<?php

class Qs_View_Helper_DateRange extends Zend_View_Helper_Abstract
{
    /*
     * November 26, 2012
     * November 26 - 28, 2012
     * November 26 - December 28, 2012
     * November 26, 2012 - December 28, 2013
     */
    protected $_formats = array(
        array('F j, Y', null),
        array('F j', 'j, Y'),
        array('F j', 'F j, Y'),
        array('F j, Y', 'F j, Y'),
    );

    /**
     * Returns human readable date range
     * @param string $startDate
     * @param string $endDate
     * @return string
     */
    public function dateRange($startDate, $endDate)
    {
        $text = '';
        $startDate = ($start = strtotime($startDate)) ? date('Y-m-d', $start) : null;
        $endDate = ($end = strtotime($endDate)) ? date('Y-m-d', $end) : null;
        if ($startDate && $endDate) {
            $startPart = $startDate;
            $endPart = $endDate;

            for ($formatIdx = 0; $formatIdx < 3; ++$formatIdx) {
                if ($startPart === $endPart) {
                    break;
                }
                $startPart = substr($startPart, 0, strrpos($startPart, '-'));
                $endPart = substr($endPart, 0, strrpos($endPart, '-'));
            }
            $format = $this->_formats[$formatIdx];

            $text = date($format[0], $start);
            if (isset($format[1])) {
                $text .= ' - ' . date($format[1], $end);
            }
        }
        return $text;
    }
}