#!/usr/bin/env python
from __future__ import print_function
import base64
import sys
import os
import mimetypes
import google.oauth2.credentials
import email
from argparse import ArgumentParser
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from email.mime.text import MIMEText
from email.mime.audio import MIMEAudio
from email.mime.base import MIMEBase
from email.mime.image import MIMEImage
from email.mime.multipart import MIMEMultipart

def add_headers_to_msg(msg, raw_header):
    headers = raw_header.splitlines()

    for header in headers:
        kv = header.split(':', 1)
        if len(kv) == 2:
            key = kv[0]
            value = kv[1]
            msg.add_header(key, value)

def concatSender(name, address):
    if name:
        return '{0} <{1}>'.format(name, address)
    else:
        return address

def create_message(sender, to_addr, cc_addr, bcc_addr, subject, message_html, message_plain, extra_header):
    message = MIMEMultipart()
    message['to'] = ', '.join(to_addr)
    message['from'] = sender
    message['subject'] = subject
    if cc_addr:
        message['cc'] = ', '.join(cc_addr)
    if bcc_addr:
        message['bcc'] = ', '.join(bcc_addr)

    if message_html:
        msg = MIMEText(message_html, 'html')
        add_headers_to_msg(msg, extra_header)
        message.attach(msg)
    if message_plain:
        msg = MIMEText(message_plain)
        add_headers_to_msg(msg, extra_header)
        message.attach(msg)

    return {'raw': base64.urlsafe_b64encode(message.as_string())}


def create_message_with_attachment(sender, to_addr, cc_addr, bcc_addr, subject, message_html, message_plain, extra_header, attachment_path, part_header):
    message = MIMEMultipart()
    message['to'] = ', '.join(to_addr)
    message['from'] = sender
    message['subject'] = subject
    if cc_addr:
        message['cc'] = ', '.join(cc_addr)
    if bcc_addr:
        message['bcc'] = ', '.join(bcc_addr)

    if message_html:
        msg = MIMEText(message_html, 'html')
        add_headers_to_msg(msg, extra_header)
        message.attach(msg)
    if message_plain:
        msg = MIMEText(message_plain)
        add_headers_to_msg(msg, extra_header)
        message.attach(msg)

    content_type, encoding = mimetypes.guess_type(attachment_path)
    if content_type is None or encoding is not None:
        content_type = 'application/octet-stream'
    main_type, sub_type = content_type.split('/', 1)
    if main_type == 'text':
        fp = open(attachment_path, 'rb')
        msg = MIMEText(fp.read(), _subtype=sub_type)
        fp.close()
    elif main_type == 'image':
        fp = open(attachment_path, 'rb')
        msg = MIMEImage(fp.read(), _subtype=sub_type)
        fp.close()
    elif main_type == 'audio':
        fp = open(attachment_path, 'rb')
        msg = MIMEAudio(fp.read(), _subtype=sub_type)
        fp.close()
    else:
        fp = open(attachment_path, 'rb')
        msg = MIMEBase(main_type, sub_type)
        msg.set_payload(fp.read())
        fp.close()

    add_headers_to_msg(msg, part_header)
    message.attach(msg)

    return {'raw': base64.urlsafe_b64encode(message.as_string())}

def create_message_with_attachment_headers(sender, to_addr, cc_addr, bcc_addr, subject, message_html, message_plain, extra_header, attachments):
    message = MIMEMultipart()
    message['to'] = ', '.join(to_addr)
    message['from'] = sender
    message['subject'] = subject
    if cc_addr:
        message['cc'] = ', '.join(cc_addr)
    if bcc_addr:
        message['bcc'] = ', '.join(bcc_addr)

    if message_html:
        msg = MIMEText(message_html, 'html')
        add_headers_to_msg(msg, extra_header)
        message.attach(msg)
    if message_plain:
        msg = MIMEText(message_plain)
        add_headers_to_msg(msg, extra_header)
        message.attach(msg)

    for attachment_header in attachments:
        attach_path = attachment_header[0]
        attach_header = attachment_header[1]

        content_type, encoding = mimetypes.guess_type(attach_path)
        if content_type is None or encoding is not None:
            content_type = 'application/octet-stream'
        main_type, sub_type = content_type.split('/', 1)
        if main_type == 'text':
            fp = open(attach_path, 'rb')
            msg = MIMEText(fp.read(), _subtype=sub_type)
            fp.close()
        elif main_type == 'image':
            fp = open(attach_path, 'rb')
            msg = MIMEImage(fp.read(), _subtype=sub_type)
            fp.close()
        elif main_type == 'audio':
            fp = open(attach_path, 'rb')
            msg = MIMEAudio(fp.read(), _subtype=sub_type)
            fp.close()
        else:
            fp = open(attach_path, 'rb')
            msg = MIMEBase(main_type, sub_type)
            msg.set_payload(fp.read())
            fp.close()

        add_headers_to_msg(msg, attach_header)
        message.attach(msg)

    return {'raw': base64.urlsafe_b64encode(message.as_string())}

def create_raw_message(raw_string):
    message = email.message_from_string(raw_string)
    return {'raw': base64.urlsafe_b64encode(message.as_string())}

def send_message(service, user_id, message):
    message = (service.users().messages().send(
        userId=user_id, body=message).execute())


def main(args):
    credentials = google.oauth2.credentials.Credentials(
        args.access_token, None)
    service = build('gmail', 'v1', credentials=credentials)

    sender = concatSender(args.sender_name, args.sender)

    if args.raw:
        msg = create_raw_message(args.raw)
    elif args.attachment_path:
        msg = create_message_with_attachment(
            sender, args.to, args.cc, args.bcc, args.subject, args.message_html, args.message_plain, args.extra_header, args.attachment_path, args.part_header)
    elif args.attachment_with_header:
        msg = create_message_with_attachment_headers(
            sender, args.to, args.cc, args.bcc, args.subject, args.message_html, args.message_plain, args.extra_header, args.attachment_with_header)
    else:
        msg = create_message(
            sender, args.to, args.cc, args.bcc, args.subject, args.message_html, args.message_plain, args.extra_header)

    send_message(service, args.sender, msg)


if __name__ == '__main__':
    parser = ArgumentParser()
    parser.add_argument('-r', '--raw', metavar='message',
                        help='Whole email content', dest='raw')
    parser.add_argument('-m', '--message-html', metavar='message',
                        help='HTML content', dest='message_html')
    parser.add_argument('-M', '--message-plain', metavar='message',
                        help='Plain text content', dest='message_plain')
    parser.add_argument(
        '--attachments', action='append', help='Attachmnent', nargs=2, metavar=('filepath', 'headers'), dest='attachment_with_header')
    parser.add_argument(
        '-a', '--attachment-path', help='Attachmnent Path', metavar='filepath', dest='attachment_path')
    parser.add_argument(
        '-F', '--from', metavar='sender_address', help='Sender mail address', dest='sender', default='me')
    parser.add_argument(
        '--sender-name', metavar='sender_name', help='Sender Name', dest='sender_name')
    parser.add_argument('-s', '--subject', metavar='subject', help='Mail subject',
                        dest='subject')
    parser.add_argument('-t', '--token', metavar='access_token', help='Gmail Oauth access token',
                        required=True, dest='access_token')
    parser.add_argument(
        '-T', '--to', action='append', metavar='recv_address', help='Receiver mail address', dest='to')
    parser.add_argument(
        '--cc', action='append', metavar='cc_address', help='Cc mail address', dest='cc')
    parser.add_argument(
        '--bcc', action='append', metavar='bcc_address', help='Bcc mail address', dest='bcc')
    parser.add_argument('--extra-header', help='Extra header for message', dest='extra_header')
    parser.add_argument('--part-header', help='Extra header for attachment', dest='part_header')
    args = parser.parse_args()

    try:
        main(args)
    except HttpError as error:
        print('Error: Connection Failed')
        print(error)
        sys.exit(3)
    except google.auth.exceptions.RefreshError as error:
        print('Error: Authentication Failed')
        print(error)
        sys.exit(4)
    except IOError as error:
        print('Error: Attachment Failed')
        print(error)
        sys.exit(5)
    except Exception as error:
        print('Unknown Error')
        print(error)
        sys.exit(2)
    except:
        print('Unknown Error')
        sys.exit(1)