<?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 MIT license. 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
 *
 *
 * @link    www.doctrine-project.org
 * @since   2.0
 * @author  Benjamin Eberlei <kontakt@beberlei.de>
 */
abstract class AbstractAsset
{
    /**
     * @var string
     */
    protected $_name;

    /**
     * Namespace of the asset. If none isset the default namespace is assumed.
     *
     * @var string
     */
    protected $_namespace;

    /**
     * @var bool
     */
    protected $_quoted = false;

    /**
     * Set name of this asset
     *
     * @param string $name
     */
    protected function _setName($name)
    {
        if ($this->isIdentifierQuoted($name)) {
            $this->_quoted = true;
            $name = $this->trimQuotes($name);
        }
        if (strpos($name, ".") !== false) {
            $parts = explode(".", $name);
            $this->_namespace = $parts[0];
            $name = $parts[1];
        }
        $this->_name = $name;
    }

    /**
     * Is this asset in the default namespace?
     *
     * @param string $defaultNamespaceName
     * @return bool
     */
    public function isInDefaultNamespace($defaultNamespaceName)
    {
        return $this->_namespace == $defaultNamespaceName || $this->_namespace === null;
    }

    /**
     * Get namespace name of this asset.
     *
     * If NULL is returned this means the default namespace is used.
     *
     * @return string
     */
    public function getNamespaceName()
    {
        return $this->_namespace;
    }

    /**
     * The shortest name is stripped of the default namespace. All other
     * namespaced elements are returned as full-qualified names.
     *
     * @param string
     * @return string
     */
    public function getShortestName($defaultNamespaceName)
    {
        $shortestName = $this->getName();
        if ($this->_namespace == $defaultNamespaceName) {
            $shortestName = $this->_name;
        }
        return strtolower($shortestName);
    }

    /**
     * The normalized name is full-qualified and lowerspaced. Lowerspacing is
     * actually wrong, but we have to do it to keep our sanity. If you are
     * using database objects that only differentiate in the casing (FOO vs
     * Foo) then you will NOT be able to use Doctrine Schema abstraction.
     *
     * Every non-namespaced element is prefixed with the default namespace
     * name which is passed as argument to this method.
     *
     * @return string
     */
    public function getFullQualifiedName($defaultNamespaceName)
    {
        $name = $this->getName();
        if ( ! $this->_namespace) {
            $name = $defaultNamespaceName . "." . $name;
        }
        return strtolower($name);
    }

    /**
     * Check if this asset's name is quoted
     *
     * @return bool
     */
    public function isQuoted()
    {
        return $this->_quoted;
    }

    /**
     * Check if this identifier is quoted.
     *
     * @param  string $identifier
     * @return bool
     */
    protected function isIdentifierQuoted($identifier)
    {
        return (isset($identifier[0]) && ($identifier[0] == '`' || $identifier[0] == '"'));
    }

    /**
     * Trim quotes from the identifier.
     *
     * @param  string $identifier
     * @return string
     */
    protected function trimQuotes($identifier)
    {
        return str_replace(array('`', '"'), '', $identifier);
    }

    /**
     * Return name of this schema asset.
     *
     * @return string
     */
    public function getName()
    {
        if ($this->_namespace) {
            return $this->_namespace . "." . $this->_name;
        }
        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)
    {
        $keywords = $platform->getReservedKeywordsList();
        $parts = explode(".", $this->getName());
        foreach ($parts as $k => $v) {
            $parts[$k] = ($this->_quoted || $keywords->isKeyword($v)) ? $platform->quoteIdentifier($v) : $v;
        }

        return implode(".", $parts);
    }

    /**
     * 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)
    {
        $hash = implode("", array_map(function($column) {
            return dechex(crc32($column));
        }, $columnNames));
        return substr(strtoupper($prefix . "_" . $hash), 0, $maxSize);
    }
}
