#!/usr/bin/env bash

SUMMERY=false

right_tabstop=30

warn (){
   echo ""
   echo -e "   [ Warning ]  $*"
   echo ""
}

function usage() {
   echo 
   [ -n  "$1" ] && echo -e "Error: $1\n"

cat<<EOF

   Usage: `basename $0` [-oq] <dir>


   Prints out a summary of disk space usage for a given directory. 
   
   The Output contains also the amount of diskspace usage of the 
   subdirectories.
   

   Options:

      -o <directory>
         A summary file will be stored in the given directory. The filename contains
         the directory name of the determined directory and also a timestamp in human
         readable form.

      -q
         Suppresses the output to stdout. Only useful in conjunction with "-o"

EOF
exit 1
}

_be_quiet=false
_output_to_file=false
while getopts o:q opt ; do
   case $opt in
      q) _be_quiet=true
         ;;
      o) _output_to_file=true
         if [ -d "$OPTARG" ]; then
            _out_dir=$OPTARG
         else
            usage "Output directory not found"
         fi
         ;;
      h) usage
         ;;
      \?) usage
   esac
done

shift `expr $OPTIND - 1`

if [ $# -eq 0 ]; then
   usage "Missing parameter for \"<dir>\""
elif [ $# -gt 1 ]; then
   usage "To many parameters given"
fi

base_dir=$1

if [ ! -d $base_dir ]; then
   usage "Directory \"$base_dir\" not found!"
fi

if $_output_to_file ; then
   _out_file="${_out_dir}/`basename \"$base_dir\"`_space_usage.`date +%Y%m%d-%H%M`"
   touch $_out_file
fi

if $_be_quiet && ! $_output_to_file ; then
   warn "You have told me to be quiet (-q), but gives no output directory."
   exit
fi 

## - print out 
## -
outnl(){
   
   echo X\\c > /tmp/shprompt$$
   if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
      if $_output_to_file ; then
         echo -e "$*\\c" >> $_out_file
      fi
      if ! $_be_quiet ; then
         echo -e "$*\\c" 1>&2
      fi
   else
      if $_output_to_file ; then
         echo -e "$*" >> $_out_file
      fi
      if ! $_be_quiet ; then
         echo -e "$*" 1>&2
      fi
   fi
   rm /tmp/shprompt$$
}


outnl ""
outnl "Disk Space Usage Directory \"$base_dir\":"
outnl ""

cd $backup_base_dir

## - Read list of (sub)directories inside $base_dir into
## - an array.
## -
dir_list_arr=()
while IFS='' read -r -d '' _dir; do
   dir_list_arr+=($_dir);
done < <(find $base_dir -mindepth 1 -maxdepth 1 -type d -print0)

## - Sort the array
## -
dir_list_sorted_arr=()
readarray -t dir_list_sorted_arr < <(for a in "${dir_list_arr[@]}"; do echo "$a"; done | sort)


for _dir in "${dir_list_sorted_arr[@]}"; do

   ## - Determin space usage of $_dir
   ## -
   _out_du=$(du -sh "$_dir")

   _space=`echo ${_out_du} | cut -d ' ' -f1`
   _host=`basename "$_dir"`


   ## - Formatted Output
   ## - 
   ## - Determin number of signs between directory name
   ## - and directory size
   ## -
   _strlen=${#_host}
   _count_blank=`expr $right_tabstop - $_strlen`
   _str_blanks=""
   while [ $_count_blank -gt 2 ]; do
      _str_blanks="${_str_blanks}."
      _count_blank=`expr $_count_blank - 1`
   done
   _str_blanks="${_str_blanks}: "
   _outstring="\t${_host}${_str_blanks}${_space}"
   outnl "$_outstring"
done

## - Summary
## -
if $SUMMERY ; then

   ## - overall usage of directory $$base_dir
   ## -
   _overall_usage=`du -sh $base_dir | awk '{print$1}'`

   ## - Print Summary Line
   ## -
   _strlen=${#_overall_usage}
   _count_blank=`expr $right_tabstop + $_strlen`
   _str_blanks=""
   _outstring="\t"
   while [ $_count_blank -gt 0 ]; do
      _str_blanks="${_str_blanks}. "
      _count_blank=`expr $_count_blank - 1`
      _outstring="${_outstring}="
   done
   outnl ""
   outnl "$_outstring"


   ## - Print Summary
   ## -
   _strlen=${#base_dir}
   _count_blank=`expr $right_tabstop - $_strlen`
   _str_blanks=""
   while [ $_count_blank -gt 0 ]; do
      _str_blanks="${_str_blanks} "
      _count_blank=`expr $_count_blank - 1`
   done
   _outstring="\t${base_dir}${_str_blanks}${_overall_usage}"
   outnl "$_outstring"
fi
outnl

exit 0