<?php
/* vim: set expandtab sw=4 ts=4 sts=4: */
/**
 * Functions for the replication GUI
 *
 * @package PhpMyAdmin
 */
namespace PhpMyAdmin;

use PhpMyAdmin\Core;
use PhpMyAdmin\Message;
use PhpMyAdmin\Replication;
use PhpMyAdmin\Response;
use PhpMyAdmin\Url;
use PhpMyAdmin\Util;

/**
 * PhpMyAdmin\ReplicationGui class
 *
 * @package PhpMyAdmin
 */
class ReplicationGui
{
    /**
     * returns HTML for error message
     *
     * @return String HTML code
     */
    public static function getHtmlForErrorMessage()
    {
        $html = '';
        if (isset($_SESSION['replication']['sr_action_status'])
            && isset($_SESSION['replication']['sr_action_info'])
        ) {
            if ($_SESSION['replication']['sr_action_status'] == 'error') {
                $error_message = $_SESSION['replication']['sr_action_info'];
                $html .= Message::error($error_message)->getDisplay();
                $_SESSION['replication']['sr_action_status'] = 'unknown';
            } elseif ($_SESSION['replication']['sr_action_status'] == 'success') {
                $success_message = $_SESSION['replication']['sr_action_info'];
                $html .= Message::success($success_message)->getDisplay();
                $_SESSION['replication']['sr_action_status'] = 'unknown';
            }
        }
        return $html;
    }

    /**
     * returns HTML for master replication
     *
     * @return String HTML code
     */
    public static function getHtmlForMasterReplication()
    {
        $html = '';
        if (! isset($_REQUEST['repl_clear_scr'])) {
            $html .= '<fieldset>';
            $html .= '<legend>' . __('Master replication') . '</legend>';
            $html .= __('This server is configured as master in a replication process.');
            $html .= '<ul>';
            $html .= '  <li><a href="#master_status_href" id="master_status_href">';
            $html .= __('Show master status') . '</a>';
            $html .= self::getHtmlForReplicationStatusTable('master', true, false);
            $html .= '  </li>';

            $html .= '  <li><a href="#master_slaves_href" id="master_slaves_href">';
            $html .= __('Show connected slaves') . '</a>';
            $html .= self::getHtmlForReplicationSlavesTable(true);
            $html .= '  </li>';

            $_url_params = $GLOBALS['url_params'];
            $_url_params['mr_adduser'] = true;
            $_url_params['repl_clear_scr'] = true;

            $html .= '  <li><a href="server_replication.php';
            $html .= Url::getCommon($_url_params)
                . '" id="master_addslaveuser_href">';
            $html .= __('Add slave replication user') . '</a></li>';
        }

        // Display 'Add replication slave user' form
        if (isset($_REQUEST['mr_adduser'])) {
            $html .= self::getHtmlForReplicationMasterAddSlaveUser();
        } elseif (! isset($_REQUEST['repl_clear_scr'])) {
            $html .= "</ul>";
            $html .= "</fieldset>";
        }

        return $html;
    }

    /**
     * returns HTML for master replication configuration
     *
     * @return String HTML code
     */
    public static function getHtmlForMasterConfiguration()
    {
        $html  = '<fieldset>';
        $html .= '<legend>' . __('Master configuration') . '</legend>';
        $html .= __(
            'This server is not configured as a master server in a '
            . 'replication process. You can choose from either replicating '
            . 'all databases and ignoring some of them (useful if you want to '
            . 'replicate a majority of the databases) or you can choose to ignore '
            . 'all databases by default and allow only certain databases to be '
            . 'replicated. Please select the mode:'
        ) . '<br /><br />';

        $html .= '<select name="db_type" id="db_type">';
        $html .= '<option value="all">' . __('Replicate all databases; Ignore:');
        $html .= '</option>';
        $html .= '<option value="ign">' . __('Ignore all databases; Replicate:');
        $html .= '</option>';
        $html .= '</select>';
        $html .= '<br /><br />';
        $html .= __('Please select databases:') . '<br />';
        $html .= self::getHtmlForReplicationDbMultibox();
        $html .= '<br /><br />';
        $html .= __(
            'Now, add the following lines at the end of [mysqld] section'
            . ' in your my.cnf and please restart the MySQL server afterwards.'
        ) . '<br />';
        $html .= '<pre id="rep"></pre>';
        $html .= __(
            'Once you restarted MySQL server, please click on Go button. '
            . 'Afterwards, you should see a message informing you, that this server'
            . ' <b>is</b> configured as master.'
        );
        $html .= '</fieldset>';
        $html .= '<fieldset class="tblFooters">';
        $html .= ' <form method="post" action="server_replication.php" >';
        $html .= Url::getHiddenInputs('', '');
        $html .= '  <input type="submit" value="' . __('Go') . '" id="goButton" />';
        $html .= ' </form>';
        $html .= '</fieldset>';

        return $html;
    }

    /**
     * returns HTML for slave replication configuration
     *
     * @param bool  $server_slave_status      Whether it is Master or Slave
     * @param array $server_slave_replication Slave replication
     *
     * @return String HTML code
     */
    public static function getHtmlForSlaveConfiguration(
        $server_slave_status, array $server_slave_replication
    ) {
        $html  = '<fieldset>';
        $html .= '<legend>' . __('Slave replication') . '</legend>';
        /**
         * check for multi-master replication functionality
         */
        $server_slave_multi_replication = $GLOBALS['dbi']->fetchResult(
            'SHOW ALL SLAVES STATUS'
        );
        if ($server_slave_multi_replication) {
            $html .= __('Master connection:');
            $html .= '<form method="get" action="server_replication.php">';
            $html .= Url::getHiddenInputs($GLOBALS['url_params']);
            $html .= ' <select name="master_connection">';
            $html .= '<option value="">' . __('Default') . '</option>';
            foreach ($server_slave_multi_replication as $server) {
                $html .= '<option' . (isset($_REQUEST['master_connection'])
                    && $_REQUEST['master_connection'] == $server['Connection_name'] ?
                        ' selected="selected"' : '') . '>' . $server['Connection_name']
                    . '</option>';
            }
            $html .= '</select>';
            $html .= ' <input type="submit" value="' . __('Go') . '" id="goButton" />';
            $html .= '</form>';
            $html .= '<br /><br />';
        }
        if ($server_slave_status) {
            $html .= '<div id="slave_configuration_gui">';

            $_url_params = $GLOBALS['url_params'];
            $_url_params['sr_take_action'] = true;
            $_url_params['sr_slave_server_control'] = true;

            if ($server_slave_replication[0]['Slave_IO_Running'] == 'No') {
                $_url_params['sr_slave_action'] = 'start';
            } else {
                $_url_params['sr_slave_action'] = 'stop';
            }

            $_url_params['sr_slave_control_parm'] = 'IO_THREAD';
            $slave_control_io_link = 'server_replication.php'
                . Url::getCommon($_url_params);

            if ($server_slave_replication[0]['Slave_SQL_Running'] == 'No') {
                $_url_params['sr_slave_action'] = 'start';
            } else {
                $_url_params['sr_slave_action'] = 'stop';
            }

            $_url_params['sr_slave_control_parm'] = 'SQL_THREAD';
            $slave_control_sql_link = 'server_replication.php'
                . Url::getCommon($_url_params);

            if ($server_slave_replication[0]['Slave_IO_Running'] == 'No'
                || $server_slave_replication[0]['Slave_SQL_Running'] == 'No'
            ) {
                $_url_params['sr_slave_action'] = 'start';
            } else {
                $_url_params['sr_slave_action'] = 'stop';
            }

            $_url_params['sr_slave_control_parm'] = null;
            $slave_control_full_link = 'server_replication.php'
                . Url::getCommon($_url_params);

            $_url_params['sr_slave_action'] = 'reset';
            $slave_control_reset_link = 'server_replication.php'
                . Url::getCommon($_url_params);

            $_url_params = $GLOBALS['url_params'];
            $_url_params['sr_take_action'] = true;
            $_url_params['sr_slave_skip_error'] = true;
            $slave_skip_error_link = 'server_replication.php'
                . Url::getCommon($_url_params);

            if ($server_slave_replication[0]['Slave_SQL_Running'] == 'No') {
                $html .= Message::error(
                    __('Slave SQL Thread not running!')
                )->getDisplay();
            }
            if ($server_slave_replication[0]['Slave_IO_Running'] == 'No') {
                $html .= Message::error(
                    __('Slave IO Thread not running!')
                )->getDisplay();
            }

            $_url_params = $GLOBALS['url_params'];
            $_url_params['sl_configure'] = true;
            $_url_params['repl_clear_scr'] = true;

            $reconfiguremaster_link = 'server_replication.php'
                . Url::getCommon($_url_params);

            $html .= __(
                'Server is configured as slave in a replication process. Would you ' .
                'like to:'
            );
            $html .= '<br />';
            $html .= '<ul>';
            $html .= ' <li><a href="#slave_status_href" id="slave_status_href">';
            $html .= __('See slave status table') . '</a>';
            $html .= self::getHtmlForReplicationStatusTable('slave', true, false);
            $html .= ' </li>';

            $html .= ' <li><a href="#slave_control_href" id="slave_control_href">';
            $html .= __('Control slave:') . '</a>';
            $html .= ' <div id="slave_control_gui" class="hide">';
            $html .= '  <ul>';
            $html .= '   <li><a href="' . $slave_control_full_link . '">';
            $html .= (($server_slave_replication[0]['Slave_IO_Running'] == 'No' ||
                       $server_slave_replication[0]['Slave_SQL_Running'] == 'No')
                     ? __('Full start')
                     : __('Full stop')) . ' </a></li>';
            $html .= '   <li><a class="ajax" id="reset_slave"'
                . ' href="' . $slave_control_reset_link . '">';
            $html .= __('Reset slave') . '</a></li>';
            if ($server_slave_replication[0]['Slave_SQL_Running'] == 'No') {
                $html .= '   <li><a href="' . $slave_control_sql_link . '">';
                $html .= __('Start SQL Thread only') . '</a></li>';
            } else {
                $html .= '   <li><a href="' . $slave_control_sql_link . '">';
                $html .= __('Stop SQL Thread only') . '</a></li>';
            }
            if ($server_slave_replication[0]['Slave_IO_Running'] == 'No') {
                $html .= '   <li><a href="' . $slave_control_io_link . '">';
                $html .= __('Start IO Thread only') . '</a></li>';
            } else {
                $html .= '   <li><a href="' . $slave_control_io_link . '">';
                $html .= __('Stop IO Thread only') . '</a></li>';
            }
            $html .= '  </ul>';
            $html .= ' </div>';
            $html .= ' </li>';
            $html .= ' <li>';
            $html .= self::getHtmlForSlaveErrorManagement($slave_skip_error_link);
            $html .= ' </li>';
            $html .= ' <li><a href="' . $reconfiguremaster_link . '">';
            $html .=  __('Change or reconfigure master server') . '</a></li>';
            $html .= '</ul>';
            $html .= '</div>';

        } elseif (! isset($_REQUEST['sl_configure'])) {
            $_url_params = $GLOBALS['url_params'];
            $_url_params['sl_configure'] = true;
            $_url_params['repl_clear_scr'] = true;

            $html .= sprintf(
                __(
                    'This server is not configured as slave in a replication process. '
                    . 'Would you like to <a href="%s">configure</a> it?'
                ),
                'server_replication.php' . Url::getCommon($_url_params)
            );
        }
        $html .= '</fieldset>';

        return $html;
    }

    /**
     * returns HTML for Slave Error Management
     *
     * @param String $slave_skip_error_link error link
     *
     * @return String HTML code
     */
    public static function getHtmlForSlaveErrorManagement($slave_skip_error_link)
    {
        $html  = '<a href="#slave_errormanagement_href" '
            . 'id="slave_errormanagement_href">';
        $html .= __('Error management:') . '</a>';
        $html .= ' <div id="slave_errormanagement_gui" class="hide">';
        $html .= Message::error(
            __('Skipping errors might lead into unsynchronized master and slave!')
        )->getDisplay();
        $html .= '  <ul>';
        $html .= '   <li><a href="' . $slave_skip_error_link . '">';
        $html .= __('Skip current error') . '</a></li>';
        $html .= '   <li>';
        $html .= '    <form method="post" action="server_replication.php">';
        $html .= Url::getHiddenInputs('', '');
        $html .= sprintf(
            __('Skip next %s errors.'),
            '<input type="text" name="sr_skip_errors_count" value="1" '
            . 'style="width: 30px" />'
        );
        $html .= '              <input type="submit" name="sr_slave_skip_error" ';
        $html .= 'value="' . __('Go') . '" />';
        $html .= '      <input type="hidden" name="sr_take_action" value="1" />';
        $html .= '    </form></li>';
        $html .= '  </ul>';
        $html .= ' </div>';
        return $html;
    }

    /**
     * returns HTML for not configure for a server replication
     *
     * @return String HTML code
     */
    public static function getHtmlForNotServerReplication()
    {
        $_url_params = $GLOBALS['url_params'];
        $_url_params['mr_configure'] = true;

        $html  = '<fieldset>';
        $html .= '<legend>' . __('Master replication') . '</legend>';
        $html .= sprintf(
            __(
                'This server is not configured as master in a replication process. '
                . 'Would you like to <a href="%s">configure</a> it?'
            ),
            'server_replication.php' . Url::getCommon($_url_params)
        );
        $html .= '</fieldset>';
        return $html;
    }

    /**
     * returns HTML code for selecting databases
     *
     * @return String HTML code
     */
    public static function getHtmlForReplicationDbMultibox()
    {
        $multi_values = '';
        $multi_values .= '<select name="db_select[]" '
            . 'size="6" multiple="multiple" id="db_select" class="width96">';

        foreach ($GLOBALS['dblist']->databases as $current_db) {
            if ($GLOBALS['dbi']->isSystemSchema($current_db)) {
                continue;
            }
            $current_db = htmlspecialchars($current_db);
            $multi_values .= '                <option value="' . $current_db . '" ';
            $multi_values .= '>';
            $multi_values .= $current_db . '</option>';
        } // end while

        $multi_values .= '</select><br />';
        $multi_values .= '<a href="#" id="db_select_href">' . __('Select all') . '</a>';
        $multi_values .= '&nbsp;/&nbsp;';
        $multi_values .= '<a href="#" id="db_reset_href">' . __('Unselect all') . '</a>';

        return $multi_values;
    }

    /**
     * returns HTML for changing master
     *
     * @param String $submitname - submit button name
     *
     * @return String HTML code
     */
    public static function getHtmlForReplicationChangeMaster($submitname)
    {
        $html = '';
        list($username_length, $hostname_length)
            = self::getUsernameHostnameLength();

        $html .= '<form method="post" action="server_replication.php">';
        $html .= Url::getHiddenInputs('', '');
        $html .= ' <fieldset id="fieldset_add_user_login">';
        $html .= '  <legend>' . __('Slave configuration');
        $html .= ' - ' . __('Change or reconfigure master server') . '</legend>';
        $html .= __(
            'Make sure you have a unique server-id in your configuration file (my.cnf). '
            . 'If not, please add the following line into [mysqld] section:'
        );
        $html .= '<br />';
        $html .= '<pre>server-id=' . time() . '</pre>';

        $html .= self::getHtmlForAddUserInputDiv(
            array('text'=>__('User name:'), 'for'=>"text_username"),
            array(
                'type'=>'text',
                'name'=>'username',
                'id'=>'text_username',
                'maxlength'=>$username_length,
                'title'=>__('User name'),
                'required'=>'required'
            )
        );

        $html .= self::getHtmlForAddUserInputDiv(
            array('text'=>__('Password:'), 'for'=>"text_pma_pw"),
            array(
                'type'=>'password',
                'name'=>'pma_pw',
                'id'=>'text_pma_pw',
                'title'=>__('Password'),
                'required'=>'required'
            )
        );

        $html .= self::getHtmlForAddUserInputDiv(
            array('text'=>__('Host:'), 'for'=>"text_hostname"),
            array(
                'type'=>'text',
                'name'=>'hostname',
                'id'=>'text_hostname',
                'maxlength'=>$hostname_length,
                'value'=>'',
                'required'=>'required'
            )
        );

        $html .= self::getHtmlForAddUserInputDiv(
            array('text'=>__('Port:'), 'for'=>"text_port"),
            array(
                'type'=>'number',
                'name'=>'text_port',
                'id'=>'text_port',
                'maxlength'=>6,
                'value'=>'3306',
                'required'=>'required'
             )
        );

        $html .= ' </fieldset>';
        $html .= ' <fieldset id="fieldset_user_privtable_footer" class="tblFooters">';
        $html .= '    <input type="hidden" name="sr_take_action" value="true" />';
        $html .= '     <input type="hidden" name="' . $submitname . '" value="1" />';
        $html .= '     <input type="submit" id="confslave_submit" value="';
        $html .= __('Go') . '" />';
        $html .= ' </fieldset>';
        $html .= '</form>';

        return $html;
    }

    /**
     * returns HTML code for Add user input div
     *
     * @param array $label_array label tag elements
     * @param array $input_array input tag elements
     *
     * @return String HTML code
     */
    public static function getHtmlForAddUserInputDiv(array $label_array, array $input_array)
    {
        $html  = '  <div class="item">';
        $html .= '     <label for="' . $label_array['for'] . '">';
        $html .=  $label_array['text'] . '</label>';

        $html .= '    <input ';
        foreach ($input_array as $key=>$value) {
            $html .= ' ' . $key . '="' . $value . '" ';
        }
        $html .= ' />';
        $html .= '  </div>';
        return $html;
    }

    /**
     * This function returns html code for table with replication status.
     *
     * @param string  $type   either master or slave
     * @param boolean $hidden if true, then default style is set to hidden,
     *                        default value false
     * @param boolean $title  if true, then title is displayed, default true
     *
     * @return String HTML code
     */
    public static function getHtmlForReplicationStatusTable($type, $hidden = false, $title = true)
    {
        global ${"{$type}_variables"};
        global ${"{$type}_variables_alerts"};
        global ${"{$type}_variables_oks"};
        global ${"server_{$type}_replication"};
        global ${"strReplicationStatus_{$type}"};

        $html = '';

        // TODO check the Masters server id?
        // seems to default to '1' when queried via SHOW VARIABLES ,
        // but resulted in error on the master when slave connects
        // [ERROR] Error reading packet from server: Misconfigured master
        // - server id was not set ( server_errno=1236)
        // [ERROR] Got fatal error 1236: 'Misconfigured master
        // - server id was not set' from master when reading data from binary log
        //
        //$server_id = $GLOBALS['dbi']->fetchValue(
        //    "SHOW VARIABLES LIKE 'server_id'", 0, 1
        //);

        $html .= '<div id="replication_' . $type . '_section" style="';
        $html .= ($hidden ? 'display: none;' : '') . '"> ';

        if ($title) {
            if ($type == 'master') {
                $html .= '<h4><a name="replication_' . $type . '"></a>';
                $html .= __('Master status') . '</h4>';
            } else {
                $html .= '<h4><a name="replication_' . $type . '"></a>';
                $html .= __('Slave status') . '</h4>';
            }
        } else {
            $html .= '<br />';
        }

        $html .= '   <table id="server' . $type . 'replicationsummary" class="data"> ';
        $html .= '   <thead>';
        $html .= '    <tr>';
        $html .= '     <th>' . __('Variable') . '</th>';
        $html .= '        <th>' . __('Value') . '</th>';
        $html .= '    </tr>';
        $html .= '   </thead>';
        $html .= '   <tbody>';

        foreach (${"{$type}_variables"} as $variable) {
            $html .= '   <tr>';
            $html .= '     <td class="name">';
            $html .= htmlspecialchars($variable);
            $html .= '     </td>';
            $html .= '     <td class="value">';

            // TODO change to regexp or something, to allow for negative match
            if (isset(${"{$type}_variables_alerts"}[$variable])
                && ${"{$type}_variables_alerts"}[$variable] == ${"server_{$type}_replication"}[0][$variable]
            ) {
                $html .= '<span class="attention">';

            } elseif (isset(${"{$type}_variables_oks"}[$variable])
                && ${"{$type}_variables_oks"}[$variable] == ${"server_{$type}_replication"}[0][$variable]
            ) {
                $html .= '<span class="allfine">';
            } else {
                $html .= '<span>';
            }
            // allow wrapping long table lists into multiple lines
            static $variables_wrap = array(
                'Replicate_Do_DB', 'Replicate_Ignore_DB',
                'Replicate_Do_Table', 'Replicate_Ignore_Table',
                'Replicate_Wild_Do_Table', 'Replicate_Wild_Ignore_Table');
            if (in_array($variable, $variables_wrap)) {
                $html .= htmlspecialchars(str_replace(
                    ',',
                    ', ',
                    ${"server_{$type}_replication"}[0][$variable]
                ));
            } else {
                $html .= htmlspecialchars(${"server_{$type}_replication"}[0][$variable]);
            }
            $html .= '</span>';

            $html .= '  </td>';
            $html .= ' </tr>';
        }

        $html .= '   </tbody>';
        $html .= ' </table>';
        $html .= ' <br />';
        $html .= '</div>';

        return $html;
    }

    /**
     * returns html code for table with slave users connected to this master
     *
     * @param boolean $hidden - if true, then default style is set to hidden,
     *                        - default value false
     *
     * @return string
     */
    public static function getHtmlForReplicationSlavesTable($hidden = false)
    {
        $html = '';
        // Fetch data
        $data = $GLOBALS['dbi']->fetchResult('SHOW SLAVE HOSTS', null, null);

        $html .= '  <br />';
        $html .= '  <div id="replication_slaves_section" style="';
        $html .=  ($hidden ? 'display: none;' : '') . '"> ';
        $html .= '    <table class="data">';
        $html .= '    <thead>';
        $html .= '      <tr>';
        $html .= '        <th>' . __('Server ID') . '</th>';
        $html .= '        <th>' . __('Host') . '</th>';
        $html .= '      </tr>';
        $html .= '    </thead>';
        $html .= '    <tbody>';

        foreach ($data as $slave) {
            $html .= '    <tr>';
            $html .= '      <td class="value">' . $slave['Server_id'] . '</td>';
            $html .= '      <td class="value">' . $slave['Host'] . '</td>';
            $html .= '    </tr>';
        }

        $html .= '    </tbody>';
        $html .= '    </table>';
        $html .= '    <br />';
        $html .= Message::notice(
            __(
                'Only slaves started with the '
                . '--report-host=host_name option are visible in this list.'
            )
        )->getDisplay();
        $html .= '    <br />';
        $html .= '  </div>';

        return $html;
    }

    /**
     * get the correct username and hostname lengths for this MySQL server
     *
     * @return array   username length, hostname length
     */
    public static function getUsernameHostnameLength()
    {
        $fields_info = $GLOBALS['dbi']->getColumns('mysql', 'user');
        $username_length = 16;
        $hostname_length = 41;
        foreach ($fields_info as $val) {
            if ($val['Field'] == 'User') {
                strtok($val['Type'], '()');
                $v = strtok('()');
                if (is_int($v)) {
                    $username_length = $v;
                }
            } elseif ($val['Field'] == 'Host') {
                strtok($val['Type'], '()');
                $v = strtok('()');
                if (is_int($v)) {
                    $hostname_length = $v;
                }
            }
        }
        return array($username_length, $hostname_length);
    }

    /**
     * returns html code to add a replication slave user to the master
     *
     * @return String HTML code
     */
    public static function getHtmlForReplicationMasterAddSlaveUser()
    {
        $html = '';
        list($username_length, $hostname_length)
            = self::getUsernameHostnameLength();

        if (isset($_REQUEST['username']) && strlen($_REQUEST['username']) === 0) {
            $GLOBALS['pred_username'] = 'any';
        }
        $html .= '<div id="master_addslaveuser_gui">';
        $html .= '<form autocomplete="off" method="post" ';
        $html .= 'action="server_privileges.php"';
        $html .= ' onsubmit="return checkAddUser(this);">';
        $html .= Url::getHiddenInputs('', '');
        $html .= '<fieldset id="fieldset_add_user_login">'
            . '<legend>' . __('Add slave replication user') . '</legend>'
            . self::getHtmlForAddUserLoginForm($username_length)
            . '<div class="item">'
            . '<label for="select_pred_hostname">'
            . '    ' . __('Host:')
            . '</label>'
            . '<span class="options">'
            . '    <select name="pred_hostname" id="select_pred_hostname" title="'
            . __('Host') . '"';

        $_current_user = $GLOBALS['dbi']->fetchValue('SELECT USER();');
        if (! empty($_current_user)) {
            $thishost = str_replace(
                "'",
                '',
                mb_substr(
                    $_current_user,
                    (mb_strrpos($_current_user, '@') + 1)
                )
            );
            if ($thishost != 'localhost' && $thishost != '127.0.0.1') {
                $html .= ' data-thishost="' . htmlspecialchars($thishost) . '" ';
            } else {
                unset($thishost);
            }
        }
        $html .= '>' . "\n";
        unset($_current_user);

        // when we start editing a user, $GLOBALS['pred_hostname'] is not defined
        if (! isset($GLOBALS['pred_hostname']) && isset($_REQUEST['hostname'])) {
            switch (mb_strtolower($_REQUEST['hostname'])) {
            case 'localhost':
            case '127.0.0.1':
                $GLOBALS['pred_hostname'] = 'localhost';
                break;
            case '%':
                $GLOBALS['pred_hostname'] = 'any';
                break;
            default:
                $GLOBALS['pred_hostname'] = 'userdefined';
                break;
            }
        }
        $html .= '        <option value="any"'
            . ((isset($GLOBALS['pred_hostname']) && $GLOBALS['pred_hostname'] == 'any')
            ? ' selected="selected"' : '') . '>' . __('Any host')
            . '</option>'
            . '        <option value="localhost"'
            . ((isset($GLOBALS['pred_hostname'])
                && $GLOBALS['pred_hostname'] == 'localhost')
            ? ' selected="selected"' : '') . '>' . __('Local')
            . '</option>';

        if (!empty($thishost)) {
            $html .= '        <option value="thishost"'
                . ((isset($GLOBALS['pred_hostname'])
                    && $GLOBALS['pred_hostname'] == 'thishost')
                ? ' selected="selected"' : '') . '>' . __('This Host')
                . '</option>';
        }
        unset($thishost);

        $html .= self::getHtmlForTableInfoForm($hostname_length);
        $html .= '</form>';
        $html .= '</div>';

        return $html;
    }

    /**
     *  returns html code to add a replication slave user to the master
     *
     * @param int $username_length Username length
     *
     * @return String HTML code
     */
    public static function getHtmlForAddUserLoginForm($username_length)
    {
        $html = '<input type="hidden" name="grant_count" value="25" />'
            . '<input type="hidden" name="createdb" id="createdb_0" value="0" />'
            . '<input id="checkbox_Repl_slave_priv" type="hidden"'
            . ' title="Needed for the replication slaves." '
            . 'value="Y" name="Repl_slave_priv"/>'
            . '<input id="checkbox_Repl_client_priv" type="hidden" '
            . 'title="Needed for the replication slaves."'
            . ' value="Y" name="Repl_client_priv"/> '
            . '<input type="hidden" name="sr_take_action" value="true" />'
            . '<div class="item">'
            . '<label for="select_pred_username">'
            . '    ' . __('User name:')
            . '</label>'
            . '<span class="options">'
            . '    <select name="pred_username" id="select_pred_username" '
            .         'title="' . __('User name') . '">'
            . '        <option value="any"'
            . ((isset($GLOBALS['pred_username'])
                && $GLOBALS['pred_username'] == 'any') ? ' selected="selected"' : '')
            . '>' . __('Any user') . '</option>'
            . '        <option value="userdefined"'
            . ((! isset($GLOBALS['pred_username'])
                || $GLOBALS['pred_username'] == 'userdefined')
                ? ' selected="selected"' : '')
            . '>' . __('Use text field:') . '</option>'
            . '    </select>'
            . '</span>'
            . '<input type="text" name="username" id="pma_username" maxlength="'
            . $username_length . '" title="' . __('User name') . '"'
            . (empty($_REQUEST['username']) ? '' : ' value="'
            . (isset($GLOBALS['new_username'])
                ? $GLOBALS['new_username']
                : htmlspecialchars($_REQUEST['username'])) . '"')
            . ' />'
            . '</div>';

        return $html;
    }

    /**
     * returns HTML for TableInfoForm
     *
     * @param int $hostname_length Selected hostname length
     *
     * @return String HTML code
     */
    public static function getHtmlForTableInfoForm($hostname_length)
    {
        $html = '        <option value="hosttable"'
            . ((isset($GLOBALS['pred_hostname'])
                && $GLOBALS['pred_hostname'] == 'hosttable')
            ? ' selected="selected"' : '') . '>' . __('Use Host Table')
            . '</option>'
            . '        <option value="userdefined"'
            . ((isset($GLOBALS['pred_hostname'])
                && $GLOBALS['pred_hostname'] == 'userdefined')
            ? ' selected="selected"' : '')
            . '>' . __('Use text field:') . '</option>'
            . '    </select>'
            . '</span>'
            . '<input type="text" name="hostname" id="pma_hostname" maxlength="'
            . $hostname_length . '" value="'
            . (isset($_REQUEST['hostname']) ? htmlspecialchars($_REQUEST['hostname']) : '')
            . '" title="' . __('Host')
            . '" />'
            . Util::showHint(
                __(
                    'When Host table is used, this field is ignored '
                    . 'and values stored in Host table are used instead.'
                )
            )
            . '</div>'
            . '<div class="item">'
            . '<label for="select_pred_password">'
            . '    ' . __('Password:')
            . '</label>'
            . '<span class="options">'
            . '    <select name="pred_password" id="select_pred_password" title="'
            . __('Password') . '">'
            . '        <option value="none"';
        if (isset($_REQUEST['username'])) {
            $html .= '  selected="selected"';
        }
        $html .= '>' . __('No Password') . '</option>'
            . '        <option value="userdefined"'
            . (isset($_REQUEST['username']) ? '' : ' selected="selected"')
            . '>' . __('Use text field:') . '</option>'
            . '    </select>'
            . '</span>'
            . '<input type="password" id="text_pma_pw" name="pma_pw" title="'
            . __('Password') . '" />'
            . '</div>'
            . '<div class="item">'
            . '<label for="text_pma_pw2">'
            . '    ' . __('Re-type:')
            . '</label>'
            . '<span class="options">&nbsp;</span>'
            . '<input type="password" name="pma_pw2" id="text_pma_pw2" title="'
            . __('Re-type') . '" />'
            . '</div>'
            . '<div class="item">'
            . '<label for="button_generate_password">'
            . '    ' . __('Generate password:')
            . '</label>'
            . '<span class="options">'
            . '    <input type="button" class="button" '
            . 'id="button_generate_password" value="' . __('Generate')
            . '" onclick="suggestPassword(this.form)" />'
            . '</span>'
            . '<input type="text" name="generated_pw" id="generated_pw" />'
            . '</div>'
            . '</fieldset>';
        $html .= '<fieldset id="fieldset_user_privtable_footer" class="tblFooters">'
            . '    <input type="hidden" name="adduser_submit" value="1" />'
            . '    <input type="submit" id="adduser_submit" value="' . __('Go') . '" />'
            . '</fieldset>';
        return $html;
    }

    /**
     * handle control requests
     *
     * @return NULL
     */
    public static function handleControlRequest()
    {
        if (isset($_REQUEST['sr_take_action'])) {
            $refresh = false;
            $result = false;
            $messageSuccess = null;
            $messageError = null;

            if (isset($_REQUEST['slave_changemaster']) && ! $GLOBALS['cfg']['AllowArbitraryServer']) {
                $_SESSION['replication']['sr_action_status'] = 'error';
                $_SESSION['replication']['sr_action_info'] = __('Connection to server is disabled, please enable $cfg[\'AllowArbitraryServer\'] in phpMyAdmin configuration.');
            } elseif (isset($_REQUEST['slave_changemaster'])) {
                $result = self::handleRequestForSlaveChangeMaster();
            } elseif (isset($_REQUEST['sr_slave_server_control'])) {
                $result = self::handleRequestForSlaveServerControl();
                $refresh = true;

                switch ($_REQUEST['sr_slave_action']) {
                case 'start':
                    $messageSuccess = __('Replication started successfully.');
                    $messageError = __('Error starting replication.');
                    break;
                case 'stop':
                    $messageSuccess = __('Replication stopped successfully.');
                    $messageError = __('Error stopping replication.');
                    break;
                case 'reset':
                    $messageSuccess = __('Replication resetting successfully.');
                    $messageError = __('Error resetting replication.');
                    break;
                default:
                    $messageSuccess = __('Success.');
                    $messageError = __('Error.');
                    break;
                }
            } elseif (isset($_REQUEST['sr_slave_skip_error'])) {
                $result = self::handleRequestForSlaveSkipError();
            }

            if ($refresh) {
                $response = Response::getInstance();
                if ($response->isAjax()) {
                    $response->setRequestStatus($result);
                    $response->addJSON(
                        'message',
                        $result
                        ? Message::success($messageSuccess)
                        : Message::error($messageError)
                    );
                } else {
                    Core::sendHeaderLocation(
                        './server_replication.php'
                        . Url::getCommonRaw($GLOBALS['url_params'])
                    );
                }
            }
            unset($refresh);
        }
    }

    /**
     * handle control requests for Slave Change Master
     *
     * @return boolean
     */
    public static function handleRequestForSlaveChangeMaster()
    {
        $sr = array();
        $_SESSION['replication']['m_username'] = $sr['username']
            = $GLOBALS['dbi']->escapeString($_REQUEST['username']);
        $_SESSION['replication']['m_password'] = $sr['pma_pw']
            = $GLOBALS['dbi']->escapeString($_REQUEST['pma_pw']);
        $_SESSION['replication']['m_hostname'] = $sr['hostname']
            = $GLOBALS['dbi']->escapeString($_REQUEST['hostname']);
        $_SESSION['replication']['m_port']     = $sr['port']
            = $GLOBALS['dbi']->escapeString($_REQUEST['text_port']);
        $_SESSION['replication']['m_correct']  = '';
        $_SESSION['replication']['sr_action_status'] = 'error';
        $_SESSION['replication']['sr_action_info'] = __('Unknown error');

        // Attempt to connect to the new master server
        $link_to_master = Replication::connectToMaster(
            $sr['username'], $sr['pma_pw'], $sr['hostname'], $sr['port']
        );

        if (! $link_to_master) {
            $_SESSION['replication']['sr_action_status'] = 'error';
            $_SESSION['replication']['sr_action_info'] = sprintf(
                __('Unable to connect to master %s.'),
                htmlspecialchars($sr['hostname'])
            );
        } else {
            // Read the current master position
            $position = Replication::slaveBinLogMaster($link_to_master);

            if (empty($position)) {
                $_SESSION['replication']['sr_action_status'] = 'error';
                $_SESSION['replication']['sr_action_info']
                    = __(
                        'Unable to read master log position. '
                        . 'Possible privilege problem on master.'
                    );
            } else {
                $_SESSION['replication']['m_correct']  = true;

                if (! Replication::slaveChangeMaster(
                    $sr['username'],
                    $sr['pma_pw'],
                    $sr['hostname'],
                    $sr['port'],
                    $position,
                    true,
                    false
                )
                ) {
                    $_SESSION['replication']['sr_action_status'] = 'error';
                    $_SESSION['replication']['sr_action_info']
                        = __('Unable to change master!');
                } else {
                    $_SESSION['replication']['sr_action_status'] = 'success';
                    $_SESSION['replication']['sr_action_info'] = sprintf(
                        __('Master server changed successfully to %s.'),
                        htmlspecialchars($sr['hostname'])
                    );
                }
            }
        }

        return $_SESSION['replication']['sr_action_status'] === 'success';
    }

    /**
     * handle control requests for Slave Server Control
     *
     * @return boolean
     */
    public static function handleRequestForSlaveServerControl()
    {
        if (empty($_REQUEST['sr_slave_control_parm'])) {
            $_REQUEST['sr_slave_control_parm'] = null;
        }
        if ($_REQUEST['sr_slave_action'] == 'reset') {
            $qStop = Replication::slaveControl("STOP");
            $qReset = $GLOBALS['dbi']->tryQuery("RESET SLAVE;");
            $qStart = Replication::slaveControl("START");

            $result = ($qStop !== false && $qStop !== -1 &&
                $qReset !== false && $qReset !== -1 &&
                $qStart !== false && $qStart !== -1);
        } else {
            $qControl = Replication::slaveControl(
                $_REQUEST['sr_slave_action'],
                $_REQUEST['sr_slave_control_parm']
            );

            $result = ($qControl !== false && $qControl !== -1);
        }

        return $result;
    }

    /**
     * handle control requests for Slave Skip Error
     *
     * @return boolean
     */
    public static function handleRequestForSlaveSkipError()
    {
        $count = 1;
        if (isset($_REQUEST['sr_skip_errors_count'])) {
            $count = $_REQUEST['sr_skip_errors_count'] * 1;
        }

        $qStop = Replication::slaveControl("STOP");
        $qSkip = $GLOBALS['dbi']->tryQuery(
            "SET GLOBAL SQL_SLAVE_SKIP_COUNTER = " . $count . ";"
        );
        $qStart = Replication::slaveControl("START");

        $result = ($qStop !== false && $qStop !== -1 &&
            $qSkip !== false && $qSkip !== -1 &&
            $qStart !== false && $qStart !== -1);

        return $result;
    }
}
