#!/bin/bash

# Copyright 2010-2012  Microsoft Corporation;  Arnab Ghoshal

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#  http://www.apache.org/licenses/LICENSE-2.0
#
# THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
# WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
# MERCHANTABLITY OR NON-INFRINGEMENT.
# See the Apache 2 License for the specific language governing permissions and
# limitations under the License.

# To be run from ..
# Triphone model training, using (e.g. MFCC) + delta + acceleration features and
# cepstral mean normalization.  It starts from an existing directory (e.g.
# exp/mono), supplied as an argument, which is assumed to be built using the same
# type of features.
#
# This script starts from previously generated state-level alignments
# (in $alidir), e.g. generated by a previous monophone or triphone
# system.  To build a context-dependent triphone system, we build 
# decision trees that map a 3-phone phonetic context window to a
# pdf index.  It's not really clear which is the right reference, but
# on is "Tree-based state tying for high accuracy acoustic modelling"
# by Steve Young et al.  
# In a typical approach, there are decision trees for
# each monophone HMM-state (i.e. 3 per phone), and each one gets to
# ask questions about the left and right phone.  These questions
# correspond to sets of phones, corresponding to phonetic classes
# (e.g. vowel, consonant, liquid, solar, ... ).  In Kaldi, we prefer
# fully automatic algorithms, and anyway we're not sure where to get
# these types of lists, so we just generate the classes automatically.
# This is based on a top-down binary tree clustering of the phones
# (see "cluster-phones"), where we take single-Gaussian statistics for 
# just the central state of each phone (assuming this to be more 
# representative of the phones), and we get a tree structure on the
# phones; each class corresponds to a node of the tree (it contains all 
# the phones that are children of that node).  Note: you could
# replace questions.txt with something derived from manually written
# questions.
#  Also, the roots of the tree correspond to classes of phones (typically
# corresponding to "real phones", because the actual phones may contain
# word-begin/end and stress information), and the tree gets to ask
# questions also about the central phone, and about the state in the HMM.
#  After building the tree, we do a number of iterations of Gaussian
# Mixture Model training; on selected iterations we redo the Viterbi
# alignments (initially, these are taken from the previous system).
# The Gaussian mixture splitting, whereby we go from a single Gaussian
# per state to multiple Gaussians, is done on all iterations (although
# we stop doing this a few iterations before the end).  We don't have
# a fixed number of Gaussians per state, but we have an overall target
# #Gaussians that's specified on each iteration, and we allocate
# the Gaussians among states according to a power-law where the #Gaussians
# is proportional to the count to the power 0.2.  The target
# increases linearly during training [note: logarithmically seems more
# natural but didn't work as well.]

function error_exit () {
  echo -e "$@" >&2; exit 1;
}

function readint () {
  local retval=${1/#*=/};  # In case --switch=ARG format was used
  retval=${retval#0*}      # Strip any leading 0's
  [[ "$retval" =~ ^-?[1-9][0-9]*$ ]] \
    || error_exit "Argument \"$retval\" not an integer."
  echo $retval
}

njobs=4    # Default number of jobs
stage=-4   # Default starting stage (start with tree building)
qcmd=""  # Options for the submit_jobs.sh script

PROG=`basename $0`;
usage="Usage: $PROG [options] <num-leaves> <tot-gauss> <data-dir> <lang-dir> <ali-dir> <exp-dir>\n
e.g.: $PROG 2000 10000 data/train_si84 data/lang exp/mono_ali exp/tri1\n\n
Options:\n
  --help\t\tPrint this message and exit\n
  --num-jobs INT\tNumber of parallel jobs to run (default=$njobs).\n
  --qcmd STRING\tCommand for submitting a job to a grid engine (e.g. qsub) including switches.\n
  --stage INT\tStarting stage (e.g. -4 for tree building; 2 for iter 2; default=$stage)\n
";

while [ $# -gt 0 ]; do
  case "${1# *}" in  # ${1# *} strips any leading spaces from the arguments
    --help) echo -e $usage; exit 0 ;;
    --num-jobs) 
      shift; njobs=`readint $1`;
      [ $njobs -lt 1 ] && error_exit "--num-jobs arg '$njobs' not positive.";
      shift ;;
    --qcmd)
      shift; qcmd=" --qcmd=${1}"; shift ;;
    --stage)
      shift; stage=`readint $1`; shift ;;
    -*)  echo "Unknown argument: $1, exiting"; echo -e $usage; exit 1 ;;
    *)   break ;;   # end of options: interpreted as num-leaves
  esac
done

if [ $# != 6 ]; then
  error_exit $usage;
fi

[ -f path.sh ] && . path.sh

numleaves=$1
totgauss=$2
data=$3
lang=$4
alidir=$5
dir=$6

if [ ! -f $alidir/final.mdl ]; then
  echo "Error: alignment dir $alidir does not contain final.mdl"
  exit 1;
fi

scale_opts="--transition-scale=1.0 --acoustic-scale=0.1 --self-loop-scale=0.1"
realign_iters="10 20 30";
silphonelist=`cat $lang/silphones.csl`
numiters=35    # Number of iterations of training
maxiterinc=25 # Last iter to increase #Gauss on.
numgauss=$numleaves
incgauss=$[($totgauss-$numgauss)/$maxiterinc] # per-iter increment for #Gauss

if [ -f $lang/oov.txt ]; then
  oov_opt="--map-oov '"`cat $lang/oov.txt`"'"
else
  oov_opt='--ignore-oov'
fi

mkdir -p $dir/log
if [ ! -d $data/split$njobs -o $data/split$njobs -ot $data/feats.scp ]; then
  split_data.sh $data $njobs
fi

# for n in `get_splits.pl $njobs`; do
featspart="ark,s,cs:apply-cmvn --norm-vars=false --utt2spk=ark:$data/split$njobs/TASK_ID/utt2spk ark:$alidir/TASK_ID.cmvn scp:$data/split$njobs/TASK_ID/feats.scp ark:- | add-deltas ark:- ark:- |"

if [ $stage -le -3 ]; then
# The next stage assumes we won't need the context of silence, which
# assumes something about $lang/roots.txt, but it seems pretty safe.
  echo "Accumulating tree stats"
  # for n in `get_splits.pl $njobs`; do
  submit_jobs.sh "$qcmd" --njobs=$njobs --log=$dir/log/acc_tree.TASK_ID.log \
    acc-tree-stats  --ci-phones=$silphonelist $alidir/final.mdl "$featspart" \
      "ark:gunzip -c $alidir/TASK_ID.ali.gz|" $dir/TASK_ID.treeacc \
      || error_exit "Error accumulating tree stats";
  
  sum-tree-stats $dir/treeacc $dir/*.treeacc 2>$dir/log/sum_tree_acc.log \
      || error_exit "Error summing tree stats.";
  rm $dir/*.treeacc
fi

if [ $stage -le -2 ]; then
# preparing questions, roots file...
  echo "Computing questions for tree clustering"
  ( sym2int.pl $lang/phones.txt $lang/phonesets_cluster.txt > $dir/phonesets.txt
    cluster-phones $dir/treeacc $dir/phonesets.txt $dir/questions.txt \
      2> $dir/log/questions.log
    [ -f $lang/extra_questions.txt ] && \
      sym2int.pl $lang/phones.txt $lang/extra_questions.txt \
      >> $dir/questions.txt
    compile-questions $lang/topo $dir/questions.txt $dir/questions.qst \
      2>$dir/log/compile_questions.log
    sym2int.pl --ignore-oov $lang/phones.txt $lang/roots.txt > $dir/roots.txt
  ) || error_exit "Error in generating questions for tree clustering."

  echo "Building tree"
  submit_jobs.sh "$qcmd" --log=$dir/log/train_tree.log \
    build-tree --verbose=1 --max-leaves=$numleaves $dir/treeacc $dir/roots.txt \
      $dir/questions.qst $lang/topo $dir/tree \
      || error_exit "Error in building tree.";

  gmm-init-model --write-occs=$dir/1.occs \
    $dir/tree $dir/treeacc $lang/topo $dir/1.mdl 2> $dir/log/init_model.log \
    || error_exit "Error in initializing the model.";

  gmm-mixup --mix-up=$numgauss $dir/1.mdl $dir/1.occs $dir/1.mdl \
    2>$dir/log/mixup.log || error_exit "Error mixing up to $numgauss Gaussains";

  rm $dir/treeacc
fi


if [ $stage -le -1 ]; then
# Convert alignments in $alidir, to use as initial alignments.
# This assumes that $alidir was split in $njobs pieces, just like the
# current dir.  Just do this locally-- it's very fast.
  echo "Converting old alignments"
  # for n in `get_splits.pl $njobs`; do
  submit_jobs.sh --njobs=$njobs --log=$dir/log/convertTASK_ID.log \
    convert-ali $alidir/final.mdl $dir/1.mdl $dir/tree \
      "ark:gunzip -c $alidir/TASK_ID.ali.gz|" \
      "ark:|gzip -c >$dir/TASK_ID.ali.gz" \
      || error_exit "Error converting old alignments.";
fi

if [ $stage -le 0 ]; then
# Make training graphs (this is split in $njobs parts).
  echo "Compiling training graphs"
  # for n in `get_splits.pl $njobs`; do
  submit_jobs.sh "$qcmd" --njobs=$njobs --log=$dir/log/compile_graphsTASK_ID.log \
    compile-train-graphs $dir/tree $dir/1.mdl  $lang/L.fst  \
      "ark:sym2int.pl $oov_opt --ignore-first-field $lang/words.txt < $data/split$njobs/TASK_ID/text |" \
      "ark:|gzip -c >$dir/TASK_ID.fsts.gz" \
      || error_exit "Error compiling training graphs";
fi

x=1
while [ $x -lt $numiters ]; do
  echo Pass $x
  if [ $stage -le $x ]; then
    if echo $realign_iters | grep -w $x >/dev/null; then
      echo "Aligning data"
      # for n in `get_splits.pl $njobs`; do
      submit_jobs.sh "$qcmd" --njobs=$njobs --log=$dir/log/align.$x.TASK_ID.log \
        gmm-align-compiled $scale_opts --beam=10 --retry-beam=40 $dir/$x.mdl \
          "ark:gunzip -c $dir/TASK_ID.fsts.gz|" "$featspart" \
          "ark:|gzip -c >$dir/TASK_ID.ali.gz" \
	  || error_exit "Error aligning data on iteration $x";
    fi  # Realign iters

    # for n in `get_splits.pl $njobs`; do
    submit_jobs.sh "$qcmd" --njobs=$njobs --log=$dir/log/acc.$x.TASK_ID.log \
      gmm-acc-stats-ali  $dir/$x.mdl "$featspart" \
        "ark,s,cs:gunzip -c $dir/TASK_ID.ali.gz|" $dir/$x.TASK_ID.acc \
	|| error_exit "Error accumulating stats on iteration $x";

    submit_jobs.sh "$qcmd" --log=$dir/log/update.$x.log \
      gmm-est --write-occs=$dir/$[$x+1].occs --mix-up=$numgauss $dir/$x.mdl \
	"gmm-sum-accs - $dir/$x.*.acc |" $dir/$[$x+1].mdl \
	|| error_exit "Error in pass $x extimation.";
    rm -f r/$x.mdl $dir/$x.*.acc rm $dir/$x.occs 
  fi  # Completed a training stage.
  if [[ $x -le $maxiterinc ]]; then 
    numgauss=$[$numgauss+$incgauss];
  fi
  x=$[$x+1];
done

( cd $dir; rm -f final.{mdl,occs}; ln -s $x.mdl final.mdl; \
  ln -s $x.occs final.occs; )

# Print out summary of the warning messages.
for x in $dir/log/*.log; do 
  n=`grep WARNING $x | wc -l`; 
  if [ $n -ne 0 ]; then echo $n warnings in $x; fi; 
done

echo Done