// sgmmbin/sgmm-rescore-lattice.cc

// Copyright 2009-2011   Saarland University (Author: Arnab Ghoshal)
//                       Cisco Systems (Author: Neha Agrawal)

// 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 "util/stl-utils.h"
#include "sgmm/am-sgmm.h"
#include "hmm/transition-model.h"
#include "fstext/fstext-lib.h"
#include "lat/kaldi-lattice.h"
#include "lat/lattice-functions.h"
#include "sgmm/decodable-am-sgmm.h"

int main(int argc, char *argv[]) {
  try {
    using namespace kaldi;
    typedef kaldi::int32 int32;
    typedef kaldi::int64 int64;
    using fst::SymbolTable;
    using fst::VectorFst;
    using fst::StdArc;

    const char *usage =
        "Replace the acoustic scores on a lattice using a new model.\n"
        "Usage: sgmm-rescore-lattice [options] <model-in> <lattice-rspecifier> "
        "<feature-rspecifier> <lattice-wspecifier>\n"
        " e.g.: sgmm-rescore-lattice 1.mdl ark:1.lats scp:trn.scp ark:2.lats\n";

    kaldi::BaseFloat old_acoustic_scale = 0.0;
    bool speedup = false;    
    BaseFloat log_prune = 5.0;
    std::string gselect_rspecifier, spkvecs_rspecifier, utt2spk_rspecifier;
    SgmmGselectConfig sgmm_opts;
    kaldi::ParseOptions po(usage);
    po.Register("old-acoustic-scale", &old_acoustic_scale,
                "Add the current acoustic scores with some scale.");
    po.Register("log-prune", &log_prune,
                "Pruning beam used to reduce number of exp() evaluations.");
    po.Register("spk-vecs", &spkvecs_rspecifier, "Speaker vectors (rspecifier)");
    po.Register("utt2spk", &utt2spk_rspecifier,
                "rspecifier for utterance to speaker map");
    po.Register("gselect", &gselect_rspecifier,
                "Precomputed Gaussian indices (rspecifier)");
    po.Register("speedup", &speedup,
                "If true, enable a faster version of the computation that "
                "saves times when there is only one pdf-id on a single frame "
                "by only sometimes (randomly) computing the probabilities, and "
                "then scaling them up to preserve corpus-level diagnostics.");
    
    sgmm_opts.Register(&po);

    po.Read(argc, argv);

    if (po.NumArgs() != 4) {
      po.PrintUsage();
      exit(1);
    }

    std::string model_filename = po.GetArg(1),
        lats_rspecifier = po.GetArg(2),
        feature_rspecifier = po.GetArg(3),
        lats_wspecifier = po.GetArg(4);

    AmSgmm am_sgmm;
    TransitionModel trans_model;
    {
      bool binary;
      Input ki(model_filename, &binary);
      trans_model.Read(ki.Stream(), binary);
      am_sgmm.Read(ki.Stream(), binary);
    }

    RandomAccessInt32VectorVectorReader gselect_reader(gselect_rspecifier);
    RandomAccessBaseFloatVectorReaderMapped spkvecs_reader(spkvecs_rspecifier,
                                                           utt2spk_rspecifier);
    RandomAccessBaseFloatMatrixReader feature_reader(feature_rspecifier);
    // Read as regular lattice
    SequentialCompactLatticeReader compact_lattice_reader(lats_rspecifier);
    // Write as compact lattice.
    CompactLatticeWriter compact_lattice_writer(lats_wspecifier);

    int32 num_done = 0, num_err = 0;
    for (; !compact_lattice_reader.Done(); compact_lattice_reader.Next()) {
      std::string utt = compact_lattice_reader.Key();
      if (!feature_reader.HasKey(utt)) {
        KALDI_WARN << "No feature found for utterance " << utt << ". Skipping";
        num_err++;
        continue;
      }

      CompactLattice clat = compact_lattice_reader.Value();
      compact_lattice_reader.FreeCurrent();
      if (old_acoustic_scale != 1.0)
        fst::ScaleLattice(fst::AcousticLatticeScale(old_acoustic_scale), &clat);

      const Matrix<BaseFloat> &feats = feature_reader.Value(utt);

      // Get speaker vectors
      SgmmPerSpkDerivedVars spk_vars;
      if (spkvecs_reader.IsOpen()) {
        if (spkvecs_reader.HasKey(utt)) {
          spk_vars.v_s = spkvecs_reader.Value(utt);
          am_sgmm.ComputePerSpkDerivedVars(&spk_vars);
        } else {
          KALDI_WARN << "Cannot find speaker vector for " << utt;
          num_err++;
          continue;
        }
      }  // else spk_vars is "empty"

      bool have_gselect  = !gselect_rspecifier.empty()
          && gselect_reader.HasKey(utt)
          && gselect_reader.Value(utt).size() == feats.NumRows();
      if (!gselect_rspecifier.empty() && !have_gselect)
        KALDI_WARN << "No Gaussian-selection info available for utterance "
                   << utt << " (or wrong size)";
      std::vector<std::vector<int32> > empty_gselect;
      const std::vector<std::vector<int32> > *gselect =
          (have_gselect ? &gselect_reader.Value(utt) : &empty_gselect);

      DecodableAmSgmm sgmm_decodable(sgmm_opts, am_sgmm, spk_vars,
                                     trans_model, feats, *gselect,
                                     log_prune);

      if (!speedup) {
        if (kaldi::RescoreCompactLattice(&sgmm_decodable, &clat)) {
          compact_lattice_writer.Write(utt, clat);
          num_done++;
        } else num_err++;
      } else {
        BaseFloat speedup_factor = 100.0; 
        if (kaldi::RescoreCompactLatticeSpeedup(trans_model, speedup_factor,
                                                &sgmm_decodable,
                                                &clat)) {
          compact_lattice_writer.Write(utt, clat);
          num_done++;
        } else num_err++;
      }        
    }

    KALDI_LOG << "Done " << num_done << " lattices, errors on "
              << num_err;
    return (num_done != 0 ? 0 : 1);
  } catch(const std::exception &e) {
    std::cerr << e.what();
    return -1;
  }
}