<?php
  
  namespace Sabre\VObject\Component;
  
  use Sabre\VObject;
  
  /**
   * The VCalendar component
   *
   * This component adds functionality to a component, specific for a VCALENDAR.

   *
   * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
   * @author Evert Pot (http://evertpot.com/)

   * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
   */

  class VCalendar extends VObject\Document {
  
      static $defaultName = 'VCALENDAR';

  
      /**

       * Returns a list of all 'base components'. For instance, if an Event has
       * a recurrence rule, and one instance is overridden, the overridden event

       * will have the same UID, but will be excluded from this list.
       *

       * VTIMEZONE components will always be excluded.

       *

       * @param string $componentName filter by component name
       * @return array

       */
      public function getBaseComponents($componentName = null) {
  
          $components = array();
          foreach($this->children as $component) {
  
              if (!$component instanceof VObject\Component)
                  continue;

              if (isset($component->{'RECURRENCE-ID'}))

                  continue;

              if ($componentName && $component->name !== strtoupper($componentName))

                  continue;
  
              if ($component->name === 'VTIMEZONE')
                  continue;
  
              $components[] = $component;
  
          }
  
          return $components;
  
      }
  
      /**

       * If this calendar object, has events with recurrence rules, this method

       * can be used to expand the event into multiple sub-events.
       *

       * Each event will be stripped from it's recurrence information, and only
       * the instances of the event in the specified timerange will be left

       * alone.
       *

       * In addition, this method will cause timezone information to be stripped,

       * and normalized to UTC.
       *
       * This method will alter the VCalendar. This cannot be reversed.
       *

       * This functionality is specifically used by the CalDAV standard. It is
       * possible for clients to request expand events, if they are rather simple

       * clients and do not have the possibility to calculate recurrences.
       *
       * @param DateTime $start

       * @param DateTime $end

       * @return void
       */
      public function expand(\DateTime $start, \DateTime $end) {
  
          $newEvents = array();
  
          foreach($this->select('VEVENT') as $key=>$vevent) {
  
              if (isset($vevent->{'RECURRENCE-ID'})) {
                  unset($this->children[$key]);
                  continue;

              }

  
  
              if (!$vevent->rrule) {
                  unset($this->children[$key]);
                  if ($vevent->isInTimeRange($start, $end)) {
                      $newEvents[] = $vevent;
                  }
                  continue;
              }
  
              $uid = (string)$vevent->uid;
              if (!$uid) {
                  throw new \LogicException('Event did not have a UID!');
              }
  
              $it = new VObject\RecurrenceIterator($this, $vevent->uid);
              $it->fastForward($start);
  
              while($it->valid() && $it->getDTStart() < $end) {
  
                  if ($it->getDTEnd() > $start) {
  
                      $newEvents[] = $it->getEventObject();
  
                  }
                  $it->next();
  
              }
              unset($this->children[$key]);
  
          }
  
          foreach($newEvents as $newEvent) {
  
              foreach($newEvent->children as $child) {
                  if ($child instanceof VObject\Property\DateTime &&
                      $child->getDateType() == VObject\Property\DateTime::LOCALTZ) {
                          $child->setDateTime($child->getDateTime(),VObject\Property\DateTime::UTC);
                      }
              }
  
              $this->add($newEvent);
  
          }
  
          // Removing all VTIMEZONE components
          unset($this->VTIMEZONE);

      }

  
      /**
       * Validates the node for correctness.
       * An array is returned with warnings.
       *
       * Every item in the array has the following properties:
       *    * level - (number between 1 and 3 with severity information)
       *    * message - (human readable message)
       *    * node - (reference to the offending node)

       *
       * @return array

       */
      /*
      public function validate() {
  
          $warnings = array();
  
          $version = $this->select('VERSION');
          if (count($version)!==1) {
              $warnings[] = array(
                  'level' => 1,
                  'message' => 'The VERSION property must appear in the VCALENDAR component exactly 1 time',
                  'node' => $this,
              );
          } else {
              if ((string)$this->VERSION !== '2.0') {
                  $warnings[] = array(
                      'level' => 1,
                      'message' => 'Only iCalendar version 2.0 as defined in rfc5545 is supported.',
                      'node' => $this,
                  );
              }

          }

          $version = $this->select('PRODID');
          if (count($version)!==1) {
              $warnings[] = array(
                  'level' => 2,
                  'message' => 'The PRODID property must appear in the VCALENDAR component exactly 1 time',
                  'node' => $this,
              );
          }
          if (count($this->CALSCALE) > 1) {
              $warnings[] = array(
                  'level' => 2,
                  'message' => 'The CALSCALE property must not be specified more than once.',
                  'node' => $this,
              );
          }
          if (count($this->METHOD) > 1) {
              $warnings[] = array(
                  'level' => 2,
                  'message' => 'The METHOD property must not be specified more than once.',
                  'node' => $this,
              );
          }
  
          $allowedComponents = array(
              'VEVENT',
              'VTODO',
              'VJOURNAL',
              'VFREEBUSY',
              'VTIMEZONE',
          );
          $allowedProperties = array(
              'PRODID',
              'VERSION',
              'CALSCALE',
              'METHOD',
          );
          $componentsFound = 0;
          foreach($this->children as $child) {
              if($child instanceof Component) {
                  $componentsFound++;
                  if (!in_array($child->name, $allowedComponents)) {
                      $warnings[] = array(
                          'level' => 1,
                          'message' => 'The ' . $child->name . " component is not allowed in the VCALENDAR component",
                          'node' => $this,
                      );
                  }
              }
              if ($child instanceof Property) {
                  if (!in_array($child->name, $allowedProperties)) {
                      $warnings[] = array(
                          'level' => 2,
                          'message' => 'The ' . $child->name . " property is not allowed in the VCALENDAR component",
                          'node' => $this,
                      );
                  }
              }
          }
  
          if ($componentsFound===0) {
              $warnings[] = array(
                  'level' => 1,
                  'message' => 'An iCalendar object must have at least 1 component.',
                  'node' => $this,
              );
          }
  
          return array_merge(
              $warnings,
              parent::validate()
          );
  
      }
       */
  
  }