<?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\Driver\OCI8;

use \PDO;

/**

 * The OCI8 implementation of the Statement interface.

 *

 * @since 2.0

 * @author Roman Borschel <roman@code-factory.org>

 */

class OCI8Statement implements \Doctrine\DBAL\Driver\Statement

{

    /** Statement handle. */

    private $_sth;

    private $_executeMode;

    private static $_PARAM = ':param';

    private static $fetchStyleMap = array(

        PDO::FETCH_BOTH => OCI_BOTH,

        PDO::FETCH_ASSOC => OCI_ASSOC,

        PDO::FETCH_NUM => OCI_NUM

    );

    private $_paramMap = array();

    /**

     * Creates a new OCI8Statement that uses the given connection handle and SQL statement.

     *

     * @param resource $dbh The connection handle.

     * @param string $statement The SQL statement.

     */

    public function __construct($dbh, $statement, $executeMode)

    {

        list($statement, $paramMap) = self::convertPositionalToNamedPlaceholders($statement);

        $this->_sth = oci_parse($dbh, $statement);

        $this->_paramMap = $paramMap;

        $this->_executeMode = $executeMode;

    }

    /**

     * Convert positional (?) into named placeholders (:param<num>)

     *

     * Oracle does not support positional parameters, hence this method converts all

     * positional parameters into artificially named parameters. Note that this conversion

     * is not perfect. All question marks (?) in the original statement are treated as

     * placeholders and converted to a named parameter.

     *

     * The algorithm uses a state machine with two possible states: InLiteral and NotInLiteral.

     * Question marks inside literal strings are therefore handled correctly by this method.

     * This comes at a cost, the whole sql statement has to be looped over.

     *

     * @todo extract into utility class in Doctrine\DBAL\Util namespace

     * @todo review and test for lost spaces. we experienced missing spaces with oci8 in some sql statements.

     * @param string $statement The SQL statement to convert.

     * @return string

     */

    static public function convertPositionalToNamedPlaceholders($statement)

    {   

        $count = 1;

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

        $stmtLen = strlen($statement);

        $paramMap = array();

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

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

                // real positional parameter detected

                $paramMap[$count] = ":param$count";

                $len = strlen($paramMap[$count]);

                $statement = substr_replace($statement, ":param$count", $i, 1);

                $i += $len-1; // jump ahead

                $stmtLen = strlen($statement); // adjust statement length

                ++$count;

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

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

            }

        }

        return array($statement, $paramMap);

    }

    /**

     * {@inheritdoc}

     */

    public function bindValue($param, $value, $type = null)

    {

        return $this->bindParam($param, $value, $type);

    }

    /**

     * {@inheritdoc}

     */

    public function bindParam($column, &$variable, $type = null)

    {

        $column = isset($this->_paramMap[$column]) ? $this->_paramMap[$column] : $column;

        return oci_bind_by_name($this->_sth, $column, $variable);

    }

    /**

     * Closes the cursor, enabling the statement to be executed again.

     *

     * @return boolean              Returns TRUE on success or FALSE on failure.

     */

    public function closeCursor()

    {

        return oci_free_statement($this->_sth);

    }

    /** 

     * {@inheritdoc}

     */

    public function columnCount()

    {

        return oci_num_fields($this->_sth);

    }

    /**

     * {@inheritdoc}

     */

    public function errorCode()

    {

        $error = oci_error($this->_sth);

        if ($error !== false) {

            $error = $error['code'];

        }

        return $error;

    }

    /**

     * {@inheritdoc}

     */

    public function errorInfo()

    {

        return oci_error($this->_sth);

    }

    /**

     * {@inheritdoc}

     */

    public function execute($params = null)

    {

        if ($params) {

            $hasZeroIndex = isset($params[0]);

            foreach ($params as $key => $val) {

                if ($hasZeroIndex && is_numeric($key)) {

                    $this->bindValue($key + 1, $val);

                } else {

                    $this->bindValue($key, $val);

                }

            }

        }

        $ret = @oci_execute($this->_sth, $this->_executeMode);

        if ( ! $ret) {

            throw OCI8Exception::fromErrorInfo($this->errorInfo());

        }

        return $ret;

    }

    /**

     * {@inheritdoc}

     */

    public function fetch($fetchStyle = PDO::FETCH_BOTH)

    {

        if ( ! isset(self::$fetchStyleMap[$fetchStyle])) {

            throw new \InvalidArgumentException("Invalid fetch style: " . $fetchStyle);

        }

        return oci_fetch_array($this->_sth, self::$fetchStyleMap[$fetchStyle] | OCI_RETURN_NULLS | OCI_RETURN_LOBS);

    }

    /**

     * {@inheritdoc}

     */

    public function fetchAll($fetchStyle = PDO::FETCH_BOTH)

    {

        if ( ! isset(self::$fetchStyleMap[$fetchStyle])) {

            throw new \InvalidArgumentException("Invalid fetch style: " . $fetchStyle);

        }

        $result = array();

        oci_fetch_all($this->_sth, $result, 0, -1,

            self::$fetchStyleMap[$fetchStyle] | OCI_RETURN_NULLS | OCI_FETCHSTATEMENT_BY_ROW | OCI_RETURN_LOBS);

        return $result;

    }

    /**

     * {@inheritdoc}

     */

    public function fetchColumn($columnIndex = 0)

    {

        $row = oci_fetch_array($this->_sth, OCI_NUM | OCI_RETURN_NULLS | OCI_RETURN_LOBS);

        return $row[$columnIndex];

    }

    /**

     * {@inheritdoc}

     */

    public function rowCount()

    {

        return oci_num_rows($this->_sth);

    }    

}