#!/bin/bash
  
  # Copyright 2014  Johns Hopkins University (Author: Daniel Povey)
  #           2016  Api.ai (Author: Ilya Platonov)
  # Apache 2.0
  
  # Begin configuration section.
  stage=0
  nj=4
  cmd=run.pl
  frames_per_chunk=20
  extra_left_context_initial=0
  min_active=200
  max_active=7000
  beam=15.0
  lattice_beam=6.0
  acwt=0.1   # note: only really affects adaptation and pruning (scoring is on
             # lattices).
  post_decode_acwt=1.0  # can be used in 'chain' systems to scale acoustics by 10 so the
                        # regular scoring script works.
  per_utt=false
  online=true  # only relevant to non-threaded decoder.
  do_endpointing=false
  do_speex_compressing=false
  scoring_opts=
  skip_scoring=false
  silence_weight=1.0  # set this to a value less than 1 (e.g. 0) to enable silence weighting.
  max_state_duration=40 # This only has an effect if you are doing silence
    # weighting.  This default is probably reasonable.  transition-ids repeated
    # more than this many times in an alignment are treated as silence.
  iter=final
  online_config=
  # End configuration section.
  
  echo "$0 $@"  # Print the command line for logging
  
  [ -f ./path.sh ] && . ./path.sh; # source the path.
  . parse_options.sh || exit 1;
  
  if [ $# != 3 ]; then
     echo "Usage: $0 [options] <graph-dir> <data-dir> <decode-dir>"
     echo "... where <decode-dir> is assumed to be a sub-directory of the directory"
     echo " where the models are, as prepared by steps/online/nnet3/prepare_online_decoding.sh"
     echo "e.g.: $0 exp/chain/tdnn/graph data/test exp/chain/tdnn_online/decode/"
     echo ""
     echo ""
     echo "main options (for others, see top of script file)"
     echo "  --config <config-file>                           # config containing options"
     echo "  --online-config <config-file>                    # online decoder options"
     echo "  --nj <nj>                                        # number of parallel jobs"
     echo "  --cmd (utils/run.pl|utils/queue.pl <queue opts>) # how to run jobs."
     echo "  --acwt <float>                                   # acoustic scale used for lattice generation "
     echo "  --per-utt <true|false>                           # If true, decode per utterance without"
     echo "                                                   # carrying forward adaptation info from previous"
     echo "                                                   # utterances of each speaker.  Default: false"
     echo "  --online <true|false>                            # Set this to false if you don't really care about"
     echo "                                                   # simulating online decoding and just want the best"
     echo "                                                   # results.  This will use all the data within each"
     echo "                                                   # utterance (plus any previous utterance, if not in"
     echo "                                                   # per-utterance mode) to estimate the iVectors."
     echo "  --scoring-opts <string>                          # options to local/score.sh"
     echo "  --iter <iter>                                    # Iteration of model to decode; default is final."
     exit 1;
  fi
  
  
  graphdir=$1
  data=$2
  dir=$3
  srcdir=`dirname $dir`; # The model directory is one level up from decoding directory.
  sdata=$data/split$nj;
  
  if [ "$online_config" == "" ]; then
    online_config=$srcdir/conf/online.conf;
  fi
  
  mkdir -p $dir/log
  [[ -d $sdata && $data/feats.scp -ot $sdata ]] || split_data.sh $data $nj || exit 1;
  echo $nj > $dir/num_jobs
  
  for f in $online_config $srcdir/${iter}.mdl \
      $graphdir/HCLG.fst $graphdir/words.txt $data/wav.scp; do
    if [ ! -f $f ]; then
      echo "$0: no such file $f"
      exit 1;
    fi
  done
  
  if ! $per_utt; then
    spk2utt_rspecifier="ark:$sdata/JOB/spk2utt"
  else
    mkdir -p $dir/per_utt
    for j in $(seq $nj); do
      awk '{print $1, $1}' <$sdata/$j/utt2spk >$dir/per_utt/utt2spk.$j || exit 1;
    done
    spk2utt_rspecifier="ark:$dir/per_utt/utt2spk.JOB"
  fi
  
  if [ -f $data/segments ]; then
    wav_rspecifier="ark,s,cs:extract-segments scp,p:$sdata/JOB/wav.scp $sdata/JOB/segments ark:- |"
  else
    wav_rspecifier="ark,s,cs:wav-copy scp,p:$sdata/JOB/wav.scp ark:- |"
  fi
  if $do_speex_compressing; then
    wav_rspecifier="$wav_rspecifier compress-uncompress-speex ark:- ark:- |"
  fi
  if $do_endpointing; then
    wav_rspecifier="$wav_rspecifier extend-wav-with-silence ark:- ark:- |"
  fi
  
  if [ "$silence_weight" != "1.0" ]; then
    silphones=$(cat $graphdir/phones/silence.csl) || exit 1
    silence_weighting_opts="--ivector-silence-weighting.max-state-duration=$max_state_duration --ivector-silence-weighting.silence_phones=$silphones --ivector-silence-weighting.silence-weight=$silence_weight"
  else
    silence_weighting_opts=
  fi
  
  
  if [ "$post_decode_acwt" == 1.0 ]; then
    lat_wspecifier="ark:|gzip -c >$dir/lat.JOB.gz"
  else
    lat_wspecifier="ark:|lattice-scale --acoustic-scale=$post_decode_acwt ark:- ark:- | gzip -c >$dir/lat.JOB.gz"
  fi
  
  
  if [ -f $srcdir/frame_subsampling_factor ]; then
    # e.g. for 'chain' systems
    frame_subsampling_opt="--frame-subsampling-factor=$(cat $srcdir/frame_subsampling_factor)"
  fi
  
  if [ $stage -le 0 ]; then
    $cmd JOB=1:$nj $dir/log/decode.JOB.log \
      online2-wav-nnet3-latgen-faster $silence_weighting_opts --do-endpointing=$do_endpointing \
      --frames-per-chunk=$frames_per_chunk \
      --extra-left-context-initial=$extra_left_context_initial \
      --online=$online \
         $frame_subsampling_opt \
       --config=$online_config \
       --min-active=$min_active --max-active=$max_active --beam=$beam --lattice-beam=$lattice_beam \
       --acoustic-scale=$acwt --word-symbol-table=$graphdir/words.txt \
       $srcdir/${iter}.mdl $graphdir/HCLG.fst $spk2utt_rspecifier "$wav_rspecifier" \
        "$lat_wspecifier" || exit 1;
  fi
  
  if ! $skip_scoring ; then
    [ ! -x local/score.sh ] && \
      echo "Not scoring because local/score.sh does not exist or not executable." && exit 1;
    local/score.sh --cmd "$cmd" $scoring_opts $data $graphdir $dir
  fi
  
  exit 0;