#!/bin/bash
#
#  prune_dir - prune directory by deleting files if we are low on space
#
DIR_FROM=$1
DIR_TO=$2
CAPACITY_LIMIT=$3

if [ "$DIR_FROM" == "" ]
then
    echo "ERROR: directory not specified"
    exit 1
fi

if ! cd $DIR_FROM
then
    echo "ERROR: unable to chdir to directory '$DIR_FROM'"
    exit 2
fi

if [ "$DIR_TO" == "" ]
then
    echo "ERROR: directory not specified"
    exit 1
fi

if ! cd $DIR_TO
then
    echo "$DIR_TO not found. Mkdir for new directory!'"
    mkdir $DIR_TO
    if [ ! cd $DIR_TO ]
	then
   	echo "ERROR: Didn't create specific directory! Something went wrong! Exit from script!"
    	exit 1
    fi
fi

if ! [[ "$CAPACITY_LIMIT" =~ ^[0-9]+$ ]]
    then
        echo "Sorry integers only"
	exit 1
fi

if [ "$CAPACITY_LIMIT" == "" ] || [ "$CAPACITY_LIMIT" -lt 60 ]
then
    CAPACITY_LIMIT=90   # default limit
fi

CAPACITY=$(df -k $DIR_FROM | awk '{gsub("%",""); capacity=$5}; END {print capacity}')

while [ $CAPACITY -gt $CAPACITY_LIMIT ] 
do
    oldest_file=$(find $DIR_FROM -type f -printf '%T+ %p\n' | sort | head -n 1 | tr -s ' ' | cut -d ' ' -f2)

    file_size=$(du -k $oldest_file | cut -f1)
    free_space=$(df -k $DIR_TO | awk '{gsub("%",""); capacity=$4}; END {print capacity}')

    zero_size=0
    if [ $file_size -gt $free_space]
    then
        SECOND_CAPACITY=$(df -k $DIR_TO | awk '{gsub("%",""); capacity=$5}; END {print capacity}')
	test_limit=6
        while [ $SECOND_CAPACITY -gt $test_limit ]
        do
	    second_disk_old_file=$(find $DIR_TO -type f -printf '%T+ %p\n' | sort | head -n 1 | tr -s ' ' | cut -d ' ' -f2)
	    parent_second_directory_path=$(dirname $second_disk_old_file)
            files_number_second=$(find $parent_second_directory_path -type f | wc -l)
            rm -rf $second_disk_old_file
            if [ $files_number_second -eq 1 ]
                then
                rm -rf $parent_second_directory_path
            fi

	    SECOND_CAPACITY=$(df -k $DIR_TO | awk '{gsub("%",""); capacity=$5}; END {print capacity}')
        done
    fi

    parent_directory_name=$(dirname $oldest_file | sed 's,^\(.*/\)\?\([^/]*\),\2,')
    parent_directory_path=$(dirname $oldest_file)
    grand_parent_directory_path=$(dirname $parent_directory_path)
    grand_parent_directory_name=$(dirname $parent_directory_path | sed 's,^\(.*/\)\?\([^/]*\),\2,')
 
    
    dest_grand_parent_directory_path="${DIR_TO}/$grand_parent_directory_name"		
    dest_directory_path="${dest_grand_parent_directory_path}/$parent_directory_name"
   
    if [ ! -d $dest_grand_parent_directory_path ]
    then
        mkdir $dest_grand_parent_directory_path
        if [ ! -d $dest_grand_parent_directory_path ] 
        then
            echo "ERROR"
            exit 1
        else 
            mkdir $dest_directory_path
            if [ ! -d $dest_directory_path ] 
            then 
                echo "ERROR"
                exit 1
            fi
        fi
    else 
        mkdir $dest_directory_path
        if [ ! -d $dest_directory_path ] 
        then 
            echo "ERROR"
            exit 1
        fi

    fi 

    parent_directory_path=$(dirname $oldest_file)
    echo "---------------"
    echo "PRZENOSZE: $oldest_file"
    echo "DO: $dest_directory_path"
    echo $'---------------\n'
    mv $oldest_file $dest_directory_path

    files_number=$(find $parent_directory_path -type f | wc -l)
    a=0
    if [ $files_number -eq $a ]
    then
        rm -rf $parent_directory_path
    fi

    CAPACITY=$(df -k $DIR_FROM | awk '{gsub("%",""); capacity=$5}; END {print capacity}')
done