import errno
import re
import socket
import sys

import pytest

import trio
from trio.testing._fake_net import FakeNet

# ENOTCONN gives different messages on different platforms
if sys.platform == "linux":
    ENOTCONN_MSG = r"^\[Errno 107\] (Transport endpoint is|Socket) not connected$"
elif sys.platform == "darwin":
    ENOTCONN_MSG = r"^\[Errno 57\] Socket is not connected$"
else:
    ENOTCONN_MSG = r"^\[Errno 10057\] Unknown error$"


def fn() -> FakeNet:
    fn = FakeNet()
    fn.enable()
    return fn


async def test_basic_udp() -> None:
    fn()
    s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
    s2 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)

    await s1.bind(("127.0.0.1", 0))
    ip, port = s1.getsockname()
    assert ip == "127.0.0.1"
    assert port != 0

    with pytest.raises(
        OSError,
        match=r"^\[\w+ \d+\] Invalid argument$",
    ) as exc:  # Cannot rebind.
        await s1.bind(("192.0.2.1", 0))
    assert exc.value.errno == errno.EINVAL

    # Cannot bind multiple sockets to the same address
    with pytest.raises(
        OSError,
        match=r"^\[\w+ \d+\] (Address (already )?in use|Unknown error)$",
    ) as exc:
        await s2.bind(("127.0.0.1", port))
    assert exc.value.errno == errno.EADDRINUSE

    await s2.sendto(b"xyz", s1.getsockname())
    data, addr = await s1.recvfrom(10)
    assert data == b"xyz"
    assert addr == s2.getsockname()
    await s1.sendto(b"abc", s2.getsockname())
    data, addr = await s2.recvfrom(10)
    assert data == b"abc"
    assert addr == s1.getsockname()


async def test_msg_trunc() -> None:
    fn()
    s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
    s2 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
    await s1.bind(("127.0.0.1", 0))
    await s2.sendto(b"xyz", s1.getsockname())
    data, addr = await s1.recvfrom(10)


async def test_recv_methods() -> None:
    """Test all recv methods for codecov"""
    fn()
    s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
    s2 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)

    # receiving on an unbound socket is a bad idea (I think?)
    with pytest.raises(NotImplementedError, match="code will most likely hang"):
        await s2.recv(10)

    await s1.bind(("127.0.0.1", 0))
    ip, port = s1.getsockname()
    assert ip == "127.0.0.1"
    assert port != 0

    # recvfrom
    await s2.sendto(b"abc", s1.getsockname())
    data, addr = await s1.recvfrom(10)
    assert data == b"abc"
    assert addr == s2.getsockname()

    # recv
    await s1.sendto(b"def", s2.getsockname())
    data = await s2.recv(10)
    assert data == b"def"

    # recvfrom_into
    assert await s1.sendto(b"ghi", s2.getsockname()) == 3
    buf = bytearray(10)

    with pytest.raises(NotImplementedError, match="^partial recvfrom_into$"):
        (nbytes, addr) = await s2.recvfrom_into(buf, nbytes=2)

    (nbytes, addr) = await s2.recvfrom_into(buf)
    assert nbytes == 3
    assert buf == b"ghi" + b"\x00" * 7
    assert addr == s1.getsockname()

    # recv_into
    assert await s1.sendto(b"jkl", s2.getsockname()) == 3
    buf2 = bytearray(10)
    nbytes = await s2.recv_into(buf2)
    assert nbytes == 3
    assert buf2 == b"jkl" + b"\x00" * 7

    if sys.platform == "linux" and sys.implementation.name == "cpython":
        flags: int = socket.MSG_MORE
    else:
        flags = 1

    # Send seems explicitly non-functional
    with pytest.raises(OSError, match=ENOTCONN_MSG) as exc:
        await s2.send(b"mno")
    assert exc.value.errno == errno.ENOTCONN
    with pytest.raises(NotImplementedError, match="^FakeNet send flags must be 0, not"):
        await s2.send(b"mno", flags)

    # sendto errors
    # it's successfully used earlier
    with pytest.raises(NotImplementedError, match="^FakeNet send flags must be 0, not"):
        await s2.sendto(b"mno", flags, s1.getsockname())
    with pytest.raises(TypeError, match="wrong number of arguments$"):
        await s2.sendto(b"mno", flags, s1.getsockname(), "extra arg")  # type: ignore[call-overload]


@pytest.mark.skipif(
    sys.platform == "win32",
    reason="functions not in socket on windows",
)
async def test_nonwindows_functionality() -> None:
    # mypy doesn't support a good way of aborting typechecking on different platforms
    if sys.platform != "win32":  # pragma: no branch
        fn()
        s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
        s2 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
        await s2.bind(("127.0.0.1", 0))

        # sendmsg
        with pytest.raises(OSError, match=ENOTCONN_MSG) as exc:
            await s2.sendmsg([b"mno"])
        assert exc.value.errno == errno.ENOTCONN

        assert await s1.sendmsg([b"jkl"], (), 0, s2.getsockname()) == 3
        (data, ancdata, msg_flags, addr) = await s2.recvmsg(10)
        assert data == b"jkl"
        assert ancdata == []
        assert msg_flags == 0
        assert addr == s1.getsockname()

        # TODO: recvmsg

        # recvmsg_into
        assert await s1.sendto(b"xyzw", s2.getsockname()) == 4
        buf1 = bytearray(2)
        buf2 = bytearray(3)
        ret = await s2.recvmsg_into([buf1, buf2])
        (nbytes, ancdata, msg_flags, addr) = ret
        assert nbytes == 4
        assert buf1 == b"xy"
        assert buf2 == b"zw" + b"\x00"
        assert ancdata == []
        assert msg_flags == 0
        assert addr == s1.getsockname()

        # recvmsg_into with MSG_TRUNC set
        assert await s1.sendto(b"xyzwv", s2.getsockname()) == 5
        buf1 = bytearray(2)
        ret = await s2.recvmsg_into([buf1])
        (nbytes, ancdata, msg_flags, addr) = ret
        assert nbytes == 2
        assert buf1 == b"xy"
        assert ancdata == []
        assert msg_flags == socket.MSG_TRUNC
        assert addr == s1.getsockname()

        with pytest.raises(
            AttributeError,
            match="^'FakeSocket' object has no attribute 'share'$",
        ):
            await s1.share(0)  # type: ignore[attr-defined]


@pytest.mark.skipif(
    sys.platform != "win32",
    reason="windows-specific fakesocket testing",
)
async def test_windows_functionality() -> None:
    # mypy doesn't support a good way of aborting typechecking on different platforms
    if sys.platform == "win32":  # pragma: no branch
        fn()
        s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
        s2 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
        await s1.bind(("127.0.0.1", 0))
        with pytest.raises(
            AttributeError,
            match="^'FakeSocket' object has no attribute 'sendmsg'$",
        ):
            await s1.sendmsg([b"jkl"], (), 0, s2.getsockname())  # type: ignore[attr-defined]
        with pytest.raises(
            AttributeError,
            match="^'FakeSocket' object has no attribute 'recvmsg'$",
        ):
            s2.recvmsg(0)  # type: ignore[attr-defined]
        with pytest.raises(
            AttributeError,
            match="^'FakeSocket' object has no attribute 'recvmsg_into'$",
        ):
            s2.recvmsg_into([])  # type: ignore[attr-defined]
        with pytest.raises(NotImplementedError):
            s1.share(0)


async def test_basic_tcp() -> None:
    fn()
    with pytest.raises(NotImplementedError):
        trio.socket.socket()


async def test_not_implemented_functions() -> None:
    fn()
    s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)

    # getsockopt
    with pytest.raises(
        OSError,
        match=r"^FakeNet doesn't implement getsockopt\(\d, \d\)$",
    ):
        s1.getsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY)

    # setsockopt
    with pytest.raises(
        NotImplementedError,
        match="^FakeNet always has IPV6_V6ONLY=True$",
    ):
        s1.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, False)
    with pytest.raises(
        OSError,
        match=r"^FakeNet doesn't implement setsockopt\(\d+, \d+, \.\.\.\)$",
    ):
        s1.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, True)
    with pytest.raises(
        OSError,
        match=r"^FakeNet doesn't implement setsockopt\(\d+, \d+, \.\.\.\)$",
    ):
        s1.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    # set_inheritable
    s1.set_inheritable(False)
    with pytest.raises(
        NotImplementedError,
        match="^FakeNet can't make inheritable sockets$",
    ):
        s1.set_inheritable(True)

    # get_inheritable
    assert not s1.get_inheritable()


async def test_getpeername() -> None:
    fn()
    s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
    with pytest.raises(OSError, match=ENOTCONN_MSG) as exc:
        s1.getpeername()
    assert exc.value.errno == errno.ENOTCONN

    await s1.bind(("127.0.0.1", 0))

    with pytest.raises(
        AssertionError,
        match="^This method seems to assume that self._binding has a remote UDPEndpoint$",
    ):
        s1.getpeername()


async def test_init() -> None:
    fn()
    with pytest.raises(
        NotImplementedError,
        match=re.escape(
            f"FakeNet doesn't (yet) support type={trio.socket.SOCK_STREAM}",
        ),
    ):
        s1 = trio.socket.socket()

    # getsockname on unbound ipv4 socket
    s1 = trio.socket.socket(type=trio.socket.SOCK_DGRAM)
    assert s1.getsockname() == ("0.0.0.0", 0)

    # getsockname on bound ipv4 socket
    await s1.bind(("0.0.0.0", 0))
    ip, port = s1.getsockname()
    assert ip == "127.0.0.1"
    assert port != 0

    # getsockname on unbound ipv6 socket
    s2 = trio.socket.socket(family=socket.AF_INET6, type=socket.SOCK_DGRAM)
    assert s2.getsockname() == ("::", 0)

    # getsockname on bound ipv6 socket
    await s2.bind(("::", 0))
    ip, port, *_ = s2.getsockname()
    assert ip == "::1"
    assert port != 0
    assert _ == [0, 0]
