<?php

/**
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; under version 2
 * of the License (non-upgradable).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2019 (original work) Open Assessment Technologies SA;
 */

declare(strict_types=1);

namespace App\Statistics;

use App\Ags\LineItemRepository;
use App\Ags\ResultRepository;
use App\Ags\ScoreRepository;
use App\BasicOutcome\BasicOutcomeProcessor;
use App\Nrps\MembershipRepository;
use App\Proctoring\Assessment;
use App\Proctoring\AssessmentRepository;
use Psr\Cache\CacheItemPoolInterface;

class PlatformStatisticsCollector
{
    /** @var CacheItemPoolInterface */
    private $cache;

    public function __construct(CacheItemPoolInterface $cache)
    {
        $this->cache = $cache;
    }

    public function collect(): array
    {
        return [
            'nrpsMemberships' => $this->countCacheEntries(MembershipRepository::CACHE_KEY) + 1,
            'basicOutcomes' => $this->countCacheEntries(BasicOutcomeProcessor::CACHE_KEY),
            'agsLineItems' => $this->countCacheEntries(LineItemRepository::CACHE_KEY),
            'agsScores' => $this->countSubCacheEntries(ScoreRepository::CACHE_KEY),
            'agsResults' => $this->countSubCacheEntries(ResultRepository::CACHE_KEY),
            'acsAssessments' => $this->countCacheEntries(AssessmentRepository::CACHE_KEY),
            'acsControls' => $this->countAcsControls(),
        ];
    }

    private function countCacheEntries(string $cacheKey): int
    {
        $cacheData = $this->cache->getItem($cacheKey);

        if ($cacheData->isHit()) {
            return $cacheData->get() !== null
                ? sizeof($cacheData->get())
                : 0;
        }

        return 0;
    }

    private function countSubCacheEntries(string $cacheKey): int
    {
        $cacheData = $this->cache->getItem($cacheKey);

        if ($cacheData->isHit()) {
            $total = 0;

            foreach ($cacheData->get() ?? [] as $item) {
                $total += sizeof($item);
            }

            return $total;
        }

        return 0;
    }

    private function countAcsControls(): int
    {
        $cacheData = $this->cache->getItem(AssessmentRepository::CACHE_KEY);

        if ($cacheData->isHit()) {
            $total = 0;

            /** @var Assessment $assessment */
            foreach ($cacheData->get() ?? [] as $assessment) {
                $total += sizeof($assessment->getControls());
            }

            return $total;
        }

        return 0;
    }
}