#!/usr/bin/python

# Update the snippet metadata for a video. Sample usage:
#   python update_video.py --video_id=<VIDEO_ID> --tags="<TAG1, TAG2>" --title="New title" --description="New description"

import argparse
import os

import google.oauth2.credentials
import google_auth_oauthlib.flow
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from google_auth_oauthlib.flow import InstalledAppFlow


# The CLIENT_SECRETS_FILE variable specifies the name of a file that contains
# the OAuth 2.0 information for this application, including its client_id and
# client_secret. You can acquire an OAuth 2.0 client ID and client secret from
# the {{ Google Cloud Console }} at
# {{ https://cloud.google.com/console }}.
# Please ensure that you have enabled the YouTube Data API for your project.
# For more information about using OAuth2 to access the YouTube Data API, see:
#   https://developers.google.com/youtube/v3/guides/authentication
# For more information about the client_secrets.json file format, see:
#   https://developers.google.com/api-client-library/python/guide/aaa_client_secrets
CLIENT_SECRETS_FILE = 'client_secret.json'

# This OAuth 2.0 access scope allows for full read/write access to the
# authenticated user's account.
SCOPES = ['https://www.googleapis.com/auth/youtube']
API_SERVICE_NAME = 'youtube'
API_VERSION = 'v3'

# Authorize the request and store authorization credentials.
def get_authenticated_service():
  flow = InstalledAppFlow.from_client_secrets_file(CLIENT_SECRETS_FILE, SCOPES)
  credentials = flow.run_console()
  return build(API_SERVICE_NAME, API_VERSION, credentials = credentials)

def update_video(youtube, args):
  # Call the API's videos.list method to retrieve the video resource.
  videos_list_response = youtube.videos().list(
    id=args.video_id,
    part='snippet'
  ).execute()

  # If the response does not contain an array of 'items' then the video was
  # not found.
  if not videos_list_response['items']:
    print 'Video "%s" was not found.' % args.video_id
    sys.exit(1)

  # Since the request specified a video ID, the response only contains one
  # video resource. This code extracts the snippet from that resource.
  videos_list_snippet = videos_list_response['items'][0]['snippet']

  # Set video title, description, default language if specified in args.
  if args.title:
    videos_list_snippet['title'] = args.title
  if args.description:
    videos_list_snippet['description'] = args.description

  # Preserve any tags already associated with the video. If the video does
  # not have any tags, create a new array. Append the provided tag to the
  # list of tags associated with the video.
  if 'tags' not in  videos_list_snippet:
    videos_list_snippet['tags'] = []
  if args.tags:
    videos_list_snippet['tags'] = args.tags.split(',')
  elif args.add_tag:
    videos_list_snippet['tags'].append(args.add_tag)

  print(videos_list_snippet);

  # Update the video resource by calling the videos.update() method.
  videos_update_response = youtube.videos().update(
    part='snippet',
    body=dict(
      snippet=videos_list_snippet,
      id=args.video_id
    )).execute()

  print('The updated video metadata is:\n' +
        'Title: ' + videos_update_response['snippet']['title'] + '\n')
  if videos_update_response['snippet']['description']:
    print ('Description: ' +
           videos_update_response['snippet']['description'] + '\n')
  if videos_update_response['snippet']['tags']:
    print ('Tags: ' + ','.join(videos_update_response['snippet']['tags']) + '\n')

if __name__ == '__main__':
  parser = argparse.ArgumentParser()
  parser.add_argument('--video_id', help='ID of video to update.',
    required=True)
  parser.add_argument('--tags',
    help='Comma-separated list of tags relevant to the video. This argument ' +
         'replaces the existing list of tags.')
  parser.add_argument('--add_tag', help='Additional tag to add to video. ' +
      'This argument does not affect current tags.')
  parser.add_argument('--title', help='Title of the video.')
  parser.add_argument('--description', help='Description of the video.')
  args = parser.parse_args()

  youtube = get_authenticated_service()
  try:
    update_video(youtube, args)
  except HttpError, e:
    print 'An HTTP error %d occurred:\n%s' % (e.resp.status, e.content)
    print 'Tag "%s" was added to video id "%s".' % (args.add_tag, args.video_id)