<?php
namespace WapplerSystems\Meilisearch\Domain\Search\ResultSet;

/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\AbstractFacet;
use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\FacetRegistry;
use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Facets\RequirementsService;
use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Sorting\Sorting;
use WapplerSystems\Meilisearch\Domain\Search\ResultSet\Spellchecking\Suggestion;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Extbase\Object\ObjectManager;
use TYPO3\CMS\Extbase\Object\ObjectManagerInterface;
use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;

/**
 * This processor is used to transform the meilisearch response into a
 * domain object hierarchy that can be used in the application (controller and view).
 *
 * @author Frans Saris <frans@beech.it>
 * @author Timo Hund <timo.hund@dkd.de>
 */
class ResultSetReconstitutionProcessor implements SearchResultSetProcessor
{
    /**
     * @var ObjectManagerInterface
     */
    protected $objectManager;

    /**
     * @return ObjectManagerInterface
     */
    public function getObjectManager()
    {
        if ($this->objectManager === null) {
            $this->objectManager = GeneralUtility::makeInstance(ObjectManager::class);
        }
        return $this->objectManager;
    }

    /**
     * @param ObjectManagerInterface $objectManager
     */
    public function setObjectManager($objectManager)
    {
        $this->objectManager = $objectManager;
    }


    /**
     * @return FacetRegistry
     */
    protected function getFacetRegistry()
    {
        // @extensionScannerIgnoreLine
        return $this->getObjectManager()->get(FacetRegistry::class);
    }

    /**
     * The implementation can be used to influence a SearchResultSet that is
     * created and processed in the SearchResultSetService.
     *
     * @param SearchResultSet $resultSet
     * @return SearchResultSet
     */
    public function process(SearchResultSet $resultSet)
    {
        if (!$resultSet instanceof SearchResultSet) {
            return $resultSet;
        }

        $resultSet = $this->parseSpellCheckingResponseIntoObjects($resultSet);
        $resultSet = $this->parseSortingIntoObjects($resultSet);

        // here we can reconstitute other domain objects from the meilisearch response
        $resultSet = $this->parseFacetsIntoObjects($resultSet);

        return $resultSet;
    }

    /**
     * @param SearchResultSet $resultSet
     * @return SearchResultSet
     */
    protected function parseSortingIntoObjects(SearchResultSet $resultSet)
    {
        $configuration = $resultSet->getUsedSearchRequest()->getContextTypoScriptConfiguration();
        $hasSorting = $resultSet->getUsedSearchRequest()->getHasSorting();
        $activeSortingName = $resultSet->getUsedSearchRequest()->getSortingName();
        $activeSortingDirection = $resultSet->getUsedSearchRequest()->getSortingDirection();

        // no configuration available
        if (!isset($configuration)) {
            return $resultSet;
        }

        // no sorting enabled
        if (!$configuration->getSearchSorting()) {
            return $resultSet;
        }
        foreach ($configuration->getSearchSortingOptionsConfiguration() as $sortingKeyName => $sortingOptions) {
            $sortingName = rtrim($sortingKeyName, '.');
            $selected = false;
            $direction = $configuration->getSearchSortingDefaultOrderBySortOptionName($sortingName);

            // when we have an active sorting in the request we compare the sortingName and mark is as active and
            // use the direction from the request
            if ($hasSorting && $activeSortingName == $sortingName) {
                $selected = true;
                $direction = $activeSortingDirection;
            }

            $field = $sortingOptions['field'];
            $label = $sortingOptions['label'];

            $isResetOption = $field === 'relevance';

            // Allow stdWrap on label:
            $labelHasSubConfiguration = is_array($sortingOptions['label.']);
            if ($labelHasSubConfiguration) {
                $cObj = GeneralUtility::makeInstance(ContentObjectRenderer::class);
                $label = $cObj->stdWrap($label, $sortingOptions['label.']);
            }

            $sorting = $this->getObjectManager()->get(Sorting::class, $resultSet, $sortingName, $field, $direction, $label, $selected, $isResetOption);
            $resultSet->addSorting($sorting);
        }

        return $resultSet;
    }

    /**
     * @param SearchResultSet $resultSet
     * @return SearchResultSet
     */
    private function parseSpellCheckingResponseIntoObjects(SearchResultSet $resultSet)
    {
        //read the response
        $response = $resultSet->getResponse();

        if (!is_array($response->spellcheck->suggestions)) {
            return $resultSet;
        }

        $misspelledTerm = '';
        foreach ($response->spellcheck->suggestions as $key => $suggestionData) {
            if (is_string($suggestionData)) {
                $misspelledTerm = $key;
                continue;
            }

            if ($misspelledTerm === '') {
                throw new \UnexpectedValueException('No missspelled term before suggestion');
            }

            if (!is_object($suggestionData) && !is_array($suggestionData->suggestion)) {
                continue;
            }

            foreach ($suggestionData->suggestion as $suggestedTerm) {
                $suggestion = $this->createSuggestionFromResponseFragment($suggestionData, $suggestedTerm, $misspelledTerm);
                //add it to the resultSet
                $resultSet->addSpellCheckingSuggestion($suggestion);
            }

        }

        return $resultSet;
    }

    /**
     * @param \stdClass $suggestionData
     * @param string $suggestedTerm
     * @param string $misspelledTerm
     * @return Suggestion
     */
    private function createSuggestionFromResponseFragment($suggestionData, $suggestedTerm, $misspelledTerm)
    {
        $numFound = isset($suggestionData->numFound) ? $suggestionData->numFound : 0;
        $startOffset = isset($suggestionData->startOffset) ? $suggestionData->startOffset : 0;
        $endOffset = isset($suggestionData->endOffset) ? $suggestionData->endOffset : 0;

        // by now we avoid to use GeneralUtility::makeInstance, since we only create a value object
        // and the usage might be a overhead.
        $suggestion = new Suggestion($suggestedTerm, $misspelledTerm, $numFound, $startOffset, $endOffset);
        return $suggestion;
    }

    /**
     * Parse available facets into objects
     *
     * @param SearchResultSet $resultSet
     * @return SearchResultSet
     */
    private function parseFacetsIntoObjects(SearchResultSet $resultSet)
    {
        // Make sure we can access the facet configuration
        if (!$resultSet->getUsedSearchRequest() || !$resultSet->getUsedSearchRequest()->getContextTypoScriptConfiguration()) {
            return $resultSet;
        }

        // Read the response
        $response = $resultSet->getResponse();
        if (!is_object($response->facet_counts) && !is_object($response->facets)) {
            return $resultSet;
        }

        /** @var FacetRegistry $facetRegistry */
        $facetRegistry = $this->getFacetRegistry();
        $facetsConfiguration = $resultSet->getUsedSearchRequest()->getContextTypoScriptConfiguration()->getSearchFacetingFacets();

        foreach ($facetsConfiguration as $name => $options) {
            if (!is_array($options)) {
                continue;
            }
            $facetName = rtrim($name, '.');
            $type = !empty($options['type']) ? $options['type'] : '';

            $parser = $facetRegistry->getPackage($type)->getParser();
            $facet = $parser->parse($resultSet, $facetName, $options);
            if ($facet !== null) {
                $resultSet->addFacet($facet);
            }
        }

        $this->applyRequirements($resultSet);

        return $resultSet;
    }

    /**
     * @param SearchResultSet $resultSet
     */
    protected function applyRequirements(SearchResultSet $resultSet)
    {
        $requirementsService = $this->getRequirementsService();
        $facets = $resultSet->getFacets();
        foreach ($facets as $facet) {
            /** @var $facet AbstractFacet */
            $requirementsMet = $requirementsService->getAllRequirementsMet($facet);
            $facet->setAllRequirementsMet($requirementsMet);
        }
    }

    /**
     * @return RequirementsService
     */
    protected function getRequirementsService()
    {
        // @extensionScannerIgnoreLine
        return $this->getObjectManager()->get(RequirementsService::class);
    }
}