Docs/update readme phase 2

README.md

@@ -56,6 +56,6 @@ php bin/phpunit
 
 - [x] Phase 0 — Project setup (Symfony skeleton, CI, PHPStan, CS Fixer)
 - [x] Phase 1 — Domain modeling (Value Objects, Entities, Aggregate Root)
-- [ ] Phase 2 — Application layer (CQRS, Symfony Messenger)
+- [x] Phase 2 — Application layer (CQRS, Symfony Messenger)
 - [ ] Phase 3 — Infrastructure (Doctrine, REST API)
 - [ ] Phase 4 — PHPStan level 8, OpenAPI docs

src/Chess/Application/Query/GetGameState/GameStateDTO.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chess\Application\Query\GetGameState;
+
+final class GameStateDTO
+{
+    /**
+     * @param array<string, array{type: string, color: string}> $pieces
+     */
+    public function __construct(
+        public readonly string $gameId,
+        public readonly string $currentTurn,
+        public readonly bool $isOver,
+        public readonly array $pieces,
+    ) {
+    }
+}

src/Chess/Application/Query/GetGameState/GetGameStateHandler.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chess\Application\Query\GetGameState;
+
+use Chess\Domain\Repository\GameRepositoryInterface;
+use Chess\Domain\Value\GameId;
+use Chess\Domain\Value\Square;
+use Symfony\Component\Messenger\Attribute\AsMessageHandler;
+
+#[AsMessageHandler(bus: 'query.bus')]
+final class GetGameStateHandler
+{
+    public function __construct(
+        private readonly GameRepositoryInterface $repository,
+    ) {
+    }
+
+    public function __invoke(GetGameStateQuery $query): GameStateDTO
+    {
+        $game = $this->repository->findById(GameId::fromString($query->gameId));
+
+        if (null === $game) {
+            throw new \DomainException(\sprintf('Game "%s" not found.', $query->gameId));
+        }
+
+        $pieces = [];
+        foreach (['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'] as $file) {
+            foreach (range(1, 8) as $rank) {
+                $square = new Square($file, $rank);
+                $piece = $game->board()->pieceAt($square);
+                if (null !== $piece) {
+                    $pieces[$square->toString()] = [
+                        'type' => $piece->type()->name,
+                        'color' => $piece->color()->name,
+                    ];
+                }
+            }
+        }
+
+        return new GameStateDTO(
+            gameId: $game->id()->toString(),
+            currentTurn: $game->currentTurn()->name,
+            isOver: $game->isOver(),
+            pieces: $pieces,
+        );
+    }
+}

src/Chess/Application/Query/GetGameState/GetGameStateQuery.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chess\Application\Query\GetGameState;
+
+final class GetGameStateQuery
+{
+    public function __construct(
+        public readonly string $gameId,
+    ) {
+    }
+}

tests/Chess/Application/Query/GetGameState/GetGameStateHandlerTest.php

@@ -0,0 +1,91 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Chess\Tests\Application\Query\GetGameState;
+
+use Chess\Application\Query\GetGameState\GameStateDTO;
+use Chess\Application\Query\GetGameState\GetGameStateHandler;
+use Chess\Application\Query\GetGameState\GetGameStateQuery;
+use Chess\Domain\Model\Game;
+use Chess\Domain\Repository\GameRepositoryInterface;
+use Chess\Domain\Value\GameId;
+use PHPUnit\Framework\TestCase;
+
+final class GetGameStateHandlerTest extends TestCase
+{
+    public function testItReturnsGameStateDTO(): void
+    {
+        $game = Game::start();
+
+        $repository = new class($game) implements GameRepositoryInterface {
+            public function __construct(private readonly Game $game)
+            {
+            }
+
+            public function save(Game $game): void
+            {
+            }
+
+            public function findById(GameId $id): Game
+            {
+                return $this->game;
+            }
+        };
+
+        $handler = new GetGameStateHandler($repository);
+        $dto = $handler(new GetGameStateQuery($game->id()->toString()));
+
+        self::assertInstanceOf(GameStateDTO::class, $dto);
+        self::assertSame($game->id()->toString(), $dto->gameId);
+        self::assertSame('White', $dto->currentTurn);
+        self::assertFalse($dto->isOver);
+        self::assertCount(32, $dto->pieces);
+    }
+
+    public function testItThrowsWhenGameNotFound(): void
+    {
+        $repository = new class implements GameRepositoryInterface {
+            public function save(Game $game): void
+            {
+            }
+
+            public function findById(GameId $id): ?Game
+            {
+                return null;
+            }
+        };
+
+        $this->expectException(\DomainException::class);
+
+        $handler = new GetGameStateHandler($repository);
+        $handler(new GetGameStateQuery('unknown-id'));
+    }
+
+    public function testPiecesContainCorrectDataForWhiteKing(): void
+    {
+        $game = Game::start();
+
+        $repository = new class($game) implements GameRepositoryInterface {
+            public function __construct(private readonly Game $game)
+            {
+            }
+
+            public function save(Game $game): void
+            {
+            }
+
+            public function findById(GameId $id): Game
+            {
+                return $this->game;
+            }
+        };
+
+        $handler = new GetGameStateHandler($repository);
+        $dto = $handler(new GetGameStateQuery($game->id()->toString()));
+
+        self::assertArrayHasKey('e1', $dto->pieces);
+        self::assertSame('King', $dto->pieces['e1']['type']);
+        self::assertSame('White', $dto->pieces['e1']['color']);
+    }
+}