# Sample Python code for user authorization

import httplib2
import os
import sys

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

# 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.
CLIENT_SECRETS_FILE = "client_secret.json"

# This OAuth 2.0 access scope allows for full read/write access to the
# authenticated user's account and requires requests to use an SSL connection.
YOUTUBE_READ_WRITE_SSL_SCOPE = "https://www.googleapis.com/auth/youtube.readonly"
API_SERVICE_NAME = "youtube"
API_VERSION = "v3"

# This variable defines a message to display if the CLIENT_SECRETS_FILE is
# missing.
MISSING_CLIENT_SECRETS_MESSAGE = "WARNING: Please configure OAuth 2.0"

# Authorize the request and store authorization credentials.
def get_authenticated_service(args):
  flow = flow_from_clientsecrets(CLIENT_SECRETS_FILE, scope=YOUTUBE_READ_WRITE_SSL_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)

  # Trusted testers can download this discovery document from the developers page
  # and it should be in the same directory with the code.
  return build(API_SERVICE_NAME, API_VERSION,
      http=credentials.authorize(httplib2.Http()))

args = argparser.parse_args()
service = get_authenticated_service(args)

### END BOILERPLATE CODE

# Sample python code for channels.list

def channels_list_by_username(service, **kwargs):
  results = service.channels().list(
    **kwargs
  ).execute()

  print('This channel\'s ID is %s. Its title is %s, and it has %s views.' %
       (results['items'][0]['id'],
        results['items'][0]['snippet']['title'],
        results['items'][0]['statistics']['viewCount']))

channels_list_by_username(service, part='snippet,contentDetails,statistics', forUsername='GoogleDevelopers')