Relationships.php

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<?php

namespace Elgg\Database;

use Doctrine\DBAL\Query\Expression\CompositeExpression;
use Elgg\Database\Clauses\MetadataWhereClause;
use Elgg\Database\Clauses\EntityWhereClause;
use Elgg\Database\Clauses\AnnotationWhereClause;
use Elgg\Database\Clauses\RelationshipWhereClause;
use Elgg\Exceptions\DomainException;
use Elgg\Exceptions\InvalidArgumentException;
use Elgg\Exceptions\LogicException;

class Relationships extends Repository {

    public function calculate($function, $property, $property_type = null) {
        if (!in_array(strtolower($function), QueryBuilder::CALCULATIONS)) {
            throw new DomainException("'{$function}' is not a valid numeric function");
        }
        
        if (!isset($property_type)) {
            if (in_array($property, \ElggEntity::PRIMARY_ATTR_NAMES)) {
                $property_type = 'attribute';
            } else {
                $property_type = 'metadata';
            }
        }
        
        $join_column = $this->getJoinColumn();
        
        $select = Select::fromTable(RelationshipsTable::TABLE_NAME, 'er');
        
        switch ($property_type) {
            case 'attribute':
                if (!in_array($property, \ElggEntity::PRIMARY_ATTR_NAMES)) {
                    throw new DomainException("'{$property}' is not a valid attribute");
                }
                
                $alias = $select->joinEntitiesTable($select->getTableAlias(), $join_column, 'inner', 'e');
                $select->select("{$function}({$alias}.{$property}) AS calculation");
                break;
                
            case 'annotation':
                $alias = AnnotationsTable::DEFAULT_JOIN_ALIAS;
                if (!empty($this->options->annotation_name_value_pairs) && $this->options->annotation_name_value_pairs[0]->names != $property) {
                    $alias = $select->joinAnnotationTable($select->getTableAlias(), $join_column, $property);
                }
                
                $select->select("{$function}({$alias}.value) AS calculation");
                break;
                
            case 'metadata':
                $alias = $select->joinMetadataTable($select->getTableAlias(), $join_column, $property);
                $select->select("{$function}({$alias}.value) AS calculation");
                break;
        }
        
        $select = $this->buildQuery($select);
        
        $result = _elgg_services()->db->getDataRow($select);
        
        return $result ? (int) $result->calculation : 0;
    }
    
    public function count() {
        $select = Select::fromTable(RelationshipsTable::TABLE_NAME, 'er');
        
        $count_expr = $this->options->distinct ? "DISTINCT {$select->getTableAlias()}.id" : '*';
        $select->select("COUNT({$count_expr}) AS total");
        
        $select = $this->buildQuery($select);
        
        $result = _elgg_services()->db->getDataRow($select);
        if (empty($result)) {
            return 0;
        }
        
        return (int) $result->total;
    }
    
    public function execute() {
        if ($this->options->annotation_calculation) {
            $clauses = $this->options->annotation_name_value_pairs;
            if (count($clauses) > 1 && $this->options->annotation_name_value_pairs_operator !== 'OR') {
                throw new LogicException('Annotation calculation can not be performed on multiple annotation name value pairs merged with AND');
            }
            
            $clause = array_shift($clauses);
            
            return $this->calculate($this->options->annotation_calculation, $clause->names, 'annotation');
        } elseif ($this->options->metadata_calculation) {
            $clauses = $this->options->metadata_name_value_pairs;
            if (count($clauses) > 1 && $this->options->metadata_name_value_pairs_operator !== 'OR') {
                throw new LogicException('Metadata calculation can not be performed on multiple metadata name value pairs merged with AND');
            }
            
            $clause = array_shift($clauses);
            
            return $this->calculate($this->options->metadata_calculation, $clause->names, 'metadata');
        } elseif ($this->options->count) {
            return $this->count();
        } elseif ($this->options->batch) {
            return $this->batch($this->options->limit, $this->options->offset, $this->options->callback);
        } else {
            return $this->get($this->options->limit, $this->options->offset, $this->options->callback);
        }
    }
    
    public function get($limit = null, $offset = null, $callback = null) {
        $select = Select::fromTable(RelationshipsTable::TABLE_NAME, 'er');
        
        $distinct = $this->options->distinct ? 'DISTINCT ' : '';
        $select->select("{$distinct}{$select->getTableAlias()}.*");
        
        $this->expandInto($select, $select->getTableAlias());
        
        $select = $this->buildQuery($select);
        
        // add default ordering
        $original_order = elgg_extract('order_by', $this->options->__original_options);
        if (empty($this->options->order_by) && $original_order !== false) {
            $select->addOrderBy("{$select->getTableAlias()}.time_created", 'desc');
            $select->addOrderBy("{$select->getTableAlias()}.id", 'desc');
        }
        
        if ($limit > 0) {
            $select->setMaxResults((int) $limit);
            $select->setFirstResult((int) $offset);
        }
        
        $callback = $callback ?: $this->options->callback;
        if (!isset($callback)) {
            $callback = function ($row) {
                return new \ElggRelationship($row);
            };
        }
        
        $results = _elgg_services()->db->getData($select, $callback);
        if (!empty($results)) {
            $preload = array_filter($results, function($e) {
                return $e instanceof \ElggRelationship;
            });
            
            _elgg_services()->entityPreloader->preload($preload, [
                'guid_one',
                'guid_two',
            ]);
        }
        
        return $results;
    }
    
    protected function buildQuery(QueryBuilder $qb) {
        $ands = [];
        
        foreach ($this->options->joins as $join) {
            $join->prepare($qb, $qb->getTableAlias());
        }
        
        foreach ($this->options->wheres as $where) {
            $ands[] = $where->prepare($qb, $qb->getTableAlias());
        }
        
        $ands[] = $this->buildEntityClause($qb);
        $ands[] = $this->buildPairedMetadataClause($qb, $this->options->metadata_name_value_pairs, $this->options->metadata_name_value_pairs_operator);
        $ands[] = $this->buildPairedMetadataClause($qb, $this->options->search_name_value_pairs, 'OR');
        $ands[] = $this->buildPairedAnnotationClause($qb, $this->options->annotation_name_value_pairs, $this->options->annotation_name_value_pairs_operator);
        $ands[] = $this->buildPairedRelationshipClause($qb, $this->options->relationship_pairs);
        
        $ands = $qb->merge($ands);
        if (!empty($ands)) {
            $qb->andWhere($ands);
        }
        
        return $qb;
    }
    
    protected function buildEntityClause(QueryBuilder $qb) {
        $joined_alias = $qb->joinEntitiesTable($qb->getTableAlias(), $this->getJoinColumn(), 'inner', 'e');
        return EntityWhereClause::factory($this->options)->prepare($qb, $joined_alias);
    }
    
    protected function buildPairedMetadataClause(QueryBuilder $qb, $clauses, $boolean = 'AND') {
        $parts = [];
        
        $join_column = $this->getJoinColumn();
        
        foreach ($clauses as $clause) {
            if ($clause instanceof MetadataWhereClause) {
                if (strtoupper($boolean) === 'OR' || count($clauses) === 1) {
                    $joined_alias = $qb->joinMetadataTable($qb->getTableAlias(), $join_column, null, 'inner', 'md');
                } else {
                    $joined_alias = $qb->joinMetadataTable($qb->getTableAlias(), $join_column, $clause->names);
                }
                
                $parts[] = $clause->prepare($qb, $joined_alias);
            }
        }
        
        return $qb->merge($parts, $boolean);
    }
    
    protected function buildPairedAnnotationClause(QueryBuilder $qb, $clauses, $boolean = 'AND') {
        $parts = [];
        
        $join_column = $this->getJoinColumn();
        
        foreach ($clauses as $clause) {
            if (strtoupper($boolean) === 'OR' || count($clauses) === 1) {
                $joined_alias = $qb->joinAnnotationTable($qb->getTableAlias(), $join_column, null, 'inner', AnnotationsTable::DEFAULT_JOIN_ALIAS);
            } else {
                $joined_alias = $qb->joinAnnotationTable($qb->getTableAlias(), $join_column, $clause->names);
            }
            
            $parts[] = $clause->prepare($qb, $joined_alias);
        }
        
        return $qb->merge($parts, $boolean);
    }
    
    protected function buildPairedRelationshipClause(QueryBuilder $qb, $clauses, $boolean = 'AND') {
        $parts = [];
        
        foreach ($clauses as $clause) {
            $parts[] = $clause->prepare($qb, $qb->getTableAlias());
        }
        
        return $qb->merge($parts, $boolean);
    }
    
    protected function getJoinColumn() {
        if (!empty($this->options->inverse_relationship)) {
            return 'guid_two';
        }
        
        return 'guid_one';
    }
}