<?php
/**
 * DropBuilder.php
 *
 * Builds the CREATE statement
 *
 * PHP version 5
 *
 * LICENSE:
 * Copyright (c) 2010-2014 Justin Swanhart and André Rothe
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 * @author    André Rothe <andre.rothe@phosco.info>
 * @copyright 2010-2014 Justin Swanhart and André Rothe
 * @license   http://www.debian.org/misc/bsd.license  BSD License (3 Clause)
 * @version   SVN: $Id$
 *
 */

namespace PHPSQLParser\builders;
use PHPSQLParser\exceptions\UnableToCreateSQLException;
use PHPSQLParser\utils\ExpressionType;

/**
 * This class implements the builder for the [DROP] part. You can overwrite
 * all functions to achieve another handling.
 */
class DropBuilder implements Builder {

	protected function buildDropIndex( $parsed ) {
		$builder = new DropIndexBuilder();

		return $builder->build( $parsed );
	}

	protected function buildReserved( $parsed ) {
		$builder = new ReservedBuilder();

		return $builder->build( $parsed );
	}

	protected function buildExpression( $parsed ) {
		$builder = new DropExpressionBuilder();

		return $builder->build( $parsed );
	}

	protected function buildSubTree( $parsed ) {
		$sql = '';
		foreach ( $parsed['sub_tree'] as $k => $v ) {
			$len = strlen( $sql );
			$sql .= $this->buildReserved( $v );
			$sql .= $this->buildExpression( $v );

			if ( $len == strlen( $sql ) ) {
				throw new UnableToCreateSQLException( 'DROP subtree', $k, $v, 'expr_type' );
			}

			$sql .= ' ';
		}

		return $sql;
	}

	public function build( array $parsed ) {
		$drop = $parsed['DROP'];
		$sql  = $this->buildSubTree( $drop );

		if ( $drop['expr_type'] === ExpressionType::INDEX ) {
			$sql .= '' . $this->buildDropIndex( $parsed['INDEX'] ) . ' ';
		}

		return 'DROP ' . substr( $sql, 0, -1 );
	}

}

?>