import pooler
from config import CONFIG
import sha
import time
import random

SESSION_TIMEOUT = 600 #seconds

_USER_CACHE = {}

def login(dbname, loginname, password, cache=True):
    loginname = loginname.encode('utf-8')
    password = password.encode('utf-8')
    cursor = pooler.get_db(dbname).cursor()
    password_sha = sha.new(password).hexdigest()
    cursor.execute('SELECT id FROM res_user '
        'WHERE login = %s and password = %s and active',
        (loginname, password_sha))
    res = cursor.fetchone()
    cursor.close()
    if res:
        user_id = res[0]
        if cache:
            _USER_CACHE.setdefault(dbname, {})
            timestamp = time.time()
            session = str(random.random())
            _USER_CACHE[dbname][user_id] = (timestamp, session)
            return (user_id, session)
        else:
            return user_id
    else:
        return False

def check_super(passwd):
    if passwd == CONFIG['admin_passwd']:
        return True
    else:
        raise Exception('AccessDenied')

def check(dbname, user, session, reset_timeout=True):
    session = session.encode('utf-8')
    if _USER_CACHE.get(dbname, {}).has_key(user):
        timestamp, real_session = _USER_CACHE[dbname][user]
        if real_session == session \
                and abs(timestamp - time.time()) < SESSION_TIMEOUT:
            if reset_timeout:
                _USER_CACHE[dbname][user] = (time.time(), real_session)
            return True
    raise Exception('NotLogged')