"""The canonical Bot Chat's title is its identity — renames must be refused.

Bot Mode resolves a bot's forever-chat by exact-title lookup on
(profile, "Bot Chat") every time it opens; there is no session-id pointer.
A user rename therefore orphans the whole conversation: resolution misses,
the next click mints an empty replacement, and UNIQUE(title) then blocks
renaming the original back (#92473).

The guard lives in SessionDB._set_session_title — the single write path
every rename surface funnels through (gateway session.title RPC, /title,
CLI rename, REST) — and keys on hidden + exact canonical title so ordinary
sessions a user happens to call "Bot Chat" stay freely renameable.
"""
import pytest

from hermes_state import SessionDB


@pytest.fixture
def db(tmp_path):
    return SessionDB(tmp_path / "state.db")


def _make_canonical(db, session_id="forever"):
    db.create_session(session_id, source="desktop")
    assert db.set_session_title(session_id, SessionDB.CANONICAL_BOT_CHAT_TITLE)
    assert db.set_session_hidden(session_id, True)
    return session_id


def test_user_rename_of_canonical_bot_chat_is_refused(db):
    sid = _make_canonical(db)
    with pytest.raises(ValueError, match="canonical Bot Chat"):
        db.set_session_title(sid, "My cool chat")
    # Identity intact: exact-title lookup still finds the forever chat.
    row = db.get_session_by_title(SessionDB.CANONICAL_BOT_CHAT_TITLE)
    assert row and row["id"] == sid


def test_clearing_the_canonical_title_is_refused(db):
    sid = _make_canonical(db)
    with pytest.raises(ValueError, match="canonical Bot Chat"):
        db.set_session_title(sid, "")
    row = db.get_session_by_title(SessionDB.CANONICAL_BOT_CHAT_TITLE)
    assert row and row["id"] == sid


def test_rewriting_the_same_canonical_title_is_a_noop_not_an_error(db):
    # The plugin's eager session.title write re-asserts the canonical title
    # on creation paths; that must never start failing.
    sid = _make_canonical(db)
    assert db.set_session_title(sid, SessionDB.CANONICAL_BOT_CHAT_TITLE)


def test_visible_session_titled_bot_chat_stays_renameable(db):
    # hidden discriminates the registry row: a normal visible session the
    # user happened to name "Bot Chat" is not canonical and renames freely.
    db.create_session("ordinary", source="cli")
    assert db.set_session_title("ordinary", SessionDB.CANONICAL_BOT_CHAT_TITLE)
    assert db.set_session_title("ordinary", "renamed away")
    assert db.get_session("ordinary")["title"] == "renamed away"


def test_deliberately_archived_canonical_chat_releases_name_for_replacement(db):
    """Retiring a Bot Chat must not leave its registry name permanently locked."""
    retired = _make_canonical(db, "retired")
    assert db.set_session_archived(retired, True)

    db.create_session("replacement", source="desktop")
    assert db.set_session_title("replacement", SessionDB.CANONICAL_BOT_CHAT_TITLE)
    assert db.set_session_hidden("replacement", True)

    # The retired row stays archived, while exact-title resolution reaches the
    # replacement that Bot Mode will subsequently open.
    assert db.get_session(retired)["archived"]
    assert db.get_session(retired)["title"] is None
    row = db.get_session_by_title(SessionDB.CANONICAL_BOT_CHAT_TITLE)
    assert row and row["id"] == "replacement"


def test_auto_archive_sweep_skips_the_canonical_chat(db):
    """Only a deliberate archive may retire a Bot Chat; the idle sweep must not
    (it would strand an unrecoverable, soon-to-be-untitled row)."""
    import time

    forever = _make_canonical(db)
    db.create_session("ordinary", source="desktop")
    stale = time.time() - 10 * 86400
    db._write_sql("UPDATE sessions SET started_at = ?, last_activity_at = ?", (stale, stale))

    assert db.archive_stale_sessions(3) == 1
    assert db.get_session("ordinary")["archived"]
    assert not db.get_session(forever)["archived"]
    assert db.get_session(forever)["title"] == SessionDB.CANONICAL_BOT_CHAT_TITLE


def test_auto_titler_still_cannot_touch_the_canonical_row(db):
    # Pre-existing provenance contract, re-pinned here: user-authority title
    # outranks derived/llm, so the turn-start auto-titler can never displace
    # the registry name.
    sid = _make_canonical(db)
    assert not db.set_auto_title(sid, "Chat about groceries", source=SessionDB.TITLE_SOURCE_LLM)
    row = db.get_session_by_title(SessionDB.CANONICAL_BOT_CHAT_TITLE)
    assert row and row["id"] == sid


def test_auto_titler_cannot_rename_derived_canonical_bot_chat(db):
    # #99517: the guard must be provenance-blind. A derived (rank 0) canonical
    # title loses to an llm (rank 1) auto-title on precedence alone, so the
    # identity check — not precedence — has to stop the write.
    db.create_session("derived", source="desktop")
    assert db._set_session_title(
        "derived",
        SessionDB.CANONICAL_BOT_CHAT_TITLE,
        source=SessionDB.TITLE_SOURCE_DERIVED,
    )
    assert db.set_session_hidden("derived", True)

    assert not db.set_auto_title(
        "derived",
        "Renamed by titler",
        source=SessionDB.TITLE_SOURCE_LLM,
    )
    row = db.get_session("derived")
    assert row["title"] == SessionDB.CANONICAL_BOT_CHAT_TITLE
    assert row["title_source"] == SessionDB.TITLE_SOURCE_DERIVED


def test_auto_titler_can_rename_visible_derived_bot_chat(db):
    # Control: hidden is still the discriminator — a visible session that
    # merely carries the text "Bot Chat" upgrades derived -> llm as usual.
    db.create_session("visible", source="desktop")
    assert db._set_session_title(
        "visible",
        SessionDB.CANONICAL_BOT_CHAT_TITLE,
        source=SessionDB.TITLE_SOURCE_DERIVED,
    )

    assert db.set_auto_title(
        "visible",
        "Renamed by titler",
        source=SessionDB.TITLE_SOURCE_LLM,
    )
    assert db.get_session("visible")["title"] == "Renamed by titler"


def test_numbered_branch_never_shadows_the_canonical_chat(db):
    """Title resolution must land on the canonical Bot Chat, never on a "#N" sibling.

    Every DM transport resolves the target bot by that exact name
    (``hermes -p <bot> chat --in ~ -c "Bot Chat"``: message_agent, bot_relay, cron
    delivery). A numbered sibling — a Desktop branch, which is visible and NOT
    Bot-Mode-managed — would otherwise swallow each teammate's message into a
    session whose bot has no message_agent and cannot answer.
    """
    canonical = _make_canonical(db, "forever")
    db.create_session("branch", source="desktop", parent_session_id=canonical)
    assert db._set_session_title(
        "branch",
        f"{SessionDB.CANONICAL_BOT_CHAT_TITLE} #2",
        source=SessionDB.TITLE_SOURCE_DERIVED,
    )
    assert db.set_session_hidden("branch", False)

    assert db.resolve_session_by_title(SessionDB.CANONICAL_BOT_CHAT_TITLE) == canonical


def test_numbered_continuation_still_wins_for_ordinary_titles(db):
    # Control: the "#N continuation" preference is the point of the lookup — it
    # stays intact for every non-Bot-Chat title.
    db.create_session("plain", source="cli")
    assert db.set_session_title("plain", "My session")
    db.create_session("plain2", source="cli")
    assert db.set_session_title("plain2", "My session #2")

    assert db.resolve_session_by_title("My session") == "plain2"