import asyncio
import json

from app.electrum.client import ElectrumClient, ElectrumError


class FakeWriter:
    def __init__(self):
        self.written = b""

    def write(self, data: bytes) -> None:
        self.written += data

    async def drain(self) -> None:
        pass

    def close(self) -> None:
        pass

    async def wait_closed(self) -> None:
        pass


async def _client_with_fake_transport() -> tuple[ElectrumClient, asyncio.StreamReader, FakeWriter]:
    client = ElectrumClient("localhost", 1234)
    reader = asyncio.StreamReader()
    writer = FakeWriter()
    client._reader = reader
    client._writer = writer
    client._read_task = asyncio.create_task(client._read_loop())
    return client, reader, writer


async def test_request_resolves_on_matching_response():
    client, reader, writer = await _client_with_fake_transport()

    task = asyncio.create_task(client.request("blockchain.headers.subscribe"))
    await asyncio.sleep(0)  # let request() write the payload
    sent = json.loads(writer.written.decode())
    assert sent["method"] == "blockchain.headers.subscribe"

    reader.feed_data((json.dumps({"id": sent["id"], "result": {"height": 100}}) + "\n").encode())
    result = await task
    assert result == {"height": 100}

    client._read_task.cancel()


async def test_error_response_raises_electrum_error():
    client, reader, writer = await _client_with_fake_transport()

    task = asyncio.create_task(client.request("blockchain.transaction.broadcast", ["deadbeef"]))
    await asyncio.sleep(0)
    sent = json.loads(writer.written.decode())

    reader.feed_data((json.dumps({"id": sent["id"], "error": "bad tx"}) + "\n").encode())
    try:
        await task
        assert False, "expected ElectrumError"
    except ElectrumError:
        pass

    client._read_task.cancel()


async def test_notification_delivered_to_subscription_queue():
    client, reader, writer = await _client_with_fake_transport()
    queue = client.notifications("blockchain.scripthash.subscribe")

    push = {"method": "blockchain.scripthash.subscribe", "params": ["abcd", "newstatus"]}
    reader.feed_data((json.dumps(push) + "\n").encode())
    await asyncio.sleep(0)

    params = await asyncio.wait_for(queue.get(), timeout=1)
    assert params == ["abcd", "newstatus"]

    client._read_task.cancel()


async def test_request_times_out_instead_of_hanging_forever(monkeypatch):
    """B-01: a server that owes us a reply and never sends one used to hang the
    caller permanently — which meant a POST /bets could hang while holding the
    per-user lock, and the confirmation poller could stop polling for good."""
    from app.electrum import client as client_module

    monkeypatch.setattr(client_module, "_REQUEST_TIMEOUT_SECONDS", 0.05)
    client, reader, writer = await _client_with_fake_transport()

    try:
        await client.request("blockchain.transaction.get", ["deadbeef"])
        assert False, "expected ElectrumError"
    except ElectrumError as exc:
        assert "timed out" in str(exc)

    # The connection is torn down, so callers stop reusing a server that owes us.
    assert client._closed.is_set()
    client._read_task.cancel()


async def test_wait_closed_resolves_when_the_read_loop_dies():
    """B-01: the read loop dying used to be invisible — the listener sat on its
    notification queues forever and never reconnected."""
    client, reader, writer = await _client_with_fake_transport()

    waiter = asyncio.create_task(client.wait_closed())
    reader.feed_eof()  # peer closed the connection

    await asyncio.wait_for(waiter, timeout=1)
    client._read_task.cancel()


async def test_pending_request_fails_when_the_connection_drops():
    client, reader, writer = await _client_with_fake_transport()

    task = asyncio.create_task(client.request("server.ping"))
    await asyncio.sleep(0)
    reader.feed_eof()

    try:
        await asyncio.wait_for(task, timeout=1)
        assert False, "expected ElectrumError"
    except ElectrumError:
        pass


def test_parse_endpoints_puts_the_primary_first_and_dedupes():
    from app.electrum.client import ElectrumEndpoint, parse_endpoints

    endpoints = parse_endpoints(
        "primary.example", 50002, True, "second.example:50002, third.example:50001:notls, primary.example:50002"
    )
    assert endpoints == [
        ElectrumEndpoint("primary.example", 50002, True),
        ElectrumEndpoint("second.example", 50002, True),
        ElectrumEndpoint("third.example", 50001, False),
    ]


def test_parse_endpoints_handles_an_empty_fallback_list():
    from app.electrum.client import ElectrumEndpoint, parse_endpoints

    assert parse_endpoints("only.example", 50002, True, "") == [ElectrumEndpoint("only.example", 50002, True)]
    assert parse_endpoints("only.example", 50002, True, "  ,  ") == [
        ElectrumEndpoint("only.example", 50002, True)
    ]


def test_parse_endpoints_rejects_a_malformed_entry():
    """A typo in a fallback server must fail at startup, not during the outage when
    the fallback is the thing that's needed."""
    import pytest

    from app.electrum.client import parse_endpoints

    for bad in ["nohost:", "host:notaport", "host", "host:50002:weird"]:
        with pytest.raises(ValueError):
            parse_endpoints("primary.example", 50002, True, bad)