import time

from opcua import ua, Server
from opcua.server.user_manager import UserManager

# users database
users_db = {
    'user1': 'passwd1',
    'user2': 'passwd2',
    'user3': 'passwd3',
}


# user manager
def user_manager(isession, username, password):
    print(isession, username, password)
    isession.user = UserManager.User
    return username in users_db and password == users_db[username]


if __name__ == "__main__":

    # setup our server
    server = Server()
    server.set_endpoint("opc.tcp://0.0.0.0:4840/freeopcua/server/")

    # load server certificate and private key. This enables endpoints
    # with signing and encryption.
    server.load_certificate("certificate-example.der")
    server.load_private_key("private-key-example.pem")

    # set all possible endpoint policies for clients to connect through
    server.set_security_policy([
        # ua.SecurityPolicyType.NoSecurity,
        ua.SecurityPolicyType.Basic256Sha256_SignAndEncrypt,
        # ua.SecurityPolicyType.Basic256Sha256_Sign,
    ])

    # set the security endpoints for identification of clients
    # self.server.set_security_IDs(["Anonymous", "Basic256Sha256", "Username"])
    server.set_security_IDs(["Username"])

    # set the user_manager function
    server.user_manager.set_user_manager(user_manager)

    # starting!
    server.start()

    print("Endpoints : ", str(server.get_endpoints()).replace(',', '\n'))

    try:
        while True:
            time.sleep(5)
    finally:
        # close connection, remove subscriptions, etc
        server.stop()

    def set_security_IDs(self, policyIDs):
        """
            Method setting up the security endpoints for identification
            of clients. During server object initialization, all possible
            endpoints are enabled:

            self._policyIDs = ["Anonymous", "Basic256Sha256", "Username"]

            E.g. to limit the number of IDs and disable anonymous clients:

                set_security_policy(["Basic256Sha256"])

            (Implementation for ID check is currently not finalized...)

        """
        self._policyIDs = policyIDs