from apiclient.discovery import build
from apiclient import errors
from httplib2 import Http
import oauth2client
from oauth2client import client, tools
import os
import json
import base64
from email.message import EmailMessage
import email
from email.utils import parseaddr, parsedate_to_datetime
import argparse
from bs4 import BeautifulSoup
from pytz import timezone

SCOPES = 'https://www.googleapis.com/auth/gmail.modify'
CLIENT_SECRET_FILE = os.path.expanduser('~/client_id.json')
APPLICATION_NAME = 'Famille'

def get_gmail_service():
    """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.
    """
    credential_dir = os.path.expanduser('~/.credentials')
    if not os.path.exists(credential_dir):
        os.makedirs(credential_dir)
    credential_path = os.path.join(credential_dir, 'news.horel@gmail.com')
    store = oauth2client.file.Storage(credential_path)
    credentials = store.get()
    if not credentials or credentials.invalid:
        flags = argparse.ArgumentParser(parents=[tools.argparser]).parse_args()
        flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
        flow.user_agent = APPLICATION_NAME
        credentials = tools.run_flow(flow, store, flags)
        print('Storing credentials to ' + credential_path)
    service = build('gmail', 'v1', http=credentials.authorize(Http()))
    return service

class GmailMessage(EmailMessage):
    _service = get_gmail_service()

    def msgdict(self):
        return {'raw': base64.urlsafe_b64encode(self.as_bytes()).decode()}

    def send(self):
        try:
            message = (self._service.users().messages().
                       send(userId='me',body=self.msgdict())
                       .execute())
            print('Message Id: %s' % message['id'])
        except errors.HttpError as error:
            print('An error occurred: %s' % error)

    @classmethod
    def from_id(cls, msg_id, user_id='me'):
        try:
            message = (cls._service.users().messages().
                       get(userId=user_id, id=msg_id, format='raw').execute())
            return email.message_from_bytes(
                base64.urlsafe_b64decode(message['raw']),
                policy=email.policy.EmailPolicy())
        except errors.HttpError as error:
            print(json.loads(error.content.decode('utf-8'))['error']['message'])

def ListMessagesWithLabels(service, user_id, label_ids=[]):
    """List all Messages of the user's mailbox with label_ids applied.

    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.
     label_ids: Only return Messages with these labelIds applied.

    Returns:
     List of Messages that have all required Labels applied. Note that the
     returned list contains Message IDs, you must use get with the
     appropriate id to get the details of a Message.
    """
    try:
        response = service.users().messages().list(userId=user_id,
                                                   labelIds=label_ids).execute()
        messages = []
        if 'messages' in response:
            messages.extend(response['messages'])
        while 'nextPageToken' in response:
            page_token = response['nextPageToken']
            response = service.users().messages().list(userId=user_id,
                                                       labelIds=label_ids,
                                                       pageToken=page_token).execute()
            messages.extend(response['messages'])

        return messages
    except errors.HttpError as error:
        print(json.loads(error.content.decode('utf-8'))['error']['message'])

def labels_dict(service, user_id):
    """Returns a dictionary mapping labels to labelids.

    Args:
     service: Authorized Gmail API service instance.
     user_id: User's email address. The special value "me"

    Returns:
     dictionary mapping labels to labelids.
    """
    try:
        response = service.users().labels().list(userId=user_id).execute()
        labels = response['labels']
        return {label['name']: label['id'] for label in labels}
    except errors.HttpError as error:
        print(json.loads(error.content.decode('utf-8'))['error']['message'])

def extract_response(content):
    soup = BeautifulSoup(content, 'lxml')
    reply = soup.find('div', dir='ltr')
    return reply

if __name__ == "__main__":
    import re
    import sqlite3

    regex = re.compile("[^+]*\+([^@]*)")
    db = sqlite3.connect("famille.db",
                         detect_types=sqlite3.PARSE_DECLTYPES)
    db.row_factory = sqlite3.Row
    db.execute("PRAGMA foreign_keys=ON")
    sql_str = "INSERT INTO comments" \
              "(date, news_id, user_id, content, content_cache) " \
              "VALUES(?, ?, ?, ?, ?)"

    for msg_id in ListMessagesWithLabels(GmailMessage._service, 'me', 'INBOX'):
        mail = GmailMessage.from_id(msg_id['id'])
        m = regex.match(mail['To'])
        if m:
            _, email_addr = parseaddr(mail['From'])
            c = db.execute("SELECT id FROM users WHERE email = ?", (email_addr,))
            user_id, = c.fetchone()
            c.close()
            body = mail.get_body()
            if body.get_content_type() == 'text/html':
                comment_cache = extract_response(body.get_content())
                comment = comment_cache.get_text()
                comment_cache = str(comment_cache)
            elif body.get_content_type() == 'text/plain':
                comment = comment_cache = body.get_content()
            news_id = int(m.groups()[0])
            date = (parsedate_to_datetime(mail['Date']).
                    astimezone(timezone('utc')).
                    replace(tzinfo=None))
            try:
                db.execute(sql_str, (date, news_id, user_id, comment, comment_cache))
            except sqlite3.Error as e:
                print(e)
                db.rollback()
                continue
            db.commit()
            print(msg_id['id'], news_id, email_addr, date, comment)