<?php

  namespace Sabre\DAV;

  /**
   * ObjectTree class
   *
   * This implementation of the Tree class makes use of the INode, IFile and ICollection API's
   *

   * @copyright Copyright (C) 2007-2014 fruux GmbH (https://fruux.com/).
   * @author Evert Pot (http://evertpot.com/)
   * @license http://sabre.io/license/ Modified BSD License

   */

  class ObjectTree extends Tree {

  
      /**
       * The root node
       *

       * @var ICollection

       */
      protected $rootNode;
  
      /**
       * This is the node cache. Accessed nodes are stored here
       *
       * @var array
       */
      protected $cache = array();
  
      /**
       * Creates the object
       *
       * This method expects the rootObject to be passed as a parameter
       *

       * @param ICollection $rootNode

       */

      public function __construct(ICollection $rootNode) {

  
          $this->rootNode = $rootNode;
  
      }
  
      /**
       * Returns the INode object for the requested path
       *
       * @param string $path

       * @return INode

       */
      public function getNodeForPath($path) {
  
          $path = trim($path,'/');
          if (isset($this->cache[$path])) return $this->cache[$path];
  
          // Is it the root node?
          if (!strlen($path)) {
              return $this->rootNode;
          }
  
          // Attempting to fetch its parent

          list($parentName, $baseName) = URLUtil::splitPath($path);

  
          // If there was no parent, we must simply ask it from the root node.
          if ($parentName==="") {
              $node = $this->rootNode->getChild($baseName);
          } else {
              // Otherwise, we recursively grab the parent and ask him/her.
              $parent = $this->getNodeForPath($parentName);

              if (!($parent instanceof ICollection))
                  throw new Exception\NotFound('Could not find node at path: ' . $path);

  
              $node = $parent->getChild($baseName);
  
          }
  
          $this->cache[$path] = $node;
          return $node;
  
      }
  
      /**
       * This function allows you to check if a node exists.
       *
       * @param string $path
       * @return bool
       */
      public function nodeExists($path) {
  
          try {
  
              // The root always exists
              if ($path==='') return true;

              list($parent, $base) = URLUtil::splitPath($path);

  
              $parentNode = $this->getNodeForPath($parent);

              if (!$parentNode instanceof ICollection) return false;

              return $parentNode->childExists($base);

          } catch (Exception\NotFound $e) {

  
              return false;
  
          }
  
      }
  
      /**
       * Returns a list of childnodes for a given path.
       *
       * @param string $path
       * @return array
       */
      public function getChildren($path) {
  
          $node = $this->getNodeForPath($path);
          $children = $node->getChildren();
          foreach($children as $child) {
  
              $this->cache[trim($path,'/') . '/' . $child->getName()] = $child;
  
          }
          return $children;
  
      }
  
      /**
       * This method is called with every tree update
       *
       * Examples of tree updates are:
       *   * node deletions
       *   * node creations
       *   * copy
       *   * move
       *   * renaming nodes
       *
       * If Tree classes implement a form of caching, this will allow
       * them to make sure caches will be expired.
       *
       * If a path is passed, it is assumed that the entire subtree is dirty
       *
       * @param string $path
       * @return void
       */
      public function markDirty($path) {
  
          // We don't care enough about sub-paths
          // flushing the entire cache
          $path = trim($path,'/');
          foreach($this->cache as $nodePath=>$node) {
              if ($nodePath == $path || strpos($nodePath,$path.'/')===0)
                  unset($this->cache[$nodePath]);
  
          }
  
      }
  
  }