<?php

declare(strict_types=1);

namespace Phred\Http\JsonApi;

use LogicException;
use Nyholm\Psr7\Response;
use Nyholm\Psr7\Stream;
use Phred\Http\ApiResponseFactoryInterface;
use Psr\Http\Message\ResponseInterface;

/**
 * Minimal JSON:API response factory stub.
 * For full functionality, require "neomerx/json-api" and replace internals accordingly.
 */
class JsonApiResponseFactory implements ApiResponseFactoryInterface
{
    public function ok(mixed $data, array $context = []): ResponseInterface
    {
        $document = $this->toResourceDocument($data, $context);
        return $this->jsonApi(200, $document);
    }

    public function created(string $location, mixed $data, array $context = []): ResponseInterface
    {
        $document = $this->toResourceDocument($data, $context);
        $response = $this->jsonApi(201, $document);
        return $response->withHeader('Location', $location);
    }

    public function error(int $status, string $title, ?string $detail = null, array $meta = []): ResponseInterface
    {
        $payload = [
            'errors' => [[
                'status' => (string) $status,
                'title' => $title,
                'detail' => $detail,
                'meta' => (object) $meta,
            ]],
        ];

        return $this->jsonApi($status, $payload);
    }

    private function jsonApi(int $status, array $document): ResponseInterface
    {
        // If neomerx/json-api is installed, you can swap this simple encoding with its encoder.
        $json = json_encode($document, JSON_THROW_ON_ERROR);
        $stream = Stream::create($json);
        return (new Response($status, ['Content-Type' => 'application/vnd.api+json']))->withBody($stream);
    }

    /**
     * Convert domain data to a very simple JSON:API resource document.
     * Context may include: 'type' (required for non-array scalars), 'id', 'includes', 'links', 'meta'.
     * This is intentionally minimal until a full encoder is wired.
     *
     * @param mixed $data
     * @param array $context
     * @return array
     */
    private function toResourceDocument(mixed $data, array $context): array
    {
        // If neomerx/json-api not present, produce a simple document requiring caller to provide 'type'.
        if (!isset($context['type'])) {
            // Keep developer feedback explicit to encourage proper setup.
            throw new LogicException('JSON:API response requires context["type"]. Consider installing neomerx/json-api for advanced encoding.');
        }

        $resource = [
            'type' => (string) $context['type'],
        ];

        if (is_array($data) && array_key_exists('id', $data)) {
            $resource['id'] = (string) $data['id'];
            $attributes = $data;
            unset($attributes['id']);
        } else {
            $attributes = $data;
            if (isset($context['id'])) {
                $resource['id'] = (string) $context['id'];
            }
        }

        $resource['attributes'] = $attributes;

        $document = ['data' => $resource];

        if (!empty($context['links']) && is_array($context['links'])) {
            $document['links'] = $context['links'];
        }
        if (!empty($context['meta']) && is_array($context['meta'])) {
            $document['meta'] = $context['meta'];
        }

        return $document;
    }
}