#!/bin/sh

# this script uses metaflac to set the genre tag.

# tags will first be set based on language:

# japanese -> J-Pop
# chinese -> C-Pop
# korean/english/etc. -> K-Pop

# then files with 'inst' or 'instrumental' in the name will also be given the Instrumental tag.

# for the script to work properly, albums must first be sorted into their appropriate language folders like so:

# YENA/Lossless/Japanese/YENA [2023.08.07] SMILEY [FLAC-16bit-44.1kHz]

check() {
	[ ! "$(command -v metaflac)" ] && echo "metaflac must be installed to use this script." && exit
	[ ! -d "$master" ] && echo "invalid directory!" && exit
	[ ! -d "$(dirname "$log")" ] && mkdir "$(dirname "$log")"
}

while getopts "d:mh" o; do case "${o}" in
	d) master="$OPTARG";;
	m) mod=1;;
	h|*) printf "usage: ./%s [OPTION]...\n\noptions:
 -d specify directory to scan
 -m modify files\n" "$(basename "$0")" && exit 1
esac done

# set log file.
log="../logs/genre.log"

# check variables and programs.
check

# begin new log.
printf "\nscript run - %s\n" "$(date)" >> "$log"

[ -z "$mod" ] && printf "\033[1mperforming DRY RUN. use -m to modify files.\033[0m\n\n"

# find sub directories in master directory.
dirs="$(find "$master" -type d -links 2)"

num=1
# main loop
echo "$dirs" | while read -r dir; do
	# check if directory contain flac files.
	if ls "$dir"/*.flac >/dev/null 2>&1; then
		printf "\033[1m[%d/%d] %s\033[0m\n" "$num" "$(echo "$dirs" | wc -l)" "$(echo "$dir" | sed 's|.*Lossless/||')"

		# get language.
		case "$(dirname "$dir" | sed 's|.*/||')" in
			Japanese) genre="J-Pop";;
			Chinese) genre="C-Pop";;
			*) genre="K-Pop";;
		esac

		# check if genre is already set correctly. doing this will leave additional genre tags intact.
		if [ "$(metaflac --show-tag=GENRE "$(ls "$dir"/*.flac | head -n 1)" | head -n 1 | cut -d '=' -f 2)" != "$genre" ]; then
			echo "setting genre -> $genre"
			if [ -n "$mod" ]; then
				# set genre.
				metaflac --remove-tag=GENRE --set-tag=GENRE="$genre" "$dir"/*.flac
				# check if genre was set correctly and no errors occurred.
				if [ "$(metaflac --show-tag=GENRE "$(ls "$dir"/*.flac | head -n 1)" | cut -d '=' -f 2)" != "$genre" ]; then
					echo "$dir -> failed setting genre: $genre" >> "$log"
				fi
			else
				echo "$dir -> $genre" >> "$log"
			fi
		else
			[ -z "$mod" ] && echo "genre already set correctly"
		fi

		# set instrumental tag.
		ls "$dir"/*.flac | while read -r file; do
			# check if file name contains 'inst' or 'instrumental'.
			if echo "${file%.*}" | grep -qE '(\([Ii]nst\)|[Ii]nst\.|[Ii]nstrumental)'; then
				# check if instrumental is already set correctly.
				if ! metaflac --show-tag=GENRE "$file" | grep -q Instrumental; then
					echo "$(basename "$file") setting genre -> Instrumental"
					if [ -n "$mod" ]; then
						metaflac --set-tag=GENRE=Instrumental "$file"
						# check if instrumental was set correctly and no errors occurred.
						if ! metaflac --show-tag=GENRE "$file" | grep -q Insrumental; then
							echo "$file -> failed setting Instrumental" >> "$log"
						fi
					else
						echo "$file -> Instrumental" >> "$log"
					fi
				else
					[ -z "$mod" ] && echo "$(basename "$file") -> Instrumental already set correctly"
				fi
			fi
		done

		num=$((num+1))
	fi
done

printf "\n\033[1mscript completed! remember to check log for errors.\033[0m\n"