from flask_peewee.auth import Auth
from models import User
from app import app, db, pad
from datetime import datetime
import ldap

class LdapAuth(Auth):
    def get_user_model(self):
        return User

    def authenticate(self, username, password):
        ldap.protocol_version = 3
        l = ldap.initialize(app.config['LDAP']['host'])
	l.set_option( ldap.OPT_X_TLS_DEMAND, True )
        try:
            user_dn = self._format_dn([('uid', username)])
            l.simple_bind_s(user_dn, password)
        except ldap.INVALID_CREDENTIALS:
            return False

	try:
            user = User.get(User.username == username)
        except User.DoesNotExist:
            user_data = l.search_s(user_dn, ldap.SCOPE_BASE)
            if (len(user_data) != 1):
                return False

            (dn, user_data) = user_data[0]
            user = User.create(
                username = username,
                email = user_data['mail'][0],
                api_id = pad.createAuthorIfNotExistsFor(user_dn, username))

        return user

    def login_user(self, user):
        user.last_login = datetime.now()
        user.save()
        super(LdapAuth, self).login_user(user)

    def _format_dn(self, attr, with_base_dn = True):
        if with_base_dn:
            attr.extend(app.config['LDAP']['base_dn'])

        dn = ['%s=%s' % (item[0], self._escape(item[1])) for item in attr]

        return ','.join(dn)

    def _escape(self, s, wildcard=False):
        chars_to_escape = ['\\',',','=','+','<','>',';','"','\'','#','(',')','\0']

        if not wildcard:
            chars_to_escape.append('*')

        escape = lambda x,y: x.replace(y,'\%02X' % ord(y))

        return reduce(escape, chars_to_escape, s)

auth = LdapAuth(app, db, user_model=User)