(* Copyright (C) 2004, HELM Team.
 * 
 * This file is part of HELM, an Hypertextual, Electronic
 * Library of Mathematics, developed at the Computer Science
 * Department, University of Bologna, Italy.
 * 
 * HELM 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 2
 * of the License, or (at your option) any later version.
 * 
 * HELM 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 HELM; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 * 
 * For details, see the HELM World-Wide-Web page,
 * http://helm.cs.unibo.it/
 *)

open Printf

let argc = Array.length Sys.argv

let rawsep = "###"
let sep = Pcre.regexp (sprintf "^%s" rawsep)
let msg_prefix = "*** REGTEST *** "
let print_msg s = prerr_endline (msg_prefix ^ s)

type state = Term | EMetasenv | ETerm | EType | EReduced

(* regtest file format
 *    < cic term in concrete syntax >
 *    separator (* see sep above *)
 *    < expected metasenv after disambiguation (CicMetaSubst.ppmetasenv)  >
 *    separator (* see sep above *)
 *    < expected cic term after disambiguation (CicPp.ppterm) >
 *    separator (* see sep above *)
 *    < expected cic type as per type_of (CicPp.ppterm) >
 *    separator (* see sep above *)
 *    < expected reduced cic term as (CicPp.ppterm) >
 *)

type regtest = {
  term: string; (* raw cic term *)
  emetasenv : string; (* expected metasenv *)
  eterm: string;  (* expected term *)
  etype: string;  (* expected type *)
  ereduced: string; (* expected reduced term *)
}

let print_test test fname =
  let oc = open_out fname in
  output_string oc
    (String.concat ""
      [ test.term;
        sprintf "%s (* METASENV after disambiguation  *)\n" rawsep;
        test.emetasenv;
        sprintf "%s (* TERM after disambiguation      *)\n" rawsep;
        test.eterm;
        sprintf "%s (* TYPE_OF the disambiguated term *)\n" rawsep;
        test.etype;
        sprintf "%s (* REDUCED disambiguated term     *)\n" rawsep;
        test.ereduced ]);
  close_out oc

let parse_regtest =
  let term = Buffer.create 1024 in  (* raw term *)
  let emetasenv = Buffer.create 1024 in  (* expected metasenv *)
  let eterm = Buffer.create 1024 in (* raw expected term *)
  let etype = Buffer.create 1024 in (* raw expected type *)
  let ereduced = Buffer.create 1024 in (* raw expected reducted term *)
  let state = ref Term in
  let bump_state () =
    match !state with
    | Term -> state := EMetasenv
    | EMetasenv -> state := ETerm
    | ETerm -> state := EType
    | EType -> state := EReduced
    | EReduced -> assert false
  in
  let buffer_of_state = function
    | Term ->  term | EMetasenv -> emetasenv | ETerm -> eterm | EType -> etype
    | EReduced -> ereduced
  in
  let clear_buffers () =
    List.iter Buffer.clear [ term; emetasenv; eterm; etype; ereduced ]
  in
  fun fname ->
    state := Term;
    clear_buffers ();
    let ic = open_in fname in
    (try
      while true do
        let line = input_line ic in
        match line with
        | l when Pcre.pmatch ~rex:sep l -> bump_state ()
        | l -> Buffer.add_string (buffer_of_state !state) (line ^ "\n")
      done
    with End_of_file -> ());
    { term = Buffer.contents term;
      emetasenv = Buffer.contents emetasenv;
      eterm = Buffer.contents eterm;
      etype = Buffer.contents etype;
      ereduced = Buffer.contents ereduced }

let as_expected expected found = (* ignores "term" field *)
  let outcome = ref true in
  if expected.eterm <> found.eterm then begin
    print_msg "Term mismatch";
    print_msg "  expected:";
    print_msg ("  " ^ expected.eterm);
    print_msg "  found:";
    print_msg ("  " ^ found.eterm);
    outcome := false;
  end;
  if expected.emetasenv <> found.emetasenv then begin
    print_msg "Metasenv mismatch";
    print_msg "  expected:";
    print_msg ("  " ^ expected.emetasenv);
    print_msg "  found:";
    print_msg ("  " ^ found.emetasenv);
    outcome := false;
  end;
  if expected.etype <> found.etype then begin
    print_msg "Type mismatch";
    print_msg "  expected:";
    print_msg ("  " ^ expected.etype);
    print_msg "  found:";
    print_msg ("  " ^ found.etype);
    outcome := false;
  end;
  if expected.ereduced <> found.ereduced then begin
    print_msg "Reduced term mismatch";
    print_msg "  expected:";
    print_msg ("  " ^ expected.ereduced);
    print_msg "  found:";
    print_msg ("  " ^ found.ereduced);
    outcome := false;
  end;
  !outcome

let test_this raw_term =
  let empty_context = [] in
  let (metasenv, cic_term) = BatchParser.parse raw_term in
  let etype =
   try
    CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv empty_context cic_term)
   with
    _ -> "MALFORMED"
  in
  let ereduced =
   try
    CicPp.ppterm (CicReduction.whd empty_context cic_term)
   with
    _ -> "MALFORMED"
  in
  {
    term = raw_term;  (* useless *)
    emetasenv = CicMetaSubst.ppmetasenv metasenv [] ^ "\n";
    eterm = CicPp.ppterm cic_term ^ "\n";
    etype = etype ^ "\n";
    ereduced = ereduced ^ "\n";
  }

let dump_environment filename =
  try
    let oc = open_out filename in
    CicEnvironment.dump_to_channel oc;
    close_out oc
  with exc ->
    prerr_endline
     ("DUMP_ENVIRONMENT FAILURE, uncaught excecption " ^
       Printexc.to_string exc) ;
    raise exc
;;

let restore_environment filename =
  if Sys.file_exists filename then
   begin
    try
      let ic = open_in filename in
      CicEnvironment.restore_from_channel ic;
      close_in ic
    with exc ->
      prerr_endline
       ("RESTORE_ENVIRONMENT FAILURE, uncaught excecption " ^
         Printexc.to_string exc) ;
      raise exc
   end
  else
   CicEnvironment.empty ()
;;

let main generate dump fnames =
 if generate then
  begin
   (* gen mode *)
   print_msg "[ Gen mode ]";
   List.iter
    (function fname ->
      let test_fname = fname ^ ".test" in
      let env_fname = fname ^ ".env" in
      print_msg (sprintf "Generating regtest %s -> %s\n ..."
        fname test_fname);
      let raw_term = (parse_regtest fname).term in
      let result = test_this raw_term in
      print_test result test_fname ;
      if dump then dump_environment env_fname ;
    ) fnames
  end else
   begin
    (* regtest mode *)
    print_msg "[ Regtest mode ]";
    let (ok, nok) = (ref 0, ref []) in
    List.iter
     (function fname ->
       let env_fname = fname ^ ".env" in
       let test_fname = fname ^ ".test" in
       restore_environment env_fname ;
       prerr_endline ("# " ^ fname);
       try
         let expected = parse_regtest test_fname in
         let actual = test_this expected.term in
         if dump then dump_environment env_fname ;
         if as_expected expected actual then
           incr ok
         else
           nok := fname :: !nok;
       with e -> nok := fname :: !nok
     ) fnames ;
    print_msg "Regtest completed:";
    print_msg (sprintf "Succeeded: %d" !ok);
    print_msg (sprintf "Failed: %d" (List.length !nok));
    List.iter (fun fname -> print_msg (sprintf "  %s failed :-(" fname))
      (List.rev !nok)
  end
;;

let _ =
 let fnames = ref [] in
 let gen = ref false in
 let dump = ref false in
 let nodump = ref false in
 let usage = "regtest [OPTION] ... test1 ..." in
 let spec =
   ["-gen",    Arg.Set gen, "generate the tests; implies -dump (unless -nodump is specified)" ;
    "--gen",    Arg.Set gen, "generate the tests; implies -dump (unless -nodump is specified)" ;
    "-dump",   Arg.Set dump, "dumps the final environment" ;
    "--dump",   Arg.Set dump, "dumps the final environment" ;
    "-nodump", Arg.Set dump, "do not dump the final environment" ;
    "--nodump", Arg.Set dump, "do not dump the final environment" ]
 in
  Arg.parse spec (function filename -> fnames := filename::!fnames ) usage ;
  if !fnames = [] then
   Arg.usage spec (Sys.argv.(0) ^ ": missing argument test. You must provide at least one test file.\n" ^ usage) ;
  main !gen ((!gen || !dump) && (not !nodump))  !fnames
;;