#!/usr/bin/env python3
"""Restore/smoke helper for Jarca Ledger backups.

This script is intentionally not exposed as an MCP tool. It restores a backup file
into an explicitly provided target DB path, then runs SQLite integrity and Jarca
ledger health/status checks. Use a synthetic fixture or repo-external validation
DB first. Do not point --target at the live operating DB unless the user has
explicitly approved the restore.
"""
from __future__ import annotations

import argparse
import json
import shutil
import sys
from pathlib import Path

from jarca_ledger_mcp import service

APPROVAL_TEXT = "RESTORE_APPROVED"


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Restore a ledger backup into a target DB and run smoke checks.")
    parser.add_argument("--backup", required=True, help="Backup sqlite3 file to restore from")
    parser.add_argument("--target", required=True, help="Target sqlite3 path to create/replace")
    parser.add_argument(
        "--approval-token",
        default="",
        help=f"Required token for overwrite/live restore. Must be {APPROVAL_TEXT!r}.",
    )
    parser.add_argument("--allow-overwrite", action="store_true", help="Allow replacing an existing target DB")
    return parser.parse_args()


def main() -> int:
    args = parse_args()
    backup = Path(args.backup).expanduser().resolve()
    target = Path(args.target).expanduser().resolve()
    if not backup.exists():
        print(json.dumps({"success": False, "error_code": "not_found", "error": f"backup not found: {backup}"}, ensure_ascii=False))
        return 1
    if target.exists() and not args.allow_overwrite:
        print(json.dumps({"success": False, "error_code": "target_exists", "error": f"target exists: {target}"}, ensure_ascii=False))
        return 2
    if target.exists() and args.approval_token != APPROVAL_TEXT:
        print(json.dumps({"success": False, "error_code": "approval_required", "error": f"overwrite requires --approval-token {APPROVAL_TEXT}"}, ensure_ascii=False))
        return 3

    before = service.get_ledger_backup_status(str(backup))
    if not before.get("success") or before.get("backup", {}).get("integrity_check") != "ok":
        print(json.dumps({"success": False, "error_code": "invalid_backup", "backup_status": before}, ensure_ascii=False))
        return 4

    target.parent.mkdir(parents=True, exist_ok=True)
    shutil.copy2(backup, target)
    health = service.health_check(str(target))
    status = service.get_ledger_db_status(str(target))
    result = {
        "success": bool(health.get("success") and status.get("success") and status.get("integrity_check") == "ok"),
        "backup": before.get("backup", {}),
        "target": status,
        "health_check": health,
        "restore_policy": service.BACKUP_RESTORE_POLICY,
    }
    print(json.dumps(result, ensure_ascii=False, indent=2))
    return 0 if result["success"] else 5


if __name__ == "__main__":
    sys.exit(main())