<?php
/**
 * Piwik - free/libre analytics platform
 *
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 *
 */
namespace Piwik\Db\Adapter\Pdo;

use Exception;
use PDO;
use PDOException;
use Piwik\Config;
use Piwik\Db\AdapterInterface;
use Piwik\Piwik;
use Zend_Db_Adapter_Pdo_Pgsql;

/**
 */
class Pgsql extends Zend_Db_Adapter_Pdo_Pgsql implements AdapterInterface
{
    /**
     * Reset the configuration variables in this adapter.
     */
    public function resetConfig()
    {
        $this->_config = array();
    }

    /**
     * Return default port.
     *
     * @return int
     */
    public static function getDefaultPort()
    {
        return 5432;
    }

    /**
     * Check PostgreSQL version
     *
     * @throws Exception
     */
    public function checkServerVersion()
    {
        $databaseVersion = $this->getServerVersion();
        $requiredVersion = Config::getInstance()->General['minimum_pgsql_version'];

        if (version_compare($databaseVersion, $requiredVersion) === -1) {
            throw new Exception(Piwik::translate('General_ExceptionDatabaseVersion', array('PostgreSQL', $databaseVersion, $requiredVersion)));
        }
    }

    /**
     * Check client version compatibility against database server
     */
    public function checkClientVersion()
    {
    }

    /**
     * Returns true if this adapter's required extensions are enabled
     *
     * @return bool
     */
    public static function isEnabled()
    {
        $extensions = @get_loaded_extensions();
        return in_array('PDO', $extensions) && in_array('pdo_pgsql', $extensions);
    }

    /**
     * Returns true if this adapter supports blobs as fields
     *
     * @return bool
     */
    public function hasBlobDataType()
    {
        // large objects must be loaded from a file using a non-SQL API
        // and then referenced by the object ID (oid);
        // the alternative, bytea fields, incur a space and time
        // penalty for encoding/decoding
        return false;
    }

    /**
     * Returns true if this adapter supports bulk loading
     *
     * @return bool
     */
    public function hasBulkLoader()
    {
        /**
         * COPY ?
         *
         * @link http://www.postgresql.org/docs/current/interactive/sql-copy.html
         */
        return false;
    }

    /**
     * Test error number
     *
     * @param Exception $e
     * @param string $errno
     * @return bool
     */
    public function isErrNo($e, $errno)
    {
        // map MySQL driver-specific error codes to PostgreSQL SQLSTATE
        $map = array(
            // MySQL: Unknown database '%s'
            // PostgreSQL: database "%s" does not exist
            '1049' => '08006',

            // MySQL: Table '%s' already exists
            // PostgreSQL: relation "%s" already exists
            '1050' => '42P07',

            // MySQL: Unknown column '%s' in '%s'
            // PostgreSQL: column "%s" does not exist
            '1054' => '42703',

            // MySQL: Duplicate column name '%s'
            // PostgreSQL: column "%s" of relation "%s" already exists
            '1060' => '42701',

            // MySQL: Duplicate key name '%s'
            // PostgreSQL: relation "%s" already exists
            '1061' => '42P07',

            // MySQL: Duplicate entry '%s' for key '%s'
            // PostgreSQL: duplicate key violates unique constraint
            '1062' => '23505',

            // MySQL: Can't DROP '%s'; check that column/key exists
            // PostgreSQL: index "%s" does not exist
            '1091' => '42704',

            // MySQL: Table '%s.%s' doesn't exist
            // PostgreSQL: relation "%s" does not exist
            '1146' => '42P01',
        );

        if (preg_match('/([0-9]{2}[0-9P][0-9]{2})/', $e->getMessage(), $match)) {
            return $match[1] == $map[$errno];
        }

        return false;
    }

    /**
     * Is the connection character set equal to utf8?
     *
     * @return bool
     */
    public function isConnectionUTF8()
    {
        $charset = $this->fetchOne('SHOW client_encoding');
        return strtolower($charset) === 'utf8';
    }

    /**
     * Retrieve client version in PHP style
     *
     * @return string
     */
    public function getClientVersion()
    {
        $this->_connect();
        try {
            $version = $this->_connection->getAttribute(PDO::ATTR_CLIENT_VERSION);
            $matches = null;
            if (preg_match('/((?:[0-9]{1,2}\.){1,3}[0-9]{1,2})/', $version, $matches)) {
                return $matches[1];
            }
        } catch (PDOException $e) {
            // In case of the driver doesn't support getting attributes
        }
        return null;
    }
}
