#!/bin/bash
# config
poll=300
video_id=`echo "${1}" | grep -o ".\{11\}$"`
format='bestvideo[ext=webm]+bestaudio[ext=webm]'
cookies=/path/to/cookies.txt
cookies_chat=/path/to/cookies_chat.txt
chat_venv=/path/to/chat-downloader/venv

echo "`date`: Downloading ${video_id}."

# wait for opus encoding
echo "`date`: Polling for Opus encoding (${poll} seconds)."
until youtube-dl -F --cookies "$cookies" "$1" | grep opus > /dev/null 2>&1 ; do
  echo "`date`: Waiting..."
  sleep $poll
done

# wait for VP9 encoding
echo "`date`: Polling for VP9 encoding (${poll} seconds)."
until youtube-dl -F --cookies "$cookies" "$1" | grep vp9 > /dev/null 2>&1 ; do
  echo "`date`: Waiting..."
  sleep $poll
done

# chat_downloader job
{
  echo "`date`: Starting chat log download."
  source $chat_venv/bin/activate
  chat_downloader --cookies "$cookies_chat" --message_type all --chat_type live "https://youtube.com/watch?v=${video_id}" > "${video_id}".log &&
  echo "`date`: Chat log download completed: `wc -l ${video_id}.log`"
} &

# youtube-dl job
{
  echo "`date`: Starting video and metadata download."
  youtube-dl --cookies "$cookies" --write-thumbnail --write-description -f "${format}" "$1" || {
    echo "`date`: Video download failed."
    exit 1
  }
  echo "`date`: Video and metadata download ended."
} &

# wait for background jobs to finish
wait

# cleanup
echo "`date`: Cleaning up."
base_filename=`echo *"${video_id}.description" | sed -e 's/\.description$//'`
mv "${video_id}.log" "${base_filename}.log"
[ -f "${base_filename}.jpg" ] || {
  echo "`date`: Missing JPEG thumbnail. Downloading maxresdefault.jpg."
  wget -O "${base_filename}.jpg" https://i.ytimg.com/vi/${video_id}/maxresdefault.jpg
}
[ -s "${base_filename}.log" ] || {
  echo "`date`: Chat log is empty. Deleting it."
  rm "${base_filename}.log"
}
echo "`date`: Updating file timestamps."
touch -cr "${base_filename}".webm "${base_filename}".{log,description,jpg,webp} 2>/dev/null
echo "`date`: Archive completed."

# print validation info
ls -lh "${base_filename}".*
[ -f "${base_filename}.log" ] && {
  tail -n 5 "${base_filename}".log
}
ffprobe -i "${base_filename}".webm 2>&1 |grep Duration: