#!/usr/bin/env python3
import datetime
import requests
import sqlite3
import json
import sys


class RedditToken(object):
    '''
    About it: https://github.com/reddit/reddit/wiki/OAuth2-Quick-Start-Example
    Version: 0.1
    '''

    def __init__(self, personal_use_script, secret, username, password,
                 user_agent, db):
        self.personal_use_script = personal_use_script
        self.secret = secret
        self.username = username
        self.password = password
        self.user_agent = user_agent
        self.db = db

        self.db = sqlite3.connect(self.db)
        self.conn = self.db.cursor()

    def request_new(self):
        self.auth = requests.auth.HTTPBasicAuth(self.personal_use_script,
                                                self.secret)
        self.data = {'grant_type': 'password', 'username': self.username,
                     'password': self.password}
        self.headers = {'User-Agent': self.user_agent}
        self.req = requests.post('https://ssl.reddit.com/api/v1/access_token',
                               auth=self.auth, data=self.data,
                               headers=self.headers)
        if self.req.status_code == requests.codes.ok:
            self.j = json.loads(self.req.text)
            return self.j
        else:
            print('ERROR {0}'.format(r.status_code))
            sys.exit(1)

    def save_new_token(self):
        self.conn.execute('CREATE TABLE IF NOT EXISTS token\
                          (access_token TEXT, expires_at TEXT)')
        self.conn.execute('DELETE FROM token')
        self.infos = self.request_new()
        self.infos['expires_at'] = datetime.datetime.now() + datetime.timedelta(seconds=self.infos['expires_in'])
        self.row = (self.infos['access_token'], self.infos['expires_at'])
        self.conn.execute('INSERT INTO token VALUES (?, ?)', self.row)
        self.db.commit()
        return self.row[0]

    def get(self):
        try:
            self.token = self.conn.execute('SELECT * FROM token')
        except sqlite3.OperationalError:
            return self.save_new_token()
        self.token_infos = self.token.fetchone()
        self.token = self.token_infos[0]
        self.last_datetime = self.token_infos[1]
        if datetime.datetime.now() > \
           datetime.datetime.strptime(self.last_datetime[:19],
                                      "%Y-%m-%d %H:%M:%S"):
            return self.save_new_token()
        else:
            return self.token


if __name__ == '__main__':

    personal_use_script = ''
    secret = ''
    username = ''
    password = ''
    user_agent = ''
    db = 'tokenreddit.db'


    token = RedditToken(personal_use_script, secret, username, password,
                        user_agent, db)

    print(token.get())   # always returns a valid token.