#!/bin/bash

#Создан:  Ср 19 фев 2020 21:59:29
#Изменён: Чт 20 фев 2020 00:45:38

# Requirements:
# - mid3v2 from media-libs/mutagen

rstc="\033[00m"
green="\033[1;32m"
yellow="\033[1;33m"
blue="\033[1;34m"

REGEXP=".*/(.*)/(.*) \[(.*)\]/(.*)/(.*?) - (.*)/(.*?) - (.*)\.([[:alnum:]]{3})$"

usage() {
	echo "$(basename "$0") - simple mp3 tagger."
	echo
	echo "USAGE: $(basename "$0") [file] [options]"
	echo
	echo "The filenames should be in the format \"[...]/GENRE/ARTIST [COUNTRY]/TYPE/YEAR - ALBUM/TRACK - TITLE.FORMAT\""
	echo
	echo "Command line arguments:"
	echo "    -h --help    - show this help"
	echo "    -v --verbose - show updating tags"
	echo "    -d --dry     - run without tags saving"
}

tag_file() {
	file="$1"

	[[ $file =~ $REGEXP ]]

	printf "${blue}%s[%02d/%02d] ${yellow}Tagging the file «%s»${rstc}\n" "$INDENT" "$((++CURRENT_TRACK))" "$TRACKS" "$file"

	GENRE="${BASH_REMATCH[1]}"
	ARTIST="${BASH_REMATCH[2]}"
	YEAR="${BASH_REMATCH[5]}"
	ALBUM="${BASH_REMATCH[6]}"
	TRACK="${BASH_REMATCH[7]}"
	TITLE="${BASH_REMATCH[8]}"

	if [ -n "$VERBOSE" ]; then
		printf "%s\t  Genre: %s | Artist: %s |" "$INDENT" "$GENRE" "$ARTIST"
		printf "Year:  %s | Album:  %s |" "$YEAR"  "$ALBUM"
		printf "Track: %s | Title:  %s\n" "$TRACK" "$TITLE"
	fi

	if [ -z "$DRY_RUN" ]; then
		mid3v2  --genre="$GENRE" --artist="$ARTIST" --year="$YEAR"   \
			--album="$ALBUM" --track="$TRACK"   --song="$TITLE"  \
		"$file"
	fi
}

tag_directory() {
	TRACKS=$(find "$1" -name '*.mp3' -print | wc -l)

	printf "${green}> %s/${rstc}\n" "$1"
	INDENT="  "


	find "$1" -name '*.mp3' | while read -r file; do tag_file "$file"; done
}

tag() {
	if [[ -d "$1" ]]; then
		tag_directory "$1"
	elif [[ "$1" =~ \.mp3 ]]; then
		tag_file "$1"
	fi
}

if (( $# == 0 )); then
	usage
	exit 1
fi

QUEUE=()

while [[ $# -gt 0 ]]; do
	key="$1"

	case $key in
	    -h|--help) usage; exit 0; shift;;
	    -v|--verbose) VERBOSE=1; shift;;
	    -d|--dry) DRY_RUN=1; VERBOSE=1; shift;;
	    *) QUEUE+=("$1"); shift;;
	esac
done

set -- "${QUEUE[@]}"

INDENT=
TRACKS="$#"
CURRENT_TRACK=0

for item in "${QUEUE[@]}"; do
	tag "$(realpath "$item")"
done