"""The syslog listener (#5999): lines queued as they arrive, bounded, read in
rounds; the listener bound as the settings say, and a port it can't open
said, not raised."""
import asyncio
import socket
from datetime import datetime, timedelta, timezone
from types import SimpleNamespace

import pytest

from plugins.syslog import receiver


@pytest.fixture(autouse=True)
def fresh(monkeypatch):
    monkeypatch.setattr(receiver, "LISTENER", receiver.Listener())
    monkeypatch.setattr(receiver, "QUEUE", receiver.deque())


def test_the_queue_is_bounded_and_says_what_it_lost(monkeypatch):
    monkeypatch.setattr(receiver, "MAX_QUEUED", 3)
    for i in range(5):
        receiver.take("10.0.0.5", f"<13>line {i}".encode())
    assert receiver.LISTENER.received == 5 and receiver.LISTENER.dropped == 2
    assert [r.message.text for r in receiver.read_round()] == ["line 2", "line 3", "line 4"]


def test_a_round_takes_at_most_its_share_and_leaves_the_rest():
    for i in range(5):
        receiver.take("10.0.0.5", f"<13>line {i}".encode())
    first = receiver.read_round(limit=2)
    assert [r.message.text for r in first] == ["line 0", "line 1"] and len(receiver.QUEUE) == 3
    assert first[0].address == "10.0.0.5"


def _app(**cfg):
    return SimpleNamespace(config={"PLUGINS": {"syslog": cfg}})


def _free_port() -> int:
    with socket.socket() as s:
        s.bind(("0.0.0.0", 0))
        return s.getsockname()[1]


def test_it_listens_on_udp_and_tcp_and_takes_what_arrives():
    async def go():
        port = _free_port()
        await receiver.ensure_listening(_app(port=port, udp=True, tcp=True))
        assert receiver.LISTENER.listening and receiver.LISTENER.error is None
        udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        udp.sendto(b"<13>over udp", ("127.0.0.1", port))
        udp.close()
        reader, writer = await asyncio.wait_for(asyncio.open_connection("127.0.0.1", port), 5)
        writer.write(b"12 <13>over tcp<14>and a line\n")
        await writer.drain()
        writer.close()
        for _ in range(50):
            if len(receiver.QUEUE) >= 3:
                break
            await asyncio.sleep(0.05)
        texts = sorted(r.message.text for r in receiver.read_round())
        await receiver.close()
        return texts

    assert asyncio.run(go()) == ["and a line", "over tcp", "over udp"]


def test_a_port_it_cannot_open_is_said_and_tried_again_later():
    async def go():
        with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as held:
            held.bind(("0.0.0.0", 0))
            port = held.getsockname()[1]
            now = datetime(2026, 10, 19, 3, 0, tzinfo=timezone.utc)
            await receiver.ensure_listening(_app(port=port, udp=True, tcp=False), now)
            said = receiver.LISTENER.error
            tried = receiver.LISTENER.tried_at
            await receiver.ensure_listening(_app(port=port, udp=True, tcp=False), now + timedelta(seconds=10))
            assert receiver.LISTENER.tried_at == tried            # not retried within the minute
        return said

    said = asyncio.run(go())
    assert said and said.startswith("Port ") and "UDP" in said


def test_a_change_of_port_moves_the_listener():
    async def go():
        a, b = _free_port(), _free_port()
        await receiver.ensure_listening(_app(port=a, udp=True, tcp=False))
        await receiver.ensure_listening(_app(port=b, udp=True, tcp=False))
        port = receiver.LISTENER._udp_transport.get_extra_info("sockname")[1]
        await receiver.close()
        return port, b

    port, b = asyncio.run(go())
    assert port == b