<?php

/** 

 * Expression class specialized for a property access.

 * 

 * PHP version 5.3

 * 

 * @category  ODataProducer

 * @package   ODataProducer_UriProcessor_QueryProcessor_ExpressionParser_Expressions

 * @author    Anu T Chandy <odataphpproducer_alias@microsoft.com>

 * @copyright 2011 Microsoft Corp. (http://www.microsoft.com)

 * @license   New BSD license, (http://www.opensource.org/licenses/bsd-license.php)

 * @version   SVN: 1.0

 * @link      http://odataphpproducer.codeplex.com

 * 

 */

namespace ODataProducer\UriProcessor\QueryProcessor\ExpressionParser\Expressions;

use ODataProducer\UriProcessor\QueryProcessor\FunctionDescription\FunctionDescription;

use ODataProducer\UriProcessor\QueryProcessor\ExpressionParser\Expressions\LogicalExpression;

use ODataProducer\UriProcessor\QueryProcessor\ExpressionParser\Expressions\AbstractExpression;

use ODataProducer\Providers\Metadata\ResourceTypeKind;

use ODataProducer\Providers\Metadata\ResourceProperty;

use ODataProducer\Providers\Metadata\Type\Navigation;

use ODataProducer\Providers\Metadata\Type\Boolean;

/**

 * Expression class for property access.

 *

 * @category  ODataProducer

 * @package   ODataProducer_UriProcessor_QueryProcessor_ExpressionParser_Expressions

 * @author    Anu T Chandy <odataphpproducer_alias@microsoft.com>

 * @copyright 2011 Microsoft Corp. (http://www.microsoft.com)

 * @license   New BSD license, (http://www.opensource.org/licenses/bsd-license.php)

 * @version   Release: 1.0

 * @link      http://odataphpproducer.codeplex.com

 */

class PropertyAccessExpression extends AbstractExpression

{

    /**

     * @var PropertyAccessExpression

     */

    protected $parent;



    /**

     * @var PropertyAccessExpression

     */

    protected $child;



    /**

     * Resource property instance describes the property represented by

     * this expression

     * 

     * @var ResourceProperty

     */

    protected $resourceProperty;



    /**

     * Creates new instance of PropertyAccessExpression

     * 

     * @param PropertyAccessExpression $parent           The parent expression

     * @param ResourceProperty         $resourceProperty The ResourceProperty 

     */

    public function __construct($parent, $resourceProperty)

    {

        $this->parent = $parent;

        $this->child = null;

        $this->nodeType = ExpressionType::PROPERTYACCESS;

        $this->resourceProperty = $resourceProperty;

        //If the property is primitive type, then _type will be primitve types 

        //implementing IType

        if ($resourceProperty->getResourceType()->getResourceTypeKind() == ResourceTypeKind::PRIMITIVE) {

            $this->type = $resourceProperty->getResourceType()->getInstanceType();

        } else { 

            //This is a navigation i.e. Complex, ResourceReference or Collection

            $this->type = new Navigation($resourceProperty->getResourceType());

        }



        if (!is_null($parent)) {

            $parent->setChild($this);

        }

    }



    /**

     * To set the child if any

     * 

     * @param PropertyAccessExpression $child The child expression

     * 

     * @return void

     */

    public function setChild($child)

    {

        $this->child = $child;

    }



    /**

     * To get the parent. If this property is property of entity 

     * then return null, If this property is property of complex type 

     * then return PropertyAccessExpression for the parent complex type

     * 

     * @return PropertyAccessExpression

     */

    public function getParent()

    {

        return $this->parent;

    }



    /**

     * To get the child. Returns null if no child property

     * 

     * @return PropertyAccessExpression

     */

    public function getChild()

    {

        return $this->child;

    }

    

    /**

     * Get the resource type of the property hold by this expression

     * 

     * @return ResourceType

     */

    public function getResourceType()

    {

        return $this->resourceProperty->getResourceType();

    }



    /**

     * Get the ResourceProperty describing the property hold by this expression

     * 

     * @return ResourceProperty

     */

    public function getResourceProperty()

    {

        return $this->resourceProperty;

    }



    /**

     * Gets collection of navigation (resource set reference or resource set) 

     * properties used in this property access. 

     * 

     * @return array()/array(ResourceProperty) Returns empty array if no 

     *                                         navigation property is used else

     *                                         array of ResourceProperty.

     */

    public function getNavigationPropertiesInThePath()

    {

        $basePropertyExpression = $this;

        while (($basePropertyExpression != null) 

            && ($basePropertyExpression->parent != null)

        ) {

            $basePropertyExpression = $basePropertyExpression->parent;

        }



        $navigationPropertiesInThePath = array();

        while ($basePropertyExpression) {

            $resourceTypeKind 

                = $basePropertyExpression->getResourceType()->getResourceTypeKind();

            if ($resourceTypeKind == ResourceTypeKind::ENTITY) {

                $navigationPropertiesInThePath[] 

                    = $basePropertyExpression->resourceProperty;

            } else {

                break;

            }



            $basePropertyExpression = $basePropertyExpression->child;

        }



        return $navigationPropertiesInThePath;

    }



    /**

     * Function to create a nullable expression subtree for checking the

     * nullablilty of parent (and current poperty optionally) properties

     * 

     * @param boolean $includeMe Boolean flag indicating whether to include null

     *                           check for this property along with parents

     * 

     * @return AbstractExpression Instance of UnaryExpression, LogicalExpression

     *                            or Null

     * 

     */

    public function createNullableExpressionTree($includeMe)

    {

        $basePropertyExpression = $this;

        while (($basePropertyExpression != null) 

            && ($basePropertyExpression->parent != null)

        ) {

            $basePropertyExpression = $basePropertyExpression->parent;

        }



        //This property is direct child of ResourceSet, no need to check

        //nullability for direct ResourceSet properties 

        // ($c->CustomerID, $c->Order, $c->Address) unless $includeMe is true

        if ($basePropertyExpression == $this) {

            if ($includeMe) {

                return new UnaryExpression(

                    new FunctionCallExpression(

                        FunctionDescription::isNullCheckFunction(

                            $basePropertyExpression->getType()

                        ), 

                        array($basePropertyExpression)

                    ), 

                    ExpressionType::NOT_LOGICAL, 

                    new Boolean()

                );

            }

            

            return null;

        }



        //This property is a property of a complex type or resource reference

        //$c->Order->OrderID, $c->Address->LineNumber, 

        // $c->complex1->complex2->primitveVar

        //($c->Order != null),($c->Address != null),   

        // (($c->complex1 != null) && ($c->complex1->complex2 != null))

        $expression = new UnaryExpression(

            new FunctionCallExpression(

                FunctionDescription::isNullCheckFunction(

                    $basePropertyExpression->getType()

                ), 

                array($basePropertyExpression)

            ), 

            ExpressionType::NOT_LOGICAL, 

            new Boolean()

        );

        while (($basePropertyExpression->getChild() != null) 

                && ($basePropertyExpression->getChild()->getChild() != null)) {

            $basePropertyExpression = $basePropertyExpression->getChild();

            $expression2 = new UnaryExpression(

                new FunctionCallExpression(

                    FunctionDescription::isNullCheckFunction(

                        $basePropertyExpression->getType()

                    ), 

                    array($basePropertyExpression)

                ), 

                ExpressionType::NOT_LOGICAL,

                new Boolean()

            );

            $expression = new LogicalExpression(

                $expression, $expression2, 

                ExpressionType::AND_LOGICAL

            );

        }



        if ($includeMe) {

            $basePropertyExpression = $basePropertyExpression->getChild();

            $expression2 = new UnaryExpression(

                new FunctionCallExpression(

                    FunctionDescription::isNullCheckFunction(

                        $basePropertyExpression->getType()

                    ), 

                    array($basePropertyExpression)

                ), 

                ExpressionType::NOT_LOGICAL, 

                new Boolean()

            );

            $expression = new LogicalExpression(

                $expression, $expression2, 

                ExpressionType::AND_LOGICAL

            );

        }



        return $expression;

    }

    

    /**

     * (non-PHPdoc)

     * 

     * @see library/ODataProducer/QueryProcessor/Expressions/ODataProducer\QueryProcessor\Expressions.AbstractExpression::free()

     * 

     * @return void

     */

    public function free()

    {

        if (!is_null($this->parent)) {

            $this->parent->free();

            unset($this->parent);

        }

        

        if (!is_null($this->child)) {

            $this->child->free();

            unset($this->child);

        }

    }

}

?>