using System;
using System.Text.Json;

public record struct LockedData( string Contents, int Hash );

public static class AntiTamper
{
	public static LockedData Lock<T>( T data, int magic )
	{
		string contents = JsonSerializer.Serialize( data );
		var hash = HashCode.Combine( contents.GetHashCode(), magic );

		return new LockedData( contents, hash );
	}

	public static T Unlock<T>( LockedData locked, int magic, T defaultValue = default( T ) )
	{
		if ( string.IsNullOrWhiteSpace( locked.Contents ) )
		{
			return defaultValue;
		}

		var hash = HashCode.Combine( locked.Contents.GetHashCode(), magic );
		if ( locked.Hash != hash )
		{
			throw new Exception( "Hash mismatch" );
		}

		return JsonSerializer.Deserialize<T>( locked.Contents );
	}
}