SearchService.php

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<?php

namespace Elgg\Search;

use Doctrine\DBAL\Query\Expression\CompositeExpression;
use Elgg\Config;
use Elgg\Database;
use Elgg\Database\Clauses\AnnotationWhereClause;
use Elgg\Database\Clauses\AttributeWhereClause;
use Elgg\Database\Clauses\MetadataWhereClause;
use Elgg\Database\QueryBuilder;
use Elgg\EventsService;
use Elgg\Exceptions\DomainException;
use Elgg\Traits\Database\LegacyQueryOptionsAdapter;

class SearchService {

    private $config;

    private $events;

    private $db;

    use LegacyQueryOptionsAdapter;
    
    public function __construct(Config $config, EventsService $events, Database $db) {
        $this->config = $config;
        $this->events = $events;
        $this->db = $db;
    }

    public function search(array $options = []) {
        $options = $this->prepareSearchOptions($options);

        $query_parts = elgg_extract('query_parts', $options);
        $fields = (array) elgg_extract('fields', $options);

        if (empty($query_parts) || empty(array_filter($fields))) {
            return false;
        }

        $entity_type = elgg_extract('type', $options, 'all', false);
        $entity_subtype = elgg_extract('subtype', $options);
        $search_type = elgg_extract('search_type', $options, 'entities');

        if ($entity_type !== 'all' && !in_array($entity_type, Config::ENTITY_TYPES)) {
            throw new DomainException("'{$entity_type}' is not a valid entity type");
        }

        $options = $this->events->triggerResults('search:options', $entity_type, $options, $options);
        if (!empty($entity_subtype) && is_string($entity_subtype)) {
            $options = $this->events->triggerResults('search:options', "{$entity_type}:{$entity_subtype}", $options, $options);
        }

        $options = $this->events->triggerResults('search:options', $search_type, $options, $options);

        if ($this->events->hasHandler('search:results', $search_type)) {
            $results = $this->events->triggerResults('search:results', $search_type, $options);
            if (isset($results)) {
                // allow events to conditionally replace the result set
                return $results;
            }
        }

        return elgg_get_entities($options);
    }

    public function normalizeOptions(array $options = []) {
        
        if (elgg_extract('_elgg_search_service_normalize_options', $options)) {
            // already normalized once before
            return $options;
        }
        
        $search_type = elgg_extract('search_type', $options, 'entities', false);
        $options['search_type'] = $search_type;

        $options = $this->events->triggerResults('search:params', $search_type, $options, $options);

        $options = $this->normalizeQuery($options);
        $options = $this->normalizeSearchFields($options);

        // prevent duplicate normalization
        $options['_elgg_search_service_normalize_options'] = true;
        
        return $options;
    }

    public function prepareSearchOptions(array $options = []) {
        $options = $this->normalizeOptions($options);

        $fields = elgg_extract('fields', $options);
        $query_parts = elgg_extract('query_parts', $options);
        $partial = elgg_extract('partial_match', $options, true);

        $options['wheres']['search'] = function (QueryBuilder $qb, $alias) use ($fields, $query_parts, $partial) {
            return $this->buildSearchWhereQuery($qb, $alias, $fields, $query_parts, $partial);
        };

        return $options;
    }

    public function normalizeQuery(array $options = []) {

        $query = elgg_extract('query', $options, '');
        $query = strip_tags($query);
        $query = htmlspecialchars($query, ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401, 'UTF-8');
        $query = trim($query);

        $words = preg_split('/\s+/', $query);
        $words = array_map(function ($e) {
            return trim($e);
        }, $words);

        $query = implode(' ', $words);

        $options['query'] = $query;

        $tokenize = elgg_extract('tokenize', $options, true);
        if ($tokenize) {
            $parts = $words;
        } else {
            $parts = [$query];
        }

        $options['query_parts'] = array_unique(array_filter($parts));

        return $options;
    }

    public function normalizeSearchFields(array $options = []) {

        $default_fields = [
            'attributes' => [],
            'metadata' => [],
            'annotations' => [],
        ];

        $fields = $default_fields;

        $clean_field_property_types = function ($new_fields) use ($default_fields) {
            $property_types = array_keys($default_fields);
            foreach ($property_types as $property_type) {
                if (empty($new_fields[$property_type])) {
                    $new_fields[$property_type] = [];
                } else {
                    $new_fields[$property_type] = array_unique($new_fields[$property_type]);
                }
            }
            
            return $new_fields;
        };

        $merge_fields = function ($new_fields) use (&$fields, $clean_field_property_types) {
            if (empty($new_fields) || !is_array($new_fields)) {
                return;
            }
            
            $new_fields = $clean_field_property_types($new_fields);
            
            $fields = array_merge_recursive($fields, $new_fields);
        };

        // normalize type/subtype to support all combinations
        $normalized_options = $this->normalizeTypeSubtypeOptions($options);

        $type_subtype_pairs = elgg_extract('type_subtype_pairs', $normalized_options);
        if (!empty($type_subtype_pairs)) {
            foreach ($type_subtype_pairs as $entity_type => $entity_subtypes) {
                $result = $this->events->triggerResults('search:fields', $entity_type, $options, $default_fields);
                $merge_fields($result);
                
                if (elgg_is_empty($entity_subtypes)) {
                    continue;
                }
                
                foreach ($entity_subtypes as $entity_subtype) {
                    $result = $this->events->triggerResults('search:fields', "{$entity_type}:{$entity_subtype}", $options, $default_fields);
                    $merge_fields($result);
                }
            }
        }

        // search fields for search type
        $search_type = elgg_extract('search_type', $options, 'entities');
        if ($search_type) {
            $fields = $this->events->triggerResults('search:fields', $search_type, $options, $fields);
        }

        // make sure all supported field types are available
        $fields = $clean_field_property_types($fields);

        if (empty($options['fields'])) {
            $options['fields'] = $fields;
        } else {
            // only allow known fields
            foreach ($fields as $property_type => $property_type_fields) {
                if (empty($options['fields'][$property_type])) {
                    $options['fields'][$property_type] = [];
                    continue;
                }

                $allowed = array_intersect($property_type_fields, (array) $options['fields'][$property_type]);
                $options['fields'][$property_type] = array_values(array_unique($allowed));
            }
        }

        return $options;
    }

    public function buildSearchWhereQuery(QueryBuilder $qb, $alias, $fields, $query_parts, $partial_match = true) {

        $attributes = elgg_extract('attributes', $fields, [], false);
        $metadata = elgg_extract('metadata', $fields, [], false);
        $annotations = elgg_extract('annotations', $fields, [], false);

        $ors = [];

        $populate_where = function ($where, $part) use ($partial_match) {
            $where->values = $partial_match ? "%{$part}%" : $part;
            $where->comparison = 'LIKE';
            $where->value_type = ELGG_VALUE_STRING;
            $where->case_sensitive = false;
        };

        if (!empty($attributes)) {
            foreach ($attributes as $attribute) {
                $attribute_ands = [];
                foreach ($query_parts as $part) {
                    $where = new AttributeWhereClause();
                    $where->names = $attribute;
                    $populate_where($where, $part);
                    $attribute_ands[] = $where->prepare($qb, $alias);
                }
                
                $ors[] = $qb->merge($attribute_ands, 'AND');
            }
        }

        if (!empty($metadata)) {
            $metadata_ands = [];
            $md_alias = $qb->joinMetadataTable($alias, 'guid', $metadata, 'left');
            foreach ($query_parts as $part) {
                $where = new MetadataWhereClause();
                $populate_where($where, $part);
                $metadata_ands[] = $where->prepare($qb, $md_alias);
            }
            
            $ors[] = $qb->merge($metadata_ands, 'AND');
        }

        if (!empty($annotations)) {
            $annotations_ands = [];
            $an_alias = $qb->joinAnnotationTable($alias, 'guid', $annotations, 'left');
            foreach ($query_parts as $part) {
                $where = new AnnotationWhereClause();
                $populate_where($where, $part);
                $annotations_ands[] = $where->prepare($qb, $an_alias);
            }
            
            $ors[] = $qb->merge($annotations_ands, 'AND');
        }

        return $qb->merge($ors, 'OR');
    }
}