#!/bin/bash
  # Copyright 2012        Johns Hopkins University (Author: Daniel Povey)
  #           2014-2015   Vimal Manohar
  # Apache 2.0.
  
  # Create denominator lattices for MMI/MPE training [deprecated].
  # This version uses the neural-net models (version 3, i.e. the nnet3 code).
  # Creates its output in $dir/lat.*.gz
  # Note: the more recent discriminative training scripts will not use this
  # script at all, they'll use get_degs.sh which combines the decoding
  # and egs-dumping into one script (to save disk space and disk I/O).
  
  # Begin configuration section.
  nj=4
  cmd=run.pl
  sub_split=1
  beam=13.0
  frames_per_chunk=50
  lattice_beam=7.0
  self_loop_scale=0.1
  acwt=0.1
  max_active=5000
  min_active=200
  max_mem=20000000 # This will stop the processes getting too large.
  # This is in bytes, but not "real" bytes-- you have to multiply
  # by something like 5 or 10 to get real bytes (not sure why so large)
  num_threads=1 # number of threads of decoder [only applicable if not looped, for now]
  online_ivector_dir=
  determinize=true
  minimize=false
  ivector_scale=1.0
  extra_left_context=0
  extra_right_context=0
  extra_left_context_initial=-1
  extra_right_context_final=-1
  # End configuration section.
  
  
  echo "$0 $@"  # Print the command line for logging
  
  [ -f ./path.sh ] && . ./path.sh; # source the path.
  . parse_options.sh || exit 1;
  
  num_threads=1 # Fixed to 1 for now
  
  if [ $# != 4 ]; then
    echo "Usage: steps/nnet3/make_denlats.sh [options] <data-dir> <lang-dir> <src-dir> <exp-dir>"
    echo "  e.g.: steps/nnet3/make_denlats.sh data/train data/lang exp/nnet4 exp/nnet4_denlats"
    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 "  --cmd (utils/run.pl|utils/queue.pl <queue opts>) # how to run jobs."
    echo "  --sub-split <n-split>                            # e.g. 40; use this for "
    echo "                           # large databases so your jobs will be smaller and"
    echo "                           # will (individually) finish reasonably soon."
    echo "  --num-threads  <n>                # number of threads per decoding job"
    exit 1;
  fi
  
  data=$1
  lang=$2
  srcdir=$3
  dir=$4
  
  
  extra_files=
  [ ! -z "$online_ivector_dir" ] && \
    extra_files="$online_ivector_dir/ivector_online.scp $online_ivector_dir/ivector_period"
  for f in $data/feats.scp $lang/L.fst $srcdir/final.mdl $extra_files; do
    [ ! -f $f ] && echo "$0: expected file $f to exist" && exit 1;
  done
  
  sdata=$data/split$nj
  splice_opts=`cat $srcdir/splice_opts 2>/dev/null`
  thread_string=
  [ $num_threads -gt 1 ] && thread_string="-parallel --num-threads=$num_threads"
  
  mkdir -p $dir/log
  split_data.sh $data $nj || exit 1;
  echo $nj > $dir/num_jobs
  
  utils/lang/check_phones_compatible.sh $lang/phones.txt $srcdir/phones.txt || exit 1;
  
  oov=`cat $lang/oov.int` || exit 1;
  
  cp -rH $lang $dir/
  
  # Compute grammar FST which corresponds to unigram decoding graph.
  new_lang="$dir/"$(basename "$lang")
  
  # mkgraph.sh expects a whole directory "lang", so put everything in one directory...
  # it gets L_disambig.fst and G.fst (among other things) from $dir/lang, and
  # final.mdl from $srcdir; the output HCLG.fst goes in $dir/graph.
  
  echo "Compiling decoding graph in $dir/dengraph"
  if [ -s $dir/dengraph/HCLG.fst ] && [ $dir/dengraph/HCLG.fst -nt $srcdir/final.mdl ]; then
    echo "Graph $dir/dengraph/HCLG.fst already exists: skipping graph creation."
  else
    echo "Making unigram grammar FST in $new_lang"
    cat $data/text | utils/sym2int.pl --map-oov $oov -f 2- $lang/words.txt | \
     awk '{for(n=2;n<=NF;n++){ printf("%s ", $n); } printf("
  "); }' | \
      utils/make_unigram_grammar.pl | fstcompile | fstarcsort --sort_type=ilabel > $new_lang/G.fst \
      || exit 1;
    utils/mkgraph.sh --self-loop-scale $self_loop_scale $new_lang $srcdir $dir/dengraph || exit 1;
  fi
  cmvn_opts=`cat $srcdir/cmvn_opts 2>/dev/null`
  cp $srcdir/cmvn_opts $dir 2>/dev/null
  
  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 this job is interrupted by the user, we want any background jobs to be
  # killed too.
  cleanup() {
    local pids=$(jobs -pr)
    [ -n "$pids" ] && kill $pids
  }
  trap "cleanup" INT QUIT TERM EXIT
  
  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 [ -f $srcdir/frame_subsampling_factor ]; then
    # e.g. for 'chain' systems
    frame_subsampling_opt="--frame-subsampling-factor=$(cat $srcdir/frame_subsampling_factor)"
    cp $srcdir/frame_subsampling_factor $dir
  fi
  
  lattice_determinize_cmd=
  if $determinize; then
    lattice_determinize_cmd="lattice-determinize-non-compact --acoustic-scale=$acwt --max-mem=$max_mem --minimize=$minimize --prune=true --beam=$lattice_beam ark:- ark:- |"
  fi
  
  if [ $sub_split -eq 1 ]; then
    $cmd --num-threads $num_threads JOB=1:$nj $dir/log/decode_den.JOB.log \
      nnet3-latgen-faster$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=false --determinize-lattice=false \
      --word-determinize=false --phone-determinize=false \
      --max-active=$max_active --min-active=$min_active --beam=$beam \
      --lattice-beam=$lattice_beam --acoustic-scale=$acwt --allow-partial=false \
      --max-mem=$max_mem --word-symbol-table=$lang/words.txt $srcdir/final.mdl  \
      $dir/dengraph/HCLG.fst "$feats" \
      "ark:|$lattice_determinize_cmd gzip -c >$dir/lat.JOB.gz" || exit 1
  else
  
    # each job from 1 to $nj is split into multiple pieces (sub-split), and we aim
    # to have at most two jobs running at each time.  The idea is that if we have stragglers
    # from one job, we can be processing another one at the same time.
    rm $dir/.error 2>/dev/null
  
    prev_pid=
    for n in `seq $[nj+1]`; do
      if [ $n -gt $nj ]; then
        this_pid=
      elif [ -f $dir/.done.$n ] && [ $dir/.done.$n -nt $srcdir/final.mdl ]; then
        echo "Not processing subset $n as already done (delete $dir/.done.$n if not)";
        this_pid=
      else
        sdata2=$data/split$nj/$n/split${sub_split}utt;
        split_data.sh --per-utt $sdata/$n $sub_split || exit 1;
        mkdir -p $dir/log/$n
        mkdir -p $dir/part
        feats_subset=`echo $feats | sed s:JOB/:$n/split${sub_split}utt/JOB/:g`
  
        $cmd --num-threads $num_threads JOB=1:$sub_split $dir/log/$n/decode_den.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=false --determinize-lattice=false \
          --word-determinize=false --phone-determinize=false \
          --max-active=$max_active --min-active=$min_active --beam=$beam \
          --lattice-beam=$lattice_beam --acoustic-scale=$acwt --allow-partial=false \
          --max-mem=$max_mem --word-symbol-table=$lang/words.txt $srcdir/final.mdl  \
          $dir/dengraph/HCLG.fst "$feats_subset" \
          "ark:|$lattice_determinize_cmd gzip -c >$dir/lat.$n.JOB.gz" || touch $dir/.error &
        this_pid=$!
      fi
      if [ ! -z "$prev_pid" ]; then  # Wait for the previous job; merge the previous set of lattices.
        wait $prev_pid
        [ -f $dir/.error ] && echo "$0: error generating denominator lattices" && exit 1;
        rm $dir/.merge_error 2>/dev/null
        echo Merging archives for data subset $prev_n
        for k in `seq $sub_split`; do
          gunzip -c $dir/lat.$prev_n.$k.gz || touch $dir/.merge_error;
        done | gzip -c > $dir/lat.$prev_n.gz || touch $dir/.merge_error;
        [ -f $dir/.merge_error ] && echo "$0: Merging lattices for subset $prev_n failed (or maybe some other error)" && exit 1;
        rm $dir/lat.$prev_n.*.gz
        touch $dir/.done.$prev_n
      fi
      prev_n=$n
      prev_pid=$this_pid
    done
  fi
  
  
  echo "$0: done generating denominator lattices."