import asyncio
from types import SimpleNamespace

import pytest

from pneumatube.smtp_server import GatewayHandler


class _StubBridge:
    def __init__(self, known=("alice", "bob", "broken"), accepted=("alice", "bob", "broken")):
        self.forwarded = []
        self.known = set(known)
        self.accepted = set(accepted)

    def forward(self, username, subject, body):
        self.forwarded.append(username)
        if username == "broken":
            raise RuntimeError("smolmail server unreachable")

    def user_exists(self, username):
        return username in self.known

    def recipient_accepted_gateway(self, username):
        return username in self.accepted

    @staticmethod
    def extract_text(message):
        return message.get_payload(decode=True).decode("utf-8", "replace")


class _InlineWorker:
    """Runs synchronously: handle_DATA's per-recipient logic doesn't depend
    on real threading, just on worker.run's (fn, *args) -> result contract."""

    async def run(self, fn, *args):
        return fn(*args)


def _envelope(rcpt_tos):
    return SimpleNamespace(
        content=b"Subject: hi\r\n\r\nbody text\r\n",
        mail_from="sender@realmail.example",
        rcpt_tos=rcpt_tos,
    )


def _config(**overrides):
    defaults = {"email_domain": "gateway.example", "require_accepted_recipient": True}
    return SimpleNamespace(**{**defaults, **overrides})


def test_handle_rcpt_rejects_wrong_domain():
    handler = GatewayHandler(_StubBridge(), _InlineWorker(), config=_config())
    reply = asyncio.run(handler.handle_RCPT(None, None, _envelope([]),
                                             "alice@other.example", None))
    assert reply.startswith("550")


def test_handle_rcpt_rejects_unknown_user():
    handler = GatewayHandler(_StubBridge(known=()), _InlineWorker(), config=_config())
    reply = asyncio.run(handler.handle_RCPT(None, None, _envelope([]),
                                             "ghost@gateway.example", None))
    assert reply.startswith("550")


def test_handle_rcpt_rejects_unaccepted_recipient_by_default():
    """The all-or-nothing gate: a recipient who exists but has not accepted
    the gateway (no token held) must be rejected live, not silently demoted
    to the recipient's own requests tier."""
    bridge = _StubBridge(known=("alice",), accepted=())
    handler = GatewayHandler(bridge, _InlineWorker(), config=_config())
    reply = asyncio.run(handler.handle_RCPT(None, None, _envelope([]),
                                             "alice@gateway.example", None))
    assert reply.startswith("550")


def test_handle_rcpt_allows_unaccepted_recipient_when_disabled():
    bridge = _StubBridge(known=("alice",), accepted=())
    handler = GatewayHandler(bridge, _InlineWorker(),
                              config=_config(require_accepted_recipient=False))
    envelope = _envelope([])
    reply = asyncio.run(handler.handle_RCPT(None, None, envelope, "alice@gateway.example", None))
    assert reply.startswith("250")
    assert envelope.rcpt_tos == ["alice@gateway.example"]


def test_handle_rcpt_accepts_known_accepted_recipient():
    bridge = _StubBridge(known=("alice",), accepted=("alice",))
    handler = GatewayHandler(bridge, _InlineWorker(), config=_config())
    envelope = _envelope([])
    reply = asyncio.run(handler.handle_RCPT(None, None, envelope, "alice@gateway.example", None))
    assert reply.startswith("250")
    assert envelope.rcpt_tos == ["alice@gateway.example"]


def test_handle_data_replies_once_per_recipient():
    bridge = _StubBridge()
    handler = GatewayHandler(bridge, _InlineWorker(), config=_config())
    envelope = _envelope(["alice@gateway.example", "broken@gateway.example"])

    reply = asyncio.run(handler.handle_DATA(None, None, envelope))
    lines = reply.split("\r\n")

    assert len(lines) == 2
    assert lines[0].startswith("250")
    assert lines[1].startswith("451")
    assert bridge.forwarded == ["alice", "broken"]


def test_handle_data_all_succeed():
    bridge = _StubBridge()
    handler = GatewayHandler(bridge, _InlineWorker(), config=_config())
    envelope = _envelope(["alice@gateway.example", "bob@gateway.example"])

    reply = asyncio.run(handler.handle_DATA(None, None, envelope))

    assert reply == "250 2.1.5 delivered\r\n250 2.1.5 delivered"