game-board.ts

1	import { Coord } from "./coord";
2
3	export class GameBoard {
4	public board: (string \| null)[];
5	public readonly size: Coord;
6	public readonly player1Id: string;
7	public readonly player2Id: string;
8
9	public constructor(player1Id: string, player2Id: string) {
10	// default board
11	const defaultBoard = ([] as (string \| null)[]).concat.apply([], [
12	[player1Id, null, null, player2Id],
13	[null, player1Id, player2Id, null],
14	[null, player2Id, player1Id, null],
15	[player2Id, null, null, player1Id]]);
16	const testBoard = ([] as (string \| null)[]).concat.apply([], [
17	[player1Id, null, player2Id, player2Id],
18	[player1Id, null, player2Id, null],
19	[player1Id, null, null, null],
20	[null, player1Id, null, player2Id]]);
21	this.board = defaultBoard;
22	this.size = new Coord(4, 4);
23	this.player1Id = player1Id;
24	this.player2Id = player2Id;
25	}
26	public move(source: Coord, dest: Coord): void {
27	const piece = this.getPiece(source);
28	if (piece === null)
29	throw `Source ${source} points to an empty space`;
30	this.setPiece(source, null);
31	this.setPiece(dest, piece);
32	}
33	public getPiece(coord: Coord): string \| null {
34	const index = this.coordToBoardIndex(coord);
35	if (!Number.isSafeInteger(index) \|\| index < 0 \|\| index >= this.board.length)
36	throw `Index ${index} is out of bounds`;
37	const id = this.board[index];
38	return id;
39	}
40	public getCoords(id: string): Coord[] {
41	const coords = this.board
42	.map((pieceId, index) => {
43	const isTarget = pieceId === id;
44	return isTarget ? this.boardIndexToCoord(index) : null;
45	})
46	.filter((coord) => coord !== null)
47	.map(coord => coord!);
48	return coords;
49	}
50	private setPiece(coord: Coord, piece: string \| null): void {
51	const { player1Id, player2Id } = this;
52	if (piece !== null && piece !== player1Id && piece !== player2Id)
53	throw `Invalid piece specified: ${piece}`;
54	const index = this.coordToBoardIndex(coord);
55	if (!Number.isSafeInteger(index) \|\| index < 0 \|\| index >= this.board.length)
56	throw `Index ${index} is out of bounds`;
57	this.board[index] = piece;
58	}
59	public coordToBoardIndex(coord: Coord): number {
60	const { row, col } = coord;
61	const index = row * this.size.col + col;
62	return index;
63	}
64	public boardIndexToCoord(index: number): Coord {
65	const col = index % this.size.col;
66	const row = Math.floor(index / this.size.col);
67	return new Coord(row, col);
68	}
69	}