#!/bin/sh

# this script renames directories and flac files using the following format:

# directories:	${artist} [${date}] ${album} [FLAC-${bitdepth}bit-${samplerate}]
# eg:		YENA [2023.01.16] Love War [FLAC-24bit-48kHz]

# files:	${discnumber}-${tracknumber} ${title}.flac
# eg:		1-03 Love War (Feat. BE'O).flac

# it is intended to be run AFTER the metadata script.

# for safety, the script will perform a dry run by default. to actually move files, run the script with the -m flag.
# if a variable cannot be set, the script will skip making changes and print a warning to the terminal and to the log file.

# check dirs and files
check() {
	[ ! -d "$master" ] && echo "invalid directory!" && exit
	[ ! -d logs ] && mkdir logs
	[ ! -f lists/tags.csv ] && echo "could not find tags.csv database. generate it using ./list.sh -d <directory> -t" && exit
}

# print to log file
log() {
	printf "\033[1m\033[38;5;210mcould not set %s. manual intervention required!\033[0m\n" "$2"
	echo "$1 - could not set $2" >> logs/rename.log
}

# filter to remove illegal characters from file names. mostly relevant for shitty windows filesystems.
filter() {
	if echo "$name" | grep -qE '(<|>|:|"|/|\\|\||\?|\*|(\.| )$)' || echo "$name" | grep -qP '\t' || echo "$name" | grep -qzP '\n'; then
		name="$(echo "$name" | tr '\n' ' ' | tr '\t' ' ' | sed 's|^-||;
								    s|^\.||;
								    s|^_||;
								    s|<||g;
								    s|>||g;
								    s|:||g;
								    s|"||g;
								    s|/|-|g;
								    s|\\||g;
								    s|\||-|g;
								    s|\?||g;
								    s|\*||g;
								    s| $||;
								    s|\.$||')"
	fi
}

# process file names
renamefile() {
	disc=$(metaflac --show-tag=DISCNUMBER "$file" | cut -d '=' -f 2)
	# if first character of DISCNUMBER is 0, remove it
	[ "$(echo "$disc" | cut -c 1)" = "0" ] && disc="$(echo "$disc" | cut -c 2)"

	track=$(metaflac --show-tag=TRACKNUMBER "$file" | cut -d '=' -f 2 | cut -d '/' -f 1)
	# if TRACKNUMBER is only a single character, prefix it with a 0
	[ "$(printf "%s" "$track" | wc -c)" -eq 1 ] && track="0${track}"

	title=$(metaflac --show-tag=TITLE "$file" | cut -d '=' -f 2-)

	if [ -z "$disc" ] || [ -z "$track" ] || [ -z "$title" ]; then
		# log missing tags
		[ -z "$disc" ] && log "$file" "disc number"
		[ -z "$track" ] && log "$file" "track number"
		[ -z "$title" ] && log "$file" "track title"
	else
		name="$disc-$track $title.flac"
		filter
		[ "$mod" = "true" ] && mv -iv "$file" "$dir/$name" || echo "$(basename "$file") -> $name"
	fi
}

# process directory names
renamedir() {
	# prefer using a track without features
	file="$(find "$dir" -type f -name '*.flac' | grep -ivE feat | head -n 1)"

	if [ "$(find "$dir" -type f -name '*.flac' | wc -l)" -eq 1 ] || [ -z "$file" ]; then
		file="$(find "$dir" -type f -name '*.flac' | head -n 1)"
	fi

	artist="$(metaflac --show-tag=ARTIST "$file" | cut -d '=' -f 2)"

	# ALBUMARTIST tag should be used unless artist is a sub-unit
	if ! grep ^U lists/tags.csv | cut -f 2 | grep -qi -m 1 "$artist"; then
		artist="$(metaflac --show-tag=ALBUMARTIST "$file" | cut -d '=' -f 2)"
	fi

	date="$(metaflac --show-tag=DATE "$file" | cut -d '=' -f 2)"
	album="$(metaflac --show-tag=ALBUM "$file" | cut -d '=' -f 2)"
	rate="$(metaflac --show-sample-rate "$file" | sed 's/0.*$//;s/44/44./;s/88/88./')"
	depth="$(metaflac --show-bps "$file")"

	# assemble date tag
	if [ -n "$date" ]; then
		y=$(echo "$date" | cut -c 1-4)
		m=$(echo "$date" | cut -c 5,6)
		d=$(echo "$date" | cut -c 7,8)
		date="$y.$m.$d"
	fi

	if [ -z "$artist" ] || [ -z "$date" ] || [ -z "$album" ] || [ -z "$rate" ] || [ -z "$depth" ]; then
		# log missing tags
		[ -z "$artist" ] && log "$dir" "artist name"
		[ -z "$date" ] && log "$dir" "release date"
		[ -z "$album" ] && log "$dir" "album name"
		[ -z "$rate" ] && log "$dir" "sample rate"
		[ -z "$depth" ] && log "$dir" "bit depth"
	else
		path="${dir%/*}"
		name="$artist [$date] $album [FLAC-${depth}bit-${rate}kHz]"
		filter
		[ "$mod" = "true" ] && mv -iv "$dir" "$path/$name" || echo "$(basename "$dir") -> $name"
	fi
}

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

check

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

[ "$mod" != "true" ] && printf "\033[1mPerforming DRY RUN. use -m to modify files.\033[0m\n"

# set numbers
total="$(find "$master" -type d -links 2 | wc -l)"
num=1

# main loop
find "$master" -type d -links 2 | while read -r dir; do
	if ls "$dir"/*.flac >/dev/null 2>&1; then
		printf "\n\033[1m[%d/%d] %s\033[0m\n" "$num" "$total" "$(basename "$dir")"
		for file in "$dir"/*.flac; do
			renamefile
		done
		renamedir

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

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