#!/bin/sh

# flatten the directory tree
# example: dir1/dir2/file1 -> dir1_dir2_file1

DIR="${1:-.}"

_flatten(){
	cmd="$1"
	find "$DIR" -mindepth 2 -type f -exec bash -c 'file=${1#./}; '"$cmd"' "$file" "${file//\//_}"' _ '{}' \;
}

toflat=$(_flatten "echo mv")
if [ -z "$toflat" ]; then
	echo "Abort: nothing to do"; exit
fi

echo "Flattening will do:"
echo "$toflat"
printf "Proceed? [y/N] "
read -r yn
case $yn in
	[Yy]* ) ;;
	* ) echo "Abort" ; exit;;
esac
_flatten "mv"


todel="$(find . -type d -empty -print)"
[ -z "$todel" ] && exit
echo "Empty subdirectories:"
echo "$todel"
printf "Remove subdirectories? [y/N]"
read -r yn
case $yn in
	[Yy]* ) find . -type d -empty -delete;;
	* ) echo "Abort" ; exit;;
esac