<?php
// $Revision: 1.1.2.9 $
// ------------------------------------------------------------------------- //
//  XooNIps - Neuroinformatics Base Platform System                          //
//  Copyright (C) 2005-2011 RIKEN, Japan All rights reserved.                //
//  http://xoonips.sourceforge.jp/                                           //
// ------------------------------------------------------------------------- //
//  This program is free software; you can redistribute it and/or modify     //
//  it under the terms of the GNU General Public License as published by     //
//  the Free Software Foundation; either version 2 of the License, or        //
//  (at your option) any later version.                                      //
//                                                                           //
//  You may not change or alter any portion of this comment or credits       //
//  of supporting developers from this source code or any supporting         //
//  source code which is considered copyrighted (c) material of the          //
//  original comment or credit authors.                                      //
//                                                                           //
//  This program is distributed in the hope that it will be useful,          //
//  but WITHOUT ANY WARRANTY; without even the implied warranty of           //
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            //
//  GNU General Public License for more details.                             //
//                                                                           //
//  You should have received a copy of the GNU General Public License        //
//  along with this program; if not, write to the Free Software              //
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA //
// ------------------------------------------------------------------------- //

class OAIPMHHarvester {
    var $_dateFormat;
    var $_earliestDatestamp;
    var $_baseUrl;
    var $_metadataPrefix;
    var $_lastError;
    var $_lastStatus;
    var $_repositoryName;

    //public
    function OAIPMHHarvester( $_baseUrl ) {
        $this->_baseUrl = $_baseUrl;
        $this->_lastError = null;
        $this->_lastStatus = null;
        $this->_metadataPrefix = null;
        $this->_dateFormat = null;
        $this->_earliestDatestamp = null;
        $this->_repositoryName = '';
    }
    function __construct( $_baseUrl ) {
        /* constructer for PHP5 */
        $this->OAIPMHHarvester( $_baseUrl );
    }
    function harvest( ) {
        global $xoopsDB;
        $handler =& xoonips_getormhandler( 'xoonips', 'oaipmh_repositories');

        $ts =& MyTextSanitizer::getInstance( );

        $criteria = new Criteria( 'URL' , $this->_baseUrl );
        $repository =& $handler->getObjects( $criteria );
        if( !$repository ) {
            return false;
        }
        $repository[0] -> set( 'last_access_date', time() );
        $repository[0] -> set( 'last_access_result', null );
        if( $handler -> insert( $repository[0], true ) ) {
            if( $this->Identify( ) ) {
                $unicode =& xoonips_getutility( 'unicode' );
                $repository[0]
                    -> set( 'repository_name',
                            $unicode->decode_utf8(
                                $this -> _repositoryName,
                                xoonips_get_server_charset(),'h') );
                $handler -> insert( $repository[0], true );
                if( $this->ListMetadataFormats( ) ) {
                    $args = array( 'metadataPrefix' => $this->_metadataPrefix );
                    if( '' == $repository[0]->get( 'last_success_date' ) )
                        $args['from'] = gmdate( $this->_dateFormat,
                                                $this->_earliestDatestamp );
                    else
                        $args['from']
                            = gmdate( $this->_dateFormat,
                                      $repository[0]->get('last_success_date'));
                    
                    if( $this->ListRecords( $args ) ) {
                        //update repositories table
                        $repository[0] -> set( 'last_access_result',
                                               $this->_lastStatus );
                        $repository[0] -> set( 'last_success_date', time( ) );
                        $repository[0] -> set('metadata_count',
                                              $this->getMetadataCount(
                                                  $repository[0] -> get(
                                                      'repository_id' ) ) );
                        return $handler -> insert( $repository[0], true );
                    }
                }
            }
        } else
            $this->_lastError = $xoopsDB->error( );
        
        //update repositories table(last_access_result)
        $repository[0] -> set( 'last_access_result', $this->_lastError );
        $handler -> insert( $repository[0], true );
        return false;
    }
    function last_error( ) {
        return $this->_lastError;
    }

    //private
    function Identify( ) {
        $snoopy =& xoonips_getutility( 'snoopy' );
        if ( ! is_object( $snoopy ) ) {
            $this->_lastError = 'snoopy object is null';
            return false;
        }
        $url = $this->_baseUrl."?verb=Identify";
        if ( ! $snoopy->fetch( $url ) ) {
            $this->_lastError = "can't retrieve ".$url;
            return false;
        }
        $this->_lastError = $http_status = $snoopy->response_code;

        $this->parser = xml_parser_create( 'UTF-8' );
        if( !$this->parser ) {
            $this->_lastError = "can't create XML parser";
            return false;
        }
        $handler = new IdentifyHandler( $this->parser );

        $result = $this->parse( $snoopy->results );
        if( !$result )
            // some error has occured in parse( $snoopy->results );
            return false;
        xml_parser_free( $this->parser );

        $this->_dateFormat = $handler->getDateFormat( );
        if( !$this->_dateFormat ) {
            $this->_lastError = "value of <granularity> is wrong";
            return false;
        }

        $this->_earliestDatestamp = $handler->getEarliestDatestamp( );
        $this->_repositoryName = $handler->getRepositoryName( );

        return true;
    }

    function ListMetadataFormats( ) {
        $snoopy =& xoonips_getutility( 'snoopy' );
        if ( ! is_object( $snoopy ) ) {
            $this->_lastError = 'snoopy object is null';
            return false;
        }
        $url = $this->_baseUrl."?verb=ListMetadataFormats";
        if ( ! $snoopy->fetch( $url ) ) {
            $this->_lastError = "can't retrieve ".$url;
            return false;
        }
        $this->_lastError = $http_status = $snoopy->response_code;

        $this->parser = xml_parser_create( 'UTF-8' );
        if( !$this->parser ) {
            $this->_lastError = "can't create XML parser";
            return false;
        }
        $handler = new ListMetadataFormatsHandler( $this->parser );

        $result = $this->parse( $snoopy->results );
        if( !$result )
            // some error has occured in parse( $snoopy->results );
            return false;   
        xml_parser_free( $this->parser );

        $this->_metadataPrefix = $handler->getMetadataPrefix( );
        if( !$this->_metadataPrefix ) {
            $this->_metadataPrefix = null;
            $this->_lastError = "can't retrieve <metadataPrefix>";
            return false;
        }
        return true;
    }

    function ListRecords( $args ) {
        global $xoopsDB;
        if( !isset( $args['metadataPrefix'] ) ) {
            $this->_lastError = "'metadataPrefix' is not specified.";
            return false;
        }
        $resumptionToken = null;
        do {
            $url = $this->_baseUrl."?verb=ListRecords";
            if( $resumptionToken == null )
                foreach( array( 'metadataPrefix',
                                'from',
                                'until',
                                'set' ) as $k ) {
                if( isset( $args[$k] ) )
                    $url .= "&".urlencode( $k )."=".urlencode( $args[$k] );
            } else {
                $url .= "&resumptionToken="
                    .htmlspecialchars( $resumptionToken, ENT_QUOTES );
            }
            $snoopy =& xoonips_getutility( 'snoopy' );
            if ( ! is_object( $snoopy ) ) {
                $this->_lastError = "can't retrieve ${url}";
                $xoopsDB -> setLogger( XoopsLogger::instance() );
                return false;
            }
            if ( ! $snoopy->fetch( $url ) ) {
                $this->_lastError = "can't retrieve ${url}";
                $xoopsDB -> setLogger( XoopsLogger::instance() );
                return false;
            }
            $this->_lastError = $this->_lastStatus = $snoopy->response_code;

            $this->parser = xml_parser_create( 'UTF-8' );
            if( !$this->parser ) {
                $this->_lastError = "can't create XML parser";
                $xoopsDB -> setLogger( XoopsLogger::instance() );
                return false;
            }
            
            $listRecordsHandler
                =& $this -> createListRecordsHandler( $this->parser,
                                                      $this->_baseUrl,
                                                      $args['metadataPrefix'] );
            $result = $this->parse( $snoopy->results );
            if( !$result ) {
                //some erorr has occured
                if( $listRecordsHandler->getIdentifier( ) != null )
                    $this->_lastError .= "[identifier]"
                        .$listRecordsHandler->getIdentifier( );
                $xoopsDB -> setLogger( XoopsLogger::instance() );
                //some error has occured in parse( $snoopy->results );
                return false;
            }
            xml_parser_free( $this->parser );
            $resumptionToken = $listRecordsHandler->getResumptionToken( );
        } while( $resumptionToken != null );
        $xoopsDB -> setLogger( XoopsLogger::instance() );
        return true;
    }

    function parse( &$data ) {
        if( !xml_parse( $this->parser, $data ) ) {
            $this->_lastError = "[XMLParser]"
                .xml_error_string( xml_get_error_code( $this->parser ) )
                ." at line ".xml_get_current_line_number( $this->parser )
                .", column ".xml_get_current_column_number( $this->parser );
            xml_parser_free( $this->parser );
            return false;
        }
        return true;
    }

    /**
     * return number of metadata of repository
     * @access private 
     * @param int $repository_id id of repository to get metadata count.
     * @return integer number of metadata or zero if failure.
     */
    function getMetadataCount( $repository_id ){
        $metadata_handler =& xoonips_getormhandler( 'xoonips',
                                                    'oaipmh_metadata');
        
        $metadata_criteria = new Criteria( 'repository_id' ,
                                           intval($repository_id) );
        $rows =& $metadata_handler->getObjects( $metadata_criteria,
                                               false, 'count(*)' );
        if( !$rows ){
            return 0;
        }else{
            return $rows[0] -> getExtraVar( 'count(*)' );
        }
    }

    /**
     * 
     * @access private
     * @param 
     * @param 
     * @param 
     * @return 
     * 
     */
    function& createListRecordsHandler( $parser, $baseUrl, $metadataPrefix ){
        $result = false;
        switch( $metadataPrefix ){
        case 'oai_dc':
            include_once dirname( __FILE__ )
                .'/oaipmh_oaidc_list_records_handler.class.php';
            $result = new OaidcListRecordsHandler( $parser, $baseUrl );
            break;
        case 'junii':
            include_once dirname( __FILE__ )
                .'/oaipmh_junii_list_records_handler.class.php';
            $result = new JuniiListRecordsHandler( $parser, $baseUrl );
            break;
        case 'junii2':
            include_once dirname( __FILE__ )
                .'/oaipmh_junii2_list_records_handler.class.php';
            $result = new Junii2ListRecordsHandler( $parser, $baseUrl );
            break;
        }
        return $result;
    }
}

