<?php
/**
* CalDAV Server - handle PROPPATCH method
*
* @package   davical
* @subpackage   caldav
* @author    Andrew McMillan <andrew@mcmillan.net.nz>
* @copyright Morphoss Ltd - http://www.morphoss.com/
* @license   http://gnu.org/copyleft/gpl.html GNU GPL v2
*/
dbg_error_log("PROPPATCH", "method handler");

require_once('vCalendar.php');
require_once('DAVResource.php');

$dav_resource = new DAVResource($request->path);
if ( !$dav_resource->HavePrivilegeTo('DAV::write-properties') ) {
  $parent = $dav_resource->GetParentContainer();
  if ( !$dav_resource->IsBinding() || !$parent->HavePrivilegeTo('DAV::write') ) {
    $request->PreconditionFailed(403, 'DAV::write-properties', 'You do not have permission to write properties to that resource' );
  }
}

$xmltree = BuildXMLTree( $request->xml_tags );

// echo $xmltree->Render();

if ( $xmltree->GetNSTag() != "DAV::propertyupdate" ) {
  $request->PreconditionFailed( 403, 'DAV::propertyupdate', 'XML request did not contain a &lt;propertyupdate&gt; tag' );
}

/**
* Find the properties being set, and the properties being removed
*/
$setprops = $xmltree->GetPath("/DAV::propertyupdate/DAV::set/DAV::prop/*");
$rmprops  = $xmltree->GetPath("/DAV::propertyupdate/DAV::remove/DAV::prop/*");

/**
* We build full status responses for failures.  For success we just record
* it, since the multistatus response only applies to failure.  While it is
* not explicitly stated in RFC2518, from reading between the lines (8.2.1)
* a success will return 200 OK [with an empty response].
*/
$failure   = array();
$success   = array();

$reply = new XMLDocument( array( 'DAV:' => '') );

/**
 * Small utility function to add propstat for one failure
 * @param unknown_type $tag
 * @param unknown_type $status
 * @param unknown_type $description
 * @param unknown_type $error_tag
 */
function add_failure( $type, $tag, $status, $description=null, $error_tag = null) {
  global $failure, $reply;
  $prop = new XMLElement('prop');
  $reply->NSElement($prop, $tag);
  $propstat = array($prop,new XMLElement( 'status', $status ));

  if ( isset($description))
    $propstat[] = new XMLElement( 'responsedescription', $description );
  if ( isset($error_tag) )
    $propstat[] = new XMLElement( 'error', new XMLElement( $error_tag ) );

  $failure[$type.'-'.$tag] = new XMLElement('propstat', $propstat );
}


/**
* Not much for it but to process the incoming settings in a big loop, doing
* the special-case stuff as needed and falling through to a default which
* stuffs the property somewhere we will be able to retrieve it from later.
*/
$qry = new AwlQuery();
$qry->Begin();
$setcalendar = count($xmltree->GetPath('/DAV::propertyupdate/DAV::set/DAV::prop/DAV::resourcetype/urn:ietf:params:xml:ns:caldav:calendar'));
foreach( $setprops AS $k => $setting ) {
  $tag = $setting->GetNSTag();
  $content = $setting->RenderContent(0,null,true);

  switch( $tag ) {

    case 'DAV::displayname':
      /**
      * Can't set displayname on resources - only collections or principals
      */
      if ( $dav_resource->IsCollection() || $dav_resource->IsPrincipal() ) {
        if ( $dav_resource->IsBinding() ) {
          $qry->QDo('UPDATE dav_binding SET dav_displayname = :displayname WHERE dav_name = :dav_name',
                                            array( ':displayname' => $content, ':dav_name' => $dav_resource->dav_name()) );
        }
        else if ( $dav_resource->IsPrincipal() ) {
          $qry->QDo('UPDATE dav_principal SET fullname = :displayname, displayname = :displayname, modified = current_timestamp WHERE user_no = :user_no',
                                            array( ':displayname' => $content, ':user_no' => $request->user_no) );
        }
        else {
          $qry->QDo('UPDATE collection SET dav_displayname = :displayname, modified = current_timestamp WHERE dav_name = :dav_name',
                                            array( ':displayname' => $content, ':dav_name' => $dav_resource->dav_name()) );
        }
        $success[$tag] = 1;
      }
      else {
        add_failure('set', $tag, 'HTTP/1.1 403 Forbidden',
             translate("The displayname may only be set on collections, principals or bindings."), 'cannot-modify-protected-property');
      }
      break;

    case 'DAV::resourcetype':
      /**
      * We only allow resourcetype setting on a normal collection, and not on a resource, a principal or a bind.
      * Only collections may be CalDAV calendars or addressbooks, and they may not be both.
      */
      $resourcetypes = $setting->GetPath('DAV::resourcetype/*');
      $setcollection = false;
      $setcalendar = false;
      $setaddressbook = false;
      $setother = false;
      foreach( $resourcetypes AS $xnode ) {
        switch( $xnode->GetNSTag() ) {
          case 'urn:ietf:params:xml:ns:caldav:calendar':      $setcalendar = true;      break;
          case 'urn:ietf:params:xml:ns:carddav:addressbook':  $setaddressbook = true;   break;
          case 'DAV::collection': $setcollection = true; break;
          default:
            $setother = true;
        }
      }
      if ( $dav_resource->IsCollection() && $setcollection && ! $dav_resource->IsPrincipal() && ! $dav_resource->IsBinding()
          && !($setcalendar && $setaddressbook) && !$setother ) {
        $resourcetypes = '<collection xmlns="DAV:"/>';
        if ( $setcalendar ) $resourcetypes .= '<calendar xmlns="urn:ietf:params:xml:ns:caldav"/>';
        else if ( $setaddressbook ) $resourcetypes .= '<addressbook xmlns="urn:ietf:params:xml:ns:carddav"/>';
        $qry->QDo('UPDATE collection SET is_calendar = :is_calendar::boolean, is_addressbook = :is_addressbook::boolean,
                     resourcetypes = :resourcetypes WHERE dav_name = :dav_name',
                    array( ':dav_name' => $dav_resource->dav_name(), ':resourcetypes' => $resourcetypes,
                           ':is_calendar' => $setcalendar, ':is_addressbook' => $setaddressbook ) );
        $success[$tag] = 1;
      }
      else if ( $setcalendar && $setaddressbook ) {
        add_failure('set', $tag, 'HTTP/1.1 409 Conflict',
            translate("A collection may not be both a calendar and an addressbook."));
      }
      else if ( $setother ) {
        add_failure('set', $tag, 'HTTP/1.1 403 Forbidden',
             translate("Unsupported resourcetype modification."), 'cannot-modify-protected-property');
      }
      else {
        add_failure('set', $tag, 'HTTP/1.1 403 Forbidden',
             translate("Resources may not be changed to / from collections."), 'cannot-modify-protected-property');
      }
      break;

    case 'DAV::group-member-set':
      if ( $dav_resource->IsProxyCollection() ) {
        $privileges_read = privilege_to_bits( array('read', 'read-free-busy', 'schedule-deliver') );
        $privileges_write = privilege_to_bits( array('write', 'schedule-send') );
        $type = 'read';
        if ( $dav_resource->IsProxyCollection('write') ) {
          $type = 'write';
        }

        $by_principal = $dav_resource->getProperty('principal_id');
        $sqlparams = array( ':by_principal' => $by_principal );

        $existing_grants = array();
        $qry->QDo('SELECT to_principal, privileges FROM grants WHERE by_principal = :by_principal', $sqlparams);
        while ( $row = $qry->Fetch() ) {
          $existing_grants[$row->to_principal] = bindec($row->privileges);
        }

        $group_members = $setting->GetElements('DAV::href');
        foreach( $group_members AS $member ) {
          $to_principal = new Principal('path', DeconstructURL( $member->GetContent() ));
          if ( !$to_principal->Exists() ) {
            add_failure('set', $tag, 'HTTP/1.1 403 Forbidden',
              translate('Principal not found') . ': ' . $member->GetContent(), 'recognized-principal');
            break;
          }
          $sqlparams[':to_principal'] = $to_principal->principal_id();

          if ( array_key_exists($to_principal->principal_id(), $existing_grants) ) {
            $sql = 'UPDATE grants SET privileges=:privileges::INT::BIT(24) WHERE to_principal=:to_principal AND by_principal=:by_principal';
            $existing_privileges = $existing_grants[$to_principal->principal_id()];
            unset( $existing_grants[$to_principal->principal_id()] );
          } else {
            $sql = 'INSERT INTO grants (by_principal, to_principal, privileges) VALUES(:by_principal, :to_principal, :privileges::INT::BIT(24))';
            $existing_privileges = 0;
          }

          $privileges = $existing_privileges | $privileges_read; // always add read privileges here
          if ( $type == 'write' ) {
            $privileges |= $privileges_write; // add write privileges as well
          } else {
            $privileges &= $privileges_write ^ DAVICAL_MAXPRIV; // substract write privileges
          }
          if ( $privileges == $existing_privileges ) continue; // unchanged
          $sqlparams[':privileges'] = $privileges;

          $qry->QDo($sql, $sqlparams);
          dbg_error_log("PROPPATCH", "group-member-set: %s (%s) is granted %s access to %s", $to_principal->username(), $to_principal->principal_id(), $type, $dav_resource->getProperty('username'));

          Principal::cacheDelete('dav_name',$to_principal->dav_name());
          Principal::cacheFlush('principal_id IN (SELECT member_id FROM group_member WHERE group_id = ?)', array($to_principal->principal_id()));
        }

        // if there are any remaining grants of our $type, we need to delete them
        // ("set" means "replace any existing property", WEBDAV RFC2518 12.13.2)
        foreach ( $existing_grants AS $id => $existing_privs ) {
          $have_write = $existing_privs & $privileges_write;
          if ( $type == 'read' && $have_write ) continue;
          if ( $type == 'write' && ! $have_write ) continue;

          $negative_readwrite = ( $privileges_read | $privileges_write ) ^ DAVICAL_MAXPRIV;
          $remaining_privs = $existing_privs & $negative_readwrite;

          if ( $remaining_privs > 0 ) {
            $sql = 'UPDATE grants SET privileges=:privileges::INT::BIT(24)';
            $sqlparams[':privileges'] = $remaining_privs;
          } else {
            $sql = 'DELETE FROM grants';
          }
          $sqlparams[':to_principal'] = $id;
          $qry->QDo($sql.' WHERE to_principal=:to_principal AND by_principal=:by_principal', $sqlparams);
          dbg_error_log("PROPPATCH", "group-member-set: %s is no longer granted %s access to %s", $id, $type, $dav_resource->getProperty('username'));
          Principal::cacheFlush('principal_id = :to_principal', $sqlparams);
        }
      }
      else {
          /* @todo PROPPATCH set group-member-set for regular group principal */
          dbg_error_log("ERROR", "PROPPATCH: set group-member-set for non-proxy collection: don't know what to do!");
          add_failure('set', $tag, 'HTTP/1.1 403 Forbidden',
            'group-member-set ' . translate('unimplemented'), 'cannot-modify-protected-property');
          break;
      }
      $success[$tag] = 1;
      break;

    case 'urn:ietf:params:xml:ns:caldav:schedule-calendar-transp':
      if ( $dav_resource->IsCollection() && ( $dav_resource->IsCalendar() || $setcalendar ) && !$dav_resource->IsBinding() ) {
        $transparency = $setting->GetPath('urn:ietf:params:xml:ns:caldav:schedule-calendar-transp/*');
        $transparency = preg_replace( '{^.*:}', '', $transparency[0]->GetNSTag());
        $qry->QDo('UPDATE collection SET schedule_transp = :transparency WHERE dav_name = :dav_name',
                    array( ':dav_name' => $dav_resource->dav_name(), ':transparency' => $transparency ) );
        $success[$tag] = 1;
      }
      else {
        add_failure('set', $tag, 'HTTP/1.1 409 Conflict',
              translate("The CalDAV:schedule-calendar-transp property may only be set on calendars."));
      }
      break;

    case 'urn:ietf:params:xml:ns:caldav:calendar-free-busy-set':
      add_failure('set', $tag, 'HTTP/1.1 409 Conflict',
            translate("The calendar-free-busy-set is superseded by the  schedule-calendar-transp property of a calendar collection.") );
      break;

    case 'urn:ietf:params:xml:ns:caldav:calendar-timezone':
      if ( $dav_resource->IsCollection() && $dav_resource->IsCalendar() && ! $dav_resource->IsBinding() ) {
        $tzcomponent = $setting->GetPath('urn:ietf:params:xml:ns:caldav:calendar-timezone');
        $tzstring = $tzcomponent[0]->GetContent();
        $calendar = new vCalendar( $tzstring );
        $timezones = $calendar->GetComponents('VTIMEZONE');
        if ( count($timezones) == 0 ) break;
        $tz = $timezones[0];  // Backward compatibility
        $tzid = $tz->GetPValue('TZID');
        $params = array( ':tzid' => $tzid );
        $qry = new AwlQuery('SELECT 1 FROM timezones WHERE tzid = :tzid', $params );
        if ( $qry->Exec('PUT',__LINE__,__FILE__) && $qry->rows() == 0 ) {
          $params[':olson_name'] = $calendar->GetOlsonName($tz);
          $params[':vtimezone'] = (isset($tz) ? $tz->Render() : null );
          $qry->QDo('INSERT INTO timezones (tzid, olson_name, active, vtimezone) VALUES(:tzid,:olson_name,false,:vtimezone)', $params );
        }

        $qry->QDo('UPDATE collection SET timezone = :tzid WHERE dav_name = :dav_name',
                                       array( ':tzid' => $tzid, ':dav_name' => $dav_resource->dav_name()) );
        require_once("instance_range.php");
        update_instance_ranges($dav_resource->dav_name());
      }
      else {
        add_failure('set', $tag, 'HTTP/1.1 409 Conflict', translate("calendar-timezone property is only valid for a calendar."));
      }
      break;

    /**
    * The following properties are read-only, so they will cause the request to fail
    */
    case 'http://calendarserver.org/ns/:getctag':
    case 'DAV::owner':
    case 'DAV::principal-collection-set':
    case 'urn:ietf:params:xml:ns:caldav:calendar-user-address-set':
    case 'urn:ietf:params:xml:ns:caldav:schedule-inbox-URL':
    case 'urn:ietf:params:xml:ns:caldav:schedule-outbox-URL':
    case 'DAV::getetag':
    case 'DAV::getcontentlength':
    case 'DAV::getcontenttype':
    case 'DAV::getlastmodified':
    case 'DAV::creationdate':
    case 'DAV::lockdiscovery':
    case 'DAV::supportedlock':
    case 'DAV::group-membership':
    case 'http://calendarserver.org/ns/:calendar-proxy-read-for':
    case 'http://calendarserver.org/ns/:calendar-proxy-write-for':
      add_failure('set', $tag, 'HTTP/1.1 403 Forbidden', translate("Property is read-only"), 'cannot-modify-protected-property');
      break;

    /**
    * If we don't have any special processing for the property, we just store it verbatim (which will be an XML fragment).
    */
    default:
      $qry->QDo('SELECT set_dav_property( :dav_name, :user_no::integer, :tag::text, :value::text)',
            array( ':dav_name' => $dav_resource->dav_name(), ':user_no' => $request->user_no, ':tag' => $tag, ':value' => $content) );
      $result = $qry->Fetch();
      if ( $result->set_dav_property ) {
        $success[$tag] = 1;
      } else {
        dbg_error_log("ERROR", "failed to set_dav_property %s on %s to '%s'", $tag, $dav_resource->dav_name(), $content);
        add_failure('set', $tag, 'HTTP/1.1 403 Forbidden');
      }
      break;
  }
}

foreach( $rmprops AS $k => $setting ) {
  $tag = $setting->GetNSTag();
  $content = $setting->RenderContent();

  switch( $tag ) {

    case 'DAV::resourcetype':
      add_failure('rm', $tag, 'HTTP/1.1 403 Forbidden',
            translate("DAV::resourcetype may only be set to a new value, it may not be removed."), 'cannot-modify-protected-property');
      break;

    case 'DAV::group-member-set':
      if ( $dav_resource->IsProxyCollection() ) {
        $type = 'read';
        $privileges = privilege_to_bits( array('read', 'read-free-busy', 'schedule-deliver') );
        if ( $dav_resource->IsProxyCollection('write') ) {
          $type = 'write';
          $privileges |= privilege_to_bits( array('write', 'schedule-send') );
        }

        $by_principal = $dav_resource->getProperty('principal_id');
        $sqlparams = array( ':by_principal' => $by_principal );

        // look up existing grants of our type
        $existing_grants = array();
        $qry->QDo('SELECT privileges, to_principal FROM grants WHERE by_principal = :by_principal', $sqlparams);
        while( $row = $qry->Fetch() ) {
          $existing_privileges = bindec($row->privileges);
          if ( ($existing_privileges & $privileges) == $privileges ) {
            $existing_grants[$row->to_principal] = $existing_privileges;
          }
        }

        // examine the members to be removed
        $group_members = $setting->GetElements('DAV::href');
        foreach( $group_members AS $member ) {
          $to_principal = new Principal('path', DeconstructURL( $member->GetContent() ));
          // "Specifying the removal of a property that does not exist is not an error."
          if ( !$to_principal->Exists() ) continue;
          if ( !array_key_exists($to_principal->principal_id(), $existing_grants) ) continue;

          $remaining_privileges = $existing_grants[$to_principal->principal_id()] & ($privileges ^ DAVICAL_MAXPRIV);
          if ($remaining_privileges > 0) {
            $sql = 'UPDATE grants SET privileges=:privileges::INT::BIT(24) ';
            $sqlparams[':privileges'] = $remaining_privileges;
          } else {
            $sql = 'DELETE FROM grants ';
          }

          $sqlparams[':to_principal'] = $to_principal->principal_id();
          $qry->QDo($sql.'WHERE by_principal = :by_principal AND to_principal = :to_principal', $sqlparams);

          dbg_error_log("PROPPATCH", "group-member-set: %s is no longer granted %s access to %s", $to_principal->username(), $type, $by_principal);
          Principal::cacheFlush('principal_id = :to_principal', $sqlparams);
        }
      }
      else {
          /* @todo PROPPATCH remove group-member-set for regular group principal */
          dbg_error_log("ERROR", "PROPPATCH: remove group-member-set for non-proxy collection: don't know what to do!");
          add_failure('rm', $tag, 'HTTP/1.1 403 Forbidden',
            'group-member-set ' . translate('unimplemented'), 'cannot-modify-protected-property');
          break;
      }
      $success[$tag] = 1;
      break;

    case 'urn:ietf:params:xml:ns:caldav:calendar-timezone':
      if ( $dav_resource->IsCollection() && $dav_resource->IsCalendar() && ! $dav_resource->IsBinding() ) {
        $qry->QDo('UPDATE collection SET timezone = NULL WHERE dav_name = :dav_name', array( ':dav_name' => $dav_resource->dav_name()) );
        require_once("instance_range.php");
        update_instance_ranges($dav_resource->dav_name());
      }
      else {
        add_failure('rm', $tag, 'HTTP/1.1 403 Forbidden',
              translate("calendar-timezone property is only valid for a calendar."), 'cannot-modify-protected-property');
      }
      break;

    /**
    * The following properties are read-only, so they will cause the request to fail
    */
    case 'http://calendarserver.org/ns/:getctag':
    case 'DAV::owner':
    case 'DAV::principal-collection-set':
    case 'urn:ietf:params:xml:ns:caldav:CALENDAR-USER-ADDRESS-SET':
    case 'urn:ietf:params:xml:ns:caldav:schedule-inbox-URL':
    case 'urn:ietf:params:xml:ns:caldav:schedule-outbox-URL':
    case 'DAV::getetag':
    case 'DAV::getcontentlength':
    case 'DAV::getcontenttype':
    case 'DAV::getlastmodified':
    case 'DAV::creationdate':
    case 'DAV::displayname':
    case 'DAV::lockdiscovery':
    case 'DAV::supportedlock':
    case 'DAV::group-membership':
    case 'http://calendarserver.org/ns/:calendar-proxy-read-for':
    case 'http://calendarserver.org/ns/:calendar-proxy-write-for':
      add_failure('rm', $tag, 'HTTP/1.1 409 Conflict', translate("Property is read-only"));
      dbg_error_log( 'PROPPATCH', ' RMProperty %s is read only and cannot be removed', $tag);
      break;

    /**
    * If we don't have any special processing then we must have to just delete it.  Nonexistence is not failure.
    */
    default:
      $qry->QDo('DELETE FROM property WHERE dav_name=:dav_name AND property_name=:property_name',
                  array( ':dav_name' => $dav_resource->dav_name(), ':property_name' => $tag) );
      $success[$tag] = 1;
      break;
  }
}


/**
* If we have encountered any instances of failure, the whole damn thing fails.
*/
if ( count($failure) > 0 ) {

  $qry->Rollback();

  $url = ConstructURL($request->path);
  $multistatus = new XMLElement('multistatus');
  array_unshift($failure,new XMLElement('responsedescription', translate("Some properties were not able to be changed.") ));
  array_unshift($failure,new XMLElement('href', $url));
  $response = $reply->DAVElement($multistatus,'response', $failure);

  if ( !empty($success) ) {
    $prop = new XMLElement('prop');
    foreach( $success AS $tag => $v ) {
      $reply->NSElement($prop, $tag);
    }
    $reply->DAVElement($response, 'propstat', array( $prop, new XMLElement( 'status', 'HTTP/1.1 424 Failed Dependency' )) );
  }
  $request->DoResponse( 207, $reply->Render($multistatus), 'text/xml; charset="utf-8"' );

}

/**
* Otherwise we will try and do the SQL. This is inside a transaction, so PostgreSQL guarantees the atomicity
*/
if ( $qry->Commit() ) {

  $cache = getCacheInstance();
  $cache_ns = null;
  if ( $dav_resource->IsPrincipal() ) {
    $cache_ns = 'principal-'.$dav_resource->dav_name();
  }
  else if ( $dav_resource->IsCollection() ) {
    // Uncache anything to do with the collection
    $cache_ns = 'collection-'.$dav_resource->dav_name();
  }

  if ( isset($cache_ns) ) $cache->delete( $cache_ns, null );

  if ( $request->PreferMinimal() ) {
    $request->DoResponse(200); // Does not return.
  }

  $url = ConstructURL($request->path);
  $multistatus = new XMLElement('multistatus');
  $response = $multistatus->NewElement('response');
  $reply->DAVElement($response,'href', $url);
  $reply->DAVElement($response,'responsedescription', translate("All requested changes were made.") );

  $prop = new XMLElement('prop');
  foreach( $success AS $tag => $v ) {
    $reply->NSElement($prop, $tag);
  }
  $reply->DAVElement($response, 'propstat', array( $prop, new XMLElement( 'status', 'HTTP/1.1 200 OK' )) );

  $url = ConstructURL($request->path);
  array_unshift( $failure, new XMLElement('href', $url ) );

  $request->DoResponse( 207, $reply->Render($multistatus), 'text/xml; charset="utf-8"' );
}

/**
* Or it was all crap.
*/
$request->DoResponse( 500 );
exit(0); // unneccessary