#/bin/bash

# This script preprocesses and binarizes the data for training translation models using fairseq.
# Only difference between this script and `prepare_data_joint_finetuning.sh` that we generate 
# fairseq dict using this script that is commonly shared across for training all the models further.


echo `date`
exp_dir=$1                                      # path to the experiment directory
vocab_dir=${2:-"$exp_dir/vocab"}                # path to the spm-based tokenizer directory
train_data_dir=${3:-"$exp_dir/train"}           # path to the train data within experiment directory
devtest_data_dir=${4:-"$exp_dir/devtest/all"}   # path to the devtest data within experiment directory

root=$(dirname $0)

echo "Running experiment ${exp_dir}"

train_processed_dir=$exp_dir/data
devtest_processed_dir=$exp_dir/data
out_data_dir=$exp_dir/final_bin

mkdir -p $train_processed_dir
mkdir -p $devtest_processed_dir
mkdir -p $out_data_dir

parallel_installed=false

# Check if GNU Parallel is installed
if command -v parallel &> /dev/null; then
    echo "GNU Parallel is installed. Version information:"
    parallel --version
    parallel_installed=true
fi

# get a list of language pairs in the `train_data_dir`
pairs=$(ls -d $train_data_dir/* | sort)


# iterate over each language pair
for pair in ${pairs[@]}; do
    # extract the source and target languages from the pair name
    pair=$(basename $pair)
    src_lang=$(echo "$pair" | cut -d "-" -f 1)
    tgt_lang=$(echo "$pair" | cut -d "-" -f 2)
    echo "$src_lang - $tgt_lang"

    train_norm_dir=$exp_dir/norm/$src_lang-$tgt_lang
	devtest_norm_dir=$exp_dir/norm/$src_lang-$tgt_lang
	mkdir -p $train_norm_dir
	mkdir -p $devtest_norm_dir


    # check if the source language text requires transliteration
    src_transliterate="true"
    if [[ $src_lang == *"Arab"* ]] || [[ $src_lang == *"Olck"* ]] || \
        [[ $src_lang == *"Mtei"* ]] || [[ $src_lang == *"Latn"* ]]; then
        src_transliterate="false"
    fi
    
    # check if the target language text requires transliteration
    tgt_transliterate="true"
    if [[ $tgt_lang == *"Arab"* ]] || [[ $tgt_lang == *"Olck"* ]] || \
        [[ $tgt_lang == *"Mtei"* ]] || [[ $tgt_lang == *"Latn"* ]]; then
        tgt_transliterate="false"
    fi


    # --------------------------------------------------------------------------
    #                           train preprocessing
    # --------------------------------------------------------------------------
	train_infname_src=$train_data_dir/${src_lang}-${tgt_lang}/train.$src_lang
	train_infname_tgt=$train_data_dir/${src_lang}-${tgt_lang}/train.$tgt_lang
	train_outfname_src=$train_norm_dir/train.$src_lang
	train_outfname_tgt=$train_norm_dir/train.$tgt_lang

    echo "Normalizing punctuations for train"
    if $parallel_installed; then
        parallel --pipe --keep-order bash $root/normalize_punctuation.sh $src_lang < $train_infname_src > $train_outfname_src._norm
        parallel --pipe --keep-order bash $root/normalize_punctuation.sh $tgt_lang < $train_infname_tgt > $train_outfname_tgt._norm
    else
        bash $root/normalize_punctuation.sh $src_lang < $train_infname_src > $train_outfname_src._norm
        bash $root/normalize_punctuation.sh $tgt_lang < $train_infname_tgt > $train_outfname_tgt._norm
    fi

	# add do not translate tags to handle special failure cases
    echo "Applying do not translate tags for train"
    python3 scripts/normalize_regex.py $train_outfname_src._norm $train_outfname_tgt._norm $train_outfname_src.norm $train_outfname_tgt.norm

	echo "Applying normalization and script conversion for train"
    # this script preprocesses the text and for indic languages, converts script to devanagari if needed
	input_size=`python3 scripts/preprocess_translate.py $train_outfname_src.norm $train_outfname_src $src_lang $src_transliterate false`
	input_size=`python3 scripts/preprocess_translate.py $train_outfname_tgt.norm $train_outfname_tgt $tgt_lang $tgt_transliterate true`
	echo "Number of sentences in train: $input_size"


    # --------------------------------------------------------------------------
    #                              dev preprocessing
    # --------------------------------------------------------------------------
	dev_infname_src=$devtest_data_dir/${src_lang}-${tgt_lang}/dev.$src_lang
	dev_infname_tgt=$devtest_data_dir/${src_lang}-${tgt_lang}/dev.$tgt_lang
	dev_outfname_src=$devtest_norm_dir/dev.$src_lang
	dev_outfname_tgt=$devtest_norm_dir/dev.$tgt_lang

    echo "Normalizing punctuations for dev"
    if $parallel_installed; then
        parallel --pipe --keep-order bash normalize_punctuation.sh $src_lang < $dev_infname_src > $dev_outfname_src._norm
        parallel --pipe --keep-order bash normalize_punctuation.sh $tgt_lang < $dev_infname_tgt > $dev_outfname_tgt._norm
    else
        bash normalize_punctuation.sh $src_lang < $dev_infname_src > $dev_outfname_src._norm
        bash normalize_punctuation.sh $tgt_lang < $dev_infname_tgt > $dev_outfname_tgt._norm
    fi

	# add do not translate tags to handle special failure cases
    echo "Applying do not translate tags for dev"
    python3 scripts/normalize_regex.py $dev_outfname_src._norm $dev_outfname_tgt._norm $dev_outfname_src.norm $dev_outfname_tgt.norm

    echo "Applying normalization and script conversion for dev"
    # this script preprocesses the text and for indic languages, converts script to devanagari if needed
	input_size=`python scripts/preprocess_translate.py $dev_outfname_src.norm $dev_outfname_src $src_lang $src_transliterate false`
	input_size=`python scripts/preprocess_translate.py $dev_outfname_tgt.norm $dev_outfname_tgt $tgt_lang $tgt_transliterate true`
	echo "Number of sentences in dev: $input_size"
done


# this concatenates lang pair data and creates text files to keep track of number of 
# lines in each lang pair. this is important for joint training, as we will merge all 
# the lang pairs and the indivitual lang lines info would be required for adding specific 
# lang tags later.
# the outputs of these scripts will  be text file like this:
# <lang1> <lang2> <number of lines>
# lang1-lang2 n1
# lang1-lang3 n2
python scripts/concat_joint_data.py $exp_dir/norm $exp_dir/data 'train'
python scripts/concat_joint_data.py $exp_dir/norm $exp_dir/data 'dev'


# tokenization of train and dev set using the spm trained models
mkdir -p $exp_dir/bpe

splits=(train dev)
for split in ${splits[@]}; do
	echo "Applying sentence piece for $split"
	bash apply_sentence_piece.sh $exp_dir $exp_dir/data $exp_dir/bpe SRC TGT $split $parallel_installed
done


# this is only required for joint training
# we apply language tags to the bpe segmented data
# if we are translating lang1 to lang2 then <lang1 line> will become <lang1> <lang2> <lang1 line>
mkdir -p $exp_dir/final

echo "Adding language tags"
python scripts/add_joint_tags_translate.py $exp_dir 'train'
python scripts/add_joint_tags_translate.py $exp_dir 'dev'


# this is important step if you are training with tpu and using num_batch_buckets
# the current implementation does not remove outliers before bucketing and hence
# removing these large sentences ourselves helps with getting better buckets
# python scripts/remove_large_sentences.py $exp_dir/bpe/train.SRC $exp_dir/bpe/train.TGT $exp_dir/final/train.SRC $exp_dir/final/train.TGT
# python scripts/remove_large_sentences.py $exp_dir/bpe/dev.SRC $exp_dir/bpe/dev.TGT $exp_dir/final/dev.SRC $exp_dir/final/dev.TGT
# python scripts/remove_large_sentences.py $exp_dir/bpe/test.SRC $exp_dir/bpe/test.TGT $exp_dir/final/test.SRC $exp_dir/final/test.TGT


echo "Binarizing data"

# use cpu_count to get num_workers instead of setting it manually when running 
# in different instances
num_workers=`python -c "import multiprocessing; print(multiprocessing.cpu_count())"`

data_dir=$exp_dir/final
out_data_dir=$exp_dir/final_bin

rm -rf $out_data_dir

fairseq-preprocess \
    --source-lang SRC --target-lang TGT \
    --trainpref $data_dir/train \
    --validpref $data_dir/dev \
    --destdir $out_data_dir \
    --workers $num_workers \
    --thresholdtgt 5