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


def _primary_columns(conn, table_name: str) -> list[str]:
    rows = conn.execute(text("""
        SELECT column_name
        FROM information_schema.key_column_usage
        WHERE table_schema = DATABASE()
          AND table_name = :table_name
          AND constraint_name = 'PRIMARY'
        ORDER BY ordinal_position
    """), {"table_name": table_name}).all()
    return [row[0] for row in rows]


def main() -> None:
    with engine.begin() as conn:
        if not _column_exists(conn, "work_session_devices", "process_name"):
            conn.execute(text("""
                ALTER TABLE work_session_devices
                ADD COLUMN process_name VARCHAR(128) NOT NULL DEFAULT '' AFTER device_no
            """))

        if not _column_exists(conn, "device_qrcodes", "process_name"):
            conn.execute(text("""
                ALTER TABLE device_qrcodes
                ADD COLUMN process_name VARCHAR(128) NOT NULL DEFAULT '' AFTER device_no
            """))

        primary_columns = _primary_columns(conn, "device_qrcodes")
        if primary_columns != ["device_no", "process_name"]:
            conn.execute(text("ALTER TABLE device_qrcodes DROP PRIMARY KEY"))
            conn.execute(text("ALTER TABLE device_qrcodes ADD PRIMARY KEY (device_no, process_name)"))

    print("mold process qrcode migrated")


if __name__ == "__main__":
    main()