#!/usr/bin/env python3

from youtube_api import YouTubeAPI
import sys, os
import youtube_dl

# Read YouTube API Key.
def getYouTubeAPIKey():
  return open('youtube.key', 'r').read()

def getTitle(info):
  return info[0]

def getUploadTime(info):
  return info[1]

def getYear(info):
  return int(getUploadTime(info)[:4])

def getChannel(info):
  return info[2]

def getChannelId(info):
  return info[3]

def getDescription(info):
  return info[4]

def getTags(info):
  if isinstance(info[5], list):
    return '[' + ','.join(info[5]) + ']'
  return info[5]

def getPrivacy(info):
  return info[6]

def getId(info):
  return info[7]

# Print out information about a video.
def printVideoInfo(info):
  title, date, channel, channelId, description, tags, privacy = info
  print('Title: ' + title)
  print('Date: ' + date)
  print('Channel: {} ({})'.format(channel, channelId) )
  print('Description: ' + description)
  print('Tags: ', tags)
  print('Privacy: ' + privacy)

playlistId = sys.argv[1]

# Create download directory
downloadDir = 'playlists'
playlistDir = downloadDir+'/'+playlistId
if not os.path.exists(downloadDir):
  os.mkdir(downloadDir)
if not os.path.exists(playlistDir):
  os.mkdir(playlistDir)
  
api = YouTubeAPI(getYouTubeAPIKey())
videos = api.getPlaylistVideos(playlistId)

videoInfo = [api.getVideoInfo(video['snippet']['resourceId']['videoId']) for video in videos]
filteredVideos = [video for video in videoInfo if getPrivacy(video) == 'unlisted' and getYear(video) <= 2017]

ydl_opts = {
  'outtmpl': '{}/%(uploader)s-%(title)s-%(id)s.%(ext)s'.format(playlistDir)
}

for v in filteredVideos:

  # Save metadata to file
  descriptionFile = '{}/{}-{}-{}.txt'.format(playlistDir,
                                              getChannel(v),
                                              getTitle(v).replace('/', ''),
                                              getId(v))
  if not os.path.exists(descriptionFile):
    description = open(descriptionFile, 'w')
    description.write('Title: ' + getTitle(v) + '\n')
    description.write('Uploaded: ' + getUploadTime(v) + '\n')
    description.write('Channel: ' + getChannel(v) + '\n')
    description.write('Channel ID: ' + getChannelId(v) + '\n')
    description.write('Description: ' + getDescription(v) + '\n')
    description.write('Tags: ' + getTags(v) + '\n')
    description.write('Video ID: ' + getId(v) + '\n')
    description.close()
    
    videoURL = 'https://www.youtube.com/watch?v='+getId(v)
    with youtube_dl.YoutubeDL(ydl_opts) as ydl:
      ydl.download([videoURL])