#!/bin/bash
  
  # Copyright 2017 Nagendra Kumar Goel
  #           2018 Vimal Manohar   
  # Apache 2.0.
  
  # This script combines targets directory into a new targets directory 
  # containing targets from all the input targets directories.
  
  echo "$0 $@"  # Print the command line for logging
  
  if [ -f path.sh ]; then . ./path.sh; fi
  . parse_options.sh || exit 1;
  
  if [ $# -lt 3 ]; then
    echo "Usage: $0 [options] <data> <dest-targets-dir> <src-targets-dir1> <src-targets-dir2> ..."
    echo "e.g.: $0 data/train exp/targets_combined exp/targets_1 exp/targets_2"
    exit 1;
  fi
  
  export LC_ALL=C
  
  data=$1;
  shift;
  dest=$1;
  shift;
  first_src=$1;
  
  mkdir -p $dest;
  rm -f $dest/{targets.*.ark,frame_subsampling_factor} 2>/dev/null
  
  frame_subsampling_factor=1
  if [ -f $first_src/frame_subsampling_factor ]; then
    cp $first_src/frame_subsampling_factor $dest
    frame_subsampling_factor=$(cat $dest/frame_subsampling_factor)
  fi
  
  for d in $*; do
    this_frame_subsampling_factor=1
    if [ -f $d/frame_subsampling_factor ]; then
      this_frame_subsampling_factor=$(cat $d/frame_subsampling_factor)
    fi
  
    if [ $this_frame_subsampling_factor != $frame_subsampling_factor ]; then
      echo "$0: Cannot combine targets directories with different frame-subsampling-factors" 1>&2
      exit 1
    fi
  
    cat $d/targets.scp
  done | sort -k1,1 > $dest/targets.scp || exit 1
  
  steps/segmentation/validate_targets_dir.sh $dest $data || exit 1
  
  echo "Combined targets and stored in $dest"
  exit 0