<?php
/**
 * Simple datasource decorator: Modal
 *
 * $Id$
 *
 * @author gERD Schaufelberger <gerd@php-tools.net>
 * @license PHP License
 * @package WB
 * @subpackage db
 */

WBClass::load('WBDatasource_Decorator');

/**
 * Simple datasource decorator: Modal
 *
 * @version 0.1.0
 * @package WB
 * @subpackage db
 */
class WBDatasource_Decorator_Modal extends WBDatasource_Decorator
{
    /**
     * decorator's parameter list
     *
     * Parameters:
     * - columns: list of columns to decorate
     * - span: number of items to calculate average of
     * - format: number format as in sprintf()
     *
     * @var array
     */
    protected $parameter    =   array(
                                'span'      =>  14,
                                'column'    =>  array(),
                                'format'    =>  '%d'
                            );

    /**
     * store values for each column to calculate average
     * @var array
     */
    private $buffer =   array();

    /**
     * setup column buffers
     */
    public function onStart(&$item)
    {
        $this->parameter['span']  = intval($this->parameter['span']);
        foreach ($this->parameter['column'] as $c) {#
            $this->buffer[$c]   =   array();
            $item[$c . '_mod']  =   null;
        }
    }

    /**
     * actually decorate list item
     *
     * @param array $item
     * @return void
     */
    public function decorate(&$item)
    {
        foreach ($this->buffer as $c => &$b) {
            if (count($b) >= $this->parameter['span']) {
                array_shift($b);
            }

            $b[]    =   $item[$c];

            if (count($b) != $this->parameter['span']) {
                $item[$c . '_mod']  =   null;
                continue;
            }

            $count  =   array();
            foreach($b as $v) {
                if (isset($count[$v])) {
                    ++$count[$v];
                } else {
                    $count[$v]  =   1;
                }
            }
            $max    =   1;
            $modal  =   array();
            foreach($count as $v => $c) {
                if ($c > $max) {
                    $max        =   $c;
                    $modal      =   array($v);
                } else if ($c == $max) {
                    $modal[]    =   $v;
                }
            }
            $item[$c . '_mod']  =   sprintf($this->parameter['format'], min($modal));
        }
    }
}
?>