"""
Automatic migration of subscriptions to another
YouTube account with Python and Selenium.

Tested with:
 - selenium 2.52
 - firefox 45.0
 - python 3.5

 1. Install selenium from pypi:
    $ pip install selenium

 2. Go to the down of page https://www.youtube.com/subscription_manager
    and download your current subscriptions feed.
    Save file as subscription_manager.xml.

 3. Enter your credentials into constants
    GOOGLE_EMAIL and GOOGLE_PASSWORD

 4. Run script and go to drink coffee.
    It will take some time.

Note YouTube will temporary block you if you have more that 80 subscriptions.
Just restart the script in a few hours.
"""

from collections import namedtuple
from selenium import webdriver
from xml.dom import minidom
import pickle
import time
import re
import os

GOOGLE_EMAIL = 'googleaccount@gmail.com'
GOOGLE_PASSWORD = 'securepassword'


def sign_in(driver, credentials):
    cookies_file = 'cookies.bin'
    if os.path.isfile(cookies_file):
        driver.get('http://www.youtube.com')
        cookies = pickle.load(open(cookies_file, 'rb'))
        for cookie in cookies:
            driver.add_cookie(cookie)
        driver.refresh()
        return

    email, password = credentials
    driver.get('https://www.google.com/accounts/Login?continue=http://www.youtube.com')
    driver.find_element_by_id('Email').send_keys(email)
    driver.find_element_by_id('next').click()
    time.sleep(1)
    driver.find_element_by_id('Passwd').send_keys(password)
    driver.find_element_by_id('signIn').click()

    pickle.dump(driver.get_cookies(), open(cookies_file, 'wb'))


def load_subcribtions():
    xmldoc = minidom.parse('subscription_manager.xml')
    itemlist = xmldoc.getElementsByTagName('outline')
    channel_id_regexp = re.compile('channel_id=(.*)$')
    Channel = namedtuple('Channel', ['id', 'title'])
    subscriptions = []

    for item in itemlist:
        try:
            feed_url = item.attributes['xmlUrl'].value
            channel = Channel(id=channel_id_regexp.findall(feed_url)[0],
                              title=item.attributes['title'].value)
            subscriptions.append(channel)
        except KeyError:
            pass

    return subscriptions


def subscribe(driver, channel):
    channel_url = 'https://www.youtube.com/channel/' + channel.id
    driver.get(channel_url)
    time.sleep(1)

    button = driver.find_element_by_css_selector('.channel-header-subscription-button-container > button')
    skip = button.get_attribute('data-is-subscribed')

    if not skip:
        button.click()

    print('{:.<50}{}'.format(channel.title, 'skip' if skip else '✔'))
    time.sleep(1)


def main():
    driver = webdriver.Firefox()
    sign_in(driver, (GOOGLE_EMAIL, GOOGLE_PASSWORD))
    for channel in load_subcribtions():
        subscribe(driver, channel)
    driver.close()


if __name__ == '__main__':
    main()