[OS] .json --> .csv

#!/bin/bash
#if the number of arguments is not 2
if [ $# -ne 2 ]
then
    echo "USAGE: `basename $0` folder_from folder_to"
    exit 1
fi
#if an input.json file does not exist in source folder
if [ ! -f $1/input.json ]
then
    echo "Vleznata datoteka ne postoi"
    exit 1
fi
#if the destination folder does not exist
if [ ! -d $2 ]
then
    mkdir $2
fi
FROM=$1
TO=$2
#create our final output.csv file and a temp.txt file for input info manipulation
touch output.csv
touch temp.txt
#include only the lines that consist double dot(info lines), then change global empty spacez, comaz and quotation markz with nothing
echo `cat $FROM/input.json | grep : | sed -e 's/ //g' -e 's/,//g' -e 's/"//g'` >> temp.txt
#get sum of all durations
sum_duration=`cat temp.txt | grep ^duration | awk -F: 'BEGIN {total=0} {total+=$2} END {print total}'`
#get number of lines that contain duration attribute
number_of_audios=`cat temp.txt | grep ^duration | wc -l`
#get average duration of an audio file
average_duration=`expr $sum_duration / $number_of_audios`
#instead of working with rows of one file, make a field with elements of each attribute
FILEPATHS=`cat temp.txt | grep ^filepath | awk -F: 'print $2'`
DURATIONS=`cat temp.txt | grep ^duration | awk -F: 'print $2'`
FILESIZES=`cat temp.txt | grep ^filesize | awk -F: 'print $2'`
count=0
echo "id,filepath,filesize,is_longer" >> output.csv
#do as many iterations of while as there are audio files
while [ count -lt $number_of_audios ]
do
    is_longer=0
    if [ ${DURATIONS[${count} -gt $average_duration ]
    then
        is_longer=1
    fi
    id_number=`expr $count + 1`
    echo "${id_number},${FILEPATHS[${count}]},${FILESIZES[${count}]},${is_longer}" >> output.csv
    count=`expr $count + 1`
done
#move the fucking file of interest
mv output.csv $TO/output.csv
cat $TO/output.csv
#FINALLY ITS OVER