#!/bin/bash

if [ $# -lt 2 ]
then
    echo "Usage: $0 from to"
    exit 1
fi

if [ "$1" = "--hard" ]
then
    LN="ln"
    shift
elif [ "$1" = "--copy" ]
then
    LN="cp"
    shift
else
    LN="ln -s"
fi

FROM=`realpath $1`; shift
TO=`realpath $1`; shift

if [ -z "$FROM" ] || [ -z "$TO" ]
then
    echo "Usage: $0 from to"
    exit 1
elif ! [ -d "$FROM" ]
then
    echo "$FROM not found"
    exit 2
fi

mkdir -p "$TO" || exit 3
rm -rf "$TO/*" || exit 3

for i in `find "$FROM" -mindepth 1 -type f`
do
    FILE=`echo $i | sed "s!^$FROM/!!"`
    HASH=`echo -n $FILE | sha384sum | cut -d " " -f 1`

    mkdir -p "$TO/$HASH/"
    $LN "$i" "$TO/$HASH/"
done