import ee
import errno
import json
import os
import urllib
import urllib2
from IPython.display import HTML
from IPython.display import display
from ee.oauthinfo import OAuthInfo

# This URI prompts user to copy and paste a code after successful                                        
# authorization.                                                                                         
ee_redirect_uri = 'urn:ietf:wg:oauth:2.0:oob'


def create_auth_url():
  # TODO(user): Add an additional, non-commandline flow for iPython notebook                               
  # for added convenience, and to work in notebook environments where                                      
  # commandline isn't available.                                                                           

  # This implements the flow from:                                                                         
  # https://developers.google.com/accounts/docs/OAuth2ForDevices                                           

  ### Request authorization from user                                                                      

  auth_request_params = {
      'scope': OAuthInfo.SCOPE,
      'redirect_uri': ee_redirect_uri,
      'response_type': 'code',
      'client_id': OAuthInfo.CLIENT_ID
  }
  auth_request_url = ('https://accounts.google.com/o/oauth2/auth?' +
                      urllib.urlencode(auth_request_params))

  return auth_request_url


def ee_authenticate(auth_code):
  token_request_params = {
    'code': auth_code,
    'client_id': OAuthInfo.CLIENT_ID,
    'client_secret': OAuthInfo.CLIENT_SECRET,
    'redirect_uri': ee_redirect_uri,
    'grant_type': 'authorization_code'
  }

  refresh_token = None
  try:
    response = urllib2.urlopen('https://accounts.google.com/o/oauth2/token',
                               urllib.urlencode(token_request_params)).read()
    tokens = json.loads(response)
    refresh_token = tokens['refresh_token']
  except urllib2.HTTPError, e:
    raise Exception('Problem requesting tokens.  Please try again.  %s %s' %
                    (e, e.read()))

  ### Write refresh token to filesystem for later use                                                      

  credentials_path = OAuthInfo.credentials_path()
  dirname = os.path.dirname(credentials_path)
  try:
    os.makedirs(dirname)
  except OSError, e:
    if e.errno != errno.EEXIST:
      raise Exception('Error creating %s: %s' % (dirname, e))

  json.dump({'refresh_token': refresh_token}, open(credentials_path, 'w'))

  print '\nSuccessfully saved authorization to %s' % credentials_path
  ee.Initialize()
  return True

def auth_html():
    return HTML(
("""You need to authorize access to your Earth Engine account.<br>
Please follow <a href="%s" target="_blank">this link</a>, """ % create_auth_url()) +

"""and paste the token you receive after authorization here: 
<input id="ee_auth_token" type="password"></input>
<button id = "ee_authenticate">Submit</button> <span id="ee_auth_result"></span>

<script>

// Send auth token to python
function ee_authenticate(token, callback) {
  cmd =  'ee_authenticate(' + JSON.stringify(token) + ')'
  console.log(cmd);
  function cb(msg) {
    console.log(msg);
    console.log(msg.content.data['text/plain'] == 'True');
    callback(msg.content.data['text/plain'] == 'True')
  }
  IPython.notebook.kernel.execute(cmd, 
                                  {iopub: {output: cb}}, {silent: false});
}

$('#ee_authenticate').click(function() {
    $('#ee_auth_result').text('...');
    console.log('debug 1');
    ee_authenticate($('#ee_auth_token').val(),
                    function(success) {
                      console.log('debug 2');
                      $('#ee_auth_result').text(success ? 'Success' : 'Failed');
                    });
});

</script>
""")

# For now, call ee_initialize() instead of ee.Initialize()
def ee_initialize():
    try:
        ee.Initialize()
        display(HTML("""Authentication successful!"""))
    except ee.EEException, e:
        display(auth_html())