Sys.Break) 
	as e -> 
	raise e
    | exn -> 
	print_exn ppf_err exn;
	Format.fprintf ppf_err "@.";
	false

let script = run Parser.prog
let topinput = run Parser.top_phrases