<?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\DBAL\Schema;

use Doctrine\DBAL\Platforms\AbstractPlatform;

/**

 * The abstract asset allows to reset the name of all assets without publishing this to the public userland.

 *

 * This encapsulation hack is necessary to keep a consistent state of the database schema. Say we have a list of tables

 * array($tableName => Table($tableName)); if you want to rename the table, you have to make sure

 *

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

 * @link    www.doctrine-project.org

 * @since   2.0

 * @version $Revision$

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

 */

abstract class AbstractAsset

{

    /**

     * @var string

     */

    protected $_name;

    protected $_quoted = false;

    /**

     * Set name of this asset

     *

     * @param string $name

     */

    protected function _setName($name)

    {

        if ($this->isQuoted($name)) {

            $this->_quoted = true;

            $name = $this->trimQuotes($name);

        }

        $this->_name = $name;

    }

    /**

     * Check if this identifier is quoted.

     *

     * @param  string $identifier

     * @return bool

     */

    protected function isQuoted($identifier)

    {

        return (isset($identifier[0]) && ($identifier[0] == '`' || $identifier[0] == '"'));

    }

    /**

     * Trim quotes from the identifier.

     * 

     * @param  string $identifier

     * @return string

     */

    protected function trimQuotes($identifier)

    {

        return trim($identifier, '`"');

    }

    /**

     * Return name of this schema asset.

     * 

     * @return string

     */

    public function getName()

    {

        return $this->_name;

    }

    /**

     * Get the quoted representation of this asset but only if it was defined with one. Otherwise

     * return the plain unquoted value as inserted.

     *

     * @param AbstractPlatform $platform

     * @return string

     */

    public function getQuotedName(AbstractPlatform $platform)

    {

        return ($this->_quoted) ? $platform->quoteIdentifier($this->_name) : $this->_name;

    }

    /**

     * Generate an identifier from a list of column names obeying a certain string length.

     *

     * This is especially important for Oracle, since it does not allow identifiers larger than 30 chars,

     * however building idents automatically for foreign keys, composite keys or such can easily create

     * very long names.

     *

     * @param  array $columnNames

     * @param  string $prefix

     * @param  int $maxSize

     * @return string

     */

    protected function _generateIdentifierName($columnNames, $prefix='', $maxSize=30)

    {

        /*$columnCount = count($columnNames);

        $postfixLen = strlen($postfix);

        $parts = array_map(function($columnName) use($columnCount, $postfixLen, $maxSize) {

            return substr($columnName, -floor(($maxSize-$postfixLen)/$columnCount - 1));

        }, $columnNames);

        $parts[] = $postfix;

        $identifier = trim(implode("_", $parts), '_');

        // using implicit schema support of DB2 and Postgres there might be dots in the auto-generated

        // identifier names which can easily be replaced by underscores.

        $identifier = str_replace(".", "_", $identifier);

        if (is_numeric(substr($identifier, 0, 1))) {

            $identifier = "i" . substr($identifier, 0, strlen($identifier)-1);

        }

        return $identifier;*/

        $hash = implode("", array_map(function($column) {

            return dechex(crc32($column));

        }, $columnNames));

        return substr(strtoupper($prefix . "_" . $hash), 0, $maxSize);

    }

}