#!/usr/bin/env python3
"""Database migration CLI tool."""

import argparse
import sys
from pathlib import Path

from alembic import command
from alembic.config import Config


def main() -> None:
    """Main CLI function for database migrations."""
    parser = argparse.ArgumentParser(description="Database migration tool")
    subparsers = parser.add_subparsers(dest="command", help="Migration commands")

    # Upgrade command
    upgrade_parser = subparsers.add_parser("upgrade", help="Upgrade database to latest revision")
    upgrade_parser.add_argument(
        "revision",
        nargs="?",
        default="head",
        help="Target revision (default: head)"
    )

    # Downgrade command
    downgrade_parser = subparsers.add_parser("downgrade", help="Downgrade database")
    downgrade_parser.add_argument("revision", help="Target revision")

    # Current command
    subparsers.add_parser("current", help="Show current revision")

    # History command
    subparsers.add_parser("history", help="Show revision history")

    # Generate migration command
    revision_parser = subparsers.add_parser("revision", help="Create new migration")
    revision_parser.add_argument("-m", "--message", required=True, help="Migration message")
    revision_parser.add_argument("--autogenerate", action="store_true", help="Auto-generate migration")

    args = parser.parse_args()

    if not args.command:
        parser.print_help()
        sys.exit(1)

    # Get the alembic config
    config_path = Path("alembic.ini")
    if not config_path.exists():
        print("Error: alembic.ini not found. Run from the backend directory.")
        sys.exit(1)

    alembic_cfg = Config(str(config_path))

    try:
        if args.command == "upgrade":
            command.upgrade(alembic_cfg, args.revision)
            print(f"Successfully upgraded database to revision: {args.revision}")

        elif args.command == "downgrade":
            command.downgrade(alembic_cfg, args.revision)
            print(f"Successfully downgraded database to revision: {args.revision}")

        elif args.command == "current":
            command.current(alembic_cfg)

        elif args.command == "history":
            command.history(alembic_cfg)

        elif args.command == "revision":
            if args.autogenerate:
                command.revision(alembic_cfg, message=args.message, autogenerate=True)
                print(f"Created new auto-generated migration: {args.message}")
            else:
                command.revision(alembic_cfg, message=args.message)
                print(f"Created new empty migration: {args.message}")

    except Exception as e:
        print(f"Error: {e}")
        sys.exit(1)


if __name__ == "__main__":
    main()