#!/bin/bash
  # Copyright 2012-2013 Karel Vesely, Daniel Povey
  # Apache 2.0.
  
  # Create denominator lattices for MMI/MPE/sMBR training.
  # Creates its output in $dir/lat.*.ark,$dir/lat.scp
  # The lattices are uncompressed, we need random access for DNN training.
  
  # Begin configuration section.
  nj=4
  cmd=run.pl
  sub_split=1
  beam=13.0
  lattice_beam=7.0
  acwt=0.1
  max_active=5000
  nnet=
  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)
  # End configuration section.
  use_gpu_id=-1 # disable gpu
  parallel_opts="-pe smp 2"
  
  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/$0 [options] <data-dir> <lang-dir> <src-dir> <exp-dir>"
     echo "  e.g.: steps/$0 data/train data/lang exp/tri1 exp/tri1_denlats"
     echo "Works for plain features (or CMN, delta), forwarded through feature-transform."
     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."
     exit 1;
  fi
  
  data=$1
  lang=$2
  srcdir=$3
  dir=$4
  
  sdata=$data/split$nj
  splice_opts=`cat $srcdir/splice_opts 2>/dev/null`
  mkdir -p $dir/log
  [[ -d $sdata && $data/feats.scp -ot $sdata ]] || split_data.sh $data $nj || exit 1;
  echo $nj > $dir/num_jobs
  
  oov=`cat $lang/oov.int` || exit 1;
  
  mkdir -p $dir
  
  cp -r $lang $dir/
  
  # Compute grammar FST which corresponds to unigram decoding graph.
  new_lang="$dir/"$(basename "$lang")
  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 > $new_lang/G.fst \
     || exit 1;
  
  # 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
    utils/mkgraph.sh $new_lang $srcdir $dir/dengraph || exit 1;
  fi
  
  
  
  #Get the files we will need
  cp $srcdir/{tree,final.mdl} $dir
  
  [ -z "$nnet" ] && nnet=$srcdir/final.nnet;
  [ ! -f "$nnet" ] && echo "Error nnet '$nnet' does not exist!" && exit 1;
  
  class_frame_counts=$srcdir/ali_train_pdf.counts
  [ -z "$class_frame_counts" ] && echo "Error class_frame_counts '$class_frame_counts' does not exist!" && exit 1;
  
  feature_transform=$srcdir/final.feature_transform
  if [ ! -f $feature_transform ]; then
    echo "Missing feature_transform '$feature_transform'"
    exit 1
  fi
  
  model=$dir/final.mdl
  [ -z "$model" ] && echo "Error transition model '$model' does not exist!" && exit 1;
  
  ###
  ### Prepare feature pipeline (same as for decoding)
  ###
  # Create the feature stream:
  feats="ark,s,cs:copy-feats scp:$sdata/JOB/feats.scp ark:- |"
  # Optionally add cmvn
  if [ -f $srcdir/norm_vars ]; then
    norm_vars=$(cat $srcdir/norm_vars 2>/dev/null)
    [ ! -f $sdata/1/cmvn.scp ] && echo "$0: cannot find cmvn stats $sdata/1/cmvn.scp" && exit 1
    feats="$feats apply-cmvn --norm-vars=$norm_vars --utt2spk=ark:$sdata/JOB/utt2spk scp:$sdata/JOB/cmvn.scp ark:- ark:- |"
  fi
  # Optionally add deltas
  if [ -f $srcdir/delta_order ]; then
    delta_order=$(cat $srcdir/delta_order)
    feats="$feats add-deltas --delta-order=$delta_order ark:- ark:- |"
  fi
  
  # Finally add feature_transform and the MLP
  feats="$feats nnet-forward --feature-transform=$feature_transform --no-softmax=true --class-frame-counts=$class_frame_counts --use-gpu-id=$use_gpu_id $nnet ark:- ark:- |"
  ###
  ###
  ###
  
  
  
  ###
  ### We will produce lattices, where the correct path is not necessarily present
  ###
  
  #1) We don't use reference path here...
  
  echo "Generating the denlats"
  #2) Generate the denominator lattices
  if [ $sub_split -eq 1 ]; then 
    $cmd $parallel_opts JOB=1:$nj $dir/log/decode_den.JOB.log \
      latgen-faster-mapped --beam=$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,scp:$dir/lat.JOB.ark,$dir/lat.JOB.scp" || exit 1;
  else
    for n in `seq $nj`; do
      if [ -f $dir/.done.$n ] && [ $dir/.done.$n -nt $alidir/final.mdl ]; then
        echo "Not processing subset $n as already done (delete $dir/.done.$n if not)";
      else
        sdata2=$data/split$nj/$n/split$sub_split;
        if [ ! -d $sdata2 ] || [ $sdata2 -ot $sdata/$n/feats.scp ]; then
          split_data.sh --per-utt $sdata/$n $sub_split || exit 1;
        fi
        mkdir -p $dir/log/$n
        mkdir -p $dir/part
        feats_subset=$(echo $feats | sed s:JOB/:$n/split$sub_split/JOB/:g)
        $cmd $parallel_opts JOB=1:$sub_split $dir/log/$n/decode_den.JOB.log \
          latgen-faster-mapped --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,scp:$dir/lat.$n.JOB.ark,$dir/lat.$n.JOB.scp" || exit 1;
        echo Merging lists for data subset $n
        for k in `seq $sub_split`; do
          cat $dir/lat.$n.$k.scp
        done > $dir/lat.$n.all.scp
        echo Merge the ark $n
        lattice-copy scp:$dir/lat.$n.all.scp ark,scp:$dir/lat.$n.ark,$dir/lat.$n.scp || exit 1;
        #remove the data
        rm $dir/lat.$n.*.ark $dir/lat.$n.*.scp $dir/lat.$n.all.scp
        touch $dir/.done.$n
      fi
    done
  fi
  
        
  
  #3) Merge the SCPs to create full list of lattices (will use random access)
  echo Merging to single list $dir/lat.scp
  for ((n=1; n<=nj; n++)); do
    cat $dir/lat.$n.scp
  done > $dir/lat.scp
  
  
  echo "$0: done generating denominator lattices."