<?php

declare(strict_types=1);

namespace App\Http;

use App\Exception\ApiException;
use Psr\Http\Message\ResponseFactoryInterface;
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Slim\Exception\HttpMethodNotAllowedException;
use Slim\Exception\HttpNotFoundException;
use Throwable;

/**
 * Renders every uncaught error as a consistent JSON envelope:
 *
 *   { "error": { "message": string, "details"?: object } }
 */
final class JsonErrorHandler
{
    public function __construct(
        private readonly ResponseFactoryInterface $responseFactory,
        private readonly bool $displayErrorDetails,
    ) {
    }

    public function __invoke(
        Request $request,
        Throwable $exception,
        bool $displayErrorDetails,
        bool $logErrors,
        bool $logErrorDetails,
    ): Response {
        [$status, $payload] = $this->describe($exception);

        $response = $this->responseFactory->createResponse($status);
        $response->getBody()->write(
            (string) json_encode($payload, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT)
        );

        return $response->withHeader('Content-Type', 'application/json');
    }

    /**
     * @return array{0: int, 1: array<string, mixed>}
     */
    private function describe(Throwable $exception): array
    {
        if ($exception instanceof ApiException) {
            $error = ['message' => $exception->getMessage()];
            if ($exception->getDetails() !== []) {
                $error['details'] = $exception->getDetails();
            }

            return [$exception->getStatusCode(), ['error' => $error]];
        }

        if ($exception instanceof HttpNotFoundException) {
            return [404, ['error' => ['message' => 'The requested resource was not found.']]];
        }

        if ($exception instanceof HttpMethodNotAllowedException) {
            return [405, ['error' => ['message' => 'Method not allowed for this resource.']]];
        }

        $error = ['message' => 'An unexpected error occurred.'];
        if ($this->displayErrorDetails) {
            $error['message'] = $exception->getMessage();
            $error['exception'] = $exception::class;
            $error['file'] = $exception->getFile() . ':' . $exception->getLine();
        }

        return [500, ['error' => $error]];
    }
}