import httplib2

from email.encoders import encode_base64
from apiclient import discovery
from oauth2client import client
from oauth2client import tools
from oauth2client.file import Storage
import base64
from email.mime.audio import MIMEAudio
from email.mime.base import MIMEBase
from email.mime.image import MIMEImage
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
import mimetypes
import os

from apiclient import errors


try:
    import argparse
    flags = argparse.ArgumentParser(parents=[tools.argparser]).parse_args()
except ImportError:
    flags = None

# If modifying these scopes, delete your previously saved credentials
# at ~/.credentials/gmail-python-quickstart.json
SCOPES = 'https://mail.google.com/'
CLIENT_SECRET_FILE = 'client_id.json'
APPLICATION_NAME = 'Gmail API Python Quickstart'


def get_credentials():
    """Gets valid user credentials from storage.

    If nothing has been stored, or if the stored credentials are invalid,
    the OAuth2 flow is completed to obtain the new credentials.

    Returns:
        Credentials, the obtained credential.
    """
    home_dir = os.path.expanduser('~')
    credential_dir = os.path.join(home_dir, '.credentials')
    if not os.path.exists(credential_dir):
        os.makedirs(credential_dir)
    credential_path = os.path.join(credential_dir,
                                   'gmail-python-quickstart.json')

    store = Storage(credential_path)
    credentials = store.get()
    if not credentials or credentials.invalid:
        flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
        flow.user_agent = APPLICATION_NAME
        if flags:
            credentials = tools.run_flow(flow, store, flags)
        else: # Needed only for compatibility with Python 2.6
            credentials = tools.run(flow, store)
        print('Storing credentials to ' + credential_path)
    return credentials


def CreateMessage(sender, to, subject, message_text):
  """Create a message for an email.

  Args:
    sender: Email address of the sender.
    to: Email address of the receiver.
    subject: The subject of the email message.
    message_text: The text of the email message.

  Returns:
    An object containing a base64url encoded email object.
  """
  message = MIMEText(message_text)
  message['to'] = to
  message['from'] = sender
  message['subject'] = subject
  return {'raw': base64.urlsafe_b64encode(message.as_string().encode('UTF-8')).decode('ascii')}


def create_message_with_attachment(
    sender, to, subject, message_text, file):
  """Create a message for an email.

  Args:
    sender: Email address of the sender.
    to: Email address of the receiver.
    subject: The subject of the email message.
    message_text: The text of the email message.
    file: The path to the file to be attached.

  Returns:
    An object containing a base64url encoded email object.
  """
  message = MIMEMultipart()
  message['to'] = to
  message['from'] = sender
  message['subject'] = subject

  msg = MIMEText(message_text)
  message.attach(msg)

  content_type, encoding = mimetypes.guess_type(file)
  print(content_type)
  if content_type is None or encoding is not None:
    content_type = 'application/octet-stream'
  main_type, sub_type = content_type.split('/', 1)
  print(main_type)
  print(sub_type)
  if main_type == 'text':
    fp = open(file, 'rb')
    msg = MIMEText(fp.read(), _subtype=sub_type)
    fp.close()
  elif main_type == 'image':
    fp = open(file, 'rb')
    msg = MIMEImage(fp.read(), _subtype=sub_type)
    fp.close()
  elif main_type == 'audio':
    fp = open(file, 'rb')
    msg = MIMEAudio(fp.read(), _subtype=sub_type)
    fp.close()
  else:
    fp = open(file, 'rb')
    msg = MIMEBase(main_type, sub_type)
    msg.set_payload(fp.read())
    encode_base64(msg)
    msg.add_header('Content-Disposition', 'attachment', filename=os.path.basename(file))
    fp.close()
  filename = os.path.basename(file)
  msg.add_header('Content-Disposition', 'attachment', filename=filename)

  message.attach(msg)

  return {'raw': base64.urlsafe_b64encode(message.as_string().encode('UTF-8')).decode('ascii')}

def SendMessage(service, user_id, message):
  """Send an email message.

  Args:
    service: Authorized Gmail API service instance.
    user_id: User's email address. The special value "me"
    can be used to indicate the authenticated user.
    message: Message to be sent.

  Returns:
    Sent Message.
  """
  try:
    message = (service.users().messages().send(userId=user_id, body=message)
               .execute())
    print('Message Id: %s' % message['id'])
    return message
  except errors.HttpError:
    print('An error occurred: %s' % error)



def main():
    """Shows basic usage of the Gmail API.

    Creates a Gmail API service object and outputs a list of label names
    of the user's Gmail account.
    """
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    service = discovery.build('gmail', 'v1', http=http)

    results = service.users().labels().list(userId='me').execute()
    labels = results.get('labels', [])
    msg_att = create_message_with_attachment()
    SendMessage(service, 'me',msg_att)

    # if not labels:
    #     print('No labels found.')
    # else:
    #   print('Labels:')
    #   for label in labels:
    #     print(label['name'])


if __name__ == '__main__':
    main()`