<?php

class Qs_View_Helper_Pagination extends Zend_View_Helper_Abstract
{
    const TYPE_LINK  = 'link';
    const TYPE_TEXT  = 'text';

    const PAGE_FIRST    = 'first';
    const PAGE_LAST     = 'last';
    const PAGE_NEXT     = 'next';
    const PAGE_PREVIOUS = 'previous';


    protected $classActive = 'active';
    protected $classDisabled = 'disabled';

    protected $pageCount;
    protected $itemCountPerPage;
    protected $first;
    protected $current;
    protected $last;
    protected $next;
    protected $previous;
    protected $pagesInRange = [];
    protected $firstPageInRange;
    protected $lastPageInRange;
    protected $currentItemCount;
    protected $totalItemCount;
    protected $firstItemNumber;
    protected $lastItemNumber;
    protected $url;
    protected $firstUrl;
    protected $pagePlaceholder;
    protected $ipp;
    protected $changeableIpp = false;
    protected $ippList = [];

    protected $containerTag = 'div';
    protected $containerAttribs = ['class' => 'pagination pagination-centered clearfix'];
    protected $infoTag = 'div';
    protected $infoAttribs = ['class' => 'pull-left'];
    protected $ippControlTag = 'div';
    protected $ippControlClass = 'input-mini';
    protected $ippControlName = 'paginator-ipp';
    protected $ippControlAttribs = ['class' => 'pull-right'];
    protected $ippTemplate = 'Items per page: %control%';
    protected $infoTemplate = 'Showing %firstItemNumber% - %lastItemNumber% of %totalItemCount%';
    protected $pagesTag = 'ul';
    protected $pageTag = 'li';

    protected $firstPageTitle = '« First';
    protected $previousPageTitle = '< Previous';
    protected $nextPageTitle = 'Next > ';
    protected $lastPageTitle = 'Last »';

    function __invoke(array $options = [])
    {
        return $this->pagination($options);
    }

    public function setOptions(array $options = [])
    {
        foreach ($options as $name => $value) {
            if (!property_exists($this, $name)) {
                throw new Exception('Undefined pagination property: ' . $name);
            }
            $this->$name = $value;
        }
        return $this;
    }

    public function pagination(array $options = [])
    {
        $this->setOptions($options);
        return $this;
    }

    public function isEmpty()
    {
        return $this->pageCount <= 1 || $this->totalItemCount <= reset($this->ippList);
    }

    protected function openTag($tag, array $attribs = [])
    {
        return '<' . $tag . $this->_renderAttribs($attribs) . '>';
    }

    protected function closeTag($tag)
    {
        return '</' . $tag . '>';
    }

    protected function _renderAttribs(array $attribs)
    {
        $xhtml = '';
        foreach ((array) $attribs as $key => $val) {
            $key = htmlspecialchars($key, ENT_COMPAT, 'UTF-8');
            if (is_array($val)) {
                $val = implode(' ', $val);
            }
            $val    = htmlspecialchars($val, ENT_COMPAT, 'UTF-8');
            $xhtml .= " $key=\"$val\"";
        }
        return $xhtml;
    }

    public function openContainer()
    {
        return $this->openTag($this->containerTag, $this->containerAttribs);
    }

    public function closeContainer()
    {
        return $this->closeTag($this->containerTag);
    }

    public function renderInfo()
    {
        $placeholders = get_object_vars($this);
        $placeholders = array_filter($placeholders, 'is_numeric');
        return $this->openTag($this->infoTag, $this->infoAttribs)
            . Qs_String::fill($this->infoTemplate, $placeholders)
            . $this->closeTag($this->infoTag);
    }

    public function renderPages()
    {
        $html = '';
        if ($this->pageCount <= 1) {
            return $html;
        }
        $html .= $this->openTag($this->pagesTag);
        $html .= $this->renderFirstPage();
        $html .= $this->renderPreviousPage();
        foreach ($this->pagesInRange as $number) {
            $html .= $this->renderPage($number);
        }
        $html .= $this->renderNextPage();
        $html .= $this->renderLastPage();
        $html .= $this->closeTag($this->pagesTag);
        return $html;
    }

    protected function renderHtmlContainer($tag, $attributes, $html)
    {
        return $this->openTag($tag, $attributes) . $html . $this->closeTag($tag);
    }

    public function renderFirstPage()
    {
        return $this->renderPage(self::PAGE_FIRST);
    }

    public function renderPreviousPage()
    {
        return $this->renderPage(self::PAGE_PREVIOUS);
    }

    public function renderNextPage()
    {
        return $this->renderPage(self::PAGE_NEXT);
    }

    public function renderLastPage()
    {
        return $this->renderPage(self::PAGE_LAST);
    }

    public function getPageUrl($number)
    {
        if ($this->first == $number) {
            return $this->firstUrl;
        }
        return str_replace($this->pagePlaceholder, $number, $this->url);
    }

    public function renderPage($number)
    {
        $type = self::TYPE_LINK;
        $class = null;
        switch ($number) {
            case self::PAGE_FIRST:
                $number = $this->first;
                $title = $this->firstPageTitle;
                if ($this->first == $this->current) {
                    $type = self::TYPE_TEXT;
                    $class = $this->classDisabled;
                }
                break;
            case self::PAGE_PREVIOUS:
                $number = $this->previous;
                $title = $this->previousPageTitle;
                if (null === $this->previous) {
                    $type = self::TYPE_TEXT;
                    $class = $this->classDisabled;
                }
                break;
            case self::PAGE_NEXT:
                $number = $this->next;
                $title = $this->nextPageTitle;
                if (null === $this->next) {
                    $type = self::TYPE_TEXT;
                    $class = $this->classDisabled;
                }
                break;
            case self::PAGE_LAST:
                $number = $this->last;
                $title = $this->lastPageTitle;
                if ($this->current == $this->last) {
                    $type = self::TYPE_TEXT;
                    $class = $this->classDisabled;
                }
                break;
            default:
                $title = $number;
                if ($number == $this->current) {
                    $type = self::TYPE_TEXT;
                    $class = $this->classActive;
                }
                break;
        }
        if (self::TYPE_LINK == $type) {
            return $this->renderHtmlContainer(
                $this->pageTag,
                [],
                $this->renderHtmlContainer('a', ['href' => $this->getPageUrl($number)], $this->view->escape($title))
            );
        }
        return $this->renderHtmlContainer(
            $this->pageTag,
            ['class' => $class],
            $this->renderHtmlContainer('span', [], $this->view->escape($title))
        );
    }

    public function renderIppControl()
    {
        $html = '';
        if (!$this->changeableIpp) {
            return $html;
        }
        $html .= $this->openTag($this->ippControlTag, $this->ippControlAttribs);
        $control = $this->view->formSelect(
            $this->ippControlName,
            $this->ipp,
            [
                'value'    => $this->ipp,
                'class'    => $this->ippControlClass,
                'onchange' => 'qs.paginator.setIpp(this.value);',
            ],
            array_combine($this->ippList, $this->ippList)
        );
        $html .= Qs_String::fill($this->ippTemplate, compact('control'));
        $html .= $this->closeTag($this->ippControlTag);
        return $html;
    }

    public function __toString()
    {
        $html = '';
        if ($this->isEmpty()) {
            return $html;
        }
        $html .= $this->openContainer();
        $html .= $this->renderInfo();
        $html .= $this->renderPages();
        $html .= $this->renderIppControl();
        $html .= $this->closeContainer();
        return $html;
    }
}