# SPDX-License-Identifier: Apache-2.0
"""Tests for the chat feature: device send, persistence, and the chat service.

All run against the :class:`MockDevice` simulator and a temporary database; no hardware.
"""

from __future__ import annotations

import asyncio
import logging
import re
from pathlib import Path

import pytest
from rich.cells import cell_len

from meshterm.core.channels import DEFAULT_PUBLIC_SECRET, derive_secret
from meshterm.core.config import Settings
from meshterm.core.connection import MockDevice
from meshterm.core.events import MeshEvent
from meshterm.core.models import (
    ChatMessage,
    Contact,
    Conversation,
    Message,
    conversation_key,
)
from meshterm.core.preferences import Preferences
from meshterm.persistence.repository import Repository
from meshterm.services.chat_service import ChatService
from meshterm.services.event_hub import EventHub
from meshterm.tools.chat import _lanes, _LiveLasts, _preview_text, _title
from meshterm.ui.chat import ChatScreen
from meshterm.ui.tui import fkeys
from meshterm.ui.tui.screen import CANCEL
from tests.conftest import plain as _strip_ansi  # THE strip-and-join screen reader


class _StubSession:
    """A session stand-in that just counts repaint requests."""

    def __init__(self) -> None:
        self.invalidations = 0

    def invalidate(self) -> None:
        self.invalidations += 1

    def run_detached(self, work):  # noqa: ANN001, ANN201
        """Start a key handler's flow as a task, as ``TuiSession.run_detached`` does."""
        return asyncio.ensure_future(work)


class _StubContext:
    """Minimal :class:`~meshterm.context.AppContext` stand-in for chat tests."""

    def __init__(self, device: MockDevice, repo: Repository) -> None:
        self._device = device
        self.repo = repo
        self.log = logging.getLogger("test.chat")
        self.profile_name = None
        self.settings = Settings()
        self.preferences = Preferences()
        self.events = EventHub(self)

    async def device(self) -> MockDevice:
        await self._device.connect()
        return self._device


@pytest.fixture()
def repo(tmp_path: Path) -> Repository:
    """A Repository on a scratch database, closed when the test finishes."""
    r = Repository(tmp_path / "chat.db")
    yield r
    r.close()


# -- domain models ------------------------------------------------------------


def test_conversation_key_distinguishes_channels_and_directs() -> None:
    """Channel keys use the channel's identity; direct keys are case-insensitive on the peer."""
    assert conversation_key(True, "deadbeef", None) == "chan:deadbeef"
    assert conversation_key(False, None, "AABBCC") == "dm:aabbcc"

    contact = Contact(name="Alice", public_key="d4e5" + "0" * 60, key_prefix="d4e5f6a7")
    conv = Conversation(label="Alice", is_channel=False, contact=contact)
    assert conv.key == "dm:d4e5f6a7"
    assert conv.peer == "d4e5f6a7"

    chan = Conversation(label="#public", is_channel=True, channel_idx=2, channel_id="deadbeef")
    assert chan.key == "chan:deadbeef"  # keyed by identity, not the slot index
    assert chan.peer is None


def test_chat_message_from_inbound_message() -> None:
    """An inbound direct Message maps to a received ChatMessage on the right thread."""
    message = Message(text="hi", sender="a1b2c3d4", is_channel=False, snr=5.5)
    chat = ChatMessage.from_message(message, peer_name="Yagi")
    assert chat.outbound is False
    assert chat.is_channel is False
    assert chat.peer == "a1b2c3d4"
    assert chat.peer_name == "Yagi"
    assert chat.snr == 5.5
    assert chat.key == "dm:a1b2c3d4"


# -- device send --------------------------------------------------------------


async def test_mock_send_direct_returns_ack() -> None:
    """The simulator acknowledges direct messages so they show as delivered."""
    device = MockDevice()
    await device.connect()
    contact = (await device.get_contacts())[0]
    delivery = await device.send_direct_message(contact, "hello")
    assert delivery.acked and delivery.code
    await device.send_channel_message(0, "hi channel")  # no return, must not raise
    await device.disconnect()


async def test_sending_to_a_contact_the_device_forgot_is_refused_by_name() -> None:
    """A recipient the radio has no entry for is refused in words, naming the contact.

    MeshTerm lists the union of the device's contacts and the ones it remembers for that
    device, so a contact the firmware dropped still appears and only the send finds out.
    The rejection has to carry the contact, so the chat can offer to write it back.
    """
    from meshterm.core.connection import ContactNotOnDeviceError

    device = MockDevice()
    await device.connect()
    stranger = Contact(name="bob_caribou", public_key="a3" * 32, key_prefix="a3a3a3a3")
    with pytest.raises(ContactNotOnDeviceError) as caught:
        await device.send_direct_message(stranger, "hello")
    assert caught.value.contact is stranger
    assert "bob_caribou" in str(caught.value)
    assert "error_code" not in str(caught.value)  # never the wire payload
    await device.disconnect()


async def test_adding_a_forgotten_contact_back_makes_it_messageable() -> None:
    """Writing the contact to the device is the whole fix — the same send then lands."""
    device = MockDevice()
    await device.connect()
    stranger = Contact(name="bob_caribou", public_key="a3" * 32, key_prefix="a3a3a3a3")
    await device.add_contact(stranger)
    assert "bob_caribou" in {c.name for c in await device.get_contacts()}
    assert (await device.send_direct_message(stranger, "hello")).acked
    await device.disconnect()


async def test_restore_contact_writes_only_when_the_dialog_is_accepted() -> None:
    """The device write is offered, not silent — declining leaves the table untouched."""
    from meshterm.core.connection import ContactNotOnDeviceError
    from meshterm.ui.chat import _restore_contact

    class _Ui:
        def __init__(self, answer: bool) -> None:
            self.answer = answer
            self.prompt = ""

        async def dialog(self, prompt, buttons, **kwargs):  # noqa: ANN001, ANN003
            self.prompt = prompt
            return self.answer

    class _Devstate:
        def __init__(self) -> None:
            self.invalidated = 0

        def invalidate_contacts(self) -> None:
            self.invalidated += 1

    class _Ctx:
        def __init__(self, device: MockDevice, answer: bool) -> None:
            self._device = device
            self.ui = _Ui(answer)
            self.devstate = _Devstate()

        async def device(self) -> MockDevice:
            return self._device

    stranger = Contact(name="bob_caribou", public_key="a3" * 32, key_prefix="a3a3a3a3")
    missing = ContactNotOnDeviceError(stranger)

    device = MockDevice()
    await device.connect()
    before = len(await device.get_contacts())

    declined = _Ctx(device, answer=False)
    assert await _restore_contact(declined, missing) is False
    assert len(await device.get_contacts()) == before
    assert declined.devstate.invalidated == 0
    assert "bob_caribou" in declined.ui.prompt

    accepted = _Ctx(device, answer=True)
    assert await _restore_contact(accepted, missing) is True
    assert len(await device.get_contacts()) == before + 1
    assert accepted.devstate.invalidated == 1
    await device.disconnect()


async def test_a_declined_restore_lets_the_rejection_stand() -> None:
    """The send retries once the contact is back, and reports the refusal when it isn't."""
    from meshterm.core.connection import ContactNotOnDeviceError
    from meshterm.ui.chat import _with_restore

    stranger = Contact(name="bob_caribou", public_key="a3" * 32)
    tries = 0

    async def attempt() -> str:
        nonlocal tries
        tries += 1
        if tries == 1:
            raise ContactNotOnDeviceError(stranger)
        return "sent"

    class _Ctx:
        def __init__(self, restored: bool) -> None:
            self.restored = restored

    async def restore(ctx, missing) -> bool:  # noqa: ANN001
        return ctx.restored

    import meshterm.ui.chat as chat_module

    original = chat_module._restore_contact
    chat_module._restore_contact = restore
    try:
        with pytest.raises(ContactNotOnDeviceError):
            await _with_restore(_Ctx(restored=False), attempt)
        assert tries == 1  # declined: no second transmission
        tries = 0
        assert await _with_restore(_Ctx(restored=True), attempt) == "sent"
        assert tries == 2  # the same send, run again once the contact was written back
    finally:
        chat_module._restore_contact = original


def test_a_rejected_command_is_explained_in_words_not_wire_codes() -> None:
    """Error codes become sentences; only an unrecognised rejection shows its payload."""
    from meshterm.core.connection import reject_reason

    class _Ev:
        def __init__(self, payload: dict) -> None:
            self.payload = payload

    assert reject_reason(_Ev({"error_code": 2})) == "the device has no contact with that key"
    assert reject_reason(_Ev({"error_code": 3})) == "the device's table is full"
    assert reject_reason(None) == "the device didn't answer"
    assert "97" in reject_reason(_Ev({"error_code": 97}))


async def test_add_contact_writes_a_flood_record_with_the_name_the_field_fits() -> None:
    """The record the firmware gets carries no learned route and a byte-clipped name."""
    from meshterm.core.connection import MeshCoreDevice

    class _Ok:
        payload: dict = {}

        def is_error(self) -> bool:
            return False

    class _FakeContacts:
        def __init__(self) -> None:
            self.record = None

        async def add_contact(self, record):  # noqa: ANN001
            self.record = record
            return _Ok()

    class _FakeMc:
        def __init__(self) -> None:
            self.commands = _FakeContacts()

    device = MeshCoreDevice.__new__(MeshCoreDevice)
    mc = _FakeMc()
    device._require = lambda: mc  # type: ignore[method-assign]
    long_name = "é" * 40  # 80 bytes: twice what the firmware's name field holds
    await device.add_contact(Contact(name=long_name, public_key="a3" * 32, node_type=1))
    record = mc.commands.record
    assert record["out_path_len"] == -1 and record["out_path"] == ""
    assert len(record["adv_name"].encode("utf-8")) == 32
    assert record["public_key"] == "a3" * 32


async def test_message_pump_drains_until_empty() -> None:
    """The RX pump pulls get_msg() until the queue is empty (the pull model).

    MeshCore never pushes message bodies, so the client must pull them; without this,
    sending works but nothing is received. Guards the immediate drain, the loop until
    NO_MORE_MSGS, the MESSAGES_WAITING subscription, and clean teardown.
    """
    from meshcore import EventType

    from meshterm.core.connection import MeshCoreDevice

    class _Ev:
        def __init__(self, t) -> None:  # noqa: ANN001
            self.type = t

    class _FakeCommands:
        def __init__(self, script: list) -> None:
            self.calls = 0
            self._script = script

        async def get_msg(self, timeout=None):  # noqa: ANN001, ANN201
            i = min(self.calls, len(self._script) - 1)
            self.calls += 1
            return _Ev(self._script[i])

    class _FakeMC:
        def __init__(self, script: list) -> None:
            self.commands = _FakeCommands(script)
            self.subs: list = []

        def subscribe(self, etype, cb):  # noqa: ANN001, ANN201
            self.subs.append(etype)
            return object()

    # One real message, then the empty sentinel: the drain loop pulls twice.
    mc = _FakeMC([EventType.CONTACT_MSG_RECV, EventType.NO_MORE_MSGS])
    device = MeshCoreDevice(port="COM_TEST")
    subs: list = []
    stop = device._message_pump(mc, subs, mc.subscribe)
    try:
        await asyncio.sleep(0.01)  # let the immediate drain task run
        assert mc.commands.calls == 2  # CONTACT_MSG_RECV then NO_MORE_MSGS
        assert EventType.MESSAGES_WAITING in mc.subs  # low-latency push subscription
    finally:
        stop()


# -- persistence --------------------------------------------------------------


def test_record_and_load_direct_conversation(repo: Repository) -> None:
    """Direct messages round-trip and come back in chronological order."""
    repo.record_chat_message(ChatMessage(text="hi", outbound=True, peer="D4E5F6A7", acked=True))
    repo.record_chat_message(ChatMessage(text="yo", outbound=False, peer="d4e5f6a7", snr=3.0))

    got = repo.recent_chat_messages(is_channel=False, peer="d4e5f6a7")
    assert [m.text for m in got] == ["hi", "yo"]
    assert got[0].outbound is True and got[0].acked is True
    assert got[1].outbound is False and got[1].snr == 3.0


def test_record_and_load_channel_conversation(repo: Repository) -> None:
    """Channel messages are keyed by channel identity, isolated from direct messages."""
    repo.record_chat_message(ChatMessage(text="c0", is_channel=True, channel_id="aa00"))
    repo.record_chat_message(ChatMessage(text="c1", is_channel=True, channel_id="bb11"))

    assert [m.text for m in repo.recent_chat_messages(is_channel=True, channel_id="aa00")] == ["c0"]
    assert [m.text for m in repo.recent_chat_messages(is_channel=True, channel_id="bb11")] == ["c1"]


def test_last_chat_messages_returns_latest_per_conversation(repo: Repository) -> None:
    """The picker preview shows the newest message in each conversation."""
    repo.record_chat_message(ChatMessage(text="old", peer="aa"))
    repo.record_chat_message(ChatMessage(text="new", peer="aa"))
    repo.record_chat_message(ChatMessage(text="chan", is_channel=True, channel_id="aa00"))

    lasts = repo.last_chat_messages()
    assert lasts["dm:aa"].text == "new"
    assert lasts["chan:aa00"].text == "chan"


# -- picker row rendering -----------------------------------------------------


class _FakeChat:
    """Stand-in for the chat service exposing just the unread lookup a row title reads."""

    def __init__(self, unread: dict[str, int]) -> None:
        self._unread = unread

    def unread(self, key: str) -> int:
        return self._unread.get(key, 0)


class _RowCtx:
    """Minimal ctx exposing only what the picker-row helpers touch (repo + chat)."""

    def __init__(self, repo: Repository, unread: dict[str, int] | None = None) -> None:
        self.repo = repo
        self.chat = _FakeChat(unread or {})


def test_live_lasts_refreshes_preview_after_ttl(repo: Repository) -> None:
    """A new message becomes visible through _LiveLasts once the cache TTL lapses."""
    repo.record_chat_message(ChatMessage(text="first", is_channel=True, channel_id="c0"))
    live = _LiveLasts(_RowCtx(repo), seed=repo.last_chat_messages(), ttl=0)  # 0 => always fresh
    assert live.get("chan:c0").text == "first"
    repo.record_chat_message(ChatMessage(text="second", is_channel=True, channel_id="c0"))
    assert live.get("chan:c0").text == "second"  # picked up live, not stuck on the seed


def test_live_lasts_serves_seed_within_ttl(repo: Repository) -> None:
    """Within the TTL the seeded snapshot is served without re-querying the repository."""
    live = _LiveLasts(_RowCtx(repo), seed={"chan:c0": ChatMessage(text="seed")}, ttl=999)
    repo.record_chat_message(ChatMessage(text="later", is_channel=True, channel_id="c0"))
    assert live.get("chan:c0").text == "seed"


#: A resolver that places no name — every hue falls back to muted.
_NO_KEYS = lambda name: None  # noqa: E731 - a one-line stub reads best inline


def _keys_of(mapping: dict[str, str]):
    """A canned name→key resolver over ``mapping`` (casefolded, like the real one)."""
    return lambda name: mapping.get(name.casefold())


def test_preview_prefixes_own_messages_only() -> None:
    """Only outbound messages get a ``you:`` prefix; inbound text is shown verbatim.

    Channel senders are embedded inline in the message text by the firmware, so no author is
    synthesized (that would double it), and a direct message's author is the row label.
    """
    chan_in = ChatMessage(text="Bob: hi", is_channel=True, channel_idx=0)  # sender inline
    assert _preview_text(chan_in, _NO_KEYS).plain == "Bob: hi"
    dm_in = ChatMessage(text="hey", peer="aa", peer_name="Bob")
    assert _preview_text(dm_in, _NO_KEYS).plain == "hey"
    mine = ChatMessage(text="yo", outbound=True, is_channel=True, channel_idx=0)
    assert _preview_text(mine, _NO_KEYS).plain == "you: yo"


def test_preview_colours_channel_sender_and_mentions() -> None:
    """A preview lights resolvable sender/mention names in their key-derived hue.

    A name no known node carries stays muted — colour is reserved for keyed identities.
    """
    from meshterm.ui.theme import node_style

    key_of = _keys_of({"bob": "d4" + "0" * 62, "alice": "60" + "0" * 62})
    msg = ChatMessage(text="Bob: hi @[Alice] @[Zed]", is_channel=True, channel_idx=0)
    preview = _preview_text(msg, key_of)
    assert preview.plain == "Bob: hi @Alice @Zed"  # brackets dropped for display
    styles = {span.style for span in preview.spans}
    assert node_style("d4") in styles and node_style("60") in styles
    # The unresolvable @Zed takes the unknown-node grey, like any name we can't place.
    zed = preview.plain.index("@Zed")
    assert any(s.style == "node.unknown" and s.start <= zed < s.end for s in preview.spans)


def test_preview_keeps_the_whole_message() -> None:
    """The preview is built whole — the row's own cut is what the ←→ scroll walks past."""
    long = ChatMessage(text="x" * 300, is_channel=True, channel_idx=0)
    assert _preview_text(long, _NO_KEYS).plain == "x" * 300


def test_title_shows_badge_and_author_preview(repo: Repository) -> None:
    """A channel row renders its live unread badge and its author-prefixed preview."""
    conv = Conversation(label="General", is_channel=True, channel_idx=0, channel_id="c0")
    ctx = _RowCtx(repo, unread={"chan:c0": 3})
    last = ChatMessage(text="Bob: hi there", is_channel=True, channel_id="c0")  # sender inline
    title = _title(ctx, conv, {"chan:c0": last}, _NO_KEYS, _lanes([conv]))
    line = title.plain  # a Text, since there is unread
    assert line.startswith("🔒 General")  # a private channel leads with its openness glyph
    assert "● 3" in line
    assert "Bob: hi there" in line


def test_title_reddens_only_the_unread_dot(repo: Repository) -> None:
    """With unread the row's ``●`` glyph (only) is styled red; with none there is no dot."""
    from rich.text import Text

    conv = Conversation(label="General", is_channel=True, channel_idx=0, channel_id="c0")
    unread = _title(_RowCtx(repo, unread={"chan:c0": 2}), conv, {}, _NO_KEYS, _lanes([conv]))
    assert isinstance(unread, Text)
    dot = unread.plain.index("●")
    reddened = [
        span for span in unread.spans if span.style == "err" and span.start <= dot < span.end
    ]
    assert reddened and all(span.end - span.start == 1 for span in reddened)  # just the glyph

    read = _title(_RowCtx(repo, unread={}), conv, {}, _NO_KEYS, _lanes([conv]))
    assert isinstance(read, Text)  # always a Text now, so its spans can carry the row's colour
    assert "●" not in read.plain  # nothing unread -> no badge dot
    assert not any(span.style == "err" for span in read.spans)


def test_title_preview_column_aligns_regardless_of_label_length(repo: Repository) -> None:
    """The preview starts at the same column whether the label is short or (clipped) long."""
    ctx = _RowCtx(repo)
    short = Conversation(label="A", is_channel=True, channel_idx=0, channel_id="c0")
    long = Conversation(
        label="A much longer channel name here", is_channel=True, channel_idx=1, channel_id="c1"
    )
    m0 = ChatMessage(text="X: hello", is_channel=True, channel_id="c0")
    m1 = ChatMessage(text="Y: hello", is_channel=True, channel_id="c1")
    lanes = _lanes([short, long])  # one measurement for the list, as the picker does
    l0 = _title(ctx, short, {"chan:c0": m0}, _NO_KEYS, lanes).plain
    l1 = _title(ctx, long, {"chan:c1": m1}, _NO_KEYS, lanes).plain
    assert l0.index("X: hello") == l1.index("Y: hello")


def test_title_leads_with_openness_glyph(repo: Repository) -> None:
    """Channel rows lead with an openness glyph: ＃ name-derived, 🌐 public, 🔒 private."""
    ctx = _RowCtx(repo)

    def head(conv):
        return _title(ctx, conv, {}, _NO_KEYS, _lanes([conv])).plain.split(" ", 1)[0]

    named = Conversation(
        label="#general", is_channel=True, channel_id="c0", secret=derive_secret("#general")
    )
    public = Conversation(
        label="Public", is_channel=True, channel_id="c1", secret=DEFAULT_PUBLIC_SECRET
    )
    private = Conversation(label="Ops", is_channel=True, channel_id="c2", secret=bytes(range(16)))
    assert head(named) == "＃"
    assert head(public) == "🌐"
    assert head(private) == "🔒"


def test_title_contact_dot_reflects_conversation_history(repo: Repository) -> None:
    """The title's contact dot reflects whether there is history with them.

    It fills ● once we've talked and is hollow ○ before, companion pink both ways,
    while the name itself carries the contact's key-derived hue.
    """
    from meshterm.tools.chat import _COMPANION_DOT_STYLE
    from meshterm.ui.theme import node_style

    ctx = _RowCtx(repo)
    contact = Conversation(
        label="Alice", is_channel=False, contact=Contact(name="Alice", public_key="d4" + "0" * 62)
    )

    def dot_is_pink(row) -> bool:
        return any(
            span.style == _COMPANION_DOT_STYLE and span.start == 0 and span.end == 1
            for span in row.spans
        )

    # No history yet — a hollow ring in the standard companion pink.
    fresh = _title(ctx, contact, {}, _NO_KEYS, _lanes([contact]))
    assert fresh.plain.startswith("○") and dot_is_pink(fresh)
    # The name lane carries Alice's key-derived hue.
    name_at = fresh.plain.index("Alice")
    assert any(s.style == node_style("d4") and s.start <= name_at < s.end for s in fresh.spans)

    # Once we've exchanged messages the same pink dot fills in.
    last = ChatMessage(text="hi", peer=contact.peer)
    talked = _title(ctx, contact, {contact.key: last}, _NO_KEYS, _lanes([contact]))
    assert talked.plain.startswith("●") and dot_is_pink(talked)


# -- chat service -------------------------------------------------------------


async def test_service_records_inbound_and_tracks_unread(repo: Repository) -> None:
    """Inbound messages are persisted and bump the conversation's unread count."""
    device = MockDevice()
    ctx = _StubContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        ctx.events.publish(
            MeshEvent.message_event(Message(text="ping", sender="ffeeddcc", is_channel=False))
        )
        await chat._queue.join()  # let the inbound worker resolve and record the message
        assert chat.unread("dm:ffeeddcc") == 1
        assert chat.unread_total() >= 1
        stored = repo.recent_chat_messages(is_channel=False, peer="ffeeddcc")
        assert [m.text for m in stored] == ["ping"]
    finally:
        await chat.stop()
        await device.disconnect()


async def test_service_active_conversation_suppresses_unread(repo: Repository) -> None:
    """The open conversation clears and stops accruing unread while it stays active."""
    device = MockDevice()
    ctx = _StubContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        chat.set_active("dm:ffeeddcc")
        ctx.events.publish(
            MeshEvent.message_event(Message(text="ping", sender="ffeeddcc", is_channel=False))
        )
        await chat._queue.join()  # let the inbound worker resolve and record the message
        assert chat.unread("dm:ffeeddcc") == 0  # active thread doesn't accrue unread
        assert repo.recent_chat_messages(is_channel=False, peer="ffeeddcc")  # still recorded
    finally:
        await chat.stop()
        await device.disconnect()


async def test_service_files_channel_message_by_current_slot_occupant(repo: Repository) -> None:
    """A channel message is filed under whatever channel is in its slot *now*.

    The wire reports only a slot index, which the firmware assigns from the channel's current
    position. Reordering the slots (here simulated out of band, without notifying the service)
    must not misroute later messages: resolution reads the slot fresh, so a message on slot 0
    lands in whatever channel occupies slot 0 at that moment — never a stale cached identity.
    """
    from meshterm.core.channels import channel_identity

    device = MockDevice()
    ctx = _StubContext(device, repo)
    await device.connect()
    secret_a, secret_b = bytes(range(16)), bytes(range(16, 32))
    await device.set_channel(0, "Alpha", secret_a)
    await device.set_channel(1, "Bravo", secret_b)
    id_a = channel_identity("Alpha", secret_a)
    id_b = channel_identity("Bravo", secret_b)

    chat = ChatService(ctx)
    await chat.start()  # primes slot 0 -> Alpha, slot 1 -> Bravo
    try:
        ctx.events.publish(
            MeshEvent.message_event(Message(text="from alpha", is_channel=True, channel=0))
        )
        await chat._queue.join()

        # Swap the occupants of slots 0 and 1 out of band — the service is never told.
        await device.set_channel(0, "Bravo", secret_b)
        await device.set_channel(1, "Alpha", secret_a)

        ctx.events.publish(
            MeshEvent.message_event(Message(text="from bravo", is_channel=True, channel=0))
        )
        await chat._queue.join()

        alpha = repo.recent_chat_messages(is_channel=True, channel_id=id_a)
        bravo = repo.recent_chat_messages(is_channel=True, channel_id=id_b)
        assert [m.text for m in alpha] == ["from alpha"]  # unaffected by the reorder
        assert [m.text for m in bravo] == ["from bravo"]  # not misfiled under Alpha's identity
    finally:
        await chat.stop()
        await device.disconnect()


async def test_service_records_channel_messages_in_arrival_order(repo: Repository) -> None:
    """A burst of channel messages is recorded in arrival order despite async resolution.

    Each channel message resolves its identity with a device read; the serial inbound worker
    guarantees they still land in the transcript (ordered by insertion) in the order received.
    """
    from meshterm.core.channels import channel_identity

    device = MockDevice()
    ctx = _StubContext(device, repo)
    await device.connect()
    secret = bytes(range(16))
    await device.set_channel(0, "Alpha", secret)
    channel_id = channel_identity("Alpha", secret)

    chat = ChatService(ctx)
    await chat.start()
    try:
        for i in range(5):
            ctx.events.publish(
                MeshEvent.message_event(Message(text=f"m{i}", is_channel=True, channel=0))
            )
        await chat._queue.join()
        stored = repo.recent_chat_messages(is_channel=True, channel_id=channel_id)
        assert [m.text for m in stored] == ["m0", "m1", "m2", "m3", "m4"]
    finally:
        await chat.stop()
        await device.disconnect()


# -- chat screen --------------------------------------------------------------


def _screen(session: _StubSession, send, *, messages=None, resend=None) -> ChatScreen:
    """Build a ChatScreen for a direct conversation with a stub session and send hook."""
    conv = Conversation(
        label="Alice",
        is_channel=False,
        contact=Contact(name="Alice", public_key="d4" + "0" * 62, key_prefix="d4e5f6a7"),
    )
    return ChatScreen(
        conv,
        messages or [],
        send=send,
        names={"d4e5f6a7": "Alice"},
        session=session,
        resend=resend,
    )


def test_chat_screen_renders_transcript_and_input() -> None:
    """The body shows each message and always ends with the input line."""
    session = _StubSession()
    messages = [ChatMessage(text="hi there", outbound=True, peer="d4e5f6a7", acked=True)]
    screen = _screen(session, send=None, messages=messages)

    lines = screen.render_body(60)
    joined = "\n".join(lines)
    assert "hi there" in joined
    assert "›" in joined  # the input editor's prompt marker


class _PasteSession(_StubSession):
    """A stub session whose paste confirm answers a scripted Cancel/Paste."""

    def __init__(self, answer: bool) -> None:
        super().__init__()
        self.answer = answer
        self.dialogs: list = []

    async def button_dialog(self, prompt, buttons, **kwargs):  # noqa: ANN001, ANN201
        self.dialogs.append((prompt, buttons, kwargs))
        return self.answer


async def _drain_paste(screen: ChatScreen) -> None:
    """Let the scheduled paste-confirm task run to completion."""
    for _ in range(100):
        await asyncio.sleep(0)
        if not screen._paste_open:
            return


async def test_chat_paste_confirms_amber_then_inserts() -> None:
    """Ctrl-V paste asks first on an amber Cancel/Paste dialog, then lands the run in compose."""
    session = _PasteSession(answer=True)
    screen = _screen(session, send=None)
    screen.handle("paste", "hello\nworld")
    await _drain_paste(screen)

    # The newline folded to a space and the run dropped into the compose line…
    assert screen._editor.text == "hello world"
    prompt, buttons, kwargs = session.dialogs[0]
    assert "Paste 11 characters" in prompt.plain  # the folded, stripped run's length
    assert kwargs.get("border_style") == "warn"  # the amber (danger) tier — "yellow"
    assert [label for label, _ in buttons] == ["Cancel", "Paste"]  # safe way out on the left


async def test_chat_paste_declined_leaves_compose_untouched() -> None:
    """Choosing Cancel on the paste confirm inserts nothing."""
    session = _PasteSession(answer=False)
    screen = _screen(session, send=None)
    screen.handle("paste", "unwanted")
    await _drain_paste(screen)
    assert screen._editor.text == ""


async def test_chat_screen_enter_sends_and_appends() -> None:
    """Pressing Enter sends the line and appends the returned message to the transcript."""
    session = _StubSession()
    sent: list[str] = []

    async def send(text: str) -> ChatMessage:
        sent.append(text)
        return ChatMessage(text=text, outbound=True, peer="d4e5f6a7", acked=True)

    screen = _screen(session, send=send)
    for ch in "hello":
        screen.handle("text", ch)
    screen.handle("enter")
    await asyncio.sleep(0)  # let the scheduled send task run

    assert sent == ["hello"]
    assert screen._messages[-1].text == "hello"
    assert session.invalidations > 0


async def test_direct_send_spins_until_the_ack_resolves(monkeypatch) -> None:
    """A pending direct message spins while the send is in flight, then settles on ✓."""
    from meshterm.ui.tui.spinner import Spinner

    monkeypatch.setattr("meshterm.ui.chat.spinner_interval", lambda: 0.005)
    session = _StubSession()
    release = asyncio.Event()

    async def send(text: str) -> ChatMessage:
        await release.wait()  # hold the send open so we can watch the glyph spin
        return ChatMessage(text=text, outbound=True, peer="d4e5f6a7", acked=True)

    screen = _screen(session, send=send)
    for ch in "hi":
        screen.handle("text", ch)
    screen.handle("enter")

    # While the send is held open the trailing glyph is a live spinner frame, and it advances.
    await asyncio.sleep(0.03)
    first = screen._spinner.frame
    joined = "\n".join(screen.render_body(60))
    assert first in Spinner.BRAILLE and first in joined and "⏳" not in joined
    await asyncio.sleep(0.03)
    assert screen._spinner.frame != first  # the animation is actually running

    # Once the ack lands, the spinner is gone and the message shows its delivered glyph.
    release.set()
    for _ in range(100):  # let _send_direct unwind (ticker cancel + swap) before asserting
        await asyncio.sleep(0.005)
        if screen._messages[-1].acked is not None:
            break
    assert screen._messages[-1].acked is True
    assert "✓" in "\n".join(screen.render_body(60))


def test_byte_counter_shows_used_over_limit_and_colors_only_used() -> None:
    """The inline budget shows ``used/limit`` with only the used count styled (the max is muted)."""
    from rich.text import Text

    screen = _screen(_StubSession(), send=None)
    for ch in "hello":
        screen.handle("text", ch)
    counter = screen._byte_counter(screen._byte_limit())
    assert isinstance(counter, Text)
    assert counter.plain.strip() == "5/150"  # 5 bytes used of the 150-byte direct-message cap
    # The budget is pinned to the input line's right edge (padded out from the compose text,
    # not trailing the cursor), while still sharing the input's own row so a full transcript
    # can never push it off the bottom of the viewport.

    body = re.sub(r"\x1b\[[0-9;]*m", "", "\n".join(screen.render_body(80)))
    input_row = next(line for line in body.splitlines() if "5/150" in line)
    assert re.search(r"› hello +5/150$", input_row.rstrip())  # a gap of padding, flush right
    assert len(input_row.rstrip()) == 80  # the counter reaches the right edge of the width
    # Only the "5" carries a color; the "/150" tail stays muted (it never changes).
    used_at = counter.plain.index("5")
    slash_at = counter.plain.index("/")
    used_spans = [s for s in counter.spans if s.start <= used_at < s.end]
    tail_spans = [s for s in counter.spans if s.start <= slash_at < s.end]
    assert used_spans and used_spans[0].style == "ok"  # green with room to spare
    assert tail_spans and tail_spans[0].style == "muted"


def test_byte_counter_stays_bottom_right_when_the_compose_wraps() -> None:
    """The byte counter stays bottom-right when the compose line wraps.

    It stays pinned to the last line's right edge, rather than trailing the cursor
    down onto the second row.
    """
    screen = _screen(_StubSession(), send=None)
    text = "this is a long compose line that certainly wraps onto several rows here ok"
    for ch in text:
        screen.handle("text", ch)
    counter = f"{len(text)}/150"
    body = re.sub(r"\x1b\[[0-9;]*m", "", "\n".join(screen.render_body(40)))
    counter_rows = [line for line in body.splitlines() if counter in line]
    assert len(counter_rows) == 1
    row = counter_rows[0]
    assert row.rstrip().endswith(counter)  # flush right, not mid-line after the text
    assert len(row.rstrip()) == 40  # reaches the render width's right edge
    assert not row.lstrip().startswith("›")  # on a wrapped row, not the first input row


def test_byte_style_escalates_as_budget_runs_out() -> None:
    """The used-byte color steps green → yellow → orange → red as fewer bytes remain."""
    from meshterm.ui.tui.prompt import _BYTES_ORANGE, _BYTES_YELLOW, byte_style

    assert byte_style(80) == "ok"  # plenty left → green
    assert byte_style(20) == _BYTES_YELLOW  # within the tight band → yellow
    assert byte_style(10) == _BYTES_ORANGE  # within the low band → orange
    assert byte_style(0) == "err"  # limit reached → red
    assert byte_style(-5) == "err"  # over the limit → still red


def test_channel_byte_limit_is_lower_than_direct() -> None:
    """A channel broadcast has a tighter byte budget than a direct message."""
    from meshterm.ui.tui.prompt import CHANNEL_BYTE_LIMIT, DM_BYTE_LIMIT

    direct = _screen(_StubSession(), send=None)
    channel = _channel_screen([])
    assert direct._byte_limit() == DM_BYTE_LIMIT == 150
    assert channel._byte_limit() == CHANNEL_BYTE_LIMIT == 130


def test_overflow_counts_multibyte_characters_by_byte() -> None:
    """An emoji (4 UTF-8 bytes) counts as 4 toward the budget, and overflow marks whole chars."""
    screen = _channel_screen([])  # 130-byte limit
    # 32 emojis = 128 bytes (under), a 33rd tips to 132 (over) at that whole character.
    for _ in range(33):
        screen.handle("text", "😀")
    assert screen._used_bytes() == 33 * 4
    assert screen._overflow_at(screen._byte_limit()) == 32  # the 33rd emoji is the first over


async def test_over_limit_message_is_not_sent_and_buffer_is_kept() -> None:
    """Enter on an over-budget line reports the overage and sends nothing, keeping the text."""
    session = _StubSession()
    sent: list[str] = []

    async def send(text: str) -> ChatMessage:
        sent.append(text)
        return ChatMessage(text=text, outbound=True, peer="d4e5f6a7", acked=True)

    screen = _screen(session, send=send)
    for ch in "x" * 151:  # one byte past the 150-byte direct cap
        screen.handle("text", ch)
    screen.handle("enter")
    await asyncio.sleep(0)  # nothing should have been scheduled, but let the loop turn

    assert sent == []  # the send was refused
    assert screen._editor.text == "x" * 151  # buffer kept intact so the user can trim it
    assert "Too long by 1 byte" in screen._status
    # Trimming back under the limit clears the notice.
    screen.handle("backspace")
    assert screen._status == ""


def test_chat_screen_shows_delivery_glyphs() -> None:
    """Outbound direct messages end with delivery marks: a spinner, then ✓ / ✗."""
    from meshterm.ui.tui.spinner import Spinner

    async def resend(message):  # noqa: ANN001, ANN202 - never awaited here
        return message

    messages = [
        ChatMessage(text="delivered", outbound=True, peer="d4e5f6a7", acked=True),
        ChatMessage(text="dropped", outbound=True, peer="d4e5f6a7", acked=False),
        ChatMessage(text="inflight", outbound=True, peer="d4e5f6a7", acked=None),
    ]
    screen = _screen(_StubSession(), send=None, messages=messages, resend=resend)

    joined = "\n".join(screen.render_body(60))
    # A message still awaiting its ack spins (a Braille frame); resolved ones show the
    # app-wide ✓/✗ status marks (never the ✅/❌ emoji, which are packet-class icons).
    assert "✓" in joined and "✗" in joined
    assert "✅" not in joined and "❌" not in joined
    assert Spinner.BRAILLE[0] in joined and "⏳" not in joined
    # A failed message advertises the retry shortcut in the footer hint (the app-wide
    # compact ^-notation for Ctrl chords).
    assert "^R" in screen.footer_hint


def test_wrapped_body_hangs_under_the_first_line() -> None:
    """A body too long for the width wraps with a hanging indent under its own first line."""
    from datetime import datetime, timezone

    base = datetime(2026, 7, 5, 14, 24, tzinfo=timezone.utc)
    # A run of short words guarantees several wrap points at a narrow width.
    text = " ".join(["word"] * 20)
    messages = [ChatMessage(text=text, peer="d4e5f6a7", created_at=base)]
    screen = _screen(_StubSession(), send=None, messages=messages)
    body_lines = [_strip_ansi(ln) for ln in screen._body_lines(text, messages[0], 30)]

    assert len(body_lines) > 1  # it actually wrapped
    stamp = base.astimezone().strftime("%H:%M")
    indent = body_lines[0].index(stamp) + len(stamp) + 2  # gutter: "  HH:MM  "
    first_word = body_lines[0].index("word")
    assert first_word == indent
    # Continuation lines start their text at the same column as the first line's body.
    for cont in body_lines[1:]:
        assert cont.startswith(" " * indent)
        assert cont[indent] != " "  # text resumes exactly under the body, not the gutter


def test_at_mention_renders_as_name_in_sender_hue() -> None:
    """An ``@[Name]`` token renders as a bare ``@Name`` in the node's key-derived hue.

    A mentioned name no contact or stored advert carries stays muted — the app-wide
    rule that colour marks a keyed identity.
    """
    from datetime import datetime, timezone

    from meshterm.ui.theme import node_style

    base = datetime(2026, 7, 5, 14, 24, tzinfo=timezone.utc)
    conv = Conversation(label="#public", is_channel=True, channel_idx=0)
    message = ChatMessage(
        text="Bob: @[Alice] and @[Zed] around?",
        is_channel=True,
        channel_idx=0,
        created_at=base,
    )
    screen = ChatScreen(
        conv,
        [message],
        send=None,
        names={},
        session=_StubSession(),
        key_of=_keys_of({"alice": "60" + "0" * 62}),
    )
    _, body = screen._sender_and_body(message)
    text = screen._render_mentions(body, selected=False)

    assert "@Alice" in text.plain  # bracketed token collapsed to a bare mention
    assert "@[Alice]" not in text.plain and "[Alice]" not in text.plain
    # The "@Alice" run carries the key-derived hue (the same the header would use).
    hue = screen._sender_style("Alice")
    assert hue == node_style("60")  # the sender's key-derived spectrum hue
    at = text.plain.index("@Alice")
    hue_spans = [
        s for s in text.spans if s.style == hue and s.start <= at and at + len("@Alice") <= s.end
    ]
    assert hue_spans
    # The unknown @Zed falls to the unknown-node grey — no key, no hue.
    assert screen._sender_style("Zed") == "node.unknown"


def test_direct_chat_unknown_mention_stays_muted() -> None:
    """In a direct chat an unresolved ``@mention`` stays muted — as it does in a channel.

    A direct thread's *sender label* falls back to the peer's own key so it keeps its
    hue even when the display name won't resolve, but that fallback must not leak onto
    an ``@mention`` in the body: a mention names an arbitrary person, so an unknown one
    is gray. Regression guard for the peer-key fallback bleeding into mentions.
    """
    from meshterm.ui.theme import node_style

    # Direct chat with peer key d4… — the sender label may borrow this hue, mentions must not.
    conv = Conversation(
        label="Alice",
        is_channel=False,
        contact=Contact(name="Alice", public_key="d4" + "0" * 62, key_prefix="d4e5f6a7"),
    )
    screen = ChatScreen(
        conv,
        [],
        send=None,
        names={"d4e5f6a7": "Alice"},
        session=_StubSession(),
        key_of=_keys_of({"alice": "60" + "0" * 62}),
    )

    # A resolvable mention still lights in its own key-derived hue…
    assert screen._sender_style("Alice", mention=True) == node_style("60")
    # …but an unknown mention is grey, not painted with the peer's (d4…) hue.
    assert screen._sender_style("Zed", mention=True) == "node.unknown"
    assert screen._sender_style("Zed", mention=True) != node_style("d4")
    # The sender label keeps the peer-key fallback (unchanged behaviour).
    assert screen._sender_style("Zed") == node_style("d4")


def test_direct_transcript_groups_under_sender_headers() -> None:
    """Direct chats use the same grouped layout as channels: one header per sender run."""
    from datetime import datetime, timezone

    base = datetime(2026, 7, 5, 14, 24, tzinfo=timezone.utc)
    messages = [
        ChatMessage(text="hi", peer="d4e5f6a7", created_at=base),
        ChatMessage(text="you there?", peer="d4e5f6a7", created_at=base),
        ChatMessage(text="yes!", outbound=True, peer="d4e5f6a7", acked=True, created_at=base),
    ]
    screen = _screen(_StubSession(), send=None, messages=messages)
    rendered = _strip_ansi("\n".join(screen._render_grouped(80)))

    # Inbound sender resolves to the contact name (from the names map), not the raw key.
    assert rendered.count("Alice") == 1  # the two inbound messages share one header
    assert "d4e5f6a7" not in rendered  # the key is never shown when a name is known
    assert "you" in rendered  # our own reply gets its own header
    assert "hi" in rendered and "you there?" in rendered and "yes!" in rendered
    assert "✓" in rendered  # the outbound message keeps its delivery mark


async def test_chat_screen_retry_resends_failed_message() -> None:
    """Ctrl-R re-attempts the latest unacknowledged message, flipping it in place."""
    session = _StubSession()
    failed = ChatMessage(text="oops", outbound=True, peer="d4e5f6a7", acked=False, row_id=7)

    async def resend(message: ChatMessage) -> ChatMessage:
        message.acked = True  # the retry gets through this time
        return message

    conv = Conversation(
        label="Alice",
        is_channel=False,
        contact=Contact(name="Alice", public_key="d4" + "0" * 62, key_prefix="d4e5f6a7"),
    )
    screen = ChatScreen(conv, [failed], send=None, names={}, session=session, resend=resend)

    screen.handle("retry")
    await asyncio.sleep(0)  # let the scheduled resend task run

    assert screen._messages[-1].acked is True  # same object, now acknowledged
    assert "✓" in "\n".join(screen.render_body(60))


async def test_chat_fkey_lane_dims_retry_and_the_nav_slots() -> None:
    """The lane offers Retry only with something to retry, and nav only with a transcript."""

    async def resend(message: ChatMessage) -> ChatMessage:
        message.acked = True
        return message

    empty = _screen(_StubSession(), send=None, resend=resend)
    assert not any(pair.enabled for pair in empty.picocalc_lyra_lane if pair)  # nothing to walk

    failed = ChatMessage(text="oops", outbound=True, peer="d4e5f6a7", acked=False)
    screen = _screen(_StubSession(), send=None, messages=[failed], resend=resend)
    assert all(pair.enabled for pair in screen.picocalc_lyra_lane[3:])  # the pager walks the pick
    assert screen.picocalc_lyra_lane[2].opp_enabled is True  # F8 Retry: the message never acked

    screen.handle("retry")
    await asyncio.sleep(0)
    assert failed.acked is True
    assert screen.picocalc_lyra_lane[2].opp_enabled is False  # acknowledged — nothing left to retry
    assert (
        screen.picocalc_lyra_lane[2].opp_label == "Retry"
    )  # dim, not gone: it belongs on this screen


def test_chat_fkey_lane_speaks_the_transcript_and_drops_channel_retry() -> None:
    """Chips name what they do here — and a channel has no such thing as a retry."""
    messages = [ChatMessage(text="hi", peer="d4e5f6a7")]
    direct = _screen(_StubSession(), send=None, messages=messages)

    # Not "Bottom"/"Top": what the Shift bank does to a conversation is come back to the
    # latest message and the compose line, or reach back to its oldest one. Relabelled in
    # place, so each jump still rides the pager heading for it.
    assert [pair.opp_label for pair in direct.picocalc_lyra_lane[3:]] == ["Latest", "Oldest"]
    assert [pair.opp_action for pair in direct.picocalc_lyra_lane[3:]] == ["ctrl_end", "ctrl_home"]
    assert [pair.label for pair in direct.picocalc_lyra_lane[3:]] == ["Page ↓", "Page ↑"]
    assert direct.picocalc_lyra_lane[2].opp_label == "Retry"

    channel = ChatScreen(
        Conversation(label="#general", is_channel=True, channel_id="1"),
        messages,
        send=None,
        names={},
        session=_StubSession(),
    )
    # A channel message is never acknowledged, so retrying one isn't a thing here: the
    # slot is empty rather than dimmed, and its key resolves to nothing.
    assert channel.picocalc_lyra_lane[2].opp_label == ""
    assert fkeys.PICOCALC_LYRA_DECK.action_for(channel.picocalc_lyra_lane, 8) is None


def test_chat_screen_up_picks_and_ctrl_end_returns_to_compose() -> None:
    """↑ picks the newest message (detaching from the tail); ^End returns to compose."""
    messages = [
        ChatMessage(text="hi", peer="d4e5f6a7"),
        ChatMessage(text="reply", outbound=True, peer="d4e5f6a7", acked=True),
    ]
    screen = _screen(_StubSession(), send=None, messages=messages)
    assert screen._stick is True and screen._selected is None
    screen.handle("up")
    assert screen._stick is False
    assert screen._selected == len(screen._messages) - 1  # the newest message
    screen.handle("ctrl_end")
    assert screen._stick is True and screen._selected is None


def test_split_channel_sender_extracts_name_prefix() -> None:
    """A ``Name: message`` channel line splits into sender and cleaned body."""
    from meshterm.core.channels import split_channel_sender

    assert split_channel_sender("Alice: hey there") == ("Alice", "hey there")
    assert split_channel_sender("Yagi Repeater: online") == ("Yagi Repeater", "online")
    # No plausible prefix: left untouched.
    assert split_channel_sender("just a message") == (None, "just a message")
    assert split_channel_sender("https://example.com") == (None, "https://example.com")
    assert split_channel_sender("14:30 standup") == (None, "14:30 standup")


def test_channel_transcript_groups_by_sender() -> None:
    """Consecutive same-sender channel messages share one header; the body is cleaned."""
    from datetime import datetime, timezone

    conv = Conversation(label="#public", is_channel=True, channel_idx=0)
    base = datetime(2026, 7, 5, 14, 24, tzinfo=timezone.utc)

    def at(minutes: int) -> datetime:
        return base.replace(minute=24 + minutes)

    messages = [
        ChatMessage(text="Alice: hi", is_channel=True, channel_idx=0, created_at=at(0)),
        ChatMessage(text="Alice: again", is_channel=True, channel_idx=0, created_at=at(6)),
        ChatMessage(text="Bob: yo", is_channel=True, channel_idx=0, created_at=at(8)),
        ChatMessage(
            text="hello all", outbound=True, is_channel=True, channel_idx=0, created_at=at(9)
        ),
    ]
    screen = ChatScreen(conv, messages, send=None, names={}, session=_StubSession())
    rendered = _strip_ansi("\n".join(screen._render_grouped(80)))

    assert rendered.count("Alice") == 1  # the two Alice messages share one header
    # Our own group is headed by the ★ a route draws our end with, never by our name.
    assert "Bob" in rendered and "★" in rendered
    assert "hi" in rendered and "again" in rendered  # bodies present, prefix stripped
    assert "Alice: hi" not in rendered  # the raw name prefix is lifted into the header
    # Each message keeps its own timestamp on its line, even when grouped under one sender.
    stamps = [at(m).astimezone().strftime("%H:%M") for m in (0, 6, 8, 9)]
    for stamp in stamps:
        assert stamp in rendered
    assert stamps[0] != stamps[1]  # grouped Alice messages show distinct times


def test_transcript_inscribes_the_sender_label_but_never_a_mention(powerline) -> None:
    """The name that *opens* a group is a chip; the same name inside a body is prose."""
    from meshterm.ui.widgets import name_chip

    powerline(True)  # this is a test *about* the chip, so ask for a glass that draws one
    conv = Conversation(label="#public", is_channel=True, channel_idx=0)
    messages = [
        ChatMessage(text="Alice: @[Bob] you around?", is_channel=True, channel_idx=0),
    ]
    screen = ChatScreen(conv, messages, send=None, names={}, session=_StubSession())
    rendered = _strip_ansi("\n".join(screen._render_grouped(80)))

    # Built through the widget rather than spelled out: the caps are the path line's, and
    # what is being asserted here is the framing, not the glyph.
    assert name_chip("Alice").plain in rendered  # the header, as a chip
    assert "@Bob" in rendered  # the mention, as it was typed
    assert name_chip("Bob").plain not in rendered  # …and never framed mid-sentence


def test_unidentified_sender_takes_the_node_grey_not_the_chrome_grey() -> None:
    """``·`` is a sender we can't place — content, so ``node.unknown``, never ``muted``.

    The two are one hex apart on the desktop and a whole slot apart on the console (light
    grey against dark), which is where a sender drawn in chrome grey stops reading as a
    node at all.
    """
    conv = Conversation(label="#public", is_channel=True, channel_idx=0)
    screen = ChatScreen(conv, [], send=None, names={}, session=_StubSession())

    assert screen._sender_style("·") == "node.unknown"
    assert screen._sender_style("nobody-knows-me") == "node.unknown"  # no key, no hue


def _two_day_messages():
    """Two days of direct messages, long enough to overflow a small viewport."""
    from datetime import datetime, timedelta, timezone

    base = datetime(2026, 7, 5, 9, 0, tzinfo=timezone.utc)
    day1 = [
        ChatMessage(text=f"day1-{i}", peer="d4e5f6a7", created_at=base + timedelta(minutes=i))
        for i in range(4)
    ]
    day2 = [
        ChatMessage(
            text=f"day2-{i}", peer="d4e5f6a7", created_at=base + timedelta(days=1, minutes=i)
        )
        for i in range(4)
    ]
    return day1 + day2


def test_chat_sticky_block_pins_the_governing_day_divider() -> None:
    """The day divider above the top row pins there once it scrolls off (like the picker).

    A day is its divider and nothing else, so each block is that one row — where a select
    list's heading may carry its description along.
    """
    screen = _screen(_StubSession(), send=None, messages=_two_day_messages())
    screen.render_body(60)
    (idx0, day0), (idx1, day1) = screen._sticky_headers
    assert len(day0) == 1 and len(day1) == 1  # one divider, no preamble under it
    assert screen.sticky_block(0) == []  # first divider is itself the top row
    assert screen.sticky_block(idx1 - 1) == day0  # still within day one — its divider pins
    assert screen.sticky_block(idx1) == []  # day two's divider is now the top row
    assert screen.sticky_block(idx1 + 1) == day1  # scrolled past it — day two's pins


def test_chat_frame_pins_a_day_divider_when_stuck_to_the_newest() -> None:
    """Rendered through the frame at the tail, a day divider occupies the pinned top row."""
    from meshterm.ui.tui import frame

    screen = _screen(_StubSession(), send=None, messages=_two_day_messages())
    lines = screen.render_body(60)  # sticks to the newest message, scrolling early days off
    visible, above, _below = frame._visible_slice(screen, lines, 6)
    top = _strip_ansi(visible[0]).strip()
    assert top.startswith("──") and "Jul" in top  # a day divider is pinned to the top row
    assert above is True  # and the frame flags there's more above the pin


def test_chat_top_of_transcript_clears_the_more_above_flag() -> None:
    """Picking the oldest message scrolls the head of the transcript into view.

    The first message's pick anchors at line 0, so the frame lands on offset 0: its day
    divider and sender chip are real rows again instead of a pin over a hidden line, and
    the title bar's clip arrow goes dim because there genuinely is nothing above.
    """
    from meshterm.ui.tui import frame

    screen = _screen(_StubSession(), send=None, messages=_two_day_messages())
    lines = screen.render_body(60)
    screen.handle("ctrl_home")  # back to the oldest message
    lines = screen.render_body(60)
    visible, above, below = frame._visible_slice(screen, lines, 6)

    assert screen.scroll == 0
    assert above is False and below is True
    assert _strip_ansi(visible[0]).strip().startswith("──")  # the head, drawn not pinned


def test_chat_home_end_and_word_keys_move_the_compose_cursor() -> None:
    """In a chat, Home/End and Ctrl+←/→ act on the compose line, not the transcript scroll."""
    screen = _screen(_StubSession(), send=None, messages=_two_day_messages())
    for ch in "hello world":
        screen.handle("text", ch)
    assert screen._editor.cursor == 11
    screen.handle("home")
    assert screen._editor.cursor == 0  # line start, not scroll-to-top
    screen.handle("end")
    assert screen._editor.cursor == 11
    screen.handle("ctrl_left")
    assert screen._editor.cursor == 6  # start of "world"


async def test_chat_paths_key_needs_a_picked_message() -> None:
    """^P presents the picked message's paths, and does nothing until one is picked."""
    import asyncio

    shown: list[str] = []

    async def paths(message) -> None:  # noqa: ANN001 - ChatMessage
        shown.append(message.text)

    messages = [
        ChatMessage(text="first", peer="d4e5f6a7"),
        ChatMessage(text="second", peer="d4e5f6a7"),
    ]
    conv = Conversation(
        label="Alice",
        is_channel=False,
        contact=Contact(name="Alice", public_key="d4" + "0" * 62, key_prefix="d4e5f6a7"),
    )
    screen = ChatScreen(conv, messages, send=None, names={}, session=_StubSession(), paths=paths)
    # A path is one message's route, so with no pick there is nothing to show — the key
    # is inert and the footer and F-key lane both say so rather than guessing at the tail.
    screen.handle("paths")
    await asyncio.sleep(0)
    assert shown == []
    assert "^P" not in screen.footer_hint
    assert screen.picocalc_lyra_lane[2].enabled is False

    screen.handle("up")
    screen.handle("up")  # pick the older message
    screen.handle("paths")
    await asyncio.sleep(0)
    assert shown == ["first"]
    # With a pick, paths are on offer — here on Enter, since a direct chat has no reply
    # to prime (a channel's hint keeps the ^P atom beside its Enter reply).
    assert "Enter paths" in screen.footer_hint
    assert screen.picocalc_lyra_lane[2].enabled is True


async def test_chat_direct_enter_on_a_pick_opens_paths() -> None:
    """In a direct chat, Enter on a picked message opens its paths (channels reply)."""
    import asyncio

    shown: list[str] = []

    async def paths(message) -> None:  # noqa: ANN001 - ChatMessage
        shown.append(message.text)

    messages = [ChatMessage(text="only", peer="d4e5f6a7")]
    conv = Conversation(
        label="Alice",
        is_channel=False,
        contact=Contact(name="Alice", public_key="d4" + "0" * 62, key_prefix="d4e5f6a7"),
    )
    screen = ChatScreen(conv, messages, send=None, names={}, session=_StubSession(), paths=paths)
    screen.handle("up")
    assert "Enter paths" in screen.footer_hint
    screen.handle("enter")
    await asyncio.sleep(0)
    assert shown == ["only"]


def test_chat_pick_walks_with_page_keys_and_ctrl_home() -> None:
    """PgUp walks the pick a screenful back; ^Home jumps it to the very first message."""
    screen = _screen(_StubSession(), send=None, messages=_two_day_messages())
    lines = screen.render_body(60)
    screen.note_metrics(total=len(lines), viewport=5)
    screen.handle("pageup")
    assert screen._stick is False and screen._selected is not None
    screen.handle("ctrl_home")
    assert screen._selected == 0  # the very first message
    screen.handle("ctrl_end")
    assert screen._stick is True and screen._selected is None


def test_chat_ctrl_page_picks_across_day_dividers() -> None:
    """Ctrl+PageDown/PageUp move the pick between day boundaries (both chat kinds)."""
    screen = _screen(_StubSession(), send=None, messages=_two_day_messages())
    starts = screen._day_start_indices()
    assert len(starts) == 2
    screen.handle("ctrl_home")
    assert screen._selected == 0
    screen.handle("ctrl_pagedown")
    assert screen._selected == starts[1]  # first message of the second day
    screen.handle("ctrl_pageup")
    assert screen._selected == starts[0]  # back to the first day


def _two_day_channel_messages():
    """Channel messages spanning two local days (one sender), for section-jump tests."""
    from datetime import datetime, timedelta, timezone

    base = datetime(2026, 7, 5, 9, 0, tzinfo=timezone.utc)
    day1 = [
        ChatMessage(
            text=f"Alice: d1-{i}",
            is_channel=True,
            channel_idx=0,
            created_at=base + timedelta(minutes=i),
        )
        for i in range(3)
    ]
    day2 = [
        ChatMessage(
            text=f"Alice: d2-{i}",
            is_channel=True,
            channel_idx=0,
            created_at=base + timedelta(days=1, minutes=i),
        )
        for i in range(3)
    ]
    return day1 + day2


def test_chat_channel_ctrl_page_selects_across_days() -> None:
    """In a channel, Ctrl+PageDown/PageUp move the reply selection to day boundaries."""
    screen = _channel_screen(_two_day_channel_messages())
    starts = screen._day_start_indices()
    assert starts == [0, 3]
    screen.handle("ctrl_home")
    assert screen._selected == 0
    screen.handle("ctrl_pagedown")
    assert screen._selected == starts[1]  # first message of the second day
    screen.handle("ctrl_pageup")
    assert screen._selected == starts[0]  # back to the first day


def test_chat_channel_home_moves_the_compose_cursor() -> None:
    """A channel's Home key edits the compose line rather than jumping the selection."""
    screen = _channel_screen(_two_day_channel_messages())
    for ch in "reply":
        screen.handle("text", ch)
    assert screen._editor.cursor == 5
    screen.handle("home")
    assert screen._editor.cursor == 0
    assert screen._selected is None  # touching the compose line clears any reply selection


def test_channel_self_style_keyed_on_concept_not_label() -> None:
    """Our white 'self' style follows the message being outbound, not the 'you' label.

    A remote sender who happens to be named 'you' must never take the white style
    reserved for us — it reads as a normal sender (its key's hue when resolvable,
    muted otherwise).
    """
    from meshterm.ui.theme import node_style

    screen = _channel_screen([])
    assert screen._sender_style("you", is_self=True) == "you"  # us → white
    assert screen._sender_style("you", is_self=False) == "node.unknown"  # no key → grey
    keyed = _channel_screen([], key_of=_keys_of({"you": "d4" + "0" * 62}))
    remote = keyed._sender_style("you", is_self=False)
    assert remote == node_style("d4")  # the key's spectrum hue


def test_channel_own_messages_do_not_merge_with_remote_namesake() -> None:
    """A remote sender literally named 'you' groups separately from our own messages."""
    from datetime import datetime, timezone

    base = datetime(2026, 7, 5, 14, 24, tzinfo=timezone.utc)
    messages = [
        ChatMessage(text="you: impostor", is_channel=True, channel_idx=0, created_at=base),
        ChatMessage(text="mine", outbound=True, is_channel=True, channel_idx=0, created_at=base),
    ]
    screen = _channel_screen(messages)
    rendered = _strip_ansi("\n".join(screen._render_grouped(80)))
    # Two headers, and not merely un-merged: theirs is the name they sent, ours is the ★.
    assert rendered.count("you") == 1 and rendered.count("★") == 1


def _channel_screen(messages, session=None, key_of=None) -> ChatScreen:
    """Build a channel ChatScreen over ``messages`` for selection/reply tests."""
    conv = Conversation(label="#public", is_channel=True, channel_idx=0)
    return ChatScreen(
        conv,
        messages,
        send=None,
        names={},
        session=session or _StubSession(),
        key_of=key_of,
    )


def _channel_messages():
    """Three inbound channel messages (Alice, Alice, Bob) for reply-selection tests."""
    from datetime import datetime, timezone

    base = datetime(2026, 7, 5, 14, 24, tzinfo=timezone.utc)
    return [
        ChatMessage(text="Alice: hi", is_channel=True, channel_idx=0, created_at=base),
        ChatMessage(text="Alice: still here", is_channel=True, channel_idx=0, created_at=base),
        ChatMessage(text="Bob: yo", is_channel=True, channel_idx=0, created_at=base),
    ]


def test_channel_up_enters_selection_from_newest() -> None:
    """No message is selected until ↑ picks the newest, then steps toward older ones."""
    screen = _channel_screen(_channel_messages())
    assert screen._selected is None  # compose focus: nothing selected initially

    screen.handle("up")
    assert screen._selected == 2  # newest message
    assert screen._stick is False
    screen.handle("up")
    assert screen._selected == 1  # steps to the previous message


def test_channel_down_past_newest_clears_selection() -> None:
    """Moving ↓ past the newest message returns focus to compose (nothing selected)."""
    screen = _channel_screen(_channel_messages())
    screen.handle("up")  # select newest (index 2)
    assert screen._selected == 2

    screen.handle("down")  # past the newest → deselect, re-stick to the tail
    assert screen._selected is None
    assert screen._stick is True


def test_channel_selected_line_tracked_for_scroll() -> None:
    """Rendering records the selected message's body line so the frame keeps it in view."""
    screen = _channel_screen(_channel_messages())
    screen.handle("up")  # select Bob (newest)
    screen.render_body(80)
    assert screen._selected_line is not None
    # No selection → no cursor line, so the transcript free-scrolls as before.
    screen.handle("end")
    screen.render_body(80)
    assert screen._selected_line is None


def test_channel_enter_on_selection_primes_at_mention() -> None:
    """Enter on a picked message seeds the compose line with the sender's @mention."""
    screen = _channel_screen(_channel_messages())
    screen.handle("up")
    screen.handle("up")  # select an Alice message (index 1)
    screen.handle("enter")

    assert screen._editor.text == "@[Alice] "
    assert screen._selected is None  # focus returns to compose after starting the reply


def test_channel_typing_clears_selection() -> None:
    """Editing the compose line drops any reply selection (compose has focus)."""
    screen = _channel_screen(_channel_messages())
    screen.handle("up")
    assert screen._selected is not None
    screen.handle("text", "x")
    assert screen._selected is None
    assert screen._editor.text == "x"


def test_chat_screen_escape_cancels() -> None:
    """Esc resolves the screen's future with CANCEL so the caller pops it."""
    screen = _screen(_StubSession(), send=None)
    loop = asyncio.new_event_loop()
    try:
        screen.future = loop.create_future()
        screen.handle("escape")
        assert screen.future.result() is CANCEL
    finally:
        loop.close()


async def test_service_send_records_outbound(repo: Repository) -> None:
    """Sending through the service records the outbound message with its ack state."""
    device = MockDevice()
    ctx = _StubContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        contact = next(c for c in await device.get_contacts() if c.name == "Alice")
        sent = await chat.send_direct(contact, "hey")
        assert sent.outbound is True and sent.acked is True

        await chat.send_channel(0, "hello all", label="#public")
        channel_id = await chat.channel_id_for(0)
        stored = repo.recent_chat_messages(is_channel=True, channel_id=channel_id)
        assert [m.text for m in stored] == ["hello all"]
        assert stored[0].outbound is True
    finally:
        await chat.stop()
        await device.disconnect()


async def test_service_resend_updates_ack_in_place(repo: Repository) -> None:
    """Resending a failed message flips its stored ack rather than adding a duplicate row."""
    device = MockDevice()
    ctx = _StubContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        contact = next(c for c in await device.get_contacts() if c.name == "Alice")
        peer = contact.key_prefix or contact.public_key[:12]
        failed = ChatMessage(
            text="retry me", outbound=True, peer=peer, peer_name=contact.name, acked=False
        )
        failed.row_id = repo.record_chat_message(failed)

        await chat.resend_direct(contact, failed)

        assert failed.acked is True  # the mock always acknowledges
        stored = repo.recent_chat_messages(is_channel=False, peer=peer)
        assert len(stored) == 1  # updated in place, not duplicated
        assert stored[0].acked is True
    finally:
        await chat.stop()
        await device.disconnect()


class _ScriptedDevice:
    """A device stub whose direct-message acks follow a fixed script.

    Each :meth:`send_direct_message` pops the next value from ``acks`` — an :class:`Ack`
    stand-in (any non-``None`` object counts as delivered) or ``None`` for an unacknowledged
    transmission — and appends the sent text to :attr:`sent`, so a test can assert exactly how
    many soft retries fired. Once the script is exhausted every further send goes unacked.
    Each send gets its own ack code, as the radio's do.
    """

    def __init__(self, acks: list) -> None:
        self._acks = list(acks)
        self.sent: list[str] = []

    async def connect(self) -> None:  # satisfies _StubContext.device()
        return None

    async def send_direct_message(self, contact: Contact, text: str):
        from meshterm.core.models import Delivery

        self.sent.append(text)
        ack = self._acks.pop(0) if self._acks else None
        return Delivery(f"{len(self.sent):08x}", ack)


def _contact() -> Contact:
    return Contact(name="Alice", public_key="d4e5" + "0" * 60, key_prefix="d4e5f6a7")


async def test_send_direct_soft_retries_until_acked(repo: Repository) -> None:
    """A DM unacked on the first tries is re-sent, and is recorded delivered once one lands."""
    device = _ScriptedDevice([None, None, object()])  # ack only on the third try
    ctx = _StubContext(device, repo)
    ctx.preferences.direct_message_soft_retries = 2  # 1 send + 2 retries = 3 tries
    chat = ChatService(ctx)

    sent = await chat.send_direct(_contact(), "hey")

    assert sent.acked is True
    assert device.sent == ["hey", "hey", "hey"]  # exactly three transmissions


async def test_send_direct_soft_retries_capped_by_setting(repo: Repository) -> None:
    """The retry budget stops the resends: an always-unacked DM is tried retries+1 times."""
    device = _ScriptedDevice([])  # never acknowledges
    ctx = _StubContext(device, repo)
    ctx.preferences.direct_message_soft_retries = 2
    chat = ChatService(ctx)

    sent = await chat.send_direct(_contact(), "hey")

    assert sent.acked is False
    assert len(device.sent) == 3  # capped: no more than one send plus two soft retries


async def test_send_direct_zero_retries_is_one_shot(repo: Repository) -> None:
    """With soft retries disabled a DM is transmitted exactly once, acked or not."""
    device = _ScriptedDevice([])  # never acknowledges
    ctx = _StubContext(device, repo)
    ctx.preferences.direct_message_soft_retries = 0
    chat = ChatService(ctx)

    sent = await chat.send_direct(_contact(), "hey")

    assert sent.acked is False
    assert device.sent == ["hey"]  # one shot, no soft retry


# -- end-to-end through the real session --------------------------------------


async def test_open_chat_sends_through_real_session(tmp_path: Path) -> None:
    """Driving open_chat with piped keys sends a message and records it, end to end."""
    from prompt_toolkit.input.defaults import create_pipe_input
    from prompt_toolkit.output import DummyOutput
    from rich.console import Console

    from meshterm.context import AppContext
    from meshterm.core.admin_store import AdminStore
    from meshterm.core.device_store import DeviceStore
    from meshterm.ui.chat import open_chat
    from meshterm.ui.surface import TuiUi
    from meshterm.ui.tui.session import TuiSession

    settings = Settings(config_dir=tmp_path, db_path=tmp_path / "e2e.db")
    ctx = AppContext(
        console=Console(),
        settings=settings,
        repo=Repository(settings.db_path),
        device_store=DeviceStore(tmp_path / "devices.json"),
        admin_store=AdminStore(tmp_path / "admin.json"),
        mock=True,
    )
    conv = Conversation(
        label="Alice",
        is_channel=False,
        contact=Contact(name="Alice", public_key="d4e5f6a7" + "0" * 56, key_prefix="d4e5f6a7"),
    )
    try:
        with create_pipe_input() as inp:
            session = TuiSession(input=inp, output=DummyOutput())
            ctx.ui = TuiUi(session)

            def stored_texts() -> list[str]:
                rows = ctx.repo.recent_chat_messages(is_channel=False, peer="d4e5f6a7")
                return [m.text for m in rows]

            async def drive() -> None:
                # Esc only once the send has been recorded: the send runs in a task the
                # screen spawns, and piping Esc beside Enter let a slow runner leave (and
                # cancel it) before the row was written.
                inp.send_text("hi\r")  # type "hi", Enter (send)
                while not stored_texts():
                    await asyncio.sleep(0.01)
                inp.send_text("\x1b")  # Esc (leave)

            async def main() -> None:
                driver = asyncio.ensure_future(drive())
                try:
                    await open_chat(ctx, conv)
                finally:
                    driver.cancel()

            await asyncio.wait_for(session.run(main()), timeout=5)

        stored = ctx.repo.recent_chat_messages(is_channel=False, peer="d4e5f6a7")
        assert [m.text for m in stored] == ["hi"]
        assert stored[0].outbound is True
    finally:
        await ctx.aclose()


# -- the picker's companion filter and history delete -------------------------


def test_delete_chat_history_removes_only_that_peer(repo: Repository) -> None:
    """Deleting one direct thread leaves other peers and channel history untouched."""
    repo.record_chat_message(ChatMessage(text="a", peer="aa"))
    repo.record_chat_message(ChatMessage(text="b", peer="bb"))
    repo.record_chat_message(ChatMessage(text="c", is_channel=True, channel_id="c0"))

    assert repo.delete_chat_history("aa") == 1
    assert repo.recent_chat_messages(is_channel=False, peer="aa") == []
    assert [m.text for m in repo.recent_chat_messages(is_channel=False, peer="bb")] == ["b"]
    assert [m.text for m in repo.recent_chat_messages(is_channel=True, channel_id="c0")] == ["c"]


class _PickerDevstate:
    def __init__(self, contacts) -> None:
        self._contacts = contacts

    async def channel_slots(self):
        return []

    async def contacts(self):
        return list(self._contacts)


class _PickerChat(_FakeChat):
    def __init__(self, unread=None) -> None:
        super().__init__(unread or {})
        self.cleared: list[str] = []

    def clear_unread(self, key: str) -> None:
        self.cleared.append(key)


async def test_picker_lists_companions_only(repo: Repository) -> None:
    """Only companion (and type-unknown) contacts appear in Direct — never repeaters."""
    from types import SimpleNamespace

    from meshterm.core.models import NODE_TYPE_REPEATER
    from meshterm.tools.chat import ChatTool
    from meshterm.ui.tui import Choice

    contacts = [
        Contact(name="Ally", public_key="d4" + "0" * 62, node_type=1),
        Contact(name="Mystery", public_key="60" + "0" * 62),  # type never advertised
        Contact(name="Tower", public_key="a1" + "0" * 62, node_type=NODE_TYPE_REPEATER),
    ]

    ctx = SimpleNamespace(devstate=_PickerDevstate(contacts), repo=repo, chat=_PickerChat())
    items = await ChatTool()._picker_items(ctx)
    direct = [
        it.value.label
        for it in items
        if isinstance(it, Choice) and isinstance(it.value, Conversation) and not it.value.is_channel
    ]
    assert "Ally" in direct and "Mystery" in direct and "Tower" not in direct


async def test_picker_pins_its_column_header_over_the_group_heading(
    repo: Repository,
) -> None:
    """Scrolled into Direct, the lane names stay overhead with ``👤 Direct`` under them."""
    from types import SimpleNamespace

    from meshterm.tools.chat import ChatTool
    from meshterm.ui.tui import SelectScreen, frame

    ansi = re.compile(r"\x1b\[[0-9;]*m")
    contacts = [
        Contact(name=f"Peer{i:02d}", public_key=f"{i:02x}" + "0" * 62, node_type=1)
        for i in range(12)
    ]

    ctx = SimpleNamespace(devstate=_PickerDevstate(contacts), repo=repo, chat=_PickerChat())
    items = await ChatTool()._picker_items(ctx)

    header = items[0]
    assert header.pinned  # the lanes mean the same in both groups — pinned for the list
    screen = SelectScreen("Chat", items)
    for _ in range(8):  # down past the Direct heading
        screen.handle("down")
    visible, above, _below = frame._visible_slice(screen, screen.render_body(72), 8)
    top = [ansi.sub("", row).strip() for row in visible[:2]]
    # Short words over a badge and an age, then the message itself.
    assert top[0].split() == ["CONVERSATION", "NEW", "LAST", "MESSAGE"]
    assert top[1] == "── 👤 Direct ──"
    assert above is True
    # Too narrow for the whole line, the trailing label shortens — never wraps. The
    # lane is sized to these six-cell names now, so the squeeze starts well below any
    # real terminal: the fallback is what is under test, not the width it happens at.
    assert header.text(36).endswith(" MSG")
    assert "\n" not in header.text(30)


async def test_picker_lane_is_sized_to_the_names_it_holds(repo: Repository) -> None:
    """The conversation lane fits the longest name, between its floor and its ceiling.

    Every cell the lane holds past that longest name is padding taken out of the message
    preview, which is the row's only unbounded content — so it is measured, not written down.
    """
    from meshterm.tools.chat import _LABEL_MAX, _LABEL_MIN, _lanes

    def lane(*names: str) -> int:
        return _lanes([Conversation(label=n, is_channel=True, channel_id=n) for n in names]).label

    assert lane("Bob", "Ann") == _LABEL_MIN  # short names can't shrink it under the header word
    assert lane("Bob", "YUL-Cartierville") == len("YUL-Cartierville")
    assert lane("A Rather Long Contact Name Indeed") == _LABEL_MAX  # nor grow it without end


async def test_picker_rows_scroll_the_message_under_pinned_lanes(repo: Repository) -> None:
    """A row hands ←→ the preview alone: the lanes in front of it are where it starts to slide.

    Those lanes are the reader's place in the list, so the scroll begins exactly where the
    message does — which is one column for every row, long name or short.
    """
    from types import SimpleNamespace

    from meshterm.tools.chat import ChatTool
    from meshterm.ui.tui import Choice

    contacts = [
        Contact(name="Alice", public_key="d4" + "0" * 62, node_type=1),
        Contact(name="A Rather Long Contact Name", public_key="60" + "0" * 62, node_type=1),
    ]
    alice = Conversation(label="Alice", is_channel=False, contact=contacts[0])
    repo.record_chat_message(ChatMessage(text="x" * 200, peer=alice.peer))
    ctx = SimpleNamespace(devstate=_PickerDevstate(contacts), repo=repo, chat=_PickerChat())
    rows = [it for it in await ChatTool()._picker_items(ctx) if isinstance(it, Choice)]

    heads = {row.hscroll_from for row in rows}
    assert len(heads) == 1 and heads.pop() > 0  # one head block for the whole list
    talked = next(row for row in rows if row.value.label == "Alice")
    line = talked.label.plain
    # Measured in cells, not characters: a channel glyph is one character and two cells.
    assert cell_len(line[: line.index("x")]) == talked.hscroll_from
    # And the preview keeps the whole message: the cut is the row's, and ←→ walk past it.
    assert talked.label.plain.endswith("x" * 200)


def test_picker_marker_lane_lines_the_two_groups_up(repo: Repository) -> None:
    """A channel glyph and a contact dot claim the same cells — on either platform.

    That glyph is double-cell on regular and single-cell in the console font, so the dot is
    padded to whatever it actually measures rather than to a written-down width: a
    hard-coded pad left every channel row a cell adrift of every direct row on the PicoCalc.
    """
    from meshterm.platforms import PICOCALC_LYRA, REGULAR, set_platform
    from meshterm.tools.chat import _lanes

    channel = Conversation(label="Public", is_channel=True, channel_idx=0, channel_id="c0")
    contact = Conversation(
        label="Alice", is_channel=False, contact=Contact(name="Alice", public_key="d4" * 32)
    )
    ctx = _RowCtx(repo)
    try:
        for platform in (REGULAR, PICOCALC_LYRA):
            set_platform(platform)
            lanes = _lanes([channel, contact])
            rows = [_title(ctx, c, {}, _NO_KEYS, lanes).plain for c in (channel, contact)]
            names = ("Public", "Alice")
            at = [cell_len(r[: r.index(n)]) for r, n in zip(rows, names, strict=True)]
            assert at[0] == at[1] == lanes.marker
    finally:
        set_platform(REGULAR)


async def test_picker_footer_fits_with_every_atom_showing(repo: Repository, monkeypatch) -> None:
    """Scroll, erase and the base atoms together stay inside the 72-cell footer budget.

    The three of them coincide on an ordinary row — a thread with history long enough to
    scroll — so the budget is the wording's constraint, not a corner case (it is what
    ``Del erase`` is: the row already names the conversation it would take the history of).
    """
    import asyncio
    from types import SimpleNamespace

    from prompt_toolkit.input.defaults import create_pipe_input
    from prompt_toolkit.output import DummyOutput

    from meshterm.tools.chat import ChatTool
    from meshterm.ui.surface import TuiUi
    from meshterm.ui.tui.screen import CANCEL
    from meshterm.ui.tui.session import TuiSession

    ally = Contact(name="Ally", public_key="d4" + "0" * 62, node_type=1)
    conv = Conversation(label="Ally", is_channel=False, contact=ally)
    repo.record_chat_message(ChatMessage(text="y" * 200, peer=conv.peer))
    ctx = SimpleNamespace(devstate=_PickerDevstate([ally]), repo=repo, chat=_PickerChat())
    hints: list[str] = []

    with create_pipe_input() as inp:
        session = TuiSession(input=inp, output=DummyOutput())
        ctx.ui = TuiUi(session)

        async def main() -> None:
            run = asyncio.ensure_future(ChatTool()._run_live(ctx))
            loop = asyncio.get_running_loop()
            deadline = loop.time() + 2
            while not session._stack:
                assert loop.time() < deadline, "the picker never opened"
                await asyncio.sleep(0)
            picker = session._stack[-1]
            picker.render_body(72)  # the overflow probe reads the last render width
            picker.handle("down")  # onto the one Direct row: deletable, and overflowing
            picker.render_body(72)
            hints.append(picker.footer_hint)
            picker.resolve(CANCEL)
            await asyncio.wait_for(run, timeout=2)

        await asyncio.wait_for(session.run(main()), timeout=5)

    hint = hints[0]
    assert cell_len(hint) <= 72, f"{cell_len(hint)} cells: {hint!r}"
    for atom in ("←→ scroll", "Enter open", "Del erase", "Esc back"):
        assert atom in hint


async def test_picker_del_deletes_history_after_a_red_confirm(repo: Repository) -> None:
    """Del on a contacted thread deletes its history, behind a red confirm.

    The confirm is the destructive one; afterwards the history is gone, unread is
    cleared, and the rebuilt rows show the thread hollow and no longer deletable.
    """
    from types import SimpleNamespace

    from meshterm.tools.chat import ChatTool

    ally = Contact(name="Ally", public_key="d4" + "0" * 62, node_type=1)
    conv = Conversation(label="Ally", is_channel=False, contact=ally)
    repo.record_chat_message(ChatMessage(text="hi", peer=conv.peer))
    repo.record_chat_message(ChatMessage(text="chan", is_channel=True, channel_id="c0"))

    class _Ui:
        def __init__(self) -> None:
            self.dialogs: list[dict] = []

        async def dialog(self, prompt, buttons, **kw):
            self.dialogs.append({"prompt": prompt, "buttons": buttons, **kw})
            return True  # commit the Delete

    chat = _PickerChat()
    ctx = SimpleNamespace(devstate=_PickerDevstate([ally]), repo=repo, ui=_Ui(), chat=chat)
    tool = ChatTool()
    assert _direct_row(await tool._picker_items(ctx)).deletable  # there is history to delete

    await tool._delete_history(ctx, conv)

    confirm = ctx.ui.dialogs[0]
    assert confirm["destructive"] is True  # the reserved red, data loss
    assert confirm["buttons"] == [("Cancel", False), ("Delete", True)]

    assert repo.recent_chat_messages(is_channel=False, peer=conv.peer) == []
    assert [m.text for m in repo.recent_chat_messages(is_channel=True, channel_id="c0")] == [
        "chan"
    ]  # channel history survives
    assert chat.cleared == [conv.key]
    # The swapped-in rows show it: history gone, so the row demotes to uncontacted.
    assert not _direct_row(await tool._picker_items(ctx)).deletable


async def test_picker_del_cancel_keeps_the_history(repo: Repository) -> None:
    """Cancelling the confirm leaves the thread's messages untouched."""
    from types import SimpleNamespace

    from meshterm.tools.chat import ChatTool

    ally = Contact(name="Ally", public_key="d4" + "0" * 62, node_type=1)
    conv = Conversation(label="Ally", is_channel=False, contact=ally)
    repo.record_chat_message(ChatMessage(text="hi", peer=conv.peer))

    class _Ui:
        async def dialog(self, prompt, buttons, **kw):
            return False  # Cancel backs out

    chat = _PickerChat()
    ctx = SimpleNamespace(devstate=_PickerDevstate([ally]), repo=repo, ui=_Ui(), chat=chat)
    await ChatTool()._delete_history(ctx, conv)
    assert [m.text for m in repo.recent_chat_messages(is_channel=False, peer=conv.peer)] == ["hi"]
    assert chat.cleared == []


def _direct_row(items: list):
    """The one Direct row in a built picker list (the tests above list a single contact)."""
    from meshterm.ui.tui import Choice

    return next(
        it
        for it in items
        if isinstance(it, Choice) and isinstance(it.value, Conversation) and not it.value.is_channel
    )


async def test_the_conversation_picker_stays_pushed_under_an_open_chat(
    repo: Repository, monkeypatch
) -> None:
    """Esc out of a chat is one pop, back onto the row it was opened from.

    The picker used to be gathered in ``prompt_params`` and rebuilt on every round, with the
    cursor put back by a ``default=`` restore; keeping the one screen keeps the typed filter
    and the scroll with it, and the rows are swapped in place so a thread that just gained
    messages sits where its recency puts it.
    """
    import asyncio
    from types import SimpleNamespace

    from prompt_toolkit.input.defaults import create_pipe_input
    from prompt_toolkit.output import DummyOutput

    from meshterm.tools.chat import ChatTool
    from meshterm.ui.surface import TuiUi
    from meshterm.ui.tui.screen import CANCEL
    from meshterm.ui.tui.session import TuiSession

    ally = Contact(name="Ally", public_key="d4" + "0" * 62, node_type=1)
    ctx = SimpleNamespace(devstate=_PickerDevstate([ally]), repo=repo, chat=_PickerChat())
    depths: list[int] = []

    with create_pipe_input() as inp:
        session = TuiSession(input=inp, output=DummyOutput())
        ctx.ui = TuiUi(session)

        async def fake_open_chat(_ctx, conversation) -> int:
            """Stand in for the chat screen: note the stack under it, then leave it."""
            depths.append(len(session._stack))
            return 3

        monkeypatch.setattr("meshterm.ui.chat.open_chat", fake_open_chat)

        async def main() -> None:
            run = asyncio.ensure_future(ChatTool()._run_live(ctx))
            loop = asyncio.get_running_loop()
            deadline = loop.time() + 2
            while not session._stack:
                assert loop.time() < deadline, "the picker never opened"
                await asyncio.sleep(0)
            picker = session._stack[-1]
            picker.resolve(Conversation(label="Ally", is_channel=False, contact=ally))
            while not depths:
                await asyncio.sleep(0)
            picker.resolve(CANCEL)  # Esc from the picker leaves for the menu
            result = await asyncio.wait_for(run, timeout=2)
            assert result.summary == {"conversations": 1, "messages": 3}

        await asyncio.wait_for(session.run(main()), timeout=5)

    assert depths == [1], "the picker is still on the stack while the chat runs"
    assert session._stack == [], "and the visit pops it on the way out"


# -- the badge rule: what raises the header's unread count --------------------


class _GatedContext(_StubContext):
    """A context with the device-state cache wired, so the badge rule can consult the device.

    The plain :class:`_StubContext` has none, which is the *benefit of the doubt* path — a
    message notifies when there is no device state to place it against.
    """

    def __init__(self, device: MockDevice, repo: Repository) -> None:
        super().__init__(device, repo)
        from meshterm.services.device_state import DeviceState

        self.devstate = DeviceState(self)


async def _record(chat: ChatService, ctx, message: Message) -> None:
    """Publish one inbound message and wait for the worker to file it."""
    ctx.events.publish(MeshEvent.message_event(message))
    await chat._queue.join()


async def test_badge_ignores_direct_messages_from_non_recipients(repo: Repository) -> None:
    """A repeater's direct messages record to history but never raise the badge.

    Repeaters aren't DM recipients, so the picker doesn't list them — but they do send us
    direct messages: every remote-CLI reply from a repeater you administer is one. Counting
    those meant a badge pointing at a conversation with no row, which could never be cleared.
    """
    device = MockDevice()  # its Yagi-Repeater contact is a NODE_TYPE_REPEATER
    ctx = _GatedContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        await _record(chat, ctx, Message(text="> ok", sender="a1b2c3d4"))
        assert chat.unread("dm:a1b2c3d4") == 0
        # Silent, not dropped — the reply is in the transcript.
        stored = repo.recent_chat_messages(is_channel=False, peer="a1b2c3d4")
        assert [m.text for m in stored] == ["> ok"]
    finally:
        await chat.stop()
        await device.disconnect()


async def test_badge_ignores_a_sender_with_no_contact(repo: Repository) -> None:
    """A sender the contact table has no record of is recorded silently — no row to open."""
    device = MockDevice()
    ctx = _GatedContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        await _record(chat, ctx, Message(text="hi", sender="ffee11223344"))
        assert chat.unread("dm:ffee11223344") == 0
        assert repo.recent_chat_messages(is_channel=False, peer="ffee11223344")
    finally:
        await chat.stop()
        await device.disconnect()


async def test_badge_ignores_a_channel_the_device_has_no_slot_for(repo: Repository) -> None:
    """A channel message with no configured slot behind it stays silent.

    Either the slot holds nothing (so the message carries the slot-derived fallback identity,
    which names no channel) or the device simply is not listing it — both leave the picker
    without a row.
    """
    device = MockDevice()
    await device.connect()
    device._channels[0] = {
        "channel_idx": 0,
        "channel_name": "Public",
        "channel_secret": DEFAULT_PUBLIC_SECRET,
    }
    ctx = _GatedContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        await _record(chat, ctx, Message(text="Bob: yo", channel=3, is_channel=True))
        assert chat.unread("chan:slot:3") == 0
        assert repo.recent_chat_messages(is_channel=True, channel_id="slot:3")
    finally:
        await chat.stop()
        await device.disconnect()


async def test_badge_counts_a_configured_channel_and_a_companion(repo: Repository) -> None:
    """The positive control: what the picker *does* list still raises the badge."""
    from meshterm.core.channels import channel_identity

    device = MockDevice()
    await device.connect()
    device._channels[0] = {
        "channel_idx": 0,
        "channel_name": "Public",
        "channel_secret": DEFAULT_PUBLIC_SECRET,
    }
    ctx = _GatedContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    try:
        await _record(chat, ctx, Message(text="Ann: hey", channel=0, is_channel=True))
        await _record(chat, ctx, Message(text="hello", sender="d4e5f6a7"))  # Alice, a companion
        public = channel_identity("Public", DEFAULT_PUBLIC_SECRET)
        assert chat.unread(f"chan:{public}") == 1
        assert chat.unread("dm:d4e5f6a7") == 1
    finally:
        await chat.stop()
        await device.disconnect()


async def test_badge_notifies_when_the_device_state_is_unavailable(repo: Repository) -> None:
    """With no device state to place a message against, it notifies rather than going unseen.

    A cold or broken cache is a reason to over-notify, never to swallow a real message.
    """
    device = MockDevice()
    ctx = _StubContext(device, repo)  # deliberately no devstate
    chat = ChatService(ctx)
    await chat.start()
    try:
        await _record(chat, ctx, Message(text="ping", sender="ffee11223344"))
        assert chat.unread("dm:ffee11223344") == 1
    finally:
        await chat.stop()
        await device.disconnect()


async def test_badge_still_respects_a_muted_channel(tmp_path: Path, repo: Repository) -> None:
    """Muting a configured channel keeps it silent — the hand-set suppression still wins."""
    from meshterm.core.channels import channel_identity
    from meshterm.core.mute_store import MuteStore

    device = MockDevice()
    await device.connect()
    device._channels[0] = {
        "channel_idx": 0,
        "channel_name": "Public",
        "channel_secret": DEFAULT_PUBLIC_SECRET,
    }
    public = channel_identity("Public", DEFAULT_PUBLIC_SECRET)
    ctx = _GatedContext(device, repo)
    ctx.mute_store = MuteStore(tmp_path / "mutes.json")
    ctx.mute_store.set_muted(public, True)
    chat = ChatService(ctx)
    await chat.start()
    try:
        await _record(chat, ctx, Message(text="Ann: hey", channel=0, is_channel=True))
        assert chat.unread(f"chan:{public}") == 0
        assert repo.recent_chat_messages(is_channel=True, channel_id=public)
    finally:
        await chat.stop()
        await device.disconnect()


async def test_channel_slot_change_drops_the_cached_channel_list(repo: Repository) -> None:
    """Resolving a slot to a new identity invalidates the screens' cached channel list.

    The recorder reads a slot per message, so it sees a channel re-keyed on another client
    (the phone app) first. The screens — and the badge rule above — read from the session
    cache, which only an in-app channel edit drops. Left stale it would keep listing the
    channels the device had at connect time, and a message on the new channel would go
    unnoticed because the cached list has no row for it.
    """
    from meshterm.core.channels import derive_secret

    device = MockDevice()
    await device.connect()
    device._channels[0] = {
        "channel_idx": 0,
        "channel_name": "Public",
        "channel_secret": DEFAULT_PUBLIC_SECRET,
    }
    ctx = _StubContext(device, repo)

    class _Devstate:
        def __init__(self) -> None:
            self.invalidations = 0

        def invalidate_channels(self) -> None:
            self.invalidations += 1

    ctx.devstate = _Devstate()
    chat = ChatService(ctx)

    first = await chat.channel_id_for(0)
    assert ctx.devstate.invalidations == 0  # first sight of a slot is not a change
    assert await chat.channel_id_for(0) == first
    assert ctx.devstate.invalidations == 0  # an unchanged slot leaves the cache alone

    # Another client re-keys slot 0 under us.
    device._channels[0] = {
        "channel_idx": 0,
        "channel_name": "#montreal",
        "channel_secret": derive_secret("#montreal"),
    }
    assert await chat.channel_id_for(0) != first
    assert ctx.devstate.invalidations == 1

    # Clearing the slot is a change too — and yields the slot-derived fallback identity.
    device._channels.pop(0)
    assert await chat.channel_id_for(0) == "slot:0"
    assert ctx.devstate.invalidations == 2
    await device.disconnect()


def test_chat_fkey_lane_steps_by_day_on_the_free_left_pair() -> None:
    """The transcript's sections are days, so F1/F2 name the section step ``Day``.

    Same keys and same actions as a grouped select list's ``Sect ↑``/``Sect ↓`` — the lane
    names what the sections *are* here — and lit only with more than one day to step
    between, the way a one-section list has no section jump.
    """
    from datetime import timedelta

    from meshterm.core.models import utcnow

    now = utcnow()
    one_day = [ChatMessage(text="hi", peer="d4e5f6a7", created_at=now)]
    single = _screen(_StubSession(), send=None, messages=one_day)
    assert [pair.label for pair in single.picocalc_lyra_lane[:2]] == ["Day ↑", "Day ↓"]
    assert [pair.action for pair in single.picocalc_lyra_lane[:2]] == [
        "ctrl_pageup",
        "ctrl_pagedown",
    ]
    assert not any(
        pair.enabled for pair in single.picocalc_lyra_lane[:2]
    )  # one day: nowhere to step

    spread = _screen(
        _StubSession(),
        send=None,
        messages=[
            ChatMessage(text="then", peer="d4e5f6a7", created_at=now - timedelta(days=2)),
            ChatMessage(text="now", peer="d4e5f6a7", created_at=now),
        ],
    )
    assert all(pair.enabled for pair in spread.picocalc_lyra_lane[:2])
    # A left-hand pair rises toward F1, so stepping *back* through the transcript is the
    # outer key — the same handedness as the pager's on the right.
    assert fkeys.PICOCALC_LYRA_DECK.action_for(spread.picocalc_lyra_lane, 1) == "ctrl_pageup"
    spread.handle(fkeys.PICOCALC_LYRA_DECK.action_for(spread.picocalc_lyra_lane, 1))
    assert spread._selected == 0  # jumped to the first message of the older day


# -- URL codes (the PicoCalc) ---------------------------------------------------


def _code_rows(lines: list[str]) -> list[str]:
    """The rendered rows that carry braille — a QR code's, in a transcript."""
    return [ln for ln in lines if any("⠀" <= ch <= "⣿" for ch in ln)]


def _decode_braille(rows: list[str], left: int, size: int) -> list[list[bool]]:
    """The ``size``-module code drawn in braille from cell ``left`` of ``rows``."""
    dots = ((0x01, 0x02, 0x04, 0x40), (0x08, 0x10, 0x20, 0x80))
    return [
        [
            bool((ord(rows[y // 4][left + x // 2]) - 0x2800) & dots[x % 2][y % 4])
            for x in range(size)
        ]
        for y in range(size)
    ]


def test_on_the_picocalc_each_url_hangs_a_code_under_its_message_side_by_side() -> None:
    """Two links, two braille codes on the same rows, hung at the body's own indent.

    Every module has to survive the packing: each code is decoded back out of the braille
    and held against segno's matrix for its URL, at the standard fit.
    """
    import segno

    from meshterm.platforms import PICOCALC_LYRA, set_platform

    set_platform(PICOCALC_LYRA)
    first, second = "https://meshterm.net", "https://github.com/jpmartineau/MeshTerm"
    conv = Conversation(label="#ops", is_channel=True, channel_idx=1)
    message = ChatMessage(text=f"Alice: map at {first}, code at {second}!", is_channel=True)
    screen = ChatScreen(conv, [message], send=None, names={}, session=_StubSession())
    rows = _code_rows(_strip_ansi(screen._render_grouped(53)).splitlines())

    indent = 9  # "  HH:MM  " — the body's hanging indent
    assert rows and all(len(row) <= 53 and row.startswith(" " * indent) for row in rows)
    cells = [row[indent:].ljust(53 - indent) for row in rows]
    left, tallest = 0, 0
    for url in (first, second):
        matrix = [
            [bool(v) for v in row] for row in segno.make(url, error="m").matrix_iter(border=4)
        ]
        assert _decode_braille(cells, left, len(matrix)) == matrix, url
        left += -(-len(matrix) // 2) + 1  # its cells, then the one-cell gap
        tallest = max(tallest, -(-len(matrix) // 4))
    assert len(rows) == tallest  # one band, as tall as its taller code


def test_a_regular_terminal_hangs_no_code_under_a_url() -> None:
    """Half-block codes are four times the area; under every link they'd swamp the chat."""
    conv = Conversation(label="#ops", is_channel=True, channel_idx=1)
    message = ChatMessage(text="Alice: map at https://meshterm.net", is_channel=True)
    screen = ChatScreen(conv, [message], send=None, names={}, session=_StubSession())
    rendered = _strip_ansi(screen._render_grouped(72))
    assert "https://meshterm.net" in rendered
    assert not _code_rows(rendered.splitlines())
    assert not any(ch in "▀▄█" for ch in rendered)


def test_codes_that_outrun_the_line_start_a_new_band() -> None:
    """Two short links fit beside each other in the 44 cells after the indent; a third wraps."""
    import segno

    from meshterm.platforms import PICOCALC_LYRA, set_platform
    from meshterm.ui.qr import qr_strip

    set_platform(PICOCALC_LYRA)
    urls = [f"https://meshterm.net/{c}" for c in "abc"]
    size = segno.make(urls[0], error="m").symbol_size(border=4)[0]
    cols, height = -(-size // 2), -(-size // 4)
    rows = qr_strip(urls, 53, indent=9).plain.splitlines()

    assert len(rows) == 2 * height and all(len(row) <= 53 for row in rows)
    assert all(row[9 + cols] == " " and row[9 + cols + 1] != " " for row in rows[:height])
    assert all(row[9 + cols :].strip() == "" for row in rows[height:])


def test_a_picked_message_keeps_its_codes_in_view() -> None:
    """Walking the pick down onto a link shows its code, not just the message's first row."""
    from meshterm.platforms import PICOCALC_LYRA, set_platform
    from meshterm.ui.tui import frame

    set_platform(PICOCALC_LYRA)
    conv = Conversation(label="#ops", is_channel=True, channel_idx=1)
    messages = [ChatMessage(text=f"Alice: line {i}", is_channel=True) for i in range(12)]
    messages.insert(6, ChatMessage(text="Bob: map at https://meshterm.net", is_channel=True))
    screen = ChatScreen(conv, messages, send=None, names={}, session=_StubSession())
    viewport = 16

    def paint() -> list[str]:
        visible, _above, _below = frame._visible_slice(screen, screen.render_body(53), viewport)
        return _strip_ansi(visible).splitlines()

    paint()
    screen.handle("ctrl_home")  # the oldest message, then walk down onto the link
    for _ in range(6):
        paint()
        screen.handle("down")
    shown = paint()
    whole = _code_rows(_strip_ansi(screen._render_grouped(53)).splitlines())
    assert any("map at https://meshterm.net" in row for row in shown)
    assert len(_code_rows(shown)) == len(whole)  # every row of the code, none below the fold


# -- URLs kept whole, and their codes on ^U --------------------------------------------

#: A link longer than the regular body lane (72 - the 9-cell gutter) but not the screen.
_LONG_URL = "https://github.com/jpmartineau/MeshTerm/blob/main/meshterm/ui/chat.py"


def _url_chat(text: str, session=None) -> ChatScreen:  # noqa: ANN001
    conv = Conversation(label="#ops", is_channel=True, channel_idx=1)
    message = ChatMessage(text=f"Alice: {text}", is_channel=True)
    return ChatScreen(conv, [message], send=None, names={}, session=session or _StubSession())


def test_a_url_too_long_to_hang_steps_out_to_the_gutter_whole() -> None:
    """A link the body lane can't hold, but the screen can, is drawn on one line, uncut.

    It starts under the timestamp — clear of the picked message's ``❯`` — and the body
    resumes at its own indent after it, so only the link leaves the block.
    """
    screen = _url_chat(f"look at {_LONG_URL} and tell me what you think of it all")
    rows = _strip_ansi(screen._render_grouped(72)).splitlines()
    link = next(row for row in rows if _LONG_URL[:20] in row)
    assert link == "  " + _LONG_URL  # whole, at the gutter
    after = rows[rows.index(link) + 1]
    assert after.startswith(" " * 9 + "and tell me")  # back under the body's indent

    screen.handle("up")  # picked: the ❯ is on the first line, never the link's
    rows = _strip_ansi(screen._render_grouped(72)).splitlines()
    assert "  " + _LONG_URL in rows


def test_a_short_tail_finishes_the_links_line_and_a_too_wide_link_still_folds() -> None:
    """What fits after a stepped-out link stays on its line; a link no screen holds folds."""
    url = "https://meshterm.net/" + "a" * 46  # 67 cells: wider than the 63-cell lane
    rows = _strip_ansi(_url_chat(f"see {url} ok")._render_grouped(72)).splitlines()
    assert "  " + url + " ok" in rows  # 2 + 67 + 3: exactly the screen
    rows = _strip_ansi(_url_chat(f"see {url} ok!")._render_grouped(72)).splitlines()
    assert "  " + url in rows and " " * 9 + "ok!" in rows  # a cell too many: below it

    wide = "https://meshterm.net/" + "b" * 60  # 81 cells: wider than the screen
    rows = _strip_ansi(_url_chat(f"see {wide}")._render_grouped(72)).splitlines()
    assert not any(wide in row for row in rows)  # cut, as before
    assert all(row.startswith(" " * 9) for row in rows if "bbb" in row)  # hanging, as before


def test_ctrl_u_opens_the_picked_messages_links_on_one_share_screen() -> None:
    """^U shows the pick's links as QR codes, all of them, in the order the message gives."""
    from meshterm.ui.qr import QrScreen

    opened: list = []

    class Session(_StubSession):
        async def run_screen(self, screen):  # noqa: ANN001, ANN202
            opened.append(screen)

    async def scenario() -> None:
        screen = _url_chat(f"map at https://meshterm.net, code at {_LONG_URL}!", Session())
        screen.handle("url_code")  # nothing picked: no telling which message's links
        await asyncio.sleep(0)
        assert opened == []

        screen.handle("up")
        screen.handle("url_code")
        await asyncio.sleep(0)
        assert len(opened) == 1 and isinstance(opened[0], QrScreen)
        assert opened[0].urls == ("https://meshterm.net", _LONG_URL)

    asyncio.run(scenario())


def test_ctrl_u_is_named_only_on_a_picked_message_with_a_link() -> None:
    """The hint names ^U where it acts and stays inside 72; the lane lights QR the same way."""
    plain = _url_chat("no links here")
    linked = _url_chat("map at https://meshterm.net")
    assert "^U" not in linked.footer_hint  # nothing picked yet
    linked.handle("up")
    plain.handle("up")
    assert "^U QR" in linked.footer_hint and "^U" not in plain.footer_hint
    assert (
        fkeys.PICOCALC_LYRA_DECK.action_for(linked.picocalc_lyra_lane, 7) == "url_code"
    )  # Shift+F2
    assert linked.picocalc_lyra_lane[1].opp_enabled and not plain.picocalc_lyra_lane[1].opp_enabled

    # Every pick state's hint, with a link in it, inside the 72-cell budget.
    direct = _screen(
        _StubSession(),
        send=None,
        messages=[ChatMessage(text="see https://meshterm.net", peer="d4e5f6a7")],
    )
    direct.handle("up")
    scoped = _url_chat("x")
    scoped._retry_target = lambda: 0  # a resendable pick, the longest hint there is
    scoped._messages[0] = ChatMessage(text="see https://meshterm.net", is_channel=True)
    scoped.handle("up")
    for screen in (linked, direct, scoped):
        assert "^U QR" in screen.footer_hint
        assert len(screen.footer_hint) <= 72, screen.footer_hint


def test_on_the_cardputer_a_link_takes_the_share_screen_as_on_the_desktop() -> None:
    """Its 14 rows can't spare a code under every message, so ^U is the way to one.

    No code hangs under the message, the lane deals QR on its Shift bank (Shift+Fn+5),
    and the share screen draws the code in braille — small enough that a link and its
    code share the 53x14 panel, URL under the code, nothing a page down.
    """
    from meshterm.platforms import CARDPUTER_ZERO, set_platform
    from meshterm.ui.qr import QrScreen

    set_platform(CARDPUTER_ZERO)
    url = "https://github.com/jpmartineau/MeshTerm"
    screen = _url_chat(f"the road list is at {url}")
    assert not _code_rows(_strip_ansi(screen._render_grouped(53)).splitlines())
    screen.handle("up")
    assert fkeys.CARDPUTER_ZERO_DECK.action_for(screen.cardputer_zero_lane, 17) == "url_code"

    share = QrScreen(url, title="Links")
    share.note_viewport(14)
    lines = _strip_ansi(share.render_body(53)).splitlines()
    assert len(lines) <= 14 and lines[-1].strip() == url
    assert _code_rows(lines), "the code is braille, one module a dot"


def test_a_link_written_without_a_scheme_gets_its_code_too() -> None:
    """``meshterm.net/map`` is as much a link as its https form, and opens as that."""
    from meshterm.ui.qr import QrScreen

    opened: list = []

    class Session(_StubSession):
        async def run_screen(self, screen):  # noqa: ANN001, ANN202
            opened.append(screen)

    async def scenario() -> None:
        screen = _url_chat("map at meshterm.net/map, notes in file.txt", Session())
        screen.handle("up")
        assert "^U QR" in screen.footer_hint
        screen.handle("url_code")
        await asyncio.sleep(0)
        assert isinstance(opened[0], QrScreen) and opened[0].urls == ("https://meshterm.net/map",)

    asyncio.run(scenario())


# -- acks: listening early, waiting long enough, and catching the late ones ----


class _AckingMeshCore:
    """A meshcore stand-in whose send accepts the message, then acks it when scripted.

    ``ack_at`` is seconds after the send returns (``None``: never); ``during_send`` pushes
    the ack before the send has even returned, as a neighbour's can.
    """

    def __init__(self, *, ack_at: float | None, during_send: bool = False, flood: bool = True):
        self.subs: list = []
        self.commands = self
        self._ack_at = ack_at
        self._during = during_send
        self._flood = flood

    def subscribe(self, event_type, callback, attribute_filters=None):  # noqa: ANN001, ANN201
        from types import SimpleNamespace

        sub = SimpleNamespace(event_type=event_type, callback=callback)
        sub.unsubscribe = lambda: self.subs.remove(sub) if sub in self.subs else None
        self.subs.append(sub)
        return sub

    def _push_ack(self) -> None:
        from types import SimpleNamespace

        from meshcore import EventType

        event = SimpleNamespace(type=EventType.ACK, payload={"code": "c0ffee01", "trip_time": 900})
        for sub in list(self.subs):
            if sub.event_type is EventType.ACK:
                sub.callback(event)

    async def send_msg(self, pub, text):  # noqa: ANN001, ANN201
        from types import SimpleNamespace

        if self._during:
            self._push_ack()
        elif self._ack_at is not None:
            asyncio.get_running_loop().call_later(self._ack_at, self._push_ack)
        return SimpleNamespace(
            type="MSG_SENT",
            is_error=lambda: False,
            payload={
                "type": 1 if self._flood else 0,
                "expected_ack": bytes.fromhex("c0ffee01"),
                "suggested_timeout": 100,  # 0.1 s: the radio's (too hopeful) estimate
            },
        )


def _acking_device(mc) -> object:  # noqa: ANN001
    from meshterm.core.connection import MeshCoreDevice

    device = MeshCoreDevice(port="mock")
    device._mc = mc
    return device


async def test_an_ack_quicker_than_the_send_is_still_caught() -> None:
    """The listener is armed before the send, so a neighbour's instant ack isn't missed."""
    device = _acking_device(_AckingMeshCore(ack_at=None, during_send=True))
    delivery = await device.send_direct_message(_contact(), "hi")
    assert delivery.acked and delivery.code == "c0ffee01" and delivery.flood is True


async def test_an_ack_after_the_radios_estimate_is_still_waited_for(monkeypatch) -> None:  # noqa: ANN001
    """THE bug: the wait was the radio's estimate × 1.2 — 0.12 s here, five on hardware.

    A flood's ack rides home on the path the message found, and on hardware took twice the
    estimate. The wait is now the estimate plus a round trip sized like a login's.
    """
    import meshterm.core.connection as connection

    monkeypatch.setattr(connection, "trace_timeout", lambda hops: 0.5)
    device = _acking_device(_AckingMeshCore(ack_at=0.3))
    delivery = await device.send_direct_message(_contact(), "hi")
    assert delivery.acked, "an ack at 0.3 s, after the old 0.12 s wait, counts"


async def test_no_ack_in_the_wait_still_says_which_code_to_listen_for(monkeypatch) -> None:  # noqa: ANN001
    """Not confirmed yet is not failed: the code goes back, for a late ack to settle."""
    import meshterm.core.connection as connection

    monkeypatch.setattr(connection, "trace_timeout", lambda hops: 0.05)
    device = _acking_device(_AckingMeshCore(ack_at=None, flood=False))
    delivery = await device.send_direct_message(_contact(), "hi")
    assert not delivery.acked and delivery.code == "c0ffee01" and delivery.flood is False


async def _late_ack_chat(tmp_path: Path, repo: Repository):  # noqa: ANN202
    """A started chat service over a simulator whose acks for Alice arrive late."""
    device = MockDevice()
    device._late_acks.add("Alice")
    ctx = _StubContext(device, repo)
    chat = ChatService(ctx)
    await chat.start()
    alice = next(c for c in await device.get_contacts() if c.name == "Alice")
    return device, chat, alice


async def test_a_late_ack_turns_the_message_delivered(tmp_path: Path, repo: Repository) -> None:
    """In history and in the very message the chat screen holds — its ✗ becomes ✓."""
    device, chat, alice = await _late_ack_chat(tmp_path, repo)
    heard: list[ChatMessage] = []
    try:
        sent = await chat.send_direct(alice, "you there?", on_late_ack=heard.append)
        assert sent.acked is False
        for _ in range(100):
            if sent.acked:
                break
            await asyncio.sleep(0.01)
        assert sent.acked is True
        stored = repo.recent_chat_messages(is_channel=False, peer=alice.key_prefix)
        assert stored[-1].acked is True
        assert heard == [sent]
    finally:
        await chat.stop()
        await device.disconnect()


async def test_a_late_ack_for_an_earlier_attempt_settles_a_retried_message(
    tmp_path: Path, repo: Repository
) -> None:
    """^R sends it again under a new code; the first attempt's ack still counts."""
    device, chat, alice = await _late_ack_chat(tmp_path, repo)
    try:
        await chat.stop()  # hold the late acks back until both attempts are out
        sent = await chat.send_direct(alice, "anyone?")
        first = next(iter(chat._awaiting))
        await chat.resend_direct(alice, sent)
        assert len(chat._awaiting) == 2 and sent.acked is False
        chat._settle_ack(first)
        assert sent.acked is True and not chat._awaiting
        stored = repo.recent_chat_messages(is_channel=False, peer=alice.key_prefix)
        assert len(stored) == 1 and stored[0].acked is True
    finally:
        await device.disconnect()


def test_only_the_acks_the_radio_could_still_push_are_awaited(repo: Repository) -> None:
    """The radio keeps its last eight codes; a few more than that are kept here, no more."""
    from meshterm.services.chat_service import _AWAITING_CAP

    chat = ChatService(_StubContext(MockDevice(), repo))
    messages = [ChatMessage(text=str(n), outbound=True, acked=False) for n in range(40)]
    for n, message in enumerate(messages):
        chat._await_ack(message, [f"{n:08x}"], None)
    assert len(chat._awaiting) == _AWAITING_CAP
    chat._settle_ack("00000000")  # long gone: nothing to settle
    assert messages[0].acked is False
    chat._settle_ack(f"{39:08x}")
    assert messages[39].acked is True