feat: wire the front controller and harden userToken path

public/index.php

@@ -2,8 +2,124 @@
 
 declare(strict_types=1);
 
-// Front controller. The router and handler dispatch land in Task 13.
-// For now this returns a 200 with a stub so the dev server is reachable.
-http_response_code(200);
-header('Content-Type: text/plain; charset=utf-8');
-echo "BattleForge dev server up.\n";
+use BattleForge\Http\CsrfToken;
+use BattleForge\Http\Handlers\GetAssets;
+use BattleForge\Http\Handlers\GetBattlefieldEditor;
+use BattleForge\Http\Handlers\GetHomePage;
+use BattleForge\Http\Handlers\GetTeamEditor;
+use BattleForge\Http\Handlers\PostBattlefieldEditor;
+use BattleForge\Http\Handlers\PostImageUpload;
+use BattleForge\Http\Handlers\PostStartMatch;
+use BattleForge\Http\Handlers\PostTeamEditor;
+use BattleForge\Http\Request;
+use BattleForge\Http\Response;
+use BattleForge\Http\Router;
+
+require __DIR__ . '/../vendor/autoload.php';
+
+// 1. Read the app secret.
+$secret = getenv('BATTLEFORGE_SECRET');
+if ($secret === false || $secret === '') {
+    $secretFile = __DIR__ . '/../var/secret.key';
+    if (!is_file($secretFile)) {
+        if (!is_dir(dirname($secretFile))) {
+            mkdir(dirname($secretFile), 0700, true);
+        }
+        file_put_contents($secretFile, random_bytes(32));
+        chmod($secretFile, 0600);
+    }
+    $secret = file_get_contents($secretFile);
+    if ($secret === false) {
+        http_response_code(500);
+        echo "Failed to read app secret.\n";
+        return;
+    }
+}
+
+// 2. Ensure the __csrf cookie is set. If absent, issue a fresh token.
+$cookies = $_COOKIE;
+$existingCookie = (string) ($cookies['__csrf'] ?? '');
+if ($existingCookie === '') {
+    [$token, $cookie] = CsrfToken::issue($secret);
+    setcookie('__csrf', $cookie, [
+        'expires' => time() + 86400,
+        'path' => '/',
+        'secure' => isset($_SERVER['HTTPS']),
+        'httponly' => true,
+        'samesite' => 'Lax',
+    ]);
+    $existingCookie = $cookie;
+    $cookies['__csrf'] = $cookie;
+}
+
+// 3. Compute the upload-endpoint user token (derived from the same secret).
+$uploadsToken = hash_hmac('sha256', $secret, 'bf-uploads');
+
+// 4. Determine the request method, path, and content type.
+$method = strtoupper((string) ($_SERVER['REQUEST_METHOD'] ?? 'GET'));
+$uri = (string) ($_SERVER['REQUEST_URI'] ?? '/');
+$path = parse_url($uri, PHP_URL_PATH) ?: '/';
+$queryString = (string) (parse_url($uri, PHP_URL_QUERY) ?? '');
+$contentType = isset($_SERVER['CONTENT_TYPE']) ? (string) $_SERVER['CONTENT_TYPE'] : null;
+if ($contentType !== null) {
+    $semicolon = strpos($contentType, ';');
+    if ($semicolon !== false) {
+        $contentType = substr($contentType, 0, $semicolon);
+    }
+    $contentType = trim($contentType);
+}
+
+// 5. Read the raw body for fetch POSTs that submit JSON.
+$rawBody = (string) file_get_contents('php://input');
+
+// 6. Build a Request with the request data, the CSRF secret, and the upload token.
+$server = $_SERVER;
+$server['__csrf_secret'] = $secret;
+$server['__uploads_token'] = $uploadsToken;
+
+$request = new Request(
+    get: $_GET,
+    post: $_POST,
+    files: $_FILES,
+    cookies: $cookies,
+    server: $server,
+    queryString: $queryString,
+    method: $method,
+    path: $path,
+    contentType: $contentType,
+    rawBody: $rawBody,
+);
+
+// 7. Configure the router with the eight routes.
+$uploadsRoot = __DIR__ . '/../var/uploads';
+$placeholderDir = __DIR__ . '/assets/placeholders';
+
+$homePage = static fn (Request $r, array $p): Response => (new GetHomePage())->handle($r, $p);
+$getTeam = static fn (Request $r, array $p): Response => (new GetTeamEditor())->handle($r, $p);
+$postTeam = static fn (Request $r, array $p): Response => (new PostTeamEditor())->handle($r, $p);
+$getBattlefield = static fn (Request $r, array $p): Response => (new GetBattlefieldEditor())->handle($r, $p);
+$postBattlefield = static fn (Request $r, array $p): Response => (new PostBattlefieldEditor())->handle($r, $p);
+$postStart = static fn (Request $r, array $p): Response => (new PostStartMatch())->handle($r, $p);
+$postUpload = static fn (Request $r, array $p): Response => (new PostImageUpload($uploadsRoot))->handle($r, $p);
+$getAssets = static function (Request $r, array $p) use ($placeholderDir, $uploadsRoot): Response {
+    return (new GetAssets($placeholderDir, $uploadsRoot))->handle($r, $p);
+};
+
+$router = new Router();
+$router->add('GET', '/', $homePage);
+$router->add('GET', '/scenarios/{id}/edit/team', $getTeam);
+$router->add('POST', '/scenarios/{id}/edit/team', $postTeam);
+$router->add('GET', '/scenarios/{id}/edit/battlefield', $getBattlefield);
+$router->add('POST', '/scenarios/{id}/edit/battlefield', $postBattlefield);
+$router->add('POST', '/scenarios/{id}/start', $postStart);
+$router->add('POST', '/assets/upload', $postUpload);
+$router->add('GET', '/assets/{kind}/{filename}', $getAssets);
+
+// 8. Dispatch and emit.
+$response = $router->dispatch($request);
+
+http_response_code($response->status);
+foreach ($response->headers as $name => $value) {
+    header($name . ': ' . $value);
+}
+echo $response->body;