(***********************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team    *)
(* <O___,, *        INRIA-Rocquencourt  &  LRI-CNRS-Orsay              *)
(*   \VV/  *************************************************************)
(*    //   *      This file is distributed under the terms of the      *)
(*         *       GNU Lesser General Public License Version 2.1       *)
(***********************************************************************)

(* $Id$ *)

(* Parsing of vernacular. *)

open Pp
open Lexer
open Util
open Options
open System
open Coqast
open Vernacexpr
open Vernacinterp
open Ppvernacnew

(* The functions in this module may raise (unexplainable!) exceptions.
   Use the module Coqtoplevel, which catches these exceptions
   (the exceptions are explained only at the toplevel). *)

exception DuringCommandInterp of Util.loc * exn

(* Like Exc_located, but specifies the outermost file read, the filename
   associated to the location of the error, and the error itself. *)

exception Error_in_file of string * (string * Util.loc) * exn

(* Specifies which file is read. The intermediate file names are
   discarded here. The Drop exception becomes an error. We forget
   if the error ocurred during interpretation or not *)

let raise_with_file file exc =
  let (cmdloc,re) =
    match exc with
      | DuringCommandInterp(loc,e) -> (loc,e)
      | e -> (dummy_loc,e) 
  in
  let (inner,inex) =
    match re with
      | Error_in_file (_, (f,loc), e) when loc <> dummy_loc ->
          ((f, loc), e)
      | Stdpp.Exc_located (loc, e) when loc <> dummy_loc ->
          ((file, loc), e)
      | _ -> ((file,cmdloc), re)
  in 
  raise (Error_in_file (file, inner, disable_drop inex))

let real_error = function
  | Stdpp.Exc_located (_, e) -> e
  | Error_in_file (_, _, e) -> e
  | e -> e

(* Opening and closing a channel. Open it twice when verbose: the first
   channel is used to read the commands, and the second one to print them.
   Note: we could use only one thanks to seek_in, but seeking on and on in
   the file we parse seems a bit risky to me.  B.B.  *)

let open_file_twice_if verbosely fname =
  let _,longfname = find_file_in_path (Library.get_load_path ()) fname in
  let in_chan = open_in longfname in
  let verb_ch = if verbosely then Some (open_in longfname) else None in
  let po = Pcoq.Gram.parsable (Stream.of_channel in_chan) in
  (in_chan, longfname, (po, verb_ch))

let close_input in_chan (_,verb) =
  try 
    close_in in_chan;
    match verb with
      | Some verb_ch -> close_in verb_ch
      | _ -> ()
  with _ -> ()

let verbose_phrase verbch loc =
  match verbch with
    | Some ch ->
	let len = snd loc - fst loc in
	let s = String.create len in
        seek_in ch (fst loc);
        really_input ch s 0 len;
        message s;
        pp_flush()
    | _ -> ()

exception End_of_input
  
let parse_phrase (po, verbch) =
  match Pcoq.Gram.Entry.parse Pcoq.main_entry po with
    | Some (loc,_ as com) -> verbose_phrase verbch loc; com
    | None -> raise End_of_input

(* vernac parses the given stream, executes interpfun on the syntax tree it
 * parses, and is verbose on "primitives" commands if verbosely is true *)

let just_parsing = ref false
let chan_translate = ref stdout

let pr_comments = function
  | None -> mt()
  | Some l -> h 0 (List.fold_left (++) (mt ()) (List.rev l))

let rec vernac_com interpfun (loc,com) =
  let rec interp = function
    | VernacLoad (verbosely, fname) ->
        read_vernac_file verbosely (make_suffix fname ".v")

    | VernacList l -> List.iter (fun (_,v) -> interp v) l

    | VernacTime v ->
	let tstart = System.get_time() in
        if not !just_parsing then interpfun v;
	let tend = System.get_time() in
        msgnl (str"Finished transaction in " ++
                 System.fmt_time_difference tstart tend)

    (* To be interpreted in v7 or translator input only *)
    | VernacV7only v ->
        if !Options.v7 || Options.do_translate() then interp v

    (* To be interpreted in translator output only *)
    | VernacV8only v -> 
        if not !Options.v7 && not (do_translate()) then
          interp v

    | v -> if not !just_parsing then interpfun v

  in 
  try
    Options.v7_only := false;
    if do_translate () then
      (Format.set_formatter_out_channel !chan_translate;
       Format.set_max_boxes max_int;
       (match com with
         | VernacV7only _ ->
             Options.v7_only := true;
             if !translate_file then msgnl (pr_comments !comments)
         | _ ->
	     let f = match com with (* Pour gérer les implicites *)
	       | VernacInductive _ -> States.with_heavy_rollback
	       | _ -> fun f -> f in
             if !translate_file then
               msgnl
		 (pr_comments !comments ++ hov 0 (f pr_vernac com) ++ sep_end)
             else
	       msgnl
                 (hov 4 (str"New Syntax:" ++ fnl() ++ pr_comments !comments ++
                         f pr_vernac com ++ sep_end)));
       comments := None;
       Format.set_formatter_out_channel stdout);
    interp com;
  with e -> 
    Format.set_formatter_out_channel stdout;
    raise (DuringCommandInterp (loc, e))

and vernac interpfun input =
  vernac_com interpfun (parse_phrase input)

and read_vernac_file verbosely s =
  let interpfun =
    if verbosely then 
      Vernacentries.interp
    else 
      Options.silently Vernacentries.interp 
  in
  let (in_chan, fname, input) = open_file_twice_if verbosely s in
  try
    (* we go out of the following infinite loop when a End_of_input is
     * raised, which means that we raised the end of the file being loaded *)
    while true do vernac interpfun input; pp_flush () done
  with e ->   (* whatever the exception *)
    Format.set_formatter_out_channel stdout;
    close_input in_chan input;    (* we must close the file first *)
    match real_error e with
      | End_of_input -> ()
      | _ -> raise_with_file fname e

(* raw_do_vernac : char Stream.t -> unit
 * parses and executes one command of the vernacular char stream.
 * Marks the end of the command in the lib_stk to make vernac undoing
 * easier. *)

let raw_do_vernac po =
  vernac (States.with_heavy_rollback Vernacentries.interp) (po,None);
  Lib.mark_end_of_command()

(* Load a vernac file. Errors are annotated with file and location *)
let load_vernac verb file =
  try 
    read_vernac_file verb file
  with e -> 
    raise_with_file file e

(* Compile a vernac file (f is assumed without .v suffix) *)
let compile verbosely f =
(*
    let s = Filename.basename f in
    let m = Names.id_of_string s in
    let _,longf = find_file_in_path (Library.get_load_path ()) (f^".v") in
    let ldir0 = Library.find_logical_path (Filename.dirname longf) in
    let ldir = Libnames.extend_dirpath ldir0 m in
    Termops.set_module ldir; (* Just for universe naming *)
    Lib.start_module ldir;
    if !dump then dump_string ("F" ^ Names.string_of_dirpath ldir ^ "\n");
    let _ = load_vernac verbosely longf in
    let mid = Lib.end_module m in
    assert (mid = ldir);
    Library.save_module_to ldir (longf^"o")
*)
  let ldir,long_f_dot_v = Library.start_library f in
  if !dump then dump_string ("F" ^ Names.string_of_dirpath ldir ^ "\n");
  chan_translate :=
    if Options.do_translate () then open_out (f^".v8") else stdout;
  let _ = load_vernac verbosely long_f_dot_v in
  let _ = close_out !chan_translate in
  if Pfedit.get_all_proof_names () <> [] then
    (message "Error: There are pending proofs"; exit 1);
  Library.save_library_to ldir (long_f_dot_v ^ "o")