#!/bin/bash
  # Copyright 2012  Johns Hopkins University (Author: Daniel Povey).  Apache 2.0.
  
  # Create denominator lattices for MMI/MPE training.
  # This version uses the online-nnet2 features.
  #
  # Creates its output in $dir/lat.*.gz
  
  # Begin configuration section.
  stage=0
  nj=4
  cmd=run.pl
  sub_split=1
  beam=13.0
  lattice_beam=7.0
  acwt=0.1
  max_active=5000
  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
  parallel_opts=  # ignored now.
  # 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 [ $# != 4 ]; then
    echo "Usage: steps/make_denlats.sh [options] <data-dir> <lang-dir> <src-dir> <exp-dir>"
    echo "  e.g.: steps/make_denlats.sh data/train data/lang exp/nnet2_online/nnet_a_online exp/nnet2_online/nnet_a_denlats"
    echo "Works for (delta|lda) features, and (with --transform-dir option) such features"
    echo " plus transforms."
    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
  
  for f in $data/wav.scp $lang/L.fst $srcdir/final.mdl $srcdir/conf/online_nnet2_decoding.conf; do
    [ ! -f $f ] && echo "$0: expected file $f to exist" && exit 1;
  done
  
  sdata=$data/split$nj
  
  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;
  
  
  # Compute grammar FST which corresponds to unigram decoding graph.
  new_lang="$dir/"$(basename "$lang")
  
  
  grep -v '^--endpoint' $srcdir/conf/online_nnet2_decoding.conf >$dir/feature.conf || exit 1;
  
  if [ $stage -le 0 ]; then
    # 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.
  
    cp -rH $lang $dir/
  
    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 $new_lang $srcdir $dir/dengraph || exit 1;
    fi
  fi
  
  
  if [ -f $data/segments ]; then
    # note: in the feature extraction, because the program online2-wav-dump-features is sensitive to the
    # previous utterances within a speaker, we do the filtering after extracting the features.
    echo "$0 [info]: segments file exists: using that."
    feats="ark,s,cs:extract-segments scp:$sdata/JOB/wav.scp $sdata/JOB/segments ark:- | online2-wav-dump-features --config=$dir/feature.conf ark:$sdata/JOB/spk2utt ark,s,cs:- ark:- |"
  else
    echo "$0 [info]: no segments file exists, using wav.scp."
    feats="ark,s,cs:online2-wav-dump-features --config=$dir/feature.conf ark:$sdata/JOB/spk2utt scp:$sdata/JOB/wav.scp ark:- |"
  fi
  
  
  
  # 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 [ $sub_split -eq 1 ]; then
    $cmd --num-threads $num_threads JOB=1:$nj $dir/log/decode_den.JOB.log \
     nnet-latgen-faster$thread_string --beam=$beam --lattice-beam=$lattice_beam --acoustic-scale=$acwt \
      --max-mem=$max_mem --max-active=$max_active --word-symbol-table=$lang/words.txt $srcdir/final.mdl  \
       $dir/dengraph/HCLG.fst "$feats" "ark:|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 $feats | sed "s/trans.JOB/trans.$n/g" | 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 \
          nnet-latgen-faster$thread_string --beam=$beam --lattice-beam=$lattice_beam --acoustic-scale=$acwt \
          --max-mem=$max_mem --max-active=$max_active --word-symbol-table=$lang/words.txt $srcdir/final.mdl  \
            $dir/dengraph/HCLG.fst "$feats_subset" "ark:|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."