require 'google/apis/youtube_v3'
require 'googleauth'
require 'googleauth/stores/file_token_store'
require 'fileutils'
require 'json'
require 'redd'
require 'dotenv'
Dotenv.load

SUBREDDIT = ARGV[0] || 'hiphopheads'
PLAYLIST_ID = ARGV[1] || 'PLGt3gNR-AoFkJR021gXUKlmqZWFosjXFm'
INTERVAL = ARGV[2] || 'day'

DONE_IDS = begin
  File.readlines('/tmp/youtube-' + SUBREDDIT + '.txt').map(&:strip)
rescue
  []
end

SERVICE = Google::Apis::YoutubeV3::YouTubeService.new

def authorize
  credentials_path = File.join(Dir.home, '.credentials','youtube-api.yaml')

  FileUtils.mkdir_p(File.dirname(credentials_path))

  client_id = Google::Auth::ClientId.from_file(__dir__ + "/client_secret.json")
  token_store = Google::Auth::Stores::FileTokenStore.new(file: credentials_path)
  authorizer = Google::Auth::UserAuthorizer.new(client_id, Google::Apis::YoutubeV3::AUTH_YOUTUBE, token_store)
  user_id = 'default'
  credentials = authorizer.get_credentials(user_id)
  if credentials.nil?
    url = authorizer.get_authorization_url(base_url: 'urn:ietf:wg:oauth:2.0:oob')
    puts "Open the following URL in the browser and enter the resulting code after authorization:"
    puts url
    code = gets
    credentials = authorizer.get_and_store_credentials_from_code(user_id: user_id, code: code, base_url: 'urn:ietf:wg:oauth:2.0:oob')
  end
  credentials
end

# --- main program starts here

SERVICE.authorization = authorize

class YouTubePlaylist
  def initialize(id)
    @id = id
  end

  def include?(video_id)
    begin
      item = SERVICE.list_playlist_items('snippet', playlist_id: @id, video_id: video_id)
    rescue Google::Apis::ClientError => e
      if e.status_code
        return false
      end
    end

    item.items.size > 0
  end

  def add_video(video_id)
    playlist_item = Google::Apis::YoutubeV3::PlaylistItem.new
    playlist_item.snippet = Google::Apis::YoutubeV3::PlaylistItemSnippet.new(playlist_id: @id)
    playlist_item.snippet.resource_id = Google::Apis::YoutubeV3::ResourceId.new(video_id: video_id, kind: 'youtube#video')

    begin
      SERVICE.insert_playlist_item('snippet', playlist_item)
      return true
    rescue
      return false
    end
  end

  def add_video_unique(video_id)
    add_video(video_id) unless self.include?(video_id)
  end
end

class YouTube
  def initialize
    @client = SERVICE
  end

  def get_video(video_id)
    vid = SERVICE.list_videos('snippet,contentDetails', id: video_id).items.first
    title = vid.snippet.title
    duration_parts = vid.content_details.duration.match(/(\d+)M(\d+)S/)
    duration_in_seconds = (duration_parts[1].to_i * 60) + duration_parts[2].to_i

    { title: title, duration: duration_in_seconds }
  rescue
    nil
  end
end

REDDIT = Redd.it(:script, ENV['REDDIT_CLIENT_ID'], ENV['REDDIT_SECRET'], ENV['REDDIT_USERNAME'], ENV['REDDIT_PASSWORD'], user_agent: ENV['REDDIT_USER_AGENT'])
playlist = YouTubePlaylist.new(PLAYLIST_ID)

items = REDDIT.get_top(SUBREDDIT, t: INTERVAL, limit: 100)

items.each do |item|
  next unless item.url =~ /youtube\.com\/watch/
  next if item.title =~ /(interview|trailer)/i
  next unless item.ups > 4

  video_id = item.url[/v=(.{11})/, 1]
  if DONE_IDS.include?(video_id)
    STDERR.puts "Already done #{video_id} - skipping"
    next
  end

  File.open('/tmp/youtube-' + SUBREDDIT + '.txt', 'a') do |f|
    f.puts video_id
  end

  STDERR.puts "Doing #{video_id}"

  video = YouTube.new.get_video(video_id)

  if video && !video[:duration].between?(120, 480)
    STDERR.puts "- video is too short or long at #{video[:duration]} seconds, skipping"
    next
  end

  if playlist.add_video_unique(video_id)
    STDERR.puts "- Done"
  else
    STDERR.puts "- Already in playlist, or failed"
  end
end