FakeChess - Uma representação MUITO RUIM de xadrez pois eu n sei jogar

Chess.php

<?php

/**
 * FakeChess - Xadrez de cadeia 
 *
 * @author danielhe4rt
 * @author merlinhohe4rt
 */

declare(strict_types=1);

class Chess
{

    public $piece;

    private $board = [];

    private $firstPawnMove = false;

    public function __construct(string $pieceName, string $position)
    {
        $this->piece = $pieceName;
        $this->generateBoard();
        $this->placePiece($position);
    }

    public function move(string $place): string
    {
        if ($this->piece == "pawn") {
            $availablePositions = ['B6', 'B5', 'A6', 'A5'];
            if (!in_array($place, $availablePositions)) {
                $this->placePiece($place, false);
                return 'false';
            }
        }
        if ($this->piece == "horse") {
            $availablePositions = ['D7', 'A6', 'C6'];
            if (!in_array($place, $availablePositions)) {
                $this->placePiece($place, false);
                return 'false';
            }
        }
        $this->placePiece($place);
        return 'true';
    }

    private function generateBoard(): void
    {
        $rowNumbers = [1, 2, 3, 4, 5, 6, 7, 8];
        $colCharacters = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',];

        for ($row = 0; $row <= 7; $row++) {
            for ($col = 0; $col <= 7; $col++) {
                $this->board[$row][$col] = $colCharacters[$col] . $rowNumbers[$row];
            }
        }
    }

    public function showBoard()
    {
        echo "=======================================" . PHP_EOL;
        foreach ($this->board as $row) {
            echo implode(' - ', $row) . PHP_EOL;
        }
        echo "=======================================" . PHP_EOL;
    }

    private function placePiece(string $position, bool $isValid = true)
    {
        $this->generateBoard();
        foreach ($this->board as $row => $rows) {
            foreach ($rows as $col => $column) {
                if ($column == $position) {
                    $this->board[$row][$col] = $isValid ? substr($this->piece, 0, 2) : "xx";
                }
            }
        }
    }
}

$expects = [
    [
        'piece' => 'pawn',
        'from' => 'A7',
        'to' => 'A4',
        'expect' => 'false'
    ],
    [
        'piece' => 'pawn',
        'from' => 'B7',
        'to' => 'B5',
        'expect' => 'true'
    ],
    [
        'piece' => 'horse',
        'from' => 'B8',
        'to' => 'A6',
        'expect' => 'true'
    ],
];


$chessBoards = [];
foreach ($expects as $key => $expect) {
    echo "Cenário ->" . $key . PHP_EOL;
    $chessBoards[$key] = new Chess($expect['piece'], $expect['from']);
    $actual = $chessBoards[$key]->move($expect['to']);
    $chessBoards[$key]->showBoard();
    echo "Esperado -> " . $expect['expect'] . PHP_EOL;
    echo "Atual -> " . $actual . PHP_EOL;
}