<?php

/**
 * Kunena Component
 *
 * @package         Kunena.Framework
 * @subpackage      Pagination
 *
 * @copyright       Copyright (C) 2005 - 2013 Open Source Matters, Inc. All rights reserved.
 * @copyright       Copyright (C) 2008 - @currentyear@ Kunena Team. All rights reserved.
 * @license         https://www.gnu.org/copyleft/gpl.html GNU/GPL
 * @link            https://www.kunena.org
 **/

namespace Kunena\Forum\Libraries\Pagination;

\defined('_JEXEC') or die();

use Exception;
use Joomla\CMS\Factory;
use Joomla\CMS\HTML\HTMLHelper;
use Joomla\CMS\Language\Text;
use Joomla\CMS\Layout\LayoutHelper;
use Joomla\CMS\Pagination\PaginationObject;
use Joomla\CMS\Router\Route;
use Joomla\CMS\Uri\Uri;
use Kunena\Forum\Libraries\Factory\KunenaFactory;
use Kunena\Forum\Libraries\Route\KunenaRoute;
use stdClass;

/**
 * Pagination Class. Provides a common interface for content pagination for the Joomla! CMS.
 *
 * @package     Joomla.Libraries
 * @subpackage  Pagination
 * @since       1.5
 */
class KunenaPagination
{
    /**
     * @var    integer  The record number to start displaying from.
     * @since  1.5
     */
    public $limitstart = null;

    /**
     * @var    integer  Number of rows to display per page.
     * @since  1.5
     */
    public $limit = null;

    /**
     * @var    integer  Total number of rows.
     * @since  1.5
     */
    public $total = null;

    /**
     * @var    integer  Prefix used for request variables.
     * @since  1.6
     */
    public $prefix = null;

    /**
     * @var    integer  Value pagination object begins at
     * @since  3.0
     */
    public $pagesStart;

    /**
     * @var    integer  Value pagination object ends at
     * @since  3.0
     */
    public $pagesStop;

    /**
     * @var    integer  Current page
     * @since  3.0
     */
    public $pagesCurrent;

    /**
     * @var    integer  Total number of pages
     * @since  3.0
     */
    public $pagesTotal;

    /**
     * @var     integer
     * @since   Kunena 6.0
     */
    public $stickyStart = null;

    /**
     * @var     integer
     * @since   Kunena 6.0
     */
    public $stickyStop = null;

    /**
     * @var     Uri
     * @since   Kunena 6.0
     */
    public $uri = null;

    /**
     * @var    boolean  View all flag
     * @since  3.0
     */
    protected $viewall = false;

    /**
     * @var     null
     * @since   Kunena 6.0
     */
    protected $itemActiveChrome = null;

    /**
     * @var     null
     * @since   Kunena 6.0
     */
    protected $itemInactiveChrome = null;

    /**
     * @var     null
     * @since   Kunena 6.0
     */
    protected $listChrome = null;

    /**
     * @var     null
     * @since   Kunena 6.0
     */
    protected $footerChrome = null;

    /**
     * Additional URL parameters to be added to the pagination URLs generated by the class.  These
     * may be useful for filters and extra values when dealing with lists and GET requests.
     *
     * @var    array
     * @since  3.0
     */
    protected $additionalUrlParams = [];

    /**
     * Constructor.
     *
     * @param   integer  $total       The total number of items.
     * @param   integer  $limitstart  The offset of the item to start at.
     * @param   integer  $limit       The number of items to display per page.
     * @param   string   $prefix      The prefix used for request variables.
     *
     * @since   1.5
     */
    public function __construct(int $total, $limitstart, int $limit, $prefix = '')
    {
        // Value/type checking.
        $this->total      = (int) $total;
        $this->limitstart = (int) max($limitstart, 0);
        $this->limit      = (int) max($limit, 0);
        $this->prefix     = $prefix;

        if ($this->limit > $this->total) {
            $this->limitstart = 0;
        }

        if (!$this->limit) {
            $this->limit      = $total;
            $this->limitstart = 0;
        }

        /*
         * If limitstart is greater than total (i.e. we are asked to display records that don't exist)
         * then set limitstart to display the last natural page of results
         */
        if ($this->limitstart > $this->total - $this->limit) {
            $this->limitstart = max(0, (int) (ceil($this->total / $this->limit) - 1) * $this->limit);
        }

        // Set the total pages and current page values.
        if ($this->limit > 0) {
            $this->pagesTotal   = ceil($this->total / $this->limit);
            $this->pagesCurrent = ceil(($this->limitstart + 1) / $this->limit);
        }

        $this->setDisplayedPages();

        // If we are viewing all records set the view all flag to true.
        if ($limit == 0) {
            $this->viewall = true;
        }
    }

    /**
     * Set number of displayed pages.
     *
     * @param   int  $displayed  Number of displayed pages.
     * @param   int  $start      How many items to display from the beginning (1 2 ...)
     * @param   int  $end        How many items to display from the end (... 49 50)
     *
     * @return  KunenaPagination  Method supports chaining.
     *
     * @since   Kunena 6.0
     */
    public function setDisplayedPages($displayed = 10, $start = 0, $end = 0): KunenaPagination
    {
        $this->stickyStart = $start;
        $this->stickyStop  = $end;

        // Set the pagination iteration loop values.
        $this->pagesStart = $this->pagesCurrent - (int) ($displayed / 2);

        if ($this->pagesStart < 1 + $start) {
            $this->pagesStart = 1 + $start;
        }

        if ($this->pagesStart + $displayed - $start > $this->pagesTotal) {
            $this->pagesStop = $this->pagesTotal;

            if ($this->pagesTotal < $displayed) {
                $this->pagesStart = 1 + $start;
            } else {
                $this->pagesStart = $this->pagesTotal - $displayed + 1 + $start;
            }
        } else {
            $this->pagesStop = $this->pagesStart + $displayed - 1 - $end;
        }

        $this->pagesStop  = max(1, $this->pagesStop);
        $this->pagesTotal = max(1, $this->pagesTotal);

        return $this;
    }

    /**
     * Set URI for pagination.
     *
     * @param   Uri  $uri  Joomla\CMS\Uri\Uri object.
     *
     * @return  KunenaPagination  Method supports chaining.
     *
     * @since   Kunena 6.0
     */
    public function setUri(Uri $uri): KunenaPagination
    {
        $this->uri = clone $uri;

        return $this;
    }

    /**
     * Method to set an additional URL parameter to be added to all pagination class generated
     * links.
     *
     * @param   string  $key    The name of the URL parameter for which to set a value.
     * @param   mixed   $value  The value to set for the URL parameter.
     *
     * @return  mixed  The old value for the parameter.
     *
     * @since   1.6
     */
    public function setAdditionalUrlParam(string $key, $value)
    {
        // Get the old value to return and set the new one for the URL parameter.
        $result = isset($this->additionalUrlParams[$key]) ? $this->additionalUrlParams[$key] : null;

        // If the passed parameter value is null unset the parameter, otherwise set it to the given value.
        if ($value === null) {
            unset($this->additionalUrlParams[$key]);
        } else {
            $this->additionalUrlParams[$key] = $value;
        }

        return $result;
    }

    /**
     * Method to get an additional URL parameter (if it exists) to be added to
     * all pagination class generated links.
     *
     * @param   string  $key  The name of the URL parameter for which to get the value.
     *
     * @return  mixed  The value if it exists or null if it does not.
     *
     * @since   1.6
     */
    public function getAdditionalUrlParam(string $key)
    {
        return isset($this->additionalUrlParams[$key]) ? $this->additionalUrlParams[$key] : null;
    }

    /**
     * Return the rationalised offset for a row with a given index.
     *
     * @param   integer  $index  The row index
     *
     * @return int|null Rationalised offset for a row with a given index.
     *
     * @since   1.5
     */
    public function getRowOffset(int $index): ?int
    {
        return $index + 1 + $this->limitstart;
    }

    /**
     * Return the pagination data object, only creating it if it doesn't already exist.
     *
     * @return  object   Pagination data object.
     *
     * @since   1.5
     */
    public function getData()
    {
        // Do not have static cache here (if needed, keep it in object context).
        return $this->_buildDataObject();
    }

    /**
     * Create and return the pagination data object.
     *
     * @return  object  Pagination data object.
     *
     * @since   1.5
     */
    protected function _buildDataObject()
    {
        $data = new stdClass();

        if (!$this->uri) {
            $this->uri = KunenaRoute::$current;
        }

        // Build the additional URL parameters string.
        foreach ($this->additionalUrlParams as $key => $value) {
            $this->uri->setVar($key, $value);
        }

        $limitstartKey = $this->prefix . 'limitstart';

        $data->all = new PaginationObject(Text::_('JLIB_HTML_VIEW_ALL'), $this->prefix);

        if (!$this->viewall) {
            $this->uri->delVar($limitstartKey);
            $data->all->base = '0';
            $data->all->link = Route::_((string) $this->uri);
        }

        // Set the start and previous data objects.
        $data->start    = new PaginationObject(Text::_('JLIB_HTML_START'), $this->prefix);
        $data->previous = new PaginationObject(Text::_('JPREV'), $this->prefix);

        if ($this->pagesCurrent > 1) {
            $page = ($this->pagesCurrent - 2) * $this->limit;

            $this->uri->setVar($limitstartKey, '0');
            $data->start->base = '0';
            $data->start->link = Route::_((string) $this->uri);

            $this->uri->setVar($limitstartKey, $page);
            $data->previous->base = $page;
            $data->previous->link = Route::_((string) $this->uri);
        }

        // Set the next and end data objects.
        $data->next = new PaginationObject(Text::_('JNEXT'), $this->prefix);
        $data->end  = new PaginationObject(Text::_('JLIB_HTML_END'), $this->prefix);

        if ($this->pagesCurrent < $this->pagesTotal) {
            $next = $this->pagesCurrent * $this->limit;
            $end  = ($this->pagesTotal - 1) * $this->limit;

            $this->uri->setVar($limitstartKey, $next);
            $data->next->base = $next;
            $data->next->link = Route::_((string) $this->uri);

            $this->uri->setVar($limitstartKey, $end);
            $data->end->base = $end;
            $data->end->link = Route::_((string) $this->uri);
        }

        $data->pages = [];
        $range       = range($this->pagesStart, $this->pagesStop);

        $range[] = 1;
        $range[] = $this->pagesTotal;
        sort($range);

        foreach ($range as $i) {
            $offset = ($i - 1) * $this->limit;

            $data->pages[$i] = new PaginationObject($i, $this->prefix);

            if ($i != $this->pagesCurrent || $this->viewall) {
                $this->uri->setVar($limitstartKey, $offset);
                $data->pages[$i]->base = $offset;
                $data->pages[$i]->link = Route::_((string) $this->uri);
            } elseif ($i == $this->pagesCurrent) {
                $data->pages[$i]->active = true;
            }
        }

        return $data;
    }

    /**
     * Create and return the pagination result set counter string, e.g. Results 1-10 of 42
     *
     * @return  string   Pagination result set counter string.
     *
     * @since   1.5
     */
    public function getResultsCounter(): string
    {
        $html       = null;
        $fromResult = $this->limitstart + 1;

        // If the limit is reached before the end of the list.
        if ($this->limitstart + $this->limit < $this->total) {
            $toResult = $this->limitstart + $this->limit;
        } else {
            $toResult = $this->total;
        }

        // If there are results found.
        if ($this->total > 0) {
            $msg  = Text::sprintf('JLIB_HTML_RESULTS_OF', $fromResult, $toResult, $this->total);
            $html .= "\n" . $msg;
        } else {
            $html .= "\n" . Text::_('JLIB_HTML_NO_RECORDS_FOUND');
        }

        return $html;
    }

    /**
     * Return the pagination footer.
     *
     * @return  string  Pagination footer.
     *
     * @since   1.5
     *
     * @throws  Exception
     */
    public function getListFooter(): string
    {
        $list                 = [];
        $list['prefix']       = $this->prefix;
        $list['limit']        = $this->limit;
        $list['limitstart']   = $this->limitstart;
        $list['total']        = $this->total;
        $list['limitfield']   = $this->getLimitBox();
        $list['pagescounter'] = $this->getPagesCounter();
        $list['pageslinks']   = $this->getPagesLinks();

        $this->setChrome();

        return \call_user_func($this->footerChrome, $list);
    }

    /**
     * Creates a dropdown box for selecting how many records to show per page.
     *
     * @param   bool  $all  True if you want to display option for all.
     *
     * @return  string  The HTML for the limit # input box.
     *
     * @since   1.5
     *
     * @throws  Exception
     */
    public function getLimitBox($all = false): string
    {
        $app    = Factory::getApplication();
        $limits = [];

        // Make the option list.
        for ($i = 5; $i <= 30; $i += 5) {
            $limits[] = HTMLHelper::_('select.option', "$i");
        }

        $limits[] = HTMLHelper::_('select.option', '50', Text::_('J50'));
        $limits[] = HTMLHelper::_('select.option', '100', Text::_('J100'));

        if ($all) {
            $limits[] = HTMLHelper::_('select.option', '0', Text::_('JALL'));
        }

        $selected = $this->viewall ? 0 : $this->limit;

        // Build the select list.
        if ($app->isClient('administrator')) {
            $html = HTMLHelper::_(
            	'select.genericlist',
            	$limits,
            	$this->prefix . 'limit',
            	'class="inputbox input-mini form-control" size="1" onchange="Joomla.submitform();"',
            	'value',
            	'text',
            	$selected
            );
        } else {
            $html = HTMLHelper::_(
            	'select.genericlist',
            	$limits,
            	$this->prefix . 'limit',
            	'class="inputbox input-mini form-control" size="1" onchange="this.form.submit()"',
            	'value',
            	'text',
            	$selected
            );
        }

        return $html;
    }

    /**
     * Create and return the pagination pages counter string, ie. Page 2 of 4.
     *
     * @return string|null Pagination pages counter string.
     *
     * @since   1.5
     */
    public function getPagesCounter(): ?string
    {
        $html = null;

        if ($this->pagesTotal > 1) {
            $html .= Text::sprintf('JLIB_HTML_PAGE_CURRENT_OF_TOTAL', $this->pagesCurrent, $this->pagesTotal);
        }

        return $html;
    }

    /**
     * Create and return the pagination page list string, ie. Previous, Next, 1 2 3 ... x.
     *
     * @return  string  Pagination page list string.
     *
     * @since   1.5
     *
     * @throws  Exception
     */
    public function getPagesLinks(): string
    {
        if ($this->total <= $this->limit) {
            return '';
        }

        // Build the page navigation list.
        $data = $this->_buildDataObject();

        $list           = [];
        $list['prefix'] = $this->prefix;

        $this->setChrome();

        // Build the select list
        if ($data->all->base !== null) {
            $list['all']['active'] = true;
            $list['all']['data']   = \call_user_func($this->itemActiveChrome, $data->all);
        } else {
            $list['all']['active'] = false;
            $list['all']['data']   = \call_user_func($this->itemInactiveChrome, $data->all);
        }

        if ($data->start->base !== null) {
            $list['start']['active'] = true;
            $list['start']['data']   = \call_user_func($this->itemActiveChrome, $data->start);
        } else {
            $list['start']['active'] = false;
            $list['start']['data']   = \call_user_func($this->itemInactiveChrome, $data->start);
        }

        if ($data->previous->base !== null) {
            $list['previous']['active'] = true;
            $list['previous']['data']   = \call_user_func($this->itemActiveChrome, $data->previous);
        } else {
            $list['previous']['active'] = false;
            $list['previous']['data']   = \call_user_func($this->itemInactiveChrome, $data->previous);
        }

        // Make sure it exists
        $list['pages'] = [];

        foreach ($data->pages as $i => $page) {
            if ($page->base !== null) {
                $list['pages'][$i]['active'] = true;
                $list['pages'][$i]['data']   = \call_user_func($this->itemActiveChrome, $page);
            } else {
                $list['pages'][$i]['active'] = false;
                $list['pages'][$i]['data']   = \call_user_func($this->itemInactiveChrome, $page);
            }
        }

        if ($data->next->base !== null) {
            $list['next']['active'] = true;
            $list['next']['data']   = \call_user_func($this->itemActiveChrome, $data->next);
        } else {
            $list['next']['active'] = false;
            $list['next']['data']   = \call_user_func($this->itemInactiveChrome, $data->next);
        }

        if ($data->end->base !== null) {
            $list['end']['active'] = true;
            $list['end']['data']   = \call_user_func($this->itemActiveChrome, $data->end);
        } else {
            $list['end']['active'] = false;
            $list['end']['data']   = \call_user_func($this->itemInactiveChrome, $data->end);
        }

        return \call_user_func($this->listChrome, $list);
    }

    /**
     * @return  void
     *
     * @since   Kunena 6.0
     *
     * @throws  Exception
     */
    protected function setChrome(): void
    {
        $template                 = KunenaFactory::getTemplate();
        $this->itemActiveChrome   = [$template, 'getPaginationItemActive'];
        $this->itemInactiveChrome = [$template, 'getPaginationItemInactive'];
        $this->listChrome         = [$template, 'getPaginationListRender'];
        $this->footerChrome       = [$template, 'getPaginationListFooter'];
    }

    /**
     * Return the icon to move an item UP.
     *
     * @param   integer  $i          The row index.
     * @param   boolean  $condition  True to show the icon.
     * @param   string   $task       The task to fire.
     * @param   string   $alt        The image alternative text string.
     * @param   boolean  $enabled    An optional setting for access control on the action.
     * @param   string   $checkbox   An optional prefix for checkboxes.
     *
     * @return  string   Either the icon to move an item up or a space.
     *
     * @since   1.5
     */
    public function orderUpIcon(int $i, $condition = true, $task = 'orderup', $alt = 'JLIB_HTML_MOVE_UP', $enabled = true, $checkbox = 'cb'): string
    {
        if (($i > 0 || ($i + $this->limitstart > 0)) && $condition) {
            return HTMLHelper::_('jgrid.orderUp', $i, $task, '', $alt, $enabled, $checkbox);
        }

        return '&#160;';
    }

    /**
     * Return the icon to move an item DOWN.
     *
     * @param   integer  $i          The row index.
     * @param   integer  $n          The number of items in the list.
     * @param   boolean  $condition  True to show the icon.
     * @param   string   $task       The task to fire.
     * @param   string   $alt        The image alternative text string.
     * @param   boolean  $enabled    An optional setting for access control on the action.
     * @param   string   $checkbox   An optional prefix for checkboxes.
     *
     * @return  string   Either the icon to move an item down or a space.
     *
     * @since   1.5
     */
    public function orderDownIcon(int $i, int $n, $condition = true, $task = 'orderdown', $alt = 'JLIB_HTML_MOVE_DOWN', $enabled = true, $checkbox = 'cb'): string
    {
        if (($i < $n - 1 || $i + $this->limitstart < $this->total - 1) && $condition) {
            return HTMLHelper::_('jgrid.orderDown', $i, $task, '', $alt, $enabled, $checkbox);
        }

        return '&#160;';
    }

    /**
     * Create the HTML for a list footer
     *
     * @param   array  $list  Pagination list data structure.
     *
     * @return  string  HTML for a list footer
     *
     * @since   1.5
     */
    protected function _list_footer(array $list): string
    {
        $html = "<div class=\"list-footer\">\n";

        $html .= "\n<div class=\"limit\">" . Text::_('JGLOBAL_DISPLAY_NUM') . $list['limitfield'] . "</div>";
        $html .= $list['pageslinks'];
        $html .= "\n<div class=\"counter\">" . $list['pagescounter'] . "</div>";

        $html .= "\n<input type=\"hidden\" name=\"" . $list['prefix'] . "limitstart\" value=\"" . $list['limitstart'] . "\" />";
        $html .= "\n</div>";

        return $html;
    }

    /**
     * Create the html for a list footer
     *
     * @param   array  $list  Pagination list data structure.
     *
     * @return  string  HTML for a list start, previous, next,end
     *
     * @since   1.5
     */
    protected function _list_render(array $list): string
    {
        // Reverse output rendering for right-to-left display.
        $html = '<ul>';
        $html .= '<li class="pagination-start">' . $list['start']['data'] . '</li>';
        $html .= '<li class="pagination-prev">' . $list['previous']['data'] . '</li>';

        foreach ($list['pages'] as $page) {
            $html .= '<li>' . $page['data'] . '</li>';
        }

        $html .= '<li class="pagination-next">' . $list['next']['data'] . '</li>';
        $html .= '<li class="pagination-end">' . $list['end']['data'] . '</li>';
        $html .= '</ul>';

        return $html;
    }

    /**
     * Method to create an active pagination link to the item
     *
     * @param   PaginationObject  $item  The object with which to make an active link.
     *
     * @return  string  HTML link
     *
     * @since   1.5
     */
    protected function _item_active(PaginationObject $item)
    {
        return LayoutHelper::render('joomla.pagination.link', ['data' => $item, 'active' => true]);
    }

    /**
     * Method to create an inactive pagination string
     *
     * @param   PaginationObject  $item  The item to be processed
     *
     * @return  string
     *
     * @since   1.5
     */
    protected function _item_inactive(PaginationObject $item)
    {
        return LayoutHelper::render('joomla.pagination.link', ['data' => $item, 'active' => false]);
    }
}