"""
Database migration utilities for memory service.

Handles archiving old database schemas during upgrades.
"""
import sqlite3
import shutil
from datetime import datetime
from pathlib import Path
from core.logger import setup_logger

logger = setup_logger('migrations', service_name='memory_service')


def archive_old_database(db_path: Path) -> None:
    """
    Archive old database if it exists (one-time migration).

    Checks if the database uses the old 'memory' table schema and archives it
    if found, allowing the service to start with a fresh schema.

    Args:
        db_path: Path to the database file
    """
    if not db_path.exists():
        logger.debug(f"[μ] No existing database found at {db_path}")
        return

    try:
        # Check if it's the old schema by trying to connect and inspect
        conn = sqlite3.connect(str(db_path))
        cursor = conn.cursor()
        cursor.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='memory'")
        result = cursor.fetchone()
        conn.close()

        if result:
            # Old database exists, archive it
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            archive_path = db_path.parent / f"{db_path.stem}_archive_{timestamp}{db_path.suffix}"
            shutil.move(str(db_path), str(archive_path))
            logger.info(f"[μ] Archived old database to {archive_path}")
        else:
            logger.debug(f"[μ] Database already uses new schema, no archive needed")

    except Exception as e:
        logger.warning(f"[μ] Could not check/archive old database: {e}")