Chess rules implementation - repost

Hello I need an chess game library, only the c# classes to handle the game logic, ready to be used in my future game. Here are the things required by the project, you MUST know the chess game (all the rules and game notation) and have experience working with C# Needs : Designing the program structure Writing the tests Writing the classes Pass the tests I'll provide The library will have to be able to : Manage a chess game from the beginning to the end Manage the pieces moves and the game rules Navigate across the moves that have been played Take back and replace a move Manage multiple variations and navigate across them Understand and work with standard chess notation Export and import game and/or positions to string according to the chess notations Obviously the code will have to execute fast I will provide you the tests to ensure the library fits the needs and before any code being written, the model and the algorithm will have to be defined and validated. What I would like to have is a project ready to be used without having to change anything in your work, this is why I insist on your code passing the tests I will provide. If you have any question, let me know. Thank you for your time