#!/bin/bash
# Copyright 2010-2012 Microsoft Corporation  Johns Hopkins University (Author: Daniel Povey)
# Apache 2.0

# This script creates a fully expanded decoding graph (HCLG) that represents
# all the language-model, pronunciation dictionary (lexicon), context-dependency,
# and HMM structure in our model.  The output is a Finite State Transducer
# that has word-ids on the output, and pdf-ids on the input (these are indexes
# that resolve to Gaussian Mixture Models).  
# See
#  http://kaldi.sourceforge.net/graph_recipe_test.html
# (this is compiled from this repository using Doxygen,
# the source for this part is in src/doc/graph_recipe_test.dox)


N=3
P=1
reverse=false

for x in `seq 2`; do 
  [ "$1" == "--mono" ] && N=1 && P=0 && shift;
  [ "$1" == "--quinphone" ] && N=5 && P=2 && shift;
  [ "$1" == "--reverse" ] && reverse=true && shift;
done

if [ $# != 3 ]; then
   echo "Usage: utils/mkgraph.sh [options] <lang-dir> <model-dir> <graphdir>"
   echo "e.g.: utils/mkgraph.sh data/lang_test exp/tri1/ exp/tri1/graph"
   echo " Options:"
   echo " --mono          #  For monophone models."
   echo " --quinphone     #  For models with 5-phone context (3 is default)"
   exit 1;
fi

if [ -f path.sh ]; then . ./path.sh; fi

lang=$1
tree=$2/tree
model=$2/final.mdl
dir=$3

mkdir -p $dir

tscale=1.0
loopscale=0.1

# If $lang/tmp/LG.fst does not exist or is older than its sources, make it...
# (note: the [[ ]] brackets make the || type operators work (inside [ ], we
# would have to use -o instead),  -f means file exists, and -ot means older than).

required="$lang/L.fst $lang/G.fst $lang/phones.txt $lang/words.txt $lang/phones/silence.csl $lang/phones/disambig.int $model $tree"
for f in $required; do
  [ ! -f $f ] && echo "mkgraph.sh: expected $f to exist" && exit 1;
done

mkdir -p $lang/tmp
# Note: [[ ]] is like [ ] but enables certain extra constructs, e.g. || in 
# place of -o
if [[ ! -s $lang/tmp/LG.fst || $lang/tmp/LG.fst -ot $lang/G.fst || \
      $lang/tmp/LG.fst -ot $lang/L_disambig.fst ]]; then
  fsttablecompose $lang/L_disambig.fst $lang/G.fst | fstdeterminizestar --use-log=true | \
    fstminimizeencoded  > $lang/tmp/LG.fst || exit 1;
  fstisstochastic $lang/tmp/LG.fst || echo "[info]: LG not stochastic."
fi


clg=$lang/tmp/CLG_${N}_${P}.fst

if [[ ! -s $clg || $clg -ot $lang/tmp/LG.fst ]]; then
  fstcomposecontext --context-size=$N --central-position=$P \
   --read-disambig-syms=$lang/phones/disambig.int \
   --write-disambig-syms=$lang/tmp/disambig_ilabels_${N}_${P}.int \
    $lang/tmp/ilabels_${N}_${P} < $lang/tmp/LG.fst >$clg
  fstisstochastic $clg  || echo "[info]: CLG not stochastic."
fi

if [[ ! -s $dir/Ha.fst || $dir/Ha.fst -ot $model  \
    || $dir/Ha.fst -ot $lang/tmp/ilabels_${N}_${P} ]]; then
  if $reverse; then
    make-h-transducer --reverse=true --push_weights=true \
      --disambig-syms-out=$dir/disambig_tid.int \
      --transition-scale=$tscale $lang/tmp/ilabels_${N}_${P} $tree $model \
      > $dir/Ha.fst  || exit 1;
  else
    make-h-transducer --disambig-syms-out=$dir/disambig_tid.int \
      --transition-scale=$tscale $lang/tmp/ilabels_${N}_${P} $tree $model \
       > $dir/Ha.fst  || exit 1;
  fi
fi

if [[ ! -s $dir/HCLGa.fst || $dir/HCLGa.fst -ot $dir/Ha.fst || \
      $dir/HCLGa.fst -ot $clg ]]; then
  fsttablecompose $dir/Ha.fst $clg | fstdeterminizestar --use-log=true \
    | fstrmsymbols $dir/disambig_tid.int | fstrmepslocal | \
     fstminimizeencoded > $dir/HCLGa.fst || exit 1;
  fstisstochastic $dir/HCLGa.fst || echo "HCLGa is not stochastic"
fi

if [[ ! -s $dir/HCLG.fst || $dir/HCLG.fst -ot $dir/HCLGa.fst ]]; then
  add-self-loops --self-loop-scale=$loopscale --reorder=true \
    $model < $dir/HCLGa.fst > $dir/HCLG.fst || exit 1;

  if [ $tscale == 1.0 -a $loopscale == 1.0 ]; then
    # No point doing this test if transition-scale not 1, as it is bound to fail. 
    fstisstochastic $dir/HCLG.fst || echo "[info]: final HCLG is not stochastic."
  fi
fi

# keep a copy of the lexicon and a list of silence phones with HCLG...
# this means we can decode without reference to the $lang directory.


cp $lang/words.txt $dir/ || exit 1;
mkdir -p $dir/phones
cp $lang/phones/word_boundary.* $dir/phones/ 2>/dev/null # might be needed for ctm scoring,
  # but ignore the error if it's not there.

cp $lang/phones/disambig.{txt,int} $dir/phones/ 2> /dev/null
cp $lang/phones/silence.csl $dir/phones/ || exit 1;
cp $lang/phones.txt $dir/ 2> /dev/null # ignore the error if it's not there.

# to make const fst:
# fstconvert --fst_type=const $dir/HCLG.fst $dir/HCLG_c.fst