// fstbin/fstdeterminizestar.cc

// Copyright 2009-2011  Microsoft Corporation

// See ../../COPYING for clarification regarding multiple authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
// THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
// WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
// MERCHANTABLITY OR NON-INFRINGEMENT.
// See the Apache 2 License for the specific language governing permissions and
// limitations under the License.


#include "base/kaldi-common.h"
#include "util/common-utils.h"
#include "fst/fstlib.h"
#include "fstext/determinize-star.h"
#include "fstext/fstext-utils.h"
#include "fstext/kaldi-fst-io.h"
#if !defined(_MSC_VER) && !defined(__APPLE__)
#include <signal.h> // Comment this line and the call to signal below if
// it causes compilation problems.  It is only to enable a debugging procedure
// when determinization does not terminate.  We are disabling this code if
// compiling on Windows because signal.h is not available there, and on
// MacOS due to a problem with <signal.h> in the initial release of Sierra.
#endif

/* some test  examples:
 ( echo "0 0 0 0"; echo "0 0" ) | fstcompile | fstdeterminizestar | fstprint
 ( echo "0 0 1 0"; echo "0 0" ) | fstcompile | fstdeterminizestar | fstprint
 ( echo "0 0 1 0"; echo "0 1 1 0"; echo "0 0" ) | fstcompile | fstdeterminizestar | fstprint
 # this last one fails [correctly]:
 ( echo "0 0 0 1"; echo "0 0" ) | fstcompile | fstdeterminizestar | fstprint

  cd ~/tmpdir
  while true; do
    fstrand > 1.fst
    fstpredeterminize out.lst 1.fst | fstdeterminizestar | fstrmsymbols out.lst > 2.fst
    fstequivalent --random=true 1.fst 2.fst || echo "Test failed"
    echo -n "."
  done

 Test of debugging [with non-determinizable input]:
 ( echo " 0 0 1 0 1.0"; echo "0 1 1 0"; echo "1 1 1 0 0"; echo "0 2 2 0"; echo "2"; echo "1" ) | fstcompile | fstdeterminizestar
  kill -SIGUSR1 [the process-id of fstdeterminizestar]
  # prints out a bunch of debugging output showing the mess it got itself into.
*/


bool debug_location = false;
void signal_handler(int) {
  debug_location = true;
}



int main(int argc, char *argv[]) {
  try {
    using namespace kaldi;
    using namespace fst;
    using kaldi::int32;

    const char *usage =
        "Removes epsilons and determinizes in one step\n"
        "\n"
        "Usage:  fstdeterminizestar [in.fst [out.fst] ]\n"
        "\n"
        "See also: fstdeterminizelog, lattice-determinize\n";

    float delta = kDelta;
    int max_states = -1;
    bool use_log = false;
    ParseOptions po(usage);
    po.Register("use-log", &use_log, "Determinize in log semiring.");
    po.Register("delta", &delta, "Delta value used to determine equivalence of weights.");
    po.Register("max-states", &max_states, "Maximum number of states in determinized FST before it will abort.");
    po.Read(argc, argv);

    if (po.NumArgs() > 2) {
      po.PrintUsage();
      exit(1);
    }

    std::string fst_in_str = po.GetOptArg(1),
        fst_out_str = po.GetOptArg(2);

    // This enables us to get traceback info from determinization that is
    // not seeming to terminate.
#if !defined(_MSC_VER) && !defined(__APPLE__)
    signal(SIGUSR1, signal_handler);
#endif
    if (ClassifyRspecifier(fst_in_str, NULL, NULL) == kNoRspecifier) {
      // Normal case: just files.
      VectorFst<StdArc> *fst = ReadFstKaldi(fst_in_str);

      ArcSort(fst, ILabelCompare<StdArc>());  // improves speed.
      if (use_log) {
        DeterminizeStarInLog(fst, delta, &debug_location, max_states);
      } else {
        VectorFst<StdArc> det_fst;
        DeterminizeStar(*fst, &det_fst, delta, &debug_location, max_states);
        *fst = det_fst;  // will do shallow copy and then det_fst goes
        // out of scope anyway.
      }
      WriteFstKaldi(*fst, fst_out_str);
      delete fst;
    } else { // Dealing with archives.
      SequentialTableReader<VectorFstHolder> fst_reader(fst_in_str);
      TableWriter<VectorFstHolder> fst_writer(fst_out_str);
      for (; !fst_reader.Done(); fst_reader.Next()) {
        std::string key = fst_reader.Key();
        VectorFst<StdArc> fst(fst_reader.Value());
        fst_reader.FreeCurrent();
        ArcSort(&fst, ILabelCompare<StdArc>()); // improves speed.
        try {
          if (use_log) {
            DeterminizeStarInLog(&fst, delta, &debug_location, max_states);
          } else {
            VectorFst<StdArc> det_fst;
            DeterminizeStar(fst, &det_fst, delta, &debug_location, max_states);
            fst = det_fst;  // will do shallow copy and then det_fst goes out
            // of scope anyway.
          }
          fst_writer.Write(key, fst);
        } catch (const std::runtime_error e) {
          KALDI_WARN << "Error during determinization for key " << key;
        }
      }
    }
    return 0;
  } catch(const std::exception &e) {
    std::cerr << e.what();
    return -1;
  }
}