<?php

declare(strict_types=1);

namespace Phred\Http\Middleware;

use Phred\Support\Config;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;

class ContentNegotiationMiddleware implements MiddlewareInterface
{
    public const ATTR_API_FORMAT = 'phred.api_format'; // 'rest' | 'jsonapi'

    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {
        $format = strtolower(Config::get('API_FORMAT', Config::get('api.format', 'rest')));

        // Optional: allow Accept header to override when JSON:API is explicitly requested
        $accept = $request->getHeaderLine('Accept');
        if (str_contains($accept, 'application/vnd.api+json')) {
            $format = 'jsonapi';
        }

        return $handler->handle($request->withAttribute(self::ATTR_API_FORMAT, $format));
    }
}