sort whatsapp to dated subfolders

sort_whatsapp.sh

#!/bin/bash
echo running;
find . -maxdepth 3 -regex ".*\-2016[0-9][0-9][0-9][0-9].*.*" | while read filename;
  do
    f=$(basename "$filename")
    echo $f
    date=$(echo "$f" | cut -c5-12)
    echo $date
    if echo "${date}" | grep '[0-9]' >/dev/null; then
      dirpath='/Users/shedali/Dropbox/Events/2016/'${date:0:4}-${date:4:2}-${date:6:2}
      echo makedir "$dirpath"
      mkdir -p "$dirpath"
      echo mo "$filename" ${dirpath}
      mv "$filename" "${dirpath}"
    else
      echo 'Invalid input'
      echo "${date}" | grep '[0-9]'
      exit 1
    fi
done
#    directory=${file%.pdf}
# mv "$filename" "$directory"/"$filename"