"""
Memory store — SQLite-backed persistence for cross-session memory.
Only active when a session is created with memory: new or memory: inherit:<token>.
"""

import logging
from typing import Optional

import aiosqlite

logger = logging.getLogger(__name__)

DB_PATH = "fellowship_memory.db"


class MemoryStore:
    def __init__(self, db_path: str = DB_PATH) -> None:
        self.db_path = db_path

    async def init(self) -> None:
        """Create tables if they don't exist. Call once at startup."""
        raise NotImplementedError

    async def save(self, session_token: str, memory: str) -> None:
        """Persist a memory string for the given session token."""
        raise NotImplementedError

    async def load(self, session_token: str) -> Optional[str]:
        """Load the stored memory for the given session token, or None if absent."""
        raise NotImplementedError

    async def delete(self, session_token: str) -> None:
        """Delete memory for a session."""
        raise NotImplementedError