from pathlib import Path
import sys

from sqlalchemy import text

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))

from app.database import engine  # noqa: E402


def column_exists(conn, column_name: str) -> bool:
    return bool(conn.execute(text("""
        SELECT COUNT(1)
        FROM information_schema.columns
        WHERE table_schema = DATABASE()
          AND table_name = 'products'
          AND column_name = :column_name
    """), {"column_name": column_name}).scalar())


def main() -> None:
    with engine.begin() as conn:
        if not column_exists(conn, "supplier"):
            conn.execute(text(
                "ALTER TABLE products ADD COLUMN supplier VARCHAR(255) NULL AFTER material_name"
            ))
    print("product supplier field migrated")


if __name__ == "__main__":
    main()