#!/usr/bin/env python3
# Copyright (c) 2020 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test addr response caching"""

import time

from test_framework.messages import msg_getaddr
from test_framework.p2p import (
    P2PInterface,
    p2p_lock
)
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import (
    assert_equal,
    p2p_port,
)

# As defined in net_processing.
MAX_ADDR_TO_SEND = 1000
MAX_PCT_ADDR_TO_SEND = 23

class AddrReceiver(P2PInterface):

    def __init__(self):
        super().__init__()
        self.received_addrs = None

    def get_received_addrs(self):
        with p2p_lock:
            return self.received_addrs

    def on_addr(self, message):
        self.received_addrs = []
        for addr in message.addrs:
            self.received_addrs.append(addr.ip)

    def addr_received(self):
        return self.received_addrs is not None


class AddrTest(BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 1
        # Use some of the remaining p2p ports for the onion binds.
        self.onion_port1 = p2p_port(self.num_nodes)
        self.onion_port2 = p2p_port(self.num_nodes + 1)
        self.extra_args = [
            [f"-bind=127.0.0.1:{self.onion_port1}=onion", f"-bind=127.0.0.1:{self.onion_port2}=onion"],
        ]

    def run_test(self):
        self.log.info('Fill peer AddrMan with a lot of records')
        for i in range(10000):
            first_octet = i >> 8
            second_octet = i % 256
            a = "{}.{}.1.1".format(first_octet, second_octet)
            self.nodes[0].addpeeraddress(a, 8333)

        # Need to make sure we hit MAX_ADDR_TO_SEND records in the addr response later because
        # only a fraction of all known addresses can be cached and returned.
        assert(len(self.nodes[0].getnodeaddresses(0)) > int(MAX_ADDR_TO_SEND / (MAX_PCT_ADDR_TO_SEND / 100)))

        last_response_on_local_bind = None
        last_response_on_onion_bind1 = None
        last_response_on_onion_bind2 = None
        self.log.info('Send many addr requests within short time to receive same response')
        N = 5
        cur_mock_time = int(time.time())
        for i in range(N):
            addr_receiver_local = self.nodes[0].add_p2p_connection(AddrReceiver())
            addr_receiver_local.send_and_ping(msg_getaddr())
            addr_receiver_onion1 = self.nodes[0].add_p2p_connection(AddrReceiver(), dstport=self.onion_port1)
            addr_receiver_onion1.send_and_ping(msg_getaddr())
            addr_receiver_onion2 = self.nodes[0].add_p2p_connection(AddrReceiver(), dstport=self.onion_port2)
            addr_receiver_onion2.send_and_ping(msg_getaddr())

            # Trigger response
            cur_mock_time += 5 * 60
            self.nodes[0].setmocktime(cur_mock_time)
            addr_receiver_local.wait_until(addr_receiver_local.addr_received)
            addr_receiver_onion1.wait_until(addr_receiver_onion1.addr_received)
            addr_receiver_onion2.wait_until(addr_receiver_onion2.addr_received)

            if i > 0:
                # Responses from different binds should be unique
                assert(last_response_on_local_bind != addr_receiver_onion1.get_received_addrs())
                assert(last_response_on_local_bind != addr_receiver_onion2.get_received_addrs())
                assert(last_response_on_onion_bind1 != addr_receiver_onion2.get_received_addrs())
                # Responses on from the same bind should be the same
                assert_equal(last_response_on_local_bind, addr_receiver_local.get_received_addrs())
                assert_equal(last_response_on_onion_bind1, addr_receiver_onion1.get_received_addrs())
                assert_equal(last_response_on_onion_bind2, addr_receiver_onion2.get_received_addrs())

            last_response_on_local_bind = addr_receiver_local.get_received_addrs()
            last_response_on_onion_bind1 = addr_receiver_onion1.get_received_addrs()
            last_response_on_onion_bind2 = addr_receiver_onion2.get_received_addrs()

            for response in [last_response_on_local_bind, last_response_on_onion_bind1, last_response_on_onion_bind2]:
                assert_equal(len(response), MAX_ADDR_TO_SEND)

        cur_mock_time += 3 * 24 * 60 * 60
        self.nodes[0].setmocktime(cur_mock_time)

        self.log.info('After time passed, see a new response to addr request')
        addr_receiver_local = self.nodes[0].add_p2p_connection(AddrReceiver())
        addr_receiver_local.send_and_ping(msg_getaddr())
        addr_receiver_onion1 = self.nodes[0].add_p2p_connection(AddrReceiver(), dstport=self.onion_port1)
        addr_receiver_onion1.send_and_ping(msg_getaddr())
        addr_receiver_onion2 = self.nodes[0].add_p2p_connection(AddrReceiver(), dstport=self.onion_port2)
        addr_receiver_onion2.send_and_ping(msg_getaddr())

        # Trigger response
        cur_mock_time += 5 * 60
        self.nodes[0].setmocktime(cur_mock_time)
        addr_receiver_local.wait_until(addr_receiver_local.addr_received)
        addr_receiver_onion1.wait_until(addr_receiver_onion1.addr_received)
        addr_receiver_onion2.wait_until(addr_receiver_onion2.addr_received)

        # new response is different
        assert(set(last_response_on_local_bind) != set(addr_receiver_local.get_received_addrs()))
        assert(set(last_response_on_onion_bind1) != set(addr_receiver_onion1.get_received_addrs()))
        assert(set(last_response_on_onion_bind2) != set(addr_receiver_onion2.get_received_addrs()))

if __name__ == '__main__':
    AddrTest().main()