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

WBClass::load('WBDatasource_Filler');

/**
 * Simple datasource filler: Ungap
 *
 * @version 0.1.1
 * @package WB
 * @subpackage db
 */
class WBDatasource_Filler_Ungap extends WBDatasource_Filler
{
    /**
     * fillers's parameter list
     *
     * Concrete classes fill these with default paremeter
     * @var array
     */
    protected $parameter    =   array(
                                    'column'    =>  '',
                                    'step'      =>  1.0,
                                    'fill'      =>  '__EMPTY'
                                );

    /**
     * Last value
     * @var float
     */
    private $last   =   0;

    /**
     * Start handler
     *
     * Things to do at first item
     *
     * @param array $item
     * @return void
     */
    public function onStart(&$item)
    {
        $this->last =   floatval($item[$this->parameter['column']]);
    }

    /**
     * actually decorate list item
     *
     * @param array $item
     * @return bool true to continue
     */
    public function mergeItem2List($item, &$list)
    {
        $new    =   floatval($item[$this->parameter['column']]);
        $gap    =   $new  - $this->last;
        $step   =   $this->parameter['step'];

        $fill   =   $this->parameter['fill'];
        switch ($fill) {
            case '__EMPTY';
                $fill   =   '';
                break;
            case '__NULL';
                $fill   =   null;
                break;
            case '__ZERO';
                $fill   =   0;
                break;
        }


        // no fill needed
        if ($gap <= $step) {
            $list       =   array($item);
            $this->last =   $new;
            return true;
        }

        // fill up gaps
        $list   =   array();
        $proto  =   $item;
        foreach ($proto as $k => &$v) {
            $v  =   $fill;
        }
        for ($i = $this->last + $step; $i < $new; $i += $step) {
            $proto[$this->parameter['column']]  =   $i;
            $list[] =   $proto;
        }
        $list[] =   $item;
        $this->last =   $new;

        return true;
    }

}