#!/bin/bash
# Copyright Daniel Jones 2018

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Make sure the script fails if the other commands fail as well
set -eo pipefail

# check for mkvextract
command -v mkvextract >/dev/null 2>&1 || { echo >&2 "Requires mkvextract. Aborting."; exit; }

POSITIONAL=();
while [[ $# -gt 0 ]]
do
	key="$1";
	case $key in
		-d|--directory)
			DIRECTORY="$2";
			shift;
			shift;
			;;
		-f|--file)
			FILE="$2";
			shift;
			shift;
			;;
		-t|--track)
			TRACK="$2";
			shift;
			shift;
			;;
		-w|--word)
			WORD="$2";
			shift;
			shift;
			;;
		-m|--merge)
			MERGE=1;
			shift;
			shift;
			;;
	esac
done
set -- "{$POSITIONAL[@]}";

# check if out directory exists
# TODO handle case out exists but other subdirs don't
if [ ! -d "out" ]; then
	echo "making out directory..";
	mkdir out;
	mkdir out/clips;
fi

if ! [[ -z $FILE || -z $DIRECTORY ]]; then
	echo "You have both -d and -f set.. choose one, not both..";
	exit;
fi

if [[ -z $FILE && -z $DIRECTORY ]]; then
	echo "no file or directory provided (use -f [file] or -d [dir])..";
	exit;
fi

if [ -z "$TRACK" ]; then
	#assume subtitle track = 2
	echo "track not set (use -t [truck number]). You kind find the subtitle track number using 'mkvinfo [file]'..";
	exit;
fi

if [ -z "$WORD" ]; then
	echo "no word set, using default word (use -w [word] to set the word)..";
	WORD="idiot"; # baka~
fi

if ! [ -z "$FILE" ]; then
	#echo "using single file..";
	SINGLEFILE=true;
fi

if ! [ -z "$DIRECTORY" ]; then
	#echo "using directory";
	SINGLEFILE=false;
fi

# we're done the boring stuff

x=0;

function getsubs
{
	# $1 = file
	#echo "getting subs for "$1"";
	rm out/subs.srt || true;
	CFILE=$(basename "$1" .mkv);
	#echo "CFILE is "$CFILE"";
	#echo "extracting subs from $1 track ${TRACK} to out/subs.srt";
	mkvextract tracks "$1" ${TRACK}:out/subs.srt;
	grepsubs "$1" "$CFILE";
}

function grepsubs
{
	# $1 = file $2 = CFILE
	while read -r line; do
		((x++)) || true;
		#echo "line in grep ${line}";
		#parselinie $x "$1" $line;
		parseline "$1" "$line" "$2";
	done < <(grep -i "$WORD" out/subs.srt);
}

function parseline
{

	# $1 = file $2 = line $3 = CFILE
	IFS=',' read -r -a array <<< "$2";
	echo "start time: ${array[1]}";
	echo "end time: ${array[2]}";
	cutvideo "$1" "${array[1]}" "${array[2]}" "$3";
}

function cutvideo
{
	# $1 = file $2 = start time $3 = end time $4 = CFILE
	
	echo "$1" start time: "$2" end time: "$3" >> out/times.txt;

	ffmpeg -i "$1" -ss 0"$2" -to 0"$3" -async 1 -c:v libx264 -preset ultrafast out/clips/clip_"$x".mkv < /dev/null

	#ffmpeg -i "$1" -ss 0"$2" -to 0"$3" -async 1 -map 0:0 -map 0:2 -c:v libx264 -preset ultrafast out/clips/clip_"$x".mkv < /dev/null;
}

function merge
{
	echo "merging mkv's..";
	str=();
	x=0;
	for f in out/clips/*.mkv; do
		if [ $x == 0 ]; then
			str+=""$f"";
		fi
		if [ $x != 0 ]; then
			str+=" +"$f"";
		fi
		((x++)) || true;
	done;
	mkvmerge $str -o out/out.mkv
}

# getsubs function will run the chain that does the whole process

if ! [ -z "$MERGE" ]; then
	merge;
	exit;
fi

if [ $SINGLEFILE == true ]; then
	echo "doing one file";
	getsubs "$FILE";
fi

if [ $SINGLEFILE == false ]; then
	for f in "$DIRECTORY"/*.mkv; do
		getsubs "$f";
	done;
fi