<?php

/*

 * 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\DBAL\Query\Expression;

/**

 * Composite expression is responsible to build a group of similar expression.

 *

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

 * @link        www.doctrine-project.org

 * @since       2.1

 * @author      Guilherme Blanco <guilhermeblanco@hotmail.com>

 * @author      Benjamin Eberlei <kontakt@beberlei.de>

 */

class CompositeExpression implements \Countable

{

    /**

     * Constant that represents an AND composite expression

     */

    const TYPE_AND = 'AND';

    /**

     * Constant that represents an OR composite expression

     */

    const TYPE_OR  = 'OR';

    /**

     * @var string Holds the instance type of composite expression

     */

    private $type;

    /**

     * @var array Each expression part of the composite expression

     */

    private $parts = array();

    /**

     * Constructor.

     * 

     * @param string $type Instance type of composite expression

     * @param array $parts Composition of expressions to be joined on composite expression

     */

    public function __construct($type, array $parts = array())

    {

        $this->type = $type;

        $this->addMultiple($parts);

    }

    /**

     * Adds multiple parts to composite expression.

     * 

     * @param array $args

     * 

     * @return CompositeExpression

     */

    public function addMultiple(array $parts = array())

    {

        foreach ((array) $parts as $part) {

            $this->add($part);

        }

        return $this;

    }

    /**

     * Adds an expression to composite expression.

     * 

     * @param mixed $part

     * @return CompositeExpression 

     */

    public function add($part)

    {

        if ( ! empty($part) || ($part instanceof self && $part->count() > 0)) {

            $this->parts[] = $part;

        }

        return $this;

    }

    /**

     * Retrieves the amount of expressions on composite expression.

     * 

     * @return integer 

     */

    public function count()

    {

        return count($this->parts);

    }

    /**

     * Retrieve the string representation of this composite expression.

     * 

     * @return string

     */

    public function __toString()

    {

        if (count($this->parts) === 1) {

            return (string) $this->parts[0];

        }

        return '(' . implode(') ' . $this->type . ' (', $this->parts) . ')';

    }

    /**

     * Return type of this composite expression (AND/OR)

     * 

     * @return string

     */

    public function getType()

    {

        return $this->type;

    }

}