#!/usr/bin/env python

"""
Get LinkedIn OAuth1 access tokens without having to open a web browser.

Notes
-----
Based upon https://developer.linkedin.com/documents/getting-oauth-token-python

Assumes that the application API key, secret key, user name, and password are stored
in an a configuration file formatted as follows:

[Secrets]
API_KEY = WWWWWWWW
SECRET_KEY = XXXXXXXX
NAME = YYYYYYYY
PASSWORD = ZZZZZZZZ
"""

import re
import ConfigParser as cp

import oauth2
import urlparse

import lxml.html
import mechanize

# Read secrets:
cfg_file = 'linkedin_config'
config = cp.ConfigParser()
config.read(cfg_file)
if not config.has_section('Secrets'):
    raise RuntimeError('no secrets specified')
secrets = {}
for s in config.items('Secrets'):
    secrets[s[0]] = s[1]

# Set up headless browser:
br = mechanize.Browser()
br.set_cookiejar(mechanize.CookieJar())
br.set_handle_redirect(True)
br.set_handle_robots(False)

# Get request token:
consumer = oauth2.Consumer(secrets['api_key'], secrets['secret_key'])
client = oauth2.Client(consumer)
request_token_url = 'https://api.linkedin.com/uas/oauth/requestToken'
response, content = client.request(request_token_url, 'POST')
if response['status'] != '200':
    raise Exception('Invalid response')
request_token = dict(urlparse.parse_qsl(content))
print 'request token:        ', request_token['oauth_token']
print 'request token secret: ', request_token['oauth_token_secret']

# Use token to redirect to user login:
authorize_url = 'https://api.linkedin.com/uas/oauth/authorize'
redirect_url = '%s?oauth_token=%s' % (authorize_url, request_token['oauth_token'])

# Login with mechanize:
br.open(redirect_url)
br.select_form(nr=0)
br.form['session_key'] = secrets['username']
br.form['session_password'] = secrets['password']
br.submit()
html = br.response().read()
tree = lxml.html.fromstring(html)
oauth_verifier = tree.xpath('.//div[@class="access-code"]')[0].text_content()

# Use PIN to obtain access token:
token = oauth2.Token(request_token['oauth_token'],
                    request_token['oauth_token_secret'])
token.set_verifier(oauth_verifier)
access_token_url = 'https://api.linkedin.com/uas/oauth/accessToken'
client = oauth2.Client(consumer, token)
response, content = client.request(access_token_url, 'POST')
access_token = dict(urlparse.parse_qsl(content))

print 'access token:         ', access_token['oauth_token']
print 'access token secret:  ', access_token['oauth_token_secret']