<?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;

use Doctrine\DBAL\Connection;

/**

 * Utility class that parses sql statements with regard to types and parameters.

 *

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

 * @link        www.doctrine-project.com

 * @since       2.0

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

 */

class SQLParserUtils

{

    /**

     * Get an array of the placeholders in an sql statements as keys and their positions in the query string.

     * 

     * Returns an integer => integer pair (indexed from zero) for a positional statement

     * and a string => int[] pair for a named statement.

     * 

     * @param string $statement

     * @param bool $isPositional

     * @return array

     */

    static public function getPlaceholderPositions($statement, $isPositional = true)

    {   

        $match = ($isPositional) ? '?' : ':';

        if (strpos($statement, $match) === false) {

            return array();

        }

        $count = 0;

        $inLiteral = false; // a valid query never starts with quotes

        $stmtLen = strlen($statement);

        $paramMap = array();

        for ($i = 0; $i < $stmtLen; $i++) {

            if ($statement[$i] == $match && !$inLiteral) {

                // real positional parameter detected

                if ($isPositional) {

                    $paramMap[$count] = $i;

                } else {

                    $name = "";

                    // TODO: Something faster/better to match this than regex?

                    for ($j = $i; ($j < $stmtLen && preg_match('(([:a-zA-Z0-9]{1}))', $statement[$j])); $j++) {

                        $name .= $statement[$j];

                    }

                    $paramMap[$name][] = $i; // named parameters can be duplicated!

                    $i = $j;

                }

                ++$count;

            } else if ($statement[$i] == "'" || $statement[$i] == '"') {

                $inLiteral = ! $inLiteral; // switch state!

            }

        }

        return $paramMap;

    }

    /**

     * For a positional query this method can rewrite the sql statement with regard to array parameters.

     * 

     * @param string $query

     * @param array $params

     * @param array $types 

     */

    static public function expandListParameters($query, $params, $types)

    {        

        $isPositional = is_int(key($params));

        $arrayPositions = array();

        $bindIndex = -1;

        foreach ($types AS $name => $type) {

            ++$bindIndex;

            if ($type === Connection::PARAM_INT_ARRAY || $type == Connection::PARAM_STR_ARRAY) {

                if ($isPositional) {

                    $name = $bindIndex;

                }

                $arrayPositions[$name] = false;

            }

        }

        if (!$arrayPositions || count($params) != count($types)) {

            return array($query, $params, $types);

        }

        $paramPos = self::getPlaceholderPositions($query, $isPositional);

        if ($isPositional) {

            $paramOffset = 0;

            $queryOffset = 0;

            foreach ($paramPos AS $needle => $needlePos) {

                if (!isset($arrayPositions[$needle])) {

                    continue;

                }

                $needle += $paramOffset;

                $needlePos += $queryOffset;

                $len = count($params[$needle]);

                $params = array_merge(

                    array_slice($params, 0, $needle),

                    $params[$needle],

                    array_slice($params, $needle + 1)

                );

                $types = array_merge(

                    array_slice($types, 0, $needle),

                    array_fill(0, $len, $types[$needle] - Connection::ARRAY_PARAM_OFFSET), // array needles are at PDO::PARAM_* + 100

                    array_slice($types, $needle + 1)

                );

                $expandStr = implode(", ", array_fill(0, $len, "?"));

                $query = substr($query, 0, $needlePos) . $expandStr . substr($query, $needlePos + 1);

                $paramOffset += ($len - 1); // Grows larger by number of parameters minus the replaced needle.

                $queryOffset += (strlen($expandStr) - 1);

            }

        } else {

            throw new DBALException("Array parameters are not supported for named placeholders.");

        }

        return array($query, $params, $types);

    }

}