#!/usr/bin/env bash

shopt -s globstar nullglob

root="${1:-.}"

for file in "$root"/**/*; do
    [[ -f "$file" ]] || continue

    case "${file##*.}" in
        epub|EPUB)
            continue
            ;;
        nfo|NFO)
            grouping="$(grep -i 'Series Name:' "$file" 2>/dev/null  | sed 's/^[Ss]eries:[[:space:]]*//')"
            ;;
        m4b|M4B|m4a|M4A|mp3|MP3|aac|AAC|flac|FLAC)
grouping="$(kid3-cli -c "get grouping" "$file" 2>/dev/null)"
            ;;
        *)
            continue
            ;;
    esac

    if [[ ! "$grouping" =~ Publication ]]; then
echo Grouping: $grouping        
echo "$file"
    fi
done