# SPDX-FileCopyrightText: 2020 The Magma Authors.
# SPDX-FileCopyrightText: 2022 Open Networking Foundation <support@opennetworking.org>
#
# SPDX-License-Identifier: BSD-3-Clause

import _thread
import socket
from wsgiref.simple_server import (
    ServerHandler,
    WSGIRequestHandler,
    WSGIServer,
    make_server,
)

from common.misc_utils import get_ip_from_if
from configuration.service_configs import load_service_config
from logger import EnodebdLogger as logger
from state_machines.enb_acs_manager import StateMachineManager
from spyne.server.wsgi import WsgiApplication

from .models import CWMP_NS
from .rpc_methods import AutoConfigServer
from .spyne_mods import Tr069Application, Tr069Soap11

# Socket timeout in seconds. Should be set larger than the longest TR-069
# response time (typically for a GetParameterValues of the entire data model),
# measured at 168secs. Should also be set smaller than ENB_CONNECTION_TIMEOUT,
# to avoid incorrectly detecting eNodeB timeout.
SOCKET_TIMEOUT = 240


class tr069_WSGIRequestHandler(WSGIRequestHandler):
    timeout = 10
    # pylint: disable=attribute-defined-outside-init

    def handle_single(self):
        """Handle a single HTTP request"""
        self.raw_requestline = self.rfile.readline(65537)
        if len(self.raw_requestline) > 65536:
            self.requestline = ''
            self.request_version = ''
            self.command = ''
            self.close_connection = 1
            self.send_error(414)
            return

        if not self.parse_request():  # An error code has been sent, just exit
            return

        handler = ServerHandler(
            self.rfile, self.wfile, self.get_stderr(), self.get_environ(),
        )
        handler.http_version = "1.1"
        handler.request_handler = self  # backpointer for logging

        # eNodeB will sometimes close connection to enodebd.
        # The cause of this is unknown, but we can safely ignore the
        # closed connection, and continue as normal otherwise.
        #
        # While this throws a BrokenPipe exception in wsgi server,
        # it also causes an AttributeError to be raised because of a
        # bug in the wsgi server.
        # https://bugs.python.org/issue27682
        try:
            handler.run(self.server.get_app())
        except BrokenPipeError:
            self.log_error("eNodeB has unexpectedly closed the TCP connection.")

    def handle(self):
        self.protocol_version = "HTTP/1.1"
        self.close_connection = 0

        try:
            while not self.close_connection:
                self.handle_single()

        except socket.timeout as e:
            self.log_error("tr069 WSGI Server Socket Timeout: %r", e)
            self.close_connection = 1
            return

        except socket.error as e:
            self.log_error("tr069 WSGI Server Socket Error: %r", e)
            self.close_connection = 1
            return

    # Disable pylint warning because we are using same parameter name as built-in
    # pylint: disable=redefined-builtin
    def log_message(self, format, *args):
        """ Overwrite message logging to use python logging framework rather
            than stderr """
        logger.debug("%s - %s", self.client_address[0], format % args)

    # Disable pylint warning because we are using same parameter name as built-in
    # pylint: disable=redefined-builtin
    def log_error(self, format, *args):
        """ Overwrite message logging to use python logging framework rather
            than stderr """
        logger.warning("%s - %s", self.client_address[0], format % args)


def tr069_server(state_machine_manager: StateMachineManager) -> None:
    """
    TR-069 server
    Inputs:
        - acs_to_cpe_queue = instance of Queue
            containing messages from parent process/thread to be sent to CPE
        - cpe_to_acs_queue = instance of Queue
            containing messages from CPE to be sent to parent process/thread
    """
    config = load_service_config("enodebd")

    AutoConfigServer.set_state_machine_manager(state_machine_manager)

    app = Tr069Application(
        [AutoConfigServer], CWMP_NS,
        in_protocol=Tr069Soap11(validator='soft'),
        out_protocol=Tr069Soap11(),
    )
    wsgi_app = WsgiApplication(app)

    try:
        ip_address = get_ip_from_if(config['tr069']['interface'])
    except (ValueError, KeyError) as e:
        # Interrupt main thread since process should not continue without TR-069
        _thread.interrupt_main()
        raise e

    socket.setdefaulttimeout(SOCKET_TIMEOUT)
    logger.info(
        'Starting TR-069 server on %s:%s',
        ip_address, config['tr069']['port'],
    )
    server = make_server(
        ip_address,
        config['tr069']['port'], wsgi_app,
        WSGIServer, tr069_WSGIRequestHandler,
    )

    # Note: use single-thread server, to avoid state contention
    try:
        server.serve_forever()
    finally:
        # Log error and interrupt main thread, to ensure that entire process
        # is restarted if this thread exits
        logger.error('Hit error in TR-069 thread. Interrupting main thread.')
        _thread.interrupt_main()