#!/usr/bin/env bash
set -e

input="$1"
EXT2="m4a"

if [ -z "$AAX_ACTIVATION_BYTES" ]; then
  echo "set AAX_ACTIVATION_BYTES env var"
  exit 1
fi

json=$(ffprobe -activation_bytes "$AAX_ACTIVATION_BYTES" -i "$input" -loglevel error -print_format json -show_format -show_chapters)
title=$(echo $json | jq -r ".format.tags.title")
count=$(echo $json | jq ".chapters | length")
target=$(echo $json | jq -r ".format.tags | .date + \" \" + .artist + \" - \" + .title")
mkdir "$target"

for i in $(seq -w 1 $count); do
  j=$((10#$i))
  n=$(($j - 1))
  start=$(echo $json | jq -r ".chapters[$n].start_time")
  end=$(echo $json | jq -r ".chapters[$n].end_time")
  name=$(echo $json | jq -r ".chapters[$n].tags.title")
  ffmpeg -activation_bytes "$AAX_ACTIVATION_BYTES" -i $input -ss $start -to $end -metadata title="$title $name" -vn -c:a copy "$target/$i $name.$EXT2"
done