#!/bin/bash
HASH=md5sum
INODE=$(stat -c %i ${1:-.})
MDF="/tmp/deldup-$INODE.md5"
DUP="/tmp/deldup-$INODE.list"
if [ $MDF -nt . ]; then
    echo found cached hash list in $MDF
else
    echo -n "hashing..."
    FC=$(find ${@:-.} -type f | wc -l)
    while true; do
        P=$(cat $MDF | wc -l)
        echo -en "\rhashing files ($P/$FC)... "
        sleep 0.25
    done &
    find -O2 ${1:-.} -type f -print0 | xargs -L 1 -P 8 -0 md5sum > $MDF
    kill $!
    wait $! 2> /dev/null
fi

cut -f1 -d" " < $MDF | sort | uniq -d > $DUP

T=$(cat $DUP | wc -l)
N=1
echo Found $T duplicate files
for dh in $(cat $DUP); do
    echo
    echo \[$N/$T\] Files with hash $dh:
    grep -a $dh $MDF | cut -f2- -d" " | {
        readarray -t -O 1 FILES

        C=1 # counter
        for line in $(seq ${#FILES[@]}); do
            printf "%4d\t%s\n" $C "${FILES[$C]}"
            let C++
        done

        echo -n 'Select to delete (eg. "1", "2,3,4", "!", "1,3-5"): '
        IFS=',' read -ra RANGE <&1;
        if [ "${RANGE[1]}" = "!" ]; then # "!" deletes all matches
            for i in "${FILES[@]}"; do
                rm -v "$(echo $i | xargs -0 echo)"
            done
        else
            for i in "${RANGE[@]}"; do
                if [[ $i =~ ^([0-9]+)-([0-9]+)$ ]]; then
                    START=${BASH_REMATCH[1]}
                    END=${BASH_REMATCH[2]}
                    for x in $(seq $START $END); do
                        rm -v "$(echo ${FILES[$x]} | xargs -0 echo)"
                    done
                elif [[ $i =~ ^[0-9]+$ ]]; then
                    rm -v "$(echo ${FILES[$i]} | xargs -0 echo)"
                else
                    echo Invalid range or number \"$i\"
                fi
            done
        fi
    }
    let N++
done

echo
read -p "delete cache [y/N]? " DC
[[ $DC =~ ^[yY] ]] && rm -v $MDF && rm -v $DUP