#!/usr/bin/python


# This sample sets a custom banner to user's channel by:
#
# 1. Uploading a banner image with "youtube.channelBanners.insert" method via resumable upload
# 2. Getting user's channel object with "youtube.channels.list" method and "mine" parameter
# 3. Updating channel's banner external URL with "youtube.channels.update" method
#
# @author Ibrahim Ulukaya

import httplib
import httplib2
import os
import random
import sys
import time

from apiclient.discovery import build
from apiclient.errors import HttpError
from apiclient.http import MediaFileUpload
from oauth2client.client import flow_from_clientsecrets
from oauth2client.file import Storage
from oauth2client.tools import argparser, run_flow


# Explicitly tell the underlying HTTP transport library not to retry, since
# we are handling retry logic ourselves.
httplib2.RETRIES = 1

# Maximum number of times to retry before giving up.
MAX_RETRIES = 10

# Always retry when these exceptions are raised.
RETRIABLE_EXCEPTIONS = (httplib2.HttpLib2Error, IOError, httplib.NotConnected,
  httplib.IncompleteRead, httplib.ImproperConnectionState,
  httplib.CannotSendRequest, httplib.CannotSendHeader,
  httplib.ResponseNotReady, httplib.BadStatusLine)

# Always retry when an apiclient.errors.HttpError with one of these status
# codes is raised.
RETRIABLE_STATUS_CODES = [500, 502, 503, 504]

# CLIENT_SECRETS_FILE, name of a file containing the OAuth 2.0 information for
# this application, including client_id and client_secret. You can acquire an
# ID/secret pair from the APIs & auth tab at
#   https://cloud.google.com/console
# For more information about using OAuth2 to access Google APIs, please visit:
#   https://developers.google.com/accounts/docs/OAuth2
# For more information about the client_secrets.json file format, please visit:
#   https://developers.google.com/api-client-library/python/guide/aaa_client_secrets
# Please ensure that you have enabled the YouTube Data API for your project.
CLIENT_SECRETS_FILE = "client_secrets.json"

# An OAuth 2 access scope that allows for full read/write access.
YOUTUBE_READ_WRITE_SCOPE = "https://www.googleapis.com/auth/youtube"
YOUTUBE_API_SERVICE_NAME = "youtube"
YOUTUBE_API_VERSION = "v3"

# Helpful message to display if the CLIENT_SECRETS_FILE is missing.
MISSING_CLIENT_SECRETS_MESSAGE = """
WARNING: Please configure OAuth 2.0

To make this sample run you will need to populate the client_secrets.json file
found at:

   %s

with information from the APIs Console
https://cloud.google.com/console

For more information about the client_secrets.json file format, please visit:
https://developers.google.com/api-client-library/python/guide/aaa_client_secrets
""" % os.path.abspath(os.path.join(os.path.dirname(__file__),
                                   CLIENT_SECRETS_FILE))

def get_authenticated_service(args):
  flow = flow_from_clientsecrets(CLIENT_SECRETS_FILE,
    scope=YOUTUBE_READ_WRITE_SCOPE,
    message=MISSING_CLIENT_SECRETS_MESSAGE)

  storage = Storage("%s-oauth2.json" % sys.argv[0])
  credentials = storage.get()

  if credentials is None or credentials.invalid:
    credentials = run_flow(flow, storage, args)

  return build(YOUTUBE_API_SERVICE_NAME, YOUTUBE_API_VERSION,
    http=credentials.authorize(httplib2.Http()))

def upload_banner(youtube, image_file):
  insert_request = youtube.channelBanners().insert(
    media_body = MediaFileUpload(image_file, chunksize=-1, resumable=True)
  )

  image_url = resumable_upload(insert_request)
  set_banner(image_url)

def resumable_upload(insert_request):
  response = None
  error = None
  retry = 0
  while response is None:
    try:
      print "Uploading file..."
      status, response = insert_request.next_chunk()
      if 'url' in response:
        print "Banner was successfully uploaded to '%s'." % (
          response['url'])
      else:
        exit("The upload failed with an unexpected response: %s" % response)
    except HttpError, e:
      if e.resp.status in RETRIABLE_STATUS_CODES:
        error = "A retriable HTTP error %d occurred:\n%s" % (e.resp.status,
                                                             e.content)
      else:
        raise
    except RETRIABLE_EXCEPTIONS, e:
      error = "A retriable error occurred: %s" % e

    if error is not None:
      print error
      retry += 1
      if retry > MAX_RETRIES:
        exit("No longer attempting to retry.")

      max_sleep = 2 ** retry
      sleep_seconds = random.random() * max_sleep
      print "Sleeping %f seconds and then retrying..." % sleep_seconds
      time.sleep(sleep_seconds)

  return response['url']

def set_banner(banner_url):
  channels_response = youtube.channels().list(
    mine=True,
    part="brandingSettings"
  ).execute()

  if "brandingSettings" not in channels_response["items"][0]:
    channels_response["items"][0]["brandingSettings"]["image"]["bannerExternalUrl"] = []

  channel_brandingSettings = channels_response["items"][0]["brandingSettings"]

  channel_brandingSettings["image"]["bannerExternalUrl"] = banner_url

  channels_update_response = youtube.channels().update(
    part='brandingSettings',
    body=dict(
      brandingSettings=channel_brandingSettings,
      id = channels_response["items"][0]["id"]
    )).execute()

  banner_mobile_url = channels_update_response["brandingSettings"]["image"]["bannerMobileImageUrl"]
  print "Banner is set to '%s'." % (banner_mobile_url)

if __name__ == "__main__":
  argparser.add_argument("--file", required=True,
    help="Path to banner image file.")
  args = argparser.parse_args()

  if not os.path.exists(args.file):
    exit("Please specify a valid file using the --file= parameter.")

  youtube = get_authenticated_service(args)
  try:
    upload_banner(youtube, args.file)
  except HttpError, e:
    print "An HTTP error %d occurred:\n%s" % (e.resp.status, e.content)
  else:
    print "The custom banner was successfully uploaded."