demo/utils.py

import gradio as gr
import chess.svg

from lczerolens import LczeroBoard, LczeroModel, Lens

from . import constants


def create_board_figure(
    board: LczeroBoard,
    *,
    orientation: bool = chess.WHITE,
    arrows: str = "",
    square: str = "",
    name: str = "board",
):
    try:
        if arrows:
            arrows_list = arrows.split(" ")
            chess_arrows = []
            for arrow in arrows_list:
                from_square, to_square = arrow[:2], arrow[2:]
                chess_arrows.append(
                    (
                        chess.parse_square(from_square),
                        chess.parse_square(to_square),
                    )
                )
        else:
            chess_arrows = []
    except ValueError:
        chess_arrows = []
        gr.Warning("Invalid arrows, using none.")

    try:
        color_dict = {chess.parse_square(square): "#FF0000"} if square else {}
    except ValueError:
        color_dict = {}
        gr.Warning("Invalid square, using none.")

    svg_board = chess.svg.board(
        board,
        size=350,
        orientation=orientation,
        arrows=chess_arrows,
        fill=color_dict,
    )
    with open(f"{constants.FIGURE_DIRECTORY}/{name}.svg", "w") as f:
        f.write(svg_board)
    return f"{constants.FIGURE_DIRECTORY}/{name}.svg"


class OutputLens(Lens):
    def _intervene(self, model: LczeroModel, **kwargs) -> dict:
        return model.output.save()

def get_info(model: LczeroModel, board: LczeroBoard):
    lens = OutputLens()
    output = lens.analyse(model, board)
    w = output["wdl"][0,0]
    d = output["wdl"][0,1]
    l = output["wdl"][0,2]
    legal_indices = board.get_legal_indices()
    best_move_idx = output["policy"].gather(dim=1, index=legal_indices.unsqueeze(0)).argmax(dim=1).item()
    best_move = board.decode_move(legal_indices[best_move_idx])
    info = f"w: {w:.2f}, d: {d:.2f}, l: {l:.2f}, best: {best_move}"
    return info