#!/bin/bash
  
  # Copyright 2014  Guoguo Chen, 2015 GoVivace Inc. (Nagendra Goel)
  #           2017  Vimal Manohar
  # Apache 2.0
  
  # This script is similar to steps/cleanup/decode_segmentation.sh, but 
  # does decoding using nnet3 model.
  
  set -e
  set -o pipefail
  
  # Begin configuration section.
  stage=-1
  nj=4 # number of decoding jobs.
  acwt=0.1  # Just a default value, used for adaptation and beam-pruning..
  post_decode_acwt=1.0  # can be used in 'chain' systems to scale acoustics by 10 so the
                        # regular scoring script works.
  cmd=run.pl
  beam=15.0
  frames_per_chunk=50
  max_active=7000
  min_active=200
  ivector_scale=1.0
  lattice_beam=8.0  # Beam we use in lattice generation. We can reduce this if 
                    # we only need the best path
  iter=final
  num_threads=1 # if >1, will use gmm-latgen-faster-parallel
  scoring_opts=
  skip_scoring=false
  allow_partial=true
  extra_left_context=0
  extra_right_context=0
  extra_left_context_initial=-1
  extra_right_context_final=-1
  online_ivector_dir=
  minimize=false
  # End configuration section.
  
  echo "$0 $@"  # Print the command line for logging
  
  [ -f ./path.sh ] && . ./path.sh; # source the path.
  . utils/parse_options.sh || exit 1;
  
  if [ $# -ne 3 ]; then
     echo "$0: This is a special decoding script for segmentation where we"
     echo "use one decoding graph per segment. We assume a file HCLG.fsts.scp exists"
     echo "which is the scp file of the graphs for each segment."
     echo "This will normally be obtained by steps/cleanup/make_biased_lm_graphs.sh."
     echo ""
     echo "Usage: $0 [options] <graph-dir> <data-dir> <decode-dir>"
     echo " e.g.: $0 --online-ivector-dir exp/nnet3/ivectors_train_si284_split "
     echo "             exp/nnet3/tdnn/graph_train_si284_split \\"
     echo "             data/train_si284_split exp/nnet3/tdnn/decode_train_si284_split"
     echo ""
     echo "where <decode-dir> is assumed to be a sub-directory of the directory"
     echo "where the model is."
     echo ""
     echo "main options (for others, see top of script file)"
     echo "  --config <config-file>                           # config containing options"
     echo "  --nj <nj>                                        # number of parallel jobs"
     echo "  --iter <iter>                                    # Iteration of model to test."
     echo "  --cmd (utils/run.pl|utils/queue.pl <queue opts>) # how to run jobs."
     echo "  --acwt <float>                                   # acoustic scale used for lattice generation "
     echo "  --scoring-opts <string>                          # options to local/score.sh"
     echo "  --num-threads <n>                                # number of threads to use, default 1."
     exit 1;
  fi
  
  
  graphdir=$1
  data=$2
  dir=$3
  
  mkdir -p $dir/log
  
  if [ -e $dir/$iter.mdl ]; then
    srcdir=$dir
  elif [ -e $dir/../$iter.mdl ]; then
    srcdir=$(dirname $dir)
  else
    echo "$0: expected either $dir/$iter.mdl or $dir/../$iter.mdl to exist"
    exit 1
  fi
  model=$srcdir/$iter.mdl
  
  
  extra_files=
  if [ ! -z "$online_ivector_dir" ]; then
    steps/nnet2/check_ivectors_compatible.sh $srcdir $online_ivector_dir || exit 1
    extra_files="$online_ivector_dir/ivector_online.scp $online_ivector_dir/ivector_period"
  fi
  
  utils/lang/check_phones_compatible.sh $graph_dir/phones.txt $srcdir/phones.txt || exit 1
  
  for f in $graphdir/HCLG.fsts.scp $data/feats.scp $model $extra_files; do
    [ ! -f $f ] && echo "$0: no such file $f" && exit 1;
  done
  
  sdata=$data/split$nj;
  cmvn_opts=`cat $srcdir/cmvn_opts` || exit 1;
  thread_string=
  [ $num_threads -gt 1 ] && thread_string="-parallel --num-threads=$num_threads"
  
  mkdir -p $dir/log
  [[ -d $sdata && $data/feats.scp -ot $sdata ]] || split_data.sh $data $nj || exit 1;
  echo $nj > $dir/num_jobs
  
  # Split HCLG.fsts.scp by input utterance
  n1=$(cat $graphdir/HCLG.fsts.scp | wc -l)
  n2=$(cat $data/feats.scp | wc -l)
  if [ $n1 != $n2 ]; then
    echo "$0: expected $n2 graphs in $graphdir/HCLG.fsts.scp, got $n1"
  fi
  
  mkdir -p $dir/split_fsts
  sort -k1,1 $graphdir/HCLG.fsts.scp > $dir/HCLG.fsts.sorted.scp
  utils/filter_scps.pl --no-warn -f 1 JOB=1:$nj \
    $sdata/JOB/feats.scp $dir/HCLG.fsts.sorted.scp $dir/split_fsts/HCLG.fsts.JOB.scp
  HCLG=scp:$dir/split_fsts/HCLG.fsts.JOB.scp
  
  ## Set up features.
  echo "$0: feature type is raw"
  
  feats="ark,s,cs:apply-cmvn $cmvn_opts --utt2spk=ark:$sdata/JOB/utt2spk scp:$sdata/JOB/cmvn.scp scp:$sdata/JOB/feats.scp ark:- |"
  
  if [ ! -z "$online_ivector_dir" ]; then
    ivector_period=$(cat $online_ivector_dir/ivector_period) || exit 1;
    ivector_opts="--online-ivectors=scp:$online_ivector_dir/ivector_online.scp --online-ivector-period=$ivector_period"
  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
  
  frame_subsampling_opt=
  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 [ $stage -le 1 ]; then
    if [ -f "$graphdir/num_pdfs" ]; then
      [ "`cat $graphdir/num_pdfs`" -eq `am-info --print-args=false $model | grep pdfs | awk '{print $NF}'` ] || \
        { echo "Mismatch in number of pdfs with $model"; exit 1; }
    fi
    $cmd --num-threads $num_threads JOB=1:$nj $dir/log/decode.JOB.log \
      nnet3-latgen-faster$thread_string $ivector_opts $frame_subsampling_opt \
       --frames-per-chunk=$frames_per_chunk \
       --extra-left-context=$extra_left_context \
       --extra-right-context=$extra_right_context \
       --extra-left-context-initial=$extra_left_context_initial \
       --extra-right-context-final=$extra_right_context_final \
       --minimize=$minimize --max-active=$max_active --min-active=$min_active --beam=$beam \
       --lattice-beam=$lattice_beam --acoustic-scale=$acwt --allow-partial=$allow_partial \
       --word-symbol-table=$graphdir/words.txt "$model" \
       "$HCLG" "$feats" "$lat_wspecifier" || exit 1;
  fi
  
  
  if [ $stage -le 2 ]; then
    if ! $skip_scoring ; then
      [ ! -x local/score.sh ] && \
        echo "$0: Not scoring because local/score.sh does not exist or not executable." && exit 1;
      iter_opt=
      [ "$iter" != "final" ] && iter_opt="--iter $iter"
      local/score.sh $iter_opt $scoring_opts --cmd "$cmd" $data $graphdir $dir ||
        { echo "$0: Scoring failed. (ignore by '--skip-scoring true')"; exit 1; }
    fi
  fi
  echo "Decoding done."
  exit 0;