<?php
/**
 * Copyright since 2014 Waynet Sp. z o.o.
 * PrestaShop is an International Registered Trademark & Property of PrestaShop SA
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.md.
 * It is also available through the world-wide-web at this URL:
 * https://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to kontakt@waynet.pl so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
 * versions in the future. If you wish to customize PrestaShop for your
 * needs please refer to https://devdocs.prestashop-project.org/ for more information.
 *
 * @author    Waynet Sp. z o.o. <kontakt@waynet.pl>
 * @copyright since 2014 Waynet Sp. z o.o.
 * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 */

declare(strict_types=1);

namespace Waynet\Security\Api\Resource;

use Waynet\Security\Api\ApiClient;

/**
 * @template T of HydraResource
 * @template-implements \IteratorAggregate<int, T>
 */
class HydraCollection implements \IteratorAggregate, \Countable
{
    public const TYPE = 'hydra:Collection';

    private $client;
    private $memberClass;
    private $collectionUri;
    private $totalItems;
    private $pageData;

    /**
     * @param class-string<T> $memberClass
     */
    public function __construct(ApiClient $client, string $memberClass, string $collectionUri)
    {
        if (!is_subclass_of($memberClass, HydraResource::class)) {
            throw new \InvalidArgumentException(sprintf('%s is not a %s', $memberClass, HydraResource::class));
        }

        $this->client = $client;
        $this->memberClass = $memberClass;
        $this->collectionUri = $collectionUri;
    }

    public function getMemberClass(): string
    {
        return $this->memberClass;
    }

    /** @return \Generator<int, T> */
    public function getIterator(): \Generator
    {
        $uri = $this->collectionUri;

        do {
            $data = $this->getPageData($uri);
            $this->totalItems = $data['hydra:totalItems'];
            foreach ($data['hydra:member'] as $member) {
                yield $this->memberClass::cast($member);
            }
            $view = isset($data['hydra:view']) ? HydraPartialCollectionView::cast($data['hydra:view']) : null;
        } while ($view && $uri = $view->getNextPageUri());
    }

    public function count(): int
    {
        if (!isset($this->totalItems)) {
            $this->pageData = $this->getPageData($this->collectionUri);
            $this->totalItems = $this->pageData['hydra:totalItems'];
        }

        return $this->totalItems;
    }

    /**
     * @param int $page
     *
     * @return HydraCollectionPage<T>
     */
    public function getPage(int $page = 1): HydraCollectionPage
    {
        if (0 >= $page) {
            throw new \InvalidArgumentException('Page must be greater than 0');
        }

        $uri = $this->getPageUri($page);
        $data = $this->client->getCollection($uri);

        return HydraCollectionPage::cast($data, $this->memberClass);
    }

    private function getPageData(string $uri): array
    {
        if (isset($this->pageData)) {
            $pageData = $this->pageData;
            unset($this->pageData);

            return $pageData;
        }

        return $this->client->getCollection($uri);
    }

    private function getPageUri(int $page): string
    {
        $pageUri = http_build_url($this->collectionUri, ['query' => 'page=' . $page], HTTP_URL_JOIN_QUERY);
        if ('/' === $this->collectionUri[0]) {
            return $pageUri;
        }

        // fix relative path
        return substr($pageUri, 1);
    }
}