<?php

/*

 *  $Id$

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * This software consists of voluntary contributions made by many individuals

 * and is licensed under the LGPL. For more information, see

 * <http://www.doctrine-project.org>.

 */

namespace Doctrine\ORM\Query\Exec;

use Doctrine\DBAL\Connection,

    Doctrine\ORM\Query\AST;

/**

 * Executes the SQL statements for bulk DQL DELETE statements on classes in

 * Class Table Inheritance (JOINED).

 *

 * @author      Roman Borschel <roman@code-factory.org>

 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL

 * @link        http://www.doctrine-project.org

 * @since       2.0

 * @version     $Revision$

 */

class MultiTableDeleteExecutor extends AbstractSqlExecutor

{

    private $_createTempTableSql;

    private $_dropTempTableSql;

    private $_insertSql;

    /**

     * Initializes a new <tt>MultiTableDeleteExecutor</tt>.

     *

     * @param Node $AST The root AST node of the DQL query.

     * @param SqlWalker $sqlWalker The walker used for SQL generation from the AST.

     * @internal Any SQL construction and preparation takes place in the constructor for

     *           best performance. With a query cache the executor will be cached.

     */

    public function __construct(AST\Node $AST, $sqlWalker)

    {

        $em = $sqlWalker->getEntityManager();

        $conn = $em->getConnection();

        $platform = $conn->getDatabasePlatform();

        $primaryClass = $em->getClassMetadata($AST->deleteClause->abstractSchemaName);

        $primaryDqlAlias = $AST->deleteClause->aliasIdentificationVariable;

        $rootClass = $em->getClassMetadata($primaryClass->rootEntityName);

        $tempTable = $platform->getTemporaryTableName($rootClass->getTemporaryIdTableName());

        $idColumnNames = $rootClass->getIdentifierColumnNames();

        $idColumnList = implode(', ', $idColumnNames);

        // 1. Create an INSERT INTO temptable ... SELECT identifiers WHERE $AST->getWhereClause()

        $sqlWalker->setSQLTableAlias($primaryClass->table['name'], 't0', $primaryDqlAlias);

        $this->_insertSql = 'INSERT INTO ' . $tempTable . ' (' . $idColumnList . ')'

                . ' SELECT t0.' . implode(', t0.', $idColumnNames);

        $rangeDecl = new AST\RangeVariableDeclaration($primaryClass->name, $primaryDqlAlias);

        $fromClause = new AST\FromClause(array(new AST\IdentificationVariableDeclaration($rangeDecl, null, array())));

        $this->_insertSql .= $sqlWalker->walkFromClause($fromClause);

        // Append WHERE clause, if there is one.

        if ($AST->whereClause) {

            $this->_insertSql .= $sqlWalker->walkWhereClause($AST->whereClause);

        }

        // 2. Create ID subselect statement used in DELETE ... WHERE ... IN (subselect)

        $idSubselect = 'SELECT ' . $idColumnList . ' FROM ' . $tempTable;

        // 3. Create and store DELETE statements

        $classNames = array_merge($primaryClass->parentClasses, array($primaryClass->name), $primaryClass->subClasses);

        foreach (array_reverse($classNames) as $className) {

            $tableName = $em->getClassMetadata($className)->getQuotedTableName($platform);

            $this->_sqlStatements[] = 'DELETE FROM ' . $tableName

                    . ' WHERE (' . $idColumnList . ') IN (' . $idSubselect . ')';

        }

        // 4. Store DDL for temporary identifier table.

        $columnDefinitions = array();

        foreach ($idColumnNames as $idColumnName) {

            $columnDefinitions[$idColumnName] = array(

                'notnull' => true,

                'type' => \Doctrine\DBAL\Types\Type::getType($rootClass->getTypeOfColumn($idColumnName))

            );

        }

        $this->_createTempTableSql = $platform->getCreateTemporaryTableSnippetSQL() . ' ' . $tempTable . ' ('

                . $platform->getColumnDeclarationListSQL($columnDefinitions) . ')';

        $this->_dropTempTableSql = 'DROP TABLE ' . $tempTable;

    }

    /**

     * Executes all SQL statements.

     *

     * @param Doctrine\DBAL\Connection $conn The database connection that is used to execute the queries.

     * @param array $params The parameters.

     * @override

     */

    public function execute(Connection $conn, array $params, array $types)

    {

        $numDeleted = 0;

        // Create temporary id table

        $conn->executeUpdate($this->_createTempTableSql);

        // Insert identifiers

        $numDeleted = $conn->executeUpdate($this->_insertSql, $params, $types);

        // Execute DELETE statements

        foreach ($this->_sqlStatements as $sql) {

            $conn->executeUpdate($sql);

        }

        // Drop temporary table

        $conn->executeUpdate($this->_dropTempTableSql);

        return $numDeleted;

    }

}