Merging and moving folders in loop - bash

Question

I have a large library of music files stored as ./"Artist Name"/"Album Name"/"audio files".
I would like to re-organize to ./"Artist name --- Album name"/"audio files"
And be able to put it back to how it was.

Answer 1

This is your first loop
mkdir "ArtistName-Albumname"
cd "ArtistName/Albumname"
for filename in *; do
mv "$filename" "$ArtistName-Albumname/" ;;
done

Answer 2

I think something like this will get you started. It doesn't do anything but just parses your structure and works out what needs doing:
#!/bin/bash
find . -depth 2 -type d | while IFS= read p
do
p=${p:2} # Trim ./ from start
album=${p##*/} # album is everything after /
artist=${p%/*} # artist is everything before /
newloc="${artist} - ${album}"
echo Would move $artist/$album to ${newloc}
done
Sample output:
Would move artist1/album1 to artist1 - album1
Would move artist1/album2 to artist1 - album2
Would move artist1/album3 to artist1 - album3
Would move artist1/album4 to artist1 - album4
Would move artist2/album1 to artist2 - album1
Would move artist2/album2 to artist2 - album2
Would move artist2/album3 to artist2 - album3
Would move artist3/album1 to artist3 - album1
Would move artist3/album2 to artist3 - album2
Would move artist3/album3 to artist3 - album3
Would move artist4/album1 to artist4 - album1
Would move artist4/album2 to artist4 - album2
Would move artist4/album3 to artist4 - album3
Would move artist4/album4 to artist4 - album4
Would move artist4/album5 to artist4 - album5
The reverse operation is tricky as there may be a hyphen naturally occurring in an album name, so it will be hard to differentiate that from the hyphen introduced by the code below.

Answer 3

Here is the script to merge folder from "Artist Name"/"Album Name" to "Artist name - Album name"
#! /usr/bin/env bash
cd /PATH
find . -type f |while read -r line
do
file=${line##*/}
folder=${line%/*}
album=${folder##*/}
folder=${folder%/*}
artist=${folder##*/}
newfolder="$artist - $album"
mkdir -p "$newfolder"
echo mv "$line" "$newfolder"
done
If you understand above script, you should be fine to write a reverse one.

Answer 4

Took some time for an amateur. But here's my final sollution. Thank you so much for your input #mark #BMW.
function flatten() {
echo flattening...
ls -ld --format=single-column */* | while IFS= read albumpath
do
echo Flattening "$albumpath"
artist=${albumpath%/*} # artist is everything before /
echo Artist: "$artist"
echo Album: "$albumpath"
album=${albumpath##*/} # album is everything after /
newfolder="$artist --- $album"
echo Moving "$albumpath" to "$newfolder"
mv "$albumpath" "$newfolder"
done
find . -depth -type d -empty -delete #delete all empty (artist)folders
}
function unflatten() {
ls -ld --format=single-column */ | while IFS= read pathname
do
echo REVERSING "$pathname" ;
artist=${pathname% ---*} # artist is everything before " ---"
echo Artist: "$artist"
if [ ! -d "$artist" ];
then
echo Creating "$artist" folder
mkdir "$artist"
fi
album=${pathname##*--- } # album is everything after "--- "
album=${album%/*} # strip trailing /
echo Album: "$album"
echo Moving "$pathname" "$artist"/"$album"
mv "$pathname" "$artist"/"$album"
done
}