Finesse/Wired

<?php

namespace Finesse\Wired\Relations;

use Finesse\Wired\Exceptions\IncorrectModelException;
use Finesse\Wired\Exceptions\NotModelException;
use Finesse\Wired\Helpers;
use Finesse\Wired\ModelInterface;

/**
 * Models relation: a parent model belongs to a child model, i.e. the child model has many parent models.
 *
 * @author Surgie
 */
class BelongsTo extends EqualFields implements AssociableRelationInterface
{
    /**
     * @param string $modelClass The child model class name
     * @param string $foreignField The name of the parent model field which contains an identifier of a child model
     * @param string|null $identifierField The name of the child model field which contains a value which the foreign
     *  key targets. Null means that the default child model identifier field should be used.
     * @throws NotModelException
     */
    public function __construct(string $modelClass, string $foreignField, string $identifierField = null)
    {
        parent::__construct($foreignField, $modelClass, $identifierField, false);
    }

    /**
     * {@inheritDoc}
     */
    public function associate(string $relationName, ModelInterface $parent, ModelInterface $child = null)
    {
        $parentModelField = $this->getParentModelField($parent);

        if ($child) {
            Helpers::checkModelObjectClass($child, $this->childModelClass);
            $childModelField = $this->getChildModelField();

            if ($child->$childModelField === null) {
                throw new IncorrectModelException(
                    "The associated model doesn't have a value in the identifier field `$childModelField`"
                        . "; perhaps it is not saved to the database"
                );
            }

            $parent->$parentModelField = $child->$childModelField;
        } else {
            $parent->$parentModelField = null;
        }

        $parent->setLoadedRelatives($relationName, $child);
    }

    /**
     * {@inheritDoc}
     */
    public function dissociate(string $relationName, ModelInterface $parent)
    {
        $this->associate($relationName, $parent, null);
    }
}