#!/bin/sh

# Copyright (c) 2012 Igor Bogomazov <ygrex@ygrex.ru>

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# revision 2012111800

# Usage:
#	split2flac.sh media_file.flac cue_sheet.cue

err() {
	echo "$@" >&2
	exit 1
}

media_file="$1"
test -n "$media_file" || err "media file is not specified"
cue_file="$2"
test -n "$cue_file" || err "CUE file is not specified"

test -n "$tmp" || tmp="$(mktemp -d --tmpdir=./ split2flac.XXXXXX)"
test -n "$tmp" || err "Temporary directory is not created"

convertMedia() {
	if mac "$media_file" -v ; then
		mac "$media_file" /dev/stdout -d \
			| flac --best -c /dev/stdin >"$tmp"/out.flac
		return $?
	fi
	# assume it is FLAC by default
	ln "$media_file" "$tmp"/out.flac
}

test -e "$tmp"/out.flac \
	|| convertMedia || err "Media file convertion failed"
flac -t "$tmp"/out.flac || err "FLAC file is corrupted: ""$tmp"/out.flac

splitMedia() {
	cuebreakpoints "$cue_file" \
		| shnsplit -d "$tmp" -O always -a track -o flac "$tmp"/out.flac
	return $?
}

splitMedia || err "Media file splitting failed"
cuetag "$cue_file" "$tmp"/track*flac || err "Setting tags failed"

renameMedia() {
	file="$1"
	cap_sed='^[[:space:]]*comment\[[[:digit:]]+\][[:space:]]*:[[:space:]]*([^[:space:]=][^=]*=.*)$'
	cap_title='TITLE'
	cap_tracknumber='TRACKNUMBER'
	name="$(
		metaflac --list --block-type=VORBIS_COMMENT "$file" \
			| sed -nr 's@'"$cap_sed"'@\1@p' \
			| awk -F= '
				BEGIN {
					title = ""
					track = ""
				}
				(toupper($1) ~ "'"$cap_title"'") {
					title = $2
				}
				(toupper($1) ~ "'"$cap_tracknumber"'") {
					track = $2
				}
				END {
					if (track == "" || title == "") exit;
					printf "%02d. %s.flac", track, title
				}
			'
	)"
	test -n "$name" && mv "$file" "$name"
}

fails=
for file in "$tmp"/track*flac ; do
	if ! renameMedia "$file" ; then
		echo "Failed to compose name for: ""$file"
		fails=true
	fi
done

test -z "$fails" && {
	rm -f "$tmp"/out.flac
	rmdir "$tmp"
}

exit 0