#!/usr/bin/env python
#
# Copyright 2014 Facebook
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

from __future__ import absolute_import, division, print_function, with_statement

from contextlib import closing
import os
import socket

from tornado.concurrent import Future
from tornado.netutil import bind_sockets, Resolver
from tornado.tcpclient import TCPClient, _Connector
from tornado.tcpserver import TCPServer
from tornado.testing import AsyncTestCase, bind_unused_port, gen_test
from tornado.test.util import skipIfNoIPv6, unittest

# Fake address families for testing.  Used in place of AF_INET
# and AF_INET6 because some installations do not have AF_INET6.
AF1, AF2 = 1, 2


class TestTCPServer(TCPServer):
    def __init__(self, family):
        super(TestTCPServer, self).__init__()
        self.streams = []
        sockets = bind_sockets(None, 'localhost', family)
        self.add_sockets(sockets)
        self.port = sockets[0].getsockname()[1]

    def handle_stream(self, stream, address):
        self.streams.append(stream)

    def stop(self):
        super(TestTCPServer, self).stop()
        for stream in self.streams:
            stream.close()


class TCPClientTest(AsyncTestCase):
    def setUp(self):
        super(TCPClientTest, self).setUp()
        self.server = None
        self.client = TCPClient()

    def start_server(self, family):
        if family == socket.AF_UNSPEC and 'TRAVIS' in os.environ:
            self.skipTest("dual-stack servers often have port conflicts on travis")
        self.server = TestTCPServer(family)
        return self.server.port

    def stop_server(self):
        if self.server is not None:
            self.server.stop()
            self.server = None

    def tearDown(self):
        self.client.close()
        self.stop_server()
        super(TCPClientTest, self).tearDown()

    def skipIfLocalhostV4(self):
        Resolver().resolve('localhost', 0, callback=self.stop)
        addrinfo = self.wait()
        families = set(addr[0] for addr in addrinfo)
        if socket.AF_INET6 not in families:
            self.skipTest("localhost does not resolve to ipv6")

    @gen_test
    def do_test_connect(self, family, host):
        port = self.start_server(family)
        stream = yield self.client.connect(host, port)
        with closing(stream):
            stream.write(b"hello")
            data = yield self.server.streams[0].read_bytes(5)
            self.assertEqual(data, b"hello")

    def test_connect_ipv4_ipv4(self):
        self.do_test_connect(socket.AF_INET, '127.0.0.1')

    def test_connect_ipv4_dual(self):
        self.do_test_connect(socket.AF_INET, 'localhost')

    @skipIfNoIPv6
    def test_connect_ipv6_ipv6(self):
        self.skipIfLocalhostV4()
        self.do_test_connect(socket.AF_INET6, '::1')

    @skipIfNoIPv6
    def test_connect_ipv6_dual(self):
        self.skipIfLocalhostV4()
        if Resolver.configured_class().__name__.endswith('TwistedResolver'):
            self.skipTest('TwistedResolver does not support multiple addresses')
        self.do_test_connect(socket.AF_INET6, 'localhost')

    def test_connect_unspec_ipv4(self):
        self.do_test_connect(socket.AF_UNSPEC, '127.0.0.1')

    @skipIfNoIPv6
    def test_connect_unspec_ipv6(self):
        self.skipIfLocalhostV4()
        self.do_test_connect(socket.AF_UNSPEC, '::1')

    def test_connect_unspec_dual(self):
        self.do_test_connect(socket.AF_UNSPEC, 'localhost')

    @gen_test
    def test_refused_ipv4(self):
        sock, port = bind_unused_port()
        sock.close()
        with self.assertRaises(IOError):
            yield self.client.connect('127.0.0.1', port)


class TestConnectorSplit(unittest.TestCase):
    def test_one_family(self):
        # These addresses aren't in the right format, but split doesn't care.
        primary, secondary = _Connector.split(
            [(AF1, 'a'),
             (AF1, 'b')])
        self.assertEqual(primary, [(AF1, 'a'),
                                   (AF1, 'b')])
        self.assertEqual(secondary, [])

    def test_mixed(self):
        primary, secondary = _Connector.split(
            [(AF1, 'a'),
             (AF2, 'b'),
             (AF1, 'c'),
             (AF2, 'd')])
        self.assertEqual(primary, [(AF1, 'a'), (AF1, 'c')])
        self.assertEqual(secondary, [(AF2, 'b'), (AF2, 'd')])


class ConnectorTest(AsyncTestCase):
    class FakeStream(object):
        def __init__(self):
            self.closed = False

        def close(self):
            self.closed = True

    def setUp(self):
        super(ConnectorTest, self).setUp()
        self.connect_futures = {}
        self.streams = {}
        self.addrinfo = [(AF1, 'a'), (AF1, 'b'),
                         (AF2, 'c'), (AF2, 'd')]

    def tearDown(self):
        # Unless explicitly checked (and popped) in the test, we shouldn't
        # be closing any streams
        for stream in self.streams.values():
            self.assertFalse(stream.closed)
        super(ConnectorTest, self).tearDown()

    def create_stream(self, af, addr):
        future = Future()
        self.connect_futures[(af, addr)] = future
        return future

    def assert_pending(self, *keys):
        self.assertEqual(sorted(self.connect_futures.keys()), sorted(keys))

    def resolve_connect(self, af, addr, success):
        future = self.connect_futures.pop((af, addr))
        if success:
            self.streams[addr] = ConnectorTest.FakeStream()
            future.set_result(self.streams[addr])
        else:
            future.set_exception(IOError())

    def start_connect(self, addrinfo):
        conn = _Connector(addrinfo, self.io_loop, self.create_stream)
        # Give it a huge timeout; we'll trigger timeouts manually.
        future = conn.start(3600)
        return conn, future

    def test_immediate_success(self):
        conn, future = self.start_connect(self.addrinfo)
        self.assertEqual(list(self.connect_futures.keys()),
                         [(AF1, 'a')])
        self.resolve_connect(AF1, 'a', True)
        self.assertEqual(future.result(), (AF1, 'a', self.streams['a']))

    def test_immediate_failure(self):
        # Fail with just one address.
        conn, future = self.start_connect([(AF1, 'a')])
        self.assert_pending((AF1, 'a'))
        self.resolve_connect(AF1, 'a', False)
        self.assertRaises(IOError, future.result)

    def test_one_family_second_try(self):
        conn, future = self.start_connect([(AF1, 'a'), (AF1, 'b')])
        self.assert_pending((AF1, 'a'))
        self.resolve_connect(AF1, 'a', False)
        self.assert_pending((AF1, 'b'))
        self.resolve_connect(AF1, 'b', True)
        self.assertEqual(future.result(), (AF1, 'b', self.streams['b']))

    def test_one_family_second_try_failure(self):
        conn, future = self.start_connect([(AF1, 'a'), (AF1, 'b')])
        self.assert_pending((AF1, 'a'))
        self.resolve_connect(AF1, 'a', False)
        self.assert_pending((AF1, 'b'))
        self.resolve_connect(AF1, 'b', False)
        self.assertRaises(IOError, future.result)

    def test_one_family_second_try_timeout(self):
        conn, future = self.start_connect([(AF1, 'a'), (AF1, 'b')])
        self.assert_pending((AF1, 'a'))
        # trigger the timeout while the first lookup is pending;
        # nothing happens.
        conn.on_timeout()
        self.assert_pending((AF1, 'a'))
        self.resolve_connect(AF1, 'a', False)
        self.assert_pending((AF1, 'b'))
        self.resolve_connect(AF1, 'b', True)
        self.assertEqual(future.result(), (AF1, 'b', self.streams['b']))

    def test_two_families_immediate_failure(self):
        conn, future = self.start_connect(self.addrinfo)
        self.assert_pending((AF1, 'a'))
        self.resolve_connect(AF1, 'a', False)
        self.assert_pending((AF1, 'b'), (AF2, 'c'))
        self.resolve_connect(AF1, 'b', False)
        self.resolve_connect(AF2, 'c', True)
        self.assertEqual(future.result(), (AF2, 'c', self.streams['c']))

    def test_two_families_timeout(self):
        conn, future = self.start_connect(self.addrinfo)
        self.assert_pending((AF1, 'a'))
        conn.on_timeout()
        self.assert_pending((AF1, 'a'), (AF2, 'c'))
        self.resolve_connect(AF2, 'c', True)
        self.assertEqual(future.result(), (AF2, 'c', self.streams['c']))
        # resolving 'a' after the connection has completed doesn't start 'b'
        self.resolve_connect(AF1, 'a', False)
        self.assert_pending()

    def test_success_after_timeout(self):
        conn, future = self.start_connect(self.addrinfo)
        self.assert_pending((AF1, 'a'))
        conn.on_timeout()
        self.assert_pending((AF1, 'a'), (AF2, 'c'))
        self.resolve_connect(AF1, 'a', True)
        self.assertEqual(future.result(), (AF1, 'a', self.streams['a']))
        # resolving 'c' after completion closes the connection.
        self.resolve_connect(AF2, 'c', True)
        self.assertTrue(self.streams.pop('c').closed)

    def test_all_fail(self):
        conn, future = self.start_connect(self.addrinfo)
        self.assert_pending((AF1, 'a'))
        conn.on_timeout()
        self.assert_pending((AF1, 'a'), (AF2, 'c'))
        self.resolve_connect(AF2, 'c', False)
        self.assert_pending((AF1, 'a'), (AF2, 'd'))
        self.resolve_connect(AF2, 'd', False)
        # one queue is now empty
        self.assert_pending((AF1, 'a'))
        self.resolve_connect(AF1, 'a', False)
        self.assert_pending((AF1, 'b'))
        self.assertFalse(future.done())
        self.resolve_connect(AF1, 'b', False)
        self.assertRaises(IOError, future.result)