"""Agent flush path: a quarantined (structurally corrupt) SessionDB diverts to JSONL.

Mirrors the replaced-file contract: the batch that SQLite will never take
again is kept on disk under ``sessions/<id>.jsonl`` instead of only in RAM,
the flush fails closed (no retry loop), and the turn-end explanation gets the
``corrupt`` cause.
"""

from __future__ import annotations

from pathlib import Path
from types import SimpleNamespace

from hermes_state import SessionDB, StateDbCorruptError
from run_agent import AIAgent


def _flush_agent(db, session_id):
    agent = SimpleNamespace(
        _session_db=db,
        _session_db_created=True,
        _persist_disabled=False,
        session_id=session_id,
        _session_persist_lock=None,
        _flushed_db_message_ids=set(),
        _flushed_db_message_session_id=None,
        _last_flushed_db_idx=0,
        _db_flush_scan_prefix=None,
        _persist_user_message_idx=None,
        _persist_user_message_override=None,
        _persist_user_message_timestamp=None,
        _pending_cli_user_message=None,
        _active_session_turn_lease_holder=None,
        _last_persistence_error_cause=None,
        _compression_adoption_failed=False,
    )
    agent._ensure_db_session = lambda: None
    agent._flush_messages_to_session_db = (
        AIAgent._flush_messages_to_session_db.__get__(agent, AIAgent)
    )
    agent._flush_messages_to_session_db_unlocked = (
        AIAgent._flush_messages_to_session_db_unlocked.__get__(agent, AIAgent)
    )
    return agent


def test_flush_diverts_batch_to_jsonl_when_handle_is_quarantined(
    tmp_path: Path, monkeypatch
) -> None:
    monkeypatch.setenv("HERMES_HOME", str(tmp_path))
    db = SessionDB(db_path=tmp_path / "state.db")
    try:
        db.create_session("live", source="cli")
        agent = _flush_agent(db, "live")

        def _quarantined(self, *, session_id, messages, **kwargs):
            raise StateDbCorruptError("database disk image is malformed (quarantined)")

        monkeypatch.setattr(SessionDB, "append_messages_batch", _quarantined)

        messages = [{"role": "user", "content": "kept-on-disk-after-corruption"}]
        result = agent._flush_messages_to_session_db(messages, [])

        assert result is False
        assert agent._last_persistence_error_cause == "corrupt"
        jsonl = tmp_path / "sessions" / "live.jsonl"
        assert jsonl.is_file()
        assert "kept-on-disk-after-corruption" in jsonl.read_text(encoding="utf-8")
    finally:
        db.close()