#!/usr/bin/env python3
"""Restore Mailu's SQLite snapshot without replacing the live database inode."""

import sqlite3
from pathlib import Path

backup_path = Path("/data/backup/main.db")
live_path = Path("/data/main.db")

# The source and destination must already exist. A missing snapshot or live
# database is a restore failure, not a reason to create an empty database.
with sqlite3.connect(
    f"{backup_path.as_uri()}?mode=ro", uri=True, timeout=60
) as source:
    if source.execute("PRAGMA integrity_check").fetchall() != [("ok",)]:
        raise RuntimeError(f"Invalid SQLite snapshot: {backup_path}")
    with sqlite3.connect(
        f"{live_path.as_uri()}?mode=rw", uri=True, timeout=60
    ) as destination:
        source.backup(destination, pages=256, sleep=0.1)

print(f"SQLite restore complete: {live_path}", flush=True)