// latbin/lattice-scale.cc

// Copyright 2009-2013  Microsoft Corporation
//                      Johns Hopkins University (author: Daniel Povey)

// 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 "fstext/fstext-lib.h"
#include "lat/kaldi-lattice.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 =
        "Apply scaling to lattice weights\n"
        "Usage: lattice-scale [options] lattice-rspecifier lattice-wspecifier\n"
        " e.g.: lattice-scale --lm-scale=0.0 ark:1.lats ark:scaled.lats\n";
      
    ParseOptions po(usage);
    BaseFloat acoustic_scale = 1.0;
    BaseFloat inv_acoustic_scale = 1.0;
    BaseFloat lm_scale = 1.0;
    BaseFloat acoustic2lm_scale = 0.0;
    BaseFloat lm2acoustic_scale = 0.0;
    
    po.Register("acoustic-scale", &acoustic_scale, "Scaling factor for acoustic likelihoods");
    po.Register("inv-acoustic-scale", &inv_acoustic_scale, "An alternative way "
                "of setting the acoustic scale: you can set its inverse.");
    po.Register("lm-scale", &lm_scale, "Scaling factor for graph/lm costs");
    po.Register("acoustic2lm-scale", &acoustic2lm_scale, "Add this times original acoustic costs to LM costs");
    po.Register("lm2acoustic-scale", &lm2acoustic_scale, "Add this times original LM costs to acoustic costs");

    po.Read(argc, argv);

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

    std::string lats_rspecifier = po.GetArg(1),
        lats_wspecifier = po.GetArg(2);

    SequentialCompactLatticeReader compact_lattice_reader(lats_rspecifier);
    
    // Write as compact lattice.
    CompactLatticeWriter compact_lattice_writer(lats_wspecifier); 

    int32 n_done = 0; 

    KALDI_ASSERT(acoustic_scale == 1.0 || inv_acoustic_scale == 1.0);
    if (inv_acoustic_scale != 1.0)
      acoustic_scale = 1.0 / inv_acoustic_scale;
    
    std::vector<std::vector<double> > scale(2);
    scale[0].resize(2);
    scale[1].resize(2);
    scale[0][0] = lm_scale;
    scale[0][1] = acoustic2lm_scale;
    scale[1][0] = lm2acoustic_scale;
    scale[1][1] = acoustic_scale;
    
    for (; !compact_lattice_reader.Done(); compact_lattice_reader.Next()) {
      CompactLattice lat = compact_lattice_reader.Value();
      ScaleLattice(scale, &lat);
      compact_lattice_writer.Write(compact_lattice_reader.Key(), lat);
      n_done++;
    }
    KALDI_LOG << "Done " << n_done << " lattices.";
    return (n_done != 0 ? 0 : 1);
  } catch(const std::exception &e) {
    std::cerr << e.what();
    return -1;
  }
}