#!/usr/bin/env ruby

# youtube-rss-dl
#   Customize CHANNELS and DESTINATION, then add to cron.

require 'logger'
require 'json'
require 'open-uri'
require 'simple-rss'
require 'youtube-dl.rb'

PROGNAME = '.youtube-rss-dl'
VERSION = '1.0.2'

SELFDIR = File.expand_path(File.dirname(__FILE__))

RSS_BASE_URL = 'https://www.youtube.com/feeds/videos.xml?channel_id='
CHANNELS = {
  'ADVChina' => 'UCwNPa8fSXzzAZuT9859GVhg',
  'Brian Lunduke' => 'UCkK9UDm_ZNrq_rIXCz3xCGA',
  'Lazy Game Reviews' => 'UCLx053rWZxCiYWsBETgdKrQ',
  'Linus Tech Tips' => 'UCXuqSBlHAE6Xw-yeJA0Tunw',
  'Marques Brownlee' => 'UCBJycsmduvYEL83R_U4JriQ',
  'Primitave Technology' => 'UCAL3JXZSzSm8AlZyD3nQdBA'

}
DESTINATION = SELFDIR
YOUTUBEDL_OPTIONS = {
  force_ipv4: true,
  format: 'bestvideo[ext=mp4][width<=1920][height<=1080]+bestaudio[ext=m4a]',
  add_metadata: true,
  xattrs: true,
  embed_thumbnail: true,
  output: "#{DESTINATION}/%(uploader)s - %(upload_date)s - %(title)s.%(ext)s"
}

# load/create log file
logger = Logger.new(File.join(SELFDIR, PROGNAME + '.log'))
logger.level = Logger::WARN

# load/create database json
json = File.join(SELFDIR, PROGNAME + '.json')
File.write(json, JSON.generate({})) unless File.file?(json)
database = JSON.parse(File.read(json))

# parse each channel
CHANNELS.each do |channel_name, channel_id|
  # check hash key
  database[channel_name] ||= []

  puts "Checking: #{channel_name}"

  # get the feed
  begin
    rss = SimpleRSS.parse open(RSS_BASE_URL + channel_id)
  rescue => e
    logger.error('RSS') {
      "'#{channel_name}':#{channel_id} - #{e}"
    }
    raise e
  end

  # parse each rss item
  rss.items.each do |video|
    next if database[channel_name].include?(video.id)

    puts "  Downloading: #{video.title}"

    # download video
    begin
### ### ### ### Comment next line to update JSON without downloading
      YoutubeDL.download video.link, YOUTUBEDL_OPTIONS
      logger.info('YoutubeDL') {
        "'#{channel_name}' '#{video.title}' OK"
      }
    rescue => e
      logger.error('YoutubeDL') {
        "'#{channel_name}':#{channel_id} #{video.id}:#{video.link} - #{e}"
      }
      raise e
    end

    # add video id to json
    database[channel_name] << video.id
    File.write(json, JSON.pretty_generate(database))
  end
end