<?php
/**
 * WBEvent_Handler_TableIndexer
 *
 *
 * $Id$
 *
 * @author gERD Schaufelberger <gerd@php-tools.net>
 * @license PHP License
 * @package WB
 * @subpackage base
 */

WBClass::load('WBEvent_Handler');

/**
 * WBEvent_Handler_TableIndexer
 *
 * concatenate list of columns into index table
 *
 * @version 0.2.1
 * @package Wombat
 * @subpackage base
 */
class WBEvent_Handler_TableIndexer extends WBEvent_Handler
{
    /**
     * table access
     * @var WBDatasource_Table
     */
    private $table;

    /**
     * handler config
     *
     * - table name of table to update
     * - column names to index
     * - foreign array list each having "table" and "columns"
     *
     * @var array
     */
    protected $config   =   array(
                                'table'         =>  '',
                                'culumns'       =>  array(),
                                'foreign'       =>  array()
                                );


    /**
     * update column in table
     *
     * Update exactly one column in one table for one row using primary key
     * Hence primary key is required, as well as column and table name.
     *
     * @param WBEvent $e
     * @return bool true to continue, false to stop processing
     * @throws Exception in case of error
     */
    public function process(WBEvent $e)
    {
        $table  =   $this->config['table'];
        $id     =   null;
        if (empty($this->config['table'])) {
            $table  =   $e->get('table');
        }
        $id =   $e->get('id');
        if (empty($id) || $id == '__new') {
            WBClass::load('WBException_Config');
            throw new WBException_Config('Key may not be empty or "__new"', 1, __CLASS__);
        }
        if (empty($this->config['columns'])) {
            WBClass::load('WBException_Config');
            throw new WBException_Config('List of columns must not be empty', 2, __CLASS__);
        }

        $this->table    =   WBClass::create('WBDatasource_Table');
        $this->table->switchTranslation(false);

        // removae old index
        $clause     =   array();
        $clause[]   =   array(
                            'field' =>  'namespace',
                            'value' =>  $table
                        );
        $clause[]   =   array(
                            'field' =>  'xid',
                            'value' =>  $id
                        );
        $this->table->delete('tableindex', null, null, $clause);

        // load origin
        $org    =   $this->table->get($table, $id);
        if (1 != count($org)) {
            return true;
        }
        $org    =   $org[0];

        $words  =   array();
        $this->addPrimaryWords($words, $org, $table, $id);
        $words  =   array_unique($words);

        // add words from foreign tables
        $this->addForeignWords($words, $org, $table, $id);
        $words  =   array_unique($words);

        // save word list
        $save   =   array();
        foreach ($words as $w) {
            $save[] =   array(
                            'namespace' =>  $table,
                            'xid'       =>  $id,
                            'word'      =>  $w
                        );
        }

        $this->table->save('tableindex', '__new', $save);
        return true;
    }

    /**
     * Add words from primary table
     *
     * @param array $words
     * @param array $data
     * @param string $table
     * @param string $id
     */
    private function addPrimaryWords(&$words, $data, $table, $id)
    {
        if (!is_array($this->config['columns'])) {
            return;
        }
        $this->addWords($words, $data, $this->config['columns']);
    }

    /**
     * Add words from foreign tables
     *
     * @param array $words
     * @param array $data
     * @param string $table
     * @param string $id
     */
    private function addForeignWords(&$words, $data, $table, $id)
    {
        if (!is_array($this->config['foreign'])) {
            return;
        }

        foreach ($this->config['foreign'] as $f) {
            if (!isset($f['table']) || empty($f['table'])) {
                continue;
            }
            if (!isset($f['columns']) || !is_array($f['columns']) || empty($f['columns'])) {
                continue;
            }

            $fKey   =   $this->table->getIdentifier($f['table']);
            $fData  =   $this->table->get($f['table'], $data[$fKey]);
            if (1 != count($fData)) {
                continue;
            }
            $fData  =   $fData[0];
            $this->addWords($words, $fData, $f['columns']);
        }
    }

    /**
     * Add words from data
     *
     * @param array $words
     * @param array $data
     * @param array $columns
     */
    private function addWords(&$words, $data, $columns)
    {
        // extract words for each colum
        foreach ($columns as $c) {
            $text   =   strip_tags($data[$c]);
            $text   =   str_replace(array('_', '-', '/', ';', ':', '.', ',', '!', '?', '"', '\'', '(', ')'), ' ', $text);
            $text   =   strtolower(trim(preg_replace('/\\s+/', ' ', $text)));
            if (empty($text)) {
                continue;
            }
            $words  =   array_merge($words, explode(' ', $text));
        }
    }
}
?>