"""Reproduction test: list_sessions drops corrupt legacy-stem sessions during repair."""
import json
from datetime import datetime
from pathlib import Path

from nanobot.session.manager import SessionManager


def test_list_sessions_repairs_corrupt_legacy_stem(tmp_path: Path, monkeypatch) -> None:
    monkeypatch.setattr(
        "nanobot.session.manager.get_legacy_sessions_dir",
        lambda: tmp_path / "legacy_sessions",
    )
    manager = SessionManager(tmp_path / "workspace")

    # Simulate a legacy lossy-path filename (telegram_12345.jsonl) with a corrupt
    # first line that triggers the repair branch in list_sessions.
    legacy_stem = "telegram_12345"
    corrupt_path = manager.sessions_dir / f"{legacy_stem}.jsonl"
    corrupt_path.parent.mkdir(parents=True, exist_ok=True)
    metadata = json.dumps({
        "_type": "metadata",
        "key": "telegram:12345",
        "created_at": datetime(2025, 1, 1).isoformat(),
        "updated_at": datetime(2025, 1, 1).isoformat(),
    })
    # Corrupt line followed by valid message
    corrupt_path.write_text(
        metadata + "\n{INVALID JSON LINE\n"
        + json.dumps({"role": "user", "content": "recoverable message"}) + "\n",
        encoding="utf-8",
    )

    sessions = manager.list_sessions()

    # BUG: repair fails because _repair re-encodes the fallback_key via
    # _get_session_path, producing a base64 stem that doesn't match the
    # actual legacy filename. The session is silently dropped.
    assert len(sessions) == 1, f"Expected 1 session, got {len(sessions)}"
    assert sessions[0]["key"] == "telegram:12345"