import type { Index, Indices, ParsedGame, ParsedMove, Piece } from './base';
import type { _ApplyMoveUnsafe, _CurrentMoves } from './game';
import { FormatSan } from './notation';
import type { IsGreater, Sum } from './utils';
/**
 * Get the next move
 */
export type NextMove<Game extends ParsedGame> = Game['turn'] extends 'w' ? _Max<_Layer<Game>> extends infer Node extends _Node ? FormatSan<Node['move']> : never : _Min<_Layer<Game>> extends infer Node extends _Node ? FormatSan<Node['move']> : never;
type _Node = {
    move: ParsedMove;
    score: number;
};
type _Layer<Game extends ParsedGame, Moves extends ParsedMove[] = _CurrentMoves<Game>, Acc extends _Node[] = []> = Moves extends [infer Head extends ParsedMove, ...infer Tail extends ParsedMove[]] ? _Layer<Game, Tail, [
    ...Acc,
    {
        move: Head;
        score: Evaluate<_ApplyMoveUnsafe<Game, Head>>;
    }
]> : Acc;
type _Max<Nodes extends _Node[], Best extends _Node | false = false> = Nodes extends [infer Head extends _Node, ...infer Tail extends _Node[]] ? Best extends infer B extends _Node ? IsGreater<Head['score'], B['score']> extends true ? _Max<Tail, Head> : _Max<Tail, Best> : _Max<Tail, Head> : Best;
type _Min<Nodes extends _Node[], Best extends _Node | false = false> = Nodes extends [infer Head extends _Node, ...infer Tail extends _Node[]] ? Best extends infer B extends _Node ? IsGreater<Head['score'], B['score']> extends true ? _Min<Tail, Best> : _Min<Tail, Head> : _Min<Tail, Head> : Best;
/**
 * Evaluate game state
 */
export type Evaluate<Game extends ParsedGame, Value extends number = 0, Remaining extends Index[] = Indices> = Remaining extends [infer Head extends Index, ...infer Tail extends Index[]] ? Game['board'][Head] extends infer P extends Piece ? Evaluate<Game, Sum<Value, _PieceValue[P]>, Tail> : Evaluate<Game, Value, Tail> : Value;
type _PieceValue = {
    'k': -90;
    'q': -9;
    'r': -5;
    'b': -3;
    'n': -3;
    'p': -1;
    'P': 1;
    'N': 3;
    'B': 3;
    'R': 5;
    'Q': 9;
    'K': 90;
};
export {};