<?php
/* vim: set expandtab sw=4 ts=4 sts=4: */
/**
 * Functionality for the navigation tree
 *
 * @package PhpMyAdmin-Navigation
 */
namespace PMA\libraries\navigation;

use PMA\libraries\navigation\nodes\Node;
use PMA\libraries\navigation\nodes\NodeDatabase;
use PMA\libraries\navigation\nodes\NodeTable;
use PMA\libraries\navigation\nodes\NodeTableContainer;
use PMA\libraries\navigation\nodes\NodeViewContainer;
use PMA\libraries\RecentFavoriteTable;
use PMA\libraries\Response;
use PMA\libraries\Util;

/**
 * Displays a collapsible of database objects in the navigation frame
 *
 * @package PhpMyAdmin-Navigation
 */
class NavigationTree
{
    /**
     * @var Node Reference to the root node of the tree
     */
    private $_tree;
    /**
     * @var array The actual paths to all expanded nodes in the tree
     *            This does not include nodes created after the grouping
     *            of nodes has been performed
     */
    private $_aPath = array();
    /**
     * @var array The virtual paths to all expanded nodes in the tree
     *            This includes nodes created after the grouping of
     *            nodes has been performed
     */
    private $_vPath = array();
    /**
     * @var int Position in the list of databases,
     *          used for pagination
     */
    private $_pos;
    /**
     * @var array The names of the type of items that are being paginated on
     *            the second level of the navigation tree. These may be
     *            tables, views, functions, procedures or events.
     */
    private $_pos2_name = array();
    /**
     * @var array The positions of nodes in the lists of tables, views,
     *            routines or events used for pagination
     */
    private $_pos2_value = array();
    /**
     * @var array The names of the type of items that are being paginated
     *            on the second level of the navigation tree.
     *            These may be columns or indexes
     */
    private $_pos3_name = array();
    /**
     * @var array The positions of nodes in the lists of columns or indexes
     *            used for pagination
     */
    private $_pos3_value = array();
    /**
     * @var string The search clause to use in SQL queries for
     *             fetching databases
     *             Used by the asynchronous fast filter
     */
    private $_searchClause = '';
    /**
     * @var string The search clause to use in SQL queries for
     *             fetching nodes
     *             Used by the asynchronous fast filter
     */
    private $_searchClause2 = '';
    /**
     * @var bool Whether a warning was raised for large item groups
     *           which can affect performance.
     */
    private $_largeGroupWarning = false;

    /**
     * Initialises the class
     */
    public function __construct()
    {
        // Save the position at which we are in the database list
        if (isset($_REQUEST['pos'])) {
            $this->_pos = (int)$_REQUEST['pos'];
        }
        if (!isset($this->_pos)) {
            $this->_pos = $this->_getNavigationDbPos();
        }
        // Get the active node
        if (isset($_REQUEST['aPath'])) {
            $this->_aPath[0] = $this->_parsePath($_REQUEST['aPath']);
            $this->_pos2_name[0] = $_REQUEST['pos2_name'];
            $this->_pos2_value[0] = $_REQUEST['pos2_value'];
            if (isset($_REQUEST['pos3_name'])) {
                $this->_pos3_name[0] = $_REQUEST['pos3_name'];
                $this->_pos3_value[0] = $_REQUEST['pos3_value'];
            }
        } else {
            if (isset($_REQUEST['n0_aPath'])) {
                $count = 0;
                while (isset($_REQUEST['n' . $count . '_aPath'])) {
                    $this->_aPath[$count] = $this->_parsePath(
                        $_REQUEST['n' . $count . '_aPath']
                    );
                    $index = 'n' . $count . '_pos2_';
                    $this->_pos2_name[$count] = $_REQUEST[$index . 'name'];
                    $this->_pos2_value[$count] = $_REQUEST[$index . 'value'];
                    $index = 'n' . $count . '_pos3_';
                    if (isset($_REQUEST[$index])) {
                        $this->_pos3_name[$count] = $_REQUEST[$index . 'name'];
                        $this->_pos3_value[$count] = $_REQUEST[$index . 'value'];
                    }
                    $count++;
                }
            }
        }
        if (isset($_REQUEST['vPath'])) {
            $this->_vPath[0] = $this->_parsePath($_REQUEST['vPath']);
        } else {
            if (isset($_REQUEST['n0_vPath'])) {
                $count = 0;
                while (isset($_REQUEST['n' . $count . '_vPath'])) {
                    $this->_vPath[$count] = $this->_parsePath(
                        $_REQUEST['n' . $count . '_vPath']
                    );
                    $count++;
                }
            }
        }
        if (isset($_REQUEST['searchClause'])) {
            $this->_searchClause = $_REQUEST['searchClause'];
        }
        if (isset($_REQUEST['searchClause2'])) {
            $this->_searchClause2 = $_REQUEST['searchClause2'];
        }
        // Initialise the tree by creating a root node
        $node = NodeFactory::getInstance('NodeDatabaseContainer', 'root');
        $this->_tree = $node;
        if ($GLOBALS['cfg']['NavigationTreeEnableGrouping']
            && $GLOBALS['cfg']['ShowDatabasesNavigationAsTree']
        ) {
            $this->_tree->separator = $GLOBALS['cfg']['NavigationTreeDbSeparator'];
            $this->_tree->separator_depth = 10000;
        }
    }

    /**
     * Returns the database position for the page selector
     *
     * @return int
     */
    private function _getNavigationDbPos()
    {
        $retval = 0;

        if (empty($GLOBALS['db'])) {
            return $retval;
        }

        /*
         * @todo describe a scenario where this code is executed
         */
        if (!$GLOBALS['cfg']['Server']['DisableIS']) {
            $query = "SELECT (COUNT(DB_first_level) DIV %d) * %d ";
            $query .= "from ( ";
            $query .= " SELECT distinct SUBSTRING_INDEX(SCHEMA_NAME, ";
            $query .= " '" . Util::sqlAddSlashes($GLOBALS['cfg']['NavigationTreeDbSeparator']) . "', 1) ";
            $query .= " DB_first_level ";
            $query .= " FROM INFORMATION_SCHEMA.SCHEMATA ";
            $query .= " WHERE `SCHEMA_NAME` < '%s' ";
            $query .= ") t ";

            $retval = $GLOBALS['dbi']->fetchValue(
                sprintf(
                    $query,
                    (int)$GLOBALS['cfg']['FirstLevelNavigationItems'],
                    (int)$GLOBALS['cfg']['FirstLevelNavigationItems'],
                    Util::sqlAddSlashes($GLOBALS['db'])
                )
            );

            return $retval;
        }

        $prefixMap = array();
        if ($GLOBALS['dbs_to_test'] === false) {
            $handle = $GLOBALS['dbi']->tryQuery("SHOW DATABASES");
            if ($handle !== false) {
                while ($arr = $GLOBALS['dbi']->fetchArray($handle)) {
                    if (strcasecmp($arr[0], $GLOBALS['db']) >= 0) {
                        break;
                    }

                    $prefix = strstr(
                        $arr[0],
                        $GLOBALS['cfg']['NavigationTreeDbSeparator'],
                        true
                    );
                    if ($prefix === false) {
                        $prefix = $arr[0];
                    }
                    $prefixMap[$prefix] = 1;
                }
            }
        } else {
            $databases = array();
            foreach ($GLOBALS['dbs_to_test'] as $db) {
                $query = "SHOW DATABASES LIKE '" . $db . "'";
                $handle = $GLOBALS['dbi']->tryQuery($query);
                if ($handle === false) {
                    continue;
                }
                while ($arr = $GLOBALS['dbi']->fetchArray($handle)) {
                    $databases[] = $arr[0];
                }
            }
            sort($databases);
            foreach ($databases as $database) {
                if (strcasecmp($database, $GLOBALS['db']) >= 0) {
                    break;
                }

                $prefix = strstr(
                    $database,
                    $GLOBALS['cfg']['NavigationTreeDbSeparator'],
                    true
                );
                if ($prefix === false) {
                    $prefix = $database;
                }
                $prefixMap[$prefix] = 1;
            }
        }

        $navItems = (int)$GLOBALS['cfg']['FirstLevelNavigationItems'];
        $retval = floor((count($prefixMap) / $navItems)) * $navItems;

        return $retval;
    }

    /**
     * Converts an encoded path to a node in string format to an array
     *
     * @param string $string The path to parse
     *
     * @return array
     */
    private function _parsePath($string)
    {
        $path = explode('.', $string);
        foreach ($path as $key => $value) {
            $path[$key] = base64_decode($value);
        }

        return $path;
    }

    /**
     * Generates the tree structure so that it can be rendered later
     *
     * @return Node|false The active node or false in case of failure
     */
    private function _buildPath()
    {
        $retval = $this->_tree;

        // Add all databases unconditionally
        $data = $this->_tree->getData(
            'databases',
            $this->_pos,
            $this->_searchClause
        );
        $hiddenCounts = $this->_tree->getNavigationHidingData();
        foreach ($data as $db) {
            $node = NodeFactory::getInstance('NodeDatabase', $db);
            if (isset($hiddenCounts[$db])) {
                $node->setHiddenCount($hiddenCounts[$db]);
            }
            $this->_tree->addChild($node);
        }

        // Whether build other parts of the tree depends
        // on whether we have any paths in $this->_aPath
        foreach ($this->_aPath as $key => $path) {
            $retval = $this->_buildPathPart(
                $path,
                $this->_pos2_name[$key],
                $this->_pos2_value[$key],
                isset($this->_pos3_name[$key]) ? $this->_pos3_name[$key] : '',
                isset($this->_pos3_value[$key]) ? $this->_pos3_value[$key] : ''
            );
        }

        return $retval;
    }

    /**
     * Builds a branch of the tree
     *
     * @param array  $path  A paths pointing to the branch
     *                      of the tree that needs to be built
     * @param string $type2 The type of item being paginated on
     *                      the second level of the tree
     * @param int    $pos2  The position for the pagination of
     *                      the branch at the second level of the tree
     * @param string $type3 The type of item being paginated on
     *                      the third level of the tree
     * @param int    $pos3  The position for the pagination of
     *                      the branch at the third level of the tree
     *
     * @return Node|false The active node or false in case of failure
     */
    private function _buildPathPart($path, $type2, $pos2, $type3, $pos3)
    {
        if (empty($pos2)) {
            $pos2 = 0;
        }
        if (empty($pos3)) {
            $pos3 = 0;
        }

        $retval = true;
        if (count($path) <= 1) {
            return $retval;
        }

        array_shift($path); // remove 'root'
        /* @var $db NodeDatabase */
        $db = $this->_tree->getChild($path[0]);
        $retval = $db;

        if ($db === false) {
            return false;
        }

        $containers = $this->_addDbContainers($db, $type2, $pos2);

        array_shift($path); // remove db

        if ((count($path) <= 0 || !array_key_exists($path[0], $containers))
            && count($containers) != 1
        ) {
            return $retval;
        }

        if (count($containers) == 1) {
            $container = array_shift($containers);
        } else {
            $container = $db->getChild($path[0], true);
            if ($container === false) {
                return false;
            }
        }
        $retval = $container;

        if (count($container->children) <= 1) {
            $dbData = $db->getData(
                $container->real_name,
                $pos2,
                $this->_searchClause2
            );
            foreach ($dbData as $item) {
                switch ($container->real_name) {
                case 'events':
                    $node = NodeFactory::getInstance(
                        'NodeEvent',
                        $item
                    );
                    break;
                case 'functions':
                    $node = NodeFactory::getInstance(
                        'NodeFunction',
                        $item
                    );
                    break;
                case 'procedures':
                    $node = NodeFactory::getInstance(
                        'NodeProcedure',
                        $item
                    );
                    break;
                case 'tables':
                    $node = NodeFactory::getInstance(
                        'NodeTable',
                        $item
                    );
                    break;
                case 'views':
                    $node = NodeFactory::getInstance(
                        'NodeView',
                        $item
                    );
                    break;
                default:
                    break;
                }
                if (isset($node)) {
                    if ($type2 == $container->real_name) {
                        $node->pos2 = $pos2;
                    }
                    $container->addChild($node);
                }
            }
        }
        if (count($path) > 1 && $path[0] != 'tables') {
            $retval = false;

            return $retval;
        }

        array_shift($path); // remove container
        if (count($path) <= 0) {
            return $retval;
        }

        /* @var $table NodeTable */
        $table = $container->getChild($path[0], true);
        if ($table === false) {
            if (!$db->getPresence('tables', $path[0])) {
                return false;
            }

            $node = NodeFactory::getInstance(
                'NodeTable',
                $path[0]
            );
            if ($type2 == $container->real_name) {
                $node->pos2 = $pos2;
            }
            $container->addChild($node);
            $table = $container->getChild($path[0], true);
        }
        $retval = $table;
        $containers = $this->_addTableContainers(
            $table,
            $pos2,
            $type3,
            $pos3
        );
        array_shift($path); // remove table
        if (count($path) <= 0
            || !array_key_exists($path[0], $containers)
        ) {
            return $retval;
        }

        $container = $table->getChild($path[0], true);
        $retval = $container;
        $tableData = $table->getData(
            $container->real_name,
            $pos3
        );
        foreach ($tableData as $item) {
            switch ($container->real_name) {
            case 'indexes':
                $node = NodeFactory::getInstance(
                    'NodeIndex',
                    $item
                );
                break;
            case 'columns':
                $node = NodeFactory::getInstance(
                    'NodeColumn',
                    $item
                );
                break;
            case 'triggers':
                $node = NodeFactory::getInstance(
                    'NodeTrigger',
                    $item
                );
                break;
            default:
                break;
            }
            if (isset($node)) {
                $node->pos2 = $container->parent->pos2;
                if ($type3 == $container->real_name) {
                    $node->pos3 = $pos3;
                }
                $container->addChild($node);
            }
        }

        return $retval;
    }

    /**
     * Adds containers to a node that is a table
     *
     * References to existing children are returned
     * if this function is called twice on the same node
     *
     * @param NodeTable $table The table node, new containers will be
     *                         attached to this node
     * @param int       $pos2  The position for the pagination of
     *                         the branch at the second level of the tree
     * @param string    $type3 The type of item being paginated on
     *                         the third level of the tree
     * @param int       $pos3  The position for the pagination of
     *                         the branch at the third level of the tree
     *
     * @return array An array of new nodes
     */
    private function _addTableContainers($table, $pos2, $type3, $pos3)
    {
        $retval = array();
        if ($table->hasChildren(true) == 0) {
            if ($table->getPresence('columns')) {
                $retval['columns'] = NodeFactory::getInstance(
                    'NodeColumnContainer'
                );
            }
            if ($table->getPresence('indexes')) {
                $retval['indexes'] = NodeFactory::getInstance(
                    'NodeIndexContainer'
                );
            }
            if ($table->getPresence('triggers')) {
                $retval['triggers'] = NodeFactory::getInstance(
                    'NodeTriggerContainer'
                );
            }
            // Add all new Nodes to the tree
            foreach ($retval as $node) {
                $node->pos2 = $pos2;
                if ($type3 == $node->real_name) {
                    $node->pos3 = $pos3;
                }
                $table->addChild($node);
            }
        } else {
            foreach ($table->children as $node) {
                if ($type3 == $node->real_name) {
                    $node->pos3 = $pos3;
                }
                $retval[$node->real_name] = $node;
            }
        }

        return $retval;
    }

    /**
     * Adds containers to a node that is a database
     *
     * References to existing children are returned
     * if this function is called twice on the same node
     *
     * @param NodeDatabase $db   The database node, new containers will be
     *                           attached to this node
     * @param string       $type The type of item being paginated on
     *                           the second level of the tree
     * @param int          $pos2 The position for the pagination of
     *                           the branch at the second level of the tree
     *
     * @return array An array of new nodes
     */
    private function _addDbContainers($db, $type, $pos2)
    {
        // Get items to hide
        $hidden = $db->getHiddenItems('group');
        if (!$GLOBALS['cfg']['NavigationTreeShowTables']
            && !in_array('tables', $hidden)
        ) {
            $hidden[] = 'tables';
        }
        if (!$GLOBALS['cfg']['NavigationTreeShowViews']
            && !in_array('views', $hidden)
        ) {
            $hidden[] = 'views';
        }
        if (!$GLOBALS['cfg']['NavigationTreeShowFunctions']
            && !in_array('functions', $hidden)
        ) {
            $hidden[] = 'functions';
        }
        if (!$GLOBALS['cfg']['NavigationTreeShowProcedures']
            && !in_array('procedures', $hidden)
        ) {
            $hidden[] = 'procedures';
        }
        if (!$GLOBALS['cfg']['NavigationTreeShowEvents']
            && !in_array('events', $hidden)
        ) {
            $hidden[] = 'events';
        }

        $retval = array();
        if ($db->hasChildren(true) == 0) {
            if (!in_array('tables', $hidden) && $db->getPresence('tables')) {
                $retval['tables'] = NodeFactory::getInstance(
                    'NodeTableContainer'
                );
            }
            if (!in_array('views', $hidden) && $db->getPresence('views')) {
                $retval['views'] = NodeFactory::getInstance(
                    'NodeViewContainer'
                );
            }
            if (!in_array('functions', $hidden) && $db->getPresence('functions')) {
                $retval['functions'] = NodeFactory::getInstance(
                    'NodeFunctionContainer'
                );
            }
            if (!in_array('procedures', $hidden) && $db->getPresence('procedures')) {
                $retval['procedures'] = NodeFactory::getInstance(
                    'NodeProcedureContainer'
                );
            }
            if (!in_array('events', $hidden) && $db->getPresence('events')) {
                $retval['events'] = NodeFactory::getInstance(
                    'NodeEventContainer'
                );
            }
            // Add all new Nodes to the tree
            foreach ($retval as $node) {
                if ($type == $node->real_name) {
                    $node->pos2 = $pos2;
                }
                $db->addChild($node);
            }
        } else {
            foreach ($db->children as $node) {
                if ($type == $node->real_name) {
                    $node->pos2 = $pos2;
                }
                $retval[$node->real_name] = $node;
            }
        }

        return $retval;
    }

    /**
     * Recursively groups tree nodes given a separator
     *
     * @param mixed $node The node to group or null
     *                    to group the whole tree. If
     *                    passed as an argument, $node
     *                    must be of type CONTAINER
     *
     * @return void
     */
    public function groupTree($node = null)
    {
        if (!isset($node)) {
            $node = $this->_tree;
        }
        $this->groupNode($node);
        foreach ($node->children as $child) {
            $this->groupTree($child);
        }
    }

    /**
     * Recursively groups tree nodes given a separator
     *
     * @param Node $node The node to group
     *
     * @return void
     */
    public function groupNode($node)
    {
        if ($node->type != Node::CONTAINER
            || !$GLOBALS['cfg']['NavigationTreeEnableExpansion']
        ) {
            return;
        }

        $separators = array();
        if (is_array($node->separator)) {
            $separators = $node->separator;
        } else {
            if (strlen($node->separator)) {
                $separators[] = $node->separator;
            }
        }
        $prefixes = array();
        if ($node->separator_depth > 0) {
            foreach ($node->children as $child) {
                $prefix_pos = false;
                foreach ($separators as $separator) {
                    $sep_pos = mb_strpos($child->name, $separator);
                    if ($sep_pos != false
                        && $sep_pos != mb_strlen($child->name)
                        && $sep_pos != 0
                        && ($prefix_pos == false || $sep_pos < $prefix_pos)
                    ) {
                        $prefix_pos = $sep_pos;
                    }
                }
                if ($prefix_pos !== false) {
                    $prefix = mb_substr($child->name, 0, $prefix_pos);
                    if (!isset($prefixes[$prefix])) {
                        $prefixes[$prefix] = 1;
                    } else {
                        $prefixes[$prefix]++;
                    }
                }
                //Bug #4375: Check if prefix is the name of a DB, to create a group.
                foreach ($node->children as $otherChild) {
                    if (array_key_exists($otherChild->name, $prefixes)) {
                        $prefixes[$otherChild->name]++;
                    }
                }
            }
            //Check if prefix is the name of a DB, to create a group.
            foreach ($node->children as $child) {
                if (array_key_exists($child->name, $prefixes)) {
                    $prefixes[$child->name]++;
                }
            }
        }
        // It is not a group if it has only one item
        foreach ($prefixes as $key => $value) {
            if ($value == 1) {
                unset($prefixes[$key]);
            }
        }
        // rfe #1634 Don't group if there's only one group and no other items
        if (count($prefixes) == 1) {
            $keys = array_keys($prefixes);
            $key = $keys[0];
            if ($prefixes[$key] == count($node->children) - 1) {
                unset($prefixes[$key]);
            }
        }
        if (count($prefixes)) {
            /** @var Node[] $groups */
            $groups = array();
            foreach ($prefixes as $key => $value) {

                // warn about large groups
                if ($value > 500 && !$this->_largeGroupWarning) {
                    trigger_error(
                        __(
                            'There are large item groups in navigation panel which '
                            . 'may affect the performance. Consider disabling item '
                            . 'grouping in the navigation panel.'
                        ),
                        E_USER_WARNING
                    );
                    $this->_largeGroupWarning = true;
                }

                $groups[$key] = new Node(
                    $key,
                    Node::CONTAINER,
                    true
                );
                $groups[$key]->separator = $node->separator;
                $groups[$key]->separator_depth = $node->separator_depth - 1;
                $groups[$key]->icon = Util::getImage(
                    'b_group.png'
                );
                $groups[$key]->pos2 = $node->pos2;
                $groups[$key]->pos3 = $node->pos3;
                if ($node instanceof NodeTableContainer
                    || $node instanceof NodeViewContainer
                ) {
                    $tblGroup = '&amp;tbl_group=' . urlencode($key);
                    $groups[$key]->links = array(
                        'text' => $node->links['text'] . $tblGroup,
                        'icon' => $node->links['icon'] . $tblGroup,
                    );
                }
                $node->addChild($groups[$key]);
                foreach ($separators as $separator) {
                    $separatorLength = strlen($separator);
                    // FIXME: this could be more efficient
                    foreach ($node->children as $child) {
                        $keySeparatorLength = mb_strlen($key) + $separatorLength;
                        $name_substring = mb_substr(
                            $child->name,
                            0,
                            $keySeparatorLength
                        );
                        if (($name_substring != $key . $separator
                            && $child->name != $key)
                            || $child->type != Node::OBJECT
                        ) {
                            continue;
                        }
                        $class = get_class($child);
                        $className = substr($class, strrpos($class, '\\') + 1);
                        unset($class);
                        $new_child = NodeFactory::getInstance(
                            $className,
                            mb_substr(
                                $child->name,
                                $keySeparatorLength
                            )
                        );

                        if ($new_child instanceof NodeDatabase
                            && $child->getHiddenCount() > 0
                        ) {
                            $new_child->setHiddenCount($child->getHiddenCount());
                        }

                        $new_child->real_name = $child->real_name;
                        $new_child->icon = $child->icon;
                        $new_child->links = $child->links;
                        $new_child->pos2 = $child->pos2;
                        $new_child->pos3 = $child->pos3;
                        $groups[$key]->addChild($new_child);
                        foreach ($child->children as $elm) {
                            $new_child->addChild($elm);
                        }
                        $node->removeChild($child->name);
                    }
                }
            }
            foreach ($prefixes as $key => $value) {
                $this->groupNode($groups[$key]);
                $groups[$key]->classes = "navGroup";
            }
        }
    }

    /**
     * Renders a state of the tree, used in light mode when
     * either JavaScript and/or Ajax are disabled
     *
     * @return string HTML code for the navigation tree
     */
    public function renderState()
    {
        $this->_buildPath();
        $retval = $this->_quickWarp();
        $retval .= '<div class="clearfloat"></div>';
        $retval .= '<ul>';
        $retval .= $this->_fastFilterHtml($this->_tree);
        if ($GLOBALS['cfg']['NavigationTreeEnableExpansion']
        ) {
            $retval .= $this->_controls();
        }
        $retval .= '</ul>';
        $retval .= $this->_getPageSelector($this->_tree);
        $this->groupTree();
        $retval .= "<div id='pma_navigation_tree_content'><ul>";
        $children = $this->_tree->children;
        usort(
            $children,
            array('PMA\\libraries\\navigation\\NavigationTree', 'sortNode')
        );
        $this->_setVisibility();
        for ($i = 0, $nbChildren = count($children); $i < $nbChildren; $i++) {
            if ($i == 0) {
                $retval .= $this->_renderNode($children[0], true, 'first');
            } else {
                if ($i + 1 != $nbChildren) {
                    $retval .= $this->_renderNode($children[$i], true);
                } else {
                    $retval .= $this->_renderNode($children[$i], true, 'last');
                }
            }
        }
        $retval .= "</ul></div>";

        return $retval;
    }

    /**
     * Renders a part of the tree, used for Ajax
     * requests in light mode
     *
     * @return string HTML code for the navigation tree
     */
    public function renderPath()
    {
        $node = $this->_buildPath();
        if ($node === false) {
            $retval = false;
        } else {
            $this->groupTree();
            $retval = "<div class='list_container' style='display: none;'>";
            if (!empty($this->_searchClause) || !empty($this->_searchClause2)) {
                $retval .= "<ul class='search_results'>";
            } else {
                $retval .= "<ul>";
            }
            $listContent = $this->_fastFilterHtml($node);
            $listContent .= $this->_getPageSelector($node);
            $children = $node->children;
            usort(
                $children,
                array('PMA\\libraries\\navigation\\NavigationTree', 'sortNode')
            );
            for ($i = 0, $nbChildren = count($children); $i < $nbChildren; $i++) {
                if ($i + 1 != $nbChildren) {
                    $listContent .= $this->_renderNode($children[$i], true);
                } else {
                    $listContent .= $this->_renderNode($children[$i], true, 'last');
                }
            }
            $retval .= $listContent;
            $retval .= "</ul>";
            if (!$GLOBALS['cfg']['ShowDatabasesNavigationAsTree']) {
                $retval .= "<span class='hide loaded_db'>";
                $parents = $node->parents(true);
                $retval .= urlencode($parents[0]->real_name);
                $retval .= "</span>";
                if (empty($listContent)) {
                    $retval .= "<div style='margin:0.75em'>";
                    $retval .= __('No tables found in database.');
                    $retval .= "</div>";
                }
            }
            $retval .= "</div>";
        }

        if (!empty($this->_searchClause) || !empty($this->_searchClause2)) {
            $results = 0;
            if (!empty($this->_searchClause2)) {
                if (is_object($node->realParent())) {
                    $results = $node->realParent()
                        ->getPresence(
                            $node->real_name,
                            $this->_searchClause2
                        );
                }
            } else {
                $results = $this->_tree->getPresence(
                    'databases',
                    $this->_searchClause
                );
            }
            $results = sprintf(
                _ngettext(
                    '%s result found',
                    '%s results found',
                    $results
                ),
                $results
            );
            Response::getInstance()
                ->addJSON(
                    'results',
                    $results
                );
        }

        return $retval;
    }

    /**
     * Renders the parameters that are required on the client
     * side to know which page(s) we will be requesting data from
     *
     * @param Node $node The node to create the pagination parameters for
     *
     * @return string
     */
    private function _getPaginationParamsHtml($node)
    {
        $retval = '';
        $paths = $node->getPaths();
        if (isset($paths['aPath_clean'][2])) {
            $retval .= "<span class='hide pos2_name'>";
            $retval .= $paths['aPath_clean'][2];
            $retval .= "</span>";
            $retval .= "<span class='hide pos2_value'>";
            $retval .= htmlspecialchars($node->pos2);
            $retval .= "</span>";
        }
        if (isset($paths['aPath_clean'][4])) {
            $retval .= "<span class='hide pos3_name'>";
            $retval .= $paths['aPath_clean'][4];
            $retval .= "</span>";
            $retval .= "<span class='hide pos3_value'>";
            $retval .= htmlspecialchars($node->pos3);
            $retval .= "</span>";
        }

        return $retval;
    }

    /**
     * Finds whether given tree matches this tree.
     *
     * @param array $tree  Tree to check
     * @param array $paths Paths to check
     *
     * @return boolean
     */
    private function _findTreeMatch($tree, $paths)
    {
        $match = false;
        foreach ($tree as $path) {
            $match = true;
            foreach ($paths as $key => $part) {
                if (!isset($path[$key]) || $part != $path[$key]) {
                    $match = false;
                    break;
                }
            }
            if ($match) {
                break;
            }
        }

        return $match;
    }

    /**
     * Renders a single node or a branch of the tree
     *
     * @param Node   $node      The node to render
     * @param bool   $recursive Bool: Whether to render a single node or a branch
     * @param string $class     An additional class for the list item
     *
     * @return string HTML code for the tree node or branch
     */
    private function _renderNode($node, $recursive, $class = '')
    {
        $retval = '';
        $paths = $node->getPaths();
        if ($node->hasSiblings()
            || $node->realParent() === false
        ) {
            if ($node->type == Node::CONTAINER
                && count($node->children) == 0
                && $GLOBALS['is_ajax_request'] != true
            ) {
                return '';
            }
            $retval .= '<li class="' . trim($class . ' ' . $node->classes) . '">';
            $sterile = array(
                'events',
                'triggers',
                'functions',
                'procedures',
                'views',
                'columns',
                'indexes',
            );
            $parentName = '';
            $parents = $node->parents(false, true);
            if (count($parents)) {
                $parentName = $parents[0]->real_name;
            }
            // if node name itself is in sterile, then allow
            if ($node->is_group
                || (!in_array($parentName, $sterile) && !$node->isNew)
                || (in_array($node->real_name, $sterile))
            ) {
                $retval .= "<div class='block'>";
                $iClass = '';
                if ($class == 'first') {
                    $iClass = " class='first'";
                }
                $retval .= "<i$iClass></i>";
                if (strpos($class, 'last') === false) {
                    $retval .= "<b></b>";
                }

                $match = $this->_findTreeMatch(
                    $this->_vPath,
                    $paths['vPath_clean']
                );

                $retval .= '<a class="' . $node->getCssClasses($match) . '"';
                $retval .= " href='#'>";
                $retval .= "<span class='hide aPath'>";
                $retval .= $paths['aPath'];
                $retval .= "</span>";
                $retval .= "<span class='hide vPath'>";
                $retval .= $paths['vPath'];
                $retval .= "</span>";
                $retval .= "<span class='hide pos'>";
                $retval .= $this->_pos;
                $retval .= "</span>";
                $retval .= $this->_getPaginationParamsHtml($node);
                if ($GLOBALS['cfg']['ShowDatabasesNavigationAsTree']
                    || $parentName != 'root'
                ) {
                    $retval .= $node->getIcon($match);
                }

                $retval .= "</a>";
                $retval .= "</div>";
            } else {
                $retval .= "<div class='block'>";
                $iClass = '';
                if ($class == 'first') {
                    $iClass = " class='first'";
                }
                $retval .= "<i$iClass></i>";
                $retval .= $this->_getPaginationParamsHtml($node);
                $retval .= "</div>";
            }

            $linkClass = '';
            $haveAjax = array(
                'functions',
                'procedures',
                'events',
                'triggers',
                'indexes',
            );
            $parent = $node->parents(false, true);
            $isNewView = $parent[0]->real_name == 'views' && $node->isNew === true;
            if ($parent[0]->type == Node::CONTAINER
                && (in_array($parent[0]->real_name, $haveAjax) || $isNewView)
            ) {
                $linkClass = ' ajax';
            }

            if ($node->type == Node::CONTAINER) {
                $retval .= "<i>";
            }

            $divClass = '';

            if (isset($node->links['icon']) && !empty($node->links['icon'])) {
                $iconLinks = $node->links['icon'];
                $icons = $node->icon;
                if (!is_array($iconLinks)) {
                    $iconLinks = array($iconLinks);
                    $icons = array($icons);
                }

                if (count($icons) > 1) {
                    $divClass = 'double';
                }
            }

            $retval .= "<div class='block " . $divClass . "'>";

            if (isset($node->links['icon']) && !empty($node->links['icon'])) {
                $args = array();
                foreach ($node->parents(true) as $parent) {
                    $args[] = urlencode($parent->real_name);
                }

                foreach ($icons as $key => $icon) {
                    $link = vsprintf($iconLinks[$key], $args);
                    if ($linkClass != '') {
                        $retval .= "<a class='$linkClass' href='$link'>";
                        $retval .= "{$icon}</a>";
                    } else {
                        $retval .= "<a href='$link'>{$icon}</a>";
                    }
                }
            } else {
                $retval .= "<u>{$node->icon}</u>";
            }
            $retval .= "</div>";

            if (isset($node->links['text'])) {
                $args = array();
                foreach ($node->parents(true) as $parent) {
                    $args[] = urlencode($parent->real_name);
                }
                $link = vsprintf($node->links['text'], $args);
                $title = empty($node->links['title']) ? '' : $node->links['title'];
                if ($node->type == Node::CONTAINER) {
                    $retval .= "&nbsp;<a class='hover_show_full' href='$link'>";
                    $retval .= htmlspecialchars($node->name);
                    $retval .= "</a>";
                } else {
                    $retval .= "<a class='hover_show_full$linkClass' href='$link'";
                    $retval .= " title='$title'>";
                    $retval .= htmlspecialchars($node->real_name);
                    $retval .= "</a>";
                }
            } else {
                $retval .= "&nbsp;{$node->name}";
            }
            $retval .= $node->getHtmlForControlButtons();
            if ($node->type == Node::CONTAINER) {
                $retval .= "</i>";
            }
            $retval .= '<div class="clearfloat"></div>';
            $wrap = true;
        } else {
            $node->visible = true;
            $wrap = false;
            $retval .= $this->_getPaginationParamsHtml($node);
        }

        if ($recursive) {
            $hide = '';
            if (!$node->visible) {
                $hide = " style='display: none;'";
            }
            $children = $node->children;
            usort(
                $children,
                array('PMA\\libraries\\navigation\\NavigationTree', 'sortNode')
            );
            $buffer = '';
            $extra_class = '';
            for ($i = 0, $nbChildren = count($children); $i < $nbChildren; $i++) {
                if ($i + 1 == $nbChildren) {
                    $extra_class = ' last';
                }
                $buffer .= $this->_renderNode(
                    $children[$i],
                    true,
                    $children[$i]->classes . $extra_class
                );
            }
            if (!empty($buffer)) {
                if ($wrap) {
                    $retval .= "<div$hide class='list_container'><ul>";
                }
                $retval .= $this->_fastFilterHtml($node);
                $retval .= $this->_getPageSelector($node);
                $retval .= $buffer;
                if ($wrap) {
                    $retval .= "</ul></div>";
                }
            }
        }
        if ($node->hasSiblings()) {
            $retval .= "</li>";
        }

        return $retval;
    }

    /**
     * Renders a database select box like the pre-4.0 navigation panel
     *
     * @return string HTML code
     */
    public function renderDbSelect()
    {
        $this->_buildPath();
        $retval = $this->_quickWarp();
        $this->_tree->is_group = false;
        $retval .= '<div id="pma_navigation_select_database">';
        // Provide for pagination in database select
        $retval .= Util::getListNavigator(
            $this->_tree->getPresence('databases', ''),
            $this->_pos,
            array('server' => $GLOBALS['server']),
            'navigation.php',
            'frame_navigation',
            $GLOBALS['cfg']['FirstLevelNavigationItems'],
            'pos',
            array('dbselector')
        );
        $children = $this->_tree->children;
        array_shift($children);
        $url_params = array(
            'token'  => $_SESSION[' PMA_token '],
            'server' => $GLOBALS['server'],
        );
        $retval .= '<div id="pma_navigation_db_select">';
        $retval .= '<form action="index.php">';
        $retval .= PMA_getHiddenFields($url_params);
        $retval .= '<select name="db" class="hide" id="navi_db_select">'
            . '<option value="" dir="' . $GLOBALS['text_dir'] . '">'
            . '(' . __('Databases') . ') ...</option>' . "\n";
        $selected = $GLOBALS['db'];
        foreach ($children as $node) {
            $paths = $node->getPaths();
            if (isset($node->links['text'])) {
                $title = empty($node->links['title']) ? '' : $node->links['title'];
                $retval .= '<option value="'
                    . htmlspecialchars($node->real_name) . '"'
                    . ' title="' . htmlspecialchars($title) . '"'
                    . ' apath="' . $paths['aPath'] . '"'
                    . ' vpath="' . $paths['vPath'] . '"'
                    . ' pos="' . $this->_pos . '"';
                if ($node->real_name == $selected) {
                    $retval .= ' selected="selected"';
                }
                $retval .= '>' . htmlspecialchars($node->real_name);
                $retval .= '</option>';
            }
        }
        $retval .= '</select></form>';
        $retval .= '</div></div>';
        $retval .= '<div id="pma_navigation_tree_content"><ul>';
        $children = $this->_tree->children;
        usort(
            $children,
            array('PMA\\libraries\\navigation\\NavigationTree', 'sortNode')
        );
        $this->_setVisibility();
        for ($i = 0, $nbChildren = count($children); $i < $nbChildren; $i++) {
            if ($i == 0) {
                $retval .= $this->_renderNode($children[0], true, 'first');
            } else {
                if ($i + 1 != $nbChildren) {
                    $retval .= $this->_renderNode($children[$i], true);
                } else {
                    $retval .= $this->_renderNode($children[$i], true, 'last');
                }
            }
        }
        $retval .= '</ul></div>';

        return $retval;
    }

    /**
     * Makes some nodes visible based on the which node is active
     *
     * @return void
     */
    private function _setVisibility()
    {
        foreach ($this->_vPath as $path) {
            $node = $this->_tree;
            foreach ($path as $value) {
                $child = $node->getChild($value);
                if ($child !== false) {
                    $child->visible = true;
                    $node = $child;
                }
            }
        }
    }

    /**
     * Generates the HTML code for displaying the fast filter for tables
     *
     * @param Node $node The node for which to generate the fast filter html
     *
     * @return string LI element used for the fast filter
     */
    private function _fastFilterHtml($node)
    {
        $retval = '';
        $filter_db_min
            = (int)$GLOBALS['cfg']['NavigationTreeDisplayDbFilterMinimum'];
        $filter_item_min
            = (int)$GLOBALS['cfg']['NavigationTreeDisplayItemFilterMinimum'];
        if ($node === $this->_tree
            && $this->_tree->getPresence() >= $filter_db_min
        ) {
            $url_params = array(
                'pos' => 0,
            );
            $retval .= '<li class="fast_filter db_fast_filter">';
            $retval .= '<form class="ajax fast_filter">';
            $retval .= PMA_getHiddenFields($url_params);
            $retval .= '<input class="searchClause" type="text"';
            $retval .= ' name="searchClause" accesskey="q"';
            // allow html5 placeholder attribute
            $placeholder_key = 'value';
            if (PMA_USR_BROWSER_AGENT !== 'IE'
                || PMA_USR_BROWSER_VER > 9
            ) {
                $placeholder_key = 'placeholder';
            }
            $retval .= " $placeholder_key='"
                . __("Type to filter these, Enter to search all");
            $retval .= "' />";
            $retval .= '<span title="' . __('Clear fast filter') . '">X</span>';
            $retval .= "</form>";
            $retval .= "</li>";

            return $retval;
        }

        if (($node->type == Node::CONTAINER
            && ($node->real_name == 'tables'
            || $node->real_name == 'views'
            || $node->real_name == 'functions'
            || $node->real_name == 'procedures'
            || $node->real_name == 'events'))
            && method_exists($node->realParent(), 'getPresence')
            && $node->realParent()->getPresence($node->real_name) >= $filter_item_min
        ) {
            $paths = $node->getPaths();
            $url_params = array(
                'pos'        => $this->_pos,
                'aPath'      => $paths['aPath'],
                'vPath'      => $paths['vPath'],
                'pos2_name'  => $node->real_name,
                'pos2_value' => 0,
            );
            $retval .= "<li class='fast_filter'>";
            $retval .= "<form class='ajax fast_filter'>";
            $retval .= PMA_getHiddenFields($url_params);
            $retval .= "<input class='searchClause' type='text'";
            $retval .= " name='searchClause2'";
            // allow html5 placeholder attribute
            $placeholder_key = 'value';
            if (PMA_USR_BROWSER_AGENT !== 'IE' || PMA_USR_BROWSER_VER > 9) {
                $placeholder_key = 'placeholder';
            }
            $retval .= " $placeholder_key='"
                . __("Type to filter these, Enter to search all") . "' />";
            $retval .= "<span title='" . __('Clear fast filter') . "'>X</span>";
            $retval .= "</form>";
            $retval .= "</li>";
        }

        return $retval;
    }

    /**
     * Creates the code for displaying the controls
     * at the top of the navigation tree
     *
     * @return string HTML code for the controls
     */
    private function _controls()
    {
        // always iconic
        $showIcon = true;
        $showText = false;

        $retval = '<!-- CONTROLS START -->';
        $retval .= '<li id="navigation_controls_outer">';
        $retval .= '<div id="navigation_controls">';
        $retval .= Util::getNavigationLink(
            '#',
            $showText,
            __('Collapse all'),
            $showIcon,
            's_collapseall.png',
            'pma_navigation_collapse'
        );
        $syncImage = 's_unlink.png';
        $title = __('Link with main panel');
        if ($GLOBALS['cfg']['NavigationLinkWithMainPanel']) {
            $syncImage = 's_link.png';
            $title = __('Unlink from main panel');
        }
        $retval .= Util::getNavigationLink(
            '#',
            $showText,
            $title,
            $showIcon,
            $syncImage,
            'pma_navigation_sync'
        );
        $retval .= '</div>';
        $retval .= '</li>';
        $retval .= '<!-- CONTROLS ENDS -->';

        return $retval;
    }

    /**
     * Generates the HTML code for displaying the list pagination
     *
     * @param Node $node The node for whose children the page
     *                   selector will be created
     *
     * @return string
     */
    private function _getPageSelector($node)
    {
        $retval = '';
        if ($node === $this->_tree) {
            $retval .= Util::getListNavigator(
                $this->_tree->getPresence('databases', $this->_searchClause),
                $this->_pos,
                array('server' => $GLOBALS['server']),
                'navigation.php',
                'frame_navigation',
                $GLOBALS['cfg']['FirstLevelNavigationItems'],
                'pos',
                array('dbselector')
            );
        } else {
            if ($node->type == Node::CONTAINER && !$node->is_group) {
                $paths = $node->getPaths();

                $level = isset($paths['aPath_clean'][4]) ? 3 : 2;
                $_url_params = array(
                    'aPath'     => $paths['aPath'],
                    'vPath'     => $paths['vPath'],
                    'pos'       => $this->_pos,
                    'server'    => $GLOBALS['server'],
                    'pos2_name' => $paths['aPath_clean'][2],
                );
                if ($level == 3) {
                    $pos = $node->pos3;
                    $_url_params['pos2_value'] = $node->pos2;
                    $_url_params['pos3_name'] = $paths['aPath_clean'][4];
                } else {
                    $pos = $node->pos2;
                }
                $num = $node->realParent()
                    ->getPresence(
                        $node->real_name,
                        $this->_searchClause2
                    );
                $retval .= Util::getListNavigator(
                    $num,
                    $pos,
                    $_url_params,
                    'navigation.php',
                    'frame_navigation',
                    $GLOBALS['cfg']['MaxNavigationItems'],
                    'pos' . $level . '_value'
                );
            }
        }

        return $retval;
    }

    /**
     * Called by usort() for sorting the nodes in a container
     *
     * @param Node $a The first element used in the comparison
     * @param Node $b The second element used in the comparison
     *
     * @return int See strnatcmp() and strcmp()
     */
    static public function sortNode($a, $b)
    {
        if ($a->isNew) {
            return -1;
        } else {
            if ($b->isNew) {
                return 1;
            }
        }
        if ($GLOBALS['cfg']['NaturalOrder']) {
            return strnatcasecmp($a->name, $b->name);
        } else {
            return strcasecmp($a->name, $b->name);
        }
    }

    /**
     * Display quick warp links, contain Recents and Favorites
     *
     * @return string HTML code
     */
    private function _quickWarp()
    {
        $retval = '<div class="pma_quick_warp">';
        if ($GLOBALS['cfg']['NumRecentTables'] > 0) {
            $retval .= RecentFavoriteTable::getInstance('recent')
                ->getHtml();
        }
        if ($GLOBALS['cfg']['NumFavoriteTables'] > 0) {
            $retval .= RecentFavoriteTable::getInstance('favorite')
                ->getHtml();
        }
        $retval .= '<div class="clearfloat"></div>';
        $retval .= '</div>';

        return $retval;
    }
}
