<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2013 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */

namespace Zend\Db\TableGateway\Feature;

use Zend\Db\Sql\Insert;
use Zend\Db\Adapter\Driver\StatementInterface;
use Zend\Db\Adapter\Driver\ResultInterface;

class SequenceFeature extends AbstractFeature
{
    /**
     * @var string
     */
    protected $primaryKeyField;

    /**
     * @var string
     */
    protected $sequenceName;

    /**
     * @var int
     */
    protected $sequenceValue;


    /**
     * @param string $primaryKeyField
     * @param string $sequenceName
     */
    public function __construct($primaryKeyField, $sequenceName)
    {
        $this->primaryKeyField = $primaryKeyField;
        $this->sequenceName    = $sequenceName;
    }


    public function preInsert(Insert $insert)
    {
        $columns = $insert->getRawState('columns');
        $values = $insert->getRawState('values');
        $key = array_search($this->primaryKeyField, $columns);
        if ($key !== false) {
            $this->sequenceValue = $values[$key];
            return $insert;
        }

        $this->sequenceValue = $this->nextSequenceId();
        if ($this->sequenceValue === null)
            return $insert;

        array_push($columns, $this->primaryKeyField);
        array_push($values, $this->sequenceValue);
        $insert->columns($columns);
        $insert->values($values);
        return $insert;
    }

    public function postInsert(StatementInterface $statement, ResultInterface $result)
    {
        if ($this->sequenceValue !== null)
            $this->tableGateway->lastInsertValue = $this->sequenceValue;
    }

    /**
     * Generate a new value from the specified sequence in the database, and return it.
     * @return int
     */
    public function nextSequenceId()
    {
        $platform = $this->tableGateway->adapter->getPlatform();
        $platformName = $platform->getName();

        $sql = '';
        switch ($platformName) {
            case 'Oracle':
                $sql = 'SELECT ' . $platform->quoteIdentifier($this->sequenceName) . '.NEXTVAL FROM dual';
                break;
            case 'PostgreSQL':
                $sql = 'SELECT NEXTVAL(\'' . $this->sequenceName . '\')';
                break;
            default :
                return null;
        }

        $statement = $this->tableGateway->adapter->createStatement();
        $statement->prepare($sql);
        $result = $statement->execute();
        $sequence = $result->getResource()->fetch(\PDO::FETCH_ASSOC);
        unset($statement, $result);
        return $sequence['nextval'];
    }

    /**
     * Return the most recent value from the specified sequence in the database.
     * @return int
     */
    public function lastSequenceId()
    {
        $platform = $this->tableGateway->adapter->getPlatform();
        $platformName = $platform->getName();

        $sql = '';
        switch ($platformName) {
            case 'Oracle':
                $sql = 'SELECT ' . $platform->quoteIdentifier($this->sequenceName) . '.CURRVAL FROM dual';
                break;
            case 'PostgreSQL':
                $sql = 'SELECT CURRVAL(\'' . $this->sequenceName . '\')';
                break;
            default :
                return null;
        }

        $statement = $this->tableGateway->adapter->createStatement();
        $statement->prepare($sql);
        $result = $statement->execute();
        $sequence = $result->getResource()->fetch(\PDO::FETCH_ASSOC);
        unset($statement, $result);
        return $sequence['currval'];
    }
}
ace $result, ResultSetInterface $resultSet)
    {
        $this->event->setName(__FUNCTION__);
        $this->event->setParams(array(
            'statement' => $statement,
            'result' => $result,
            'result_set' => $resultSet
        ));
        $this->eventManager->trigger($this->event);
    }

    /**
     * Trigger the "preInsert" event
     *
     * Triggers the "preInsert" event mapping the following parameters:
     * - $insert as "insert"
     *
     * @param  Insert $insert
     * @return void
     */
    public function preInsert(Insert $insert)
    {
        $this->event->setName(__FUNCTION__);
        $this->event->setParams(array('insert' => $insert));
        $this->eventManager->trigger($this->event);
    }

    /**
     * Trigger the "postInsert" event
     *
     * Triggers the "postInsert" event mapping the following parameters:
     * - $statement as "statement"
     * - $result as "result"
     *
     * @param  StatementInterface $statement
     * @param  ResultInterface $result
     * @return void
     */
    public function postInsert(StatementInterface $statement, ResultInterface $result)
    {
        $this->event->setName(__FUNCTION__);
        $this->event->setParams(array(
            'statement' => $statement,
            'result' => $result,
        ));
        $this->eventManager->trigger($this->event);
    }

    /**
     * Trigger the "preUpdate" event
     *
     * Triggers the "preUpdate" event mapping the following parameters:
     * - $update as "update"
     *
     * @param  Update $update
     * @return void
     */
    public function preUpdate(Update $update)
    {
        $this->event->setName(__FUNCTION__);
        $this->event->setParams(array('update' => $update));
        $this->eventManager->trigger($this->event);
    }

    /**
     * Trigger the "postUpdate" event
     *
     * Triggers the "postUpdate" event mapping the following parameters:
     * - $statement as "statement"
     * - $result as "result"
     *
     * @param  StatementInterface $statement
     * @param  ResultInterface $result
     * @return void
     */
    public function postUpdate(StatementInterface $statement, ResultInterface $result)
    {
        $this->event->setName(__FUNCTION__);
        $this->event->setParams(array(
            'statement' => $statement,
            'result' => $result,
        ));
        $this->eventManager->trigger($this->event);
    }

    /**
     * Trigger the "preDelete" event
     *
     * Triggers the "preDelete" event mapping the following parameters:
     * - $delete as "delete"
     *
     * @param  Delete $delete
     * @return void
     */
    public function preDelete(Delete $delete)
    {
        $this->event->setName(__FUNCTION__);
        $this->event->setParams(array('delete' => $delete));
        $this->eventManager->trigger($this->event);
    }

    /**
     * Trigger the "postDelete" event
     *
     * Triggers the "postDelete" event mapping the following parameters:
     * - $statement as "statement"
     * - $result as "result"
     *
     * @param  StatementInterface $statement
     * @param  ResultInterface $result
     * @return void
     */
    public function postDelete(StatementInterface $statement, ResultInterface $result)
    {
        $this->event->setName(__FUNCTION__);
        $this->event->setParams(array(
            'statement' => $statement,
            'result' => $result,
        ));
        $this->eventManager->trigger($this->event);
    }
}