import type { Color, FriendlyPiece, Graph, Index, ParsedGame, ParsedMove, Unoccupied } from '../base';
import type { ToMoves } from '../utils';
export type PawnMoves<Game extends ParsedGame, Friendly extends Color, From extends Index, Portside extends 0 | 8 = Friendly extends 'w' ? 0 : 8, Starboard extends 2 | 6 = Friendly extends 'w' ? 2 : 6> = _ExpandPromotions<ToMoves<[
    ..._PawnAdvance<Game, Friendly, From>,
    ..._PawnCapture<Game, Friendly, From, Portside>,
    ..._PawnCapture<Game, Friendly, From, Starboard>,
    ..._PawnEnPassant<Game, Friendly, From, Portside>,
    ..._PawnEnPassant<Game, Friendly, From, Starboard>
], From>, Friendly>;
/** advance pawn forward, and if allowed advance again */
type _PawnAdvance<Game extends ParsedGame, Friendly extends Color, From extends Index, Forward extends 1 | 7 = Friendly extends 'w' ? 1 : 7> = Graph[From][Forward] extends infer First extends Index ? Game['board'][First] extends Unoccupied ? [
    First,
    ...From extends _PawnStartingPositions ? Graph[First][Forward] extends infer Second extends Index ? Game['board'][Second] extends Unoccupied ? [Second] : [] : [] : []
] : [] : [];
type _PawnStartingPositions = 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55;
/** capture enemy piece */
type _PawnCapture<Game extends ParsedGame, Friendly extends Color, From extends Index, Direction extends 0 | 2 | 6 | 8> = Graph[From][Direction] extends infer To extends Index ? Game['board'][To] extends FriendlyPiece<Friendly> | Unoccupied ? [] : [To] : [];
/** capture en passant */
type _PawnEnPassant<Game extends ParsedGame, Friendly extends Color, From extends Index, Direction extends 0 | 2 | 6 | 8> = Graph[From][Direction] extends infer To extends Game['ep'] ? Game['turn'] extends Friendly ? To extends Index ? [To] : [] : [] : [];
/** promotions */
export type _ExpandPromotions<T extends ParsedMove[], U extends Color, Acc extends ParsedMove[] = []> = T extends [infer Head extends ParsedMove, ...infer Tail extends ParsedMove[]] ? Head['to'] extends _PawnPromotionPositions ? _ExpandPromotions<Tail, U, [
    ...Acc,
    {
        castle: false;
        to: Head['to'];
        from: Head['from'];
        promotion: U extends 'w' ? 'Q' : 'q';
    },
    {
        castle: false;
        to: Head['to'];
        from: Head['from'];
        promotion: U extends 'w' ? 'R' : 'r';
    },
    {
        castle: false;
        to: Head['to'];
        from: Head['from'];
        promotion: U extends 'w' ? 'N' : 'n';
    },
    {
        castle: false;
        to: Head['to'];
        from: Head['from'];
        promotion: U extends 'w' ? 'B' : 'b';
    }
]> : _ExpandPromotions<Tail, U, [...Acc, Head]> : Acc;
type _PawnPromotionPositions = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63;
export {};