<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Paginator
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Paginator.php 10362 2008-07-24 15:49:12Z mratzloff $
 */

/**
 * @see Zend_Loader_PluginLoader
 */
require_once 'Zend/Loader/PluginLoader.php';

/**
 * @category   Zend
 * @package    Zend_Paginator
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Paginator implements Countable, IteratorAggregate
{
    /**
     * Config file
     *
     * @var Zend_Config
     */
    protected static $_config = null;
    
    /**
     * Default scrolling style
     *
     * @var string
     */
    protected static $_defaultScrollingStyle = 'Sliding';

    /**
     * Scrolling style plugin loader
     *
     * @var Zend_Loader_PluginLoader
     */
    protected static $_scrollingStyleLoader = null;

    /**
     * Adapter
     *
     * @var Zend_Paginator_Adapter_Interface
     */
    protected $_adapter = null;

    /**
     * Number of items in the current page
     *
     * @var integer
     */
    protected $_currentItemCount = null;

    /**
     * Current page items
     *
     * @var Iterator
     */
    protected $_currentItems = null;

    /**
     * Current page number (starting from 1)
     *
     * @var integer
     */
    protected $_currentPageNumber = 1;

    /**
     * Number of items per page
     *
     * @var integer
     */
    protected $_itemCountPerPage = 10;

    /**
     * Number of pages
     *
     * @var integer
     */
    protected $_pageCount = null;

    /**
     * A collection of page items used as temporary page cache
     *
     * @var array
     */
    protected $_pageItems = array();
    
    /**
     * Number of local pages (i.e., the number of discrete page numbers
     * that will be displayed, including the current page number)
     *
     * @var integer
     */
    protected $_pageRange = 10;

    /**
     * Pages
     *
     * @var array
     */
    protected $_pages = null;
    
    /**
     * View instance used for self rendering
     *
     * @var Zend_View_Interface
     */
    protected $_view = null;

    /**
     * Adds a scrolling style prefix path to the plugin loader.
     *
     * @param string $prefix
     * @param string $path
     */
    public static function addScrollingStylePrefixPath($prefix, $path)
    {
        self::getScrollingStyleLoader()->addPrefixPath($prefix, $path);
    }

    /**
     * Adds an array of scrolling style prefix paths to the plugin 
     * loader.
     *
     * <code>
     * $prefixPaths = array(
     *     'My_Paginator_ScrollingStyle'   => 'My/Paginator/ScrollingStyle/',
     *     'Your_Paginator_ScrollingStyle' => 'Your/Paginator/ScrollingStyle/'
     * );
     * </code>
     *
     * @param array $prefixPaths
     */
    public static function addScrollingStylePrefixPaths(array $prefixPaths)
    {
        if (isset($prefixPaths['prefix']) && isset($prefixPaths['path'])) {
            self::addScrollingStylePrefixPath($prefixPaths['prefix'], $prefixPaths['path']);
        } else {
            foreach ($prefixPaths as $prefix => $path) {
                if (is_array($path) && isset($path['prefix']) && isset($path['path'])) {
                    $prefix = $path['prefix'];
                    $path   = $path['path'];
                }
                
                self::addScrollingStylePrefixPath($prefix, $path);
            }
        }
    }
    
    /**
     * Returns the scrolling style loader.  If it doesn't exist it's
     * created.
     *
     * @return Zend_Loader_PluginLoader
     */
    public static function getScrollingStyleLoader()
    {
        if (self::$_scrollingStyleLoader === null) {
            self::$_scrollingStyleLoader = new Zend_Loader_PluginLoader(
                array('Zend_Paginator_ScrollingStyle' => 'Zend/Paginator/ScrollingStyle')
            );
        }
        
        return self::$_scrollingStyleLoader;
    }

    /**
     * Factory.
     *
     * @param  array|Zend_Db_Select|Iterator $data
     * @return Zend_Paginator
     * @throws Zend_Paginator_Exception
     */
    public static function factory($data)
    {
        if (is_array($data)) {
            /**
             * @see Zend_Paginator_Adapter_Array
             */
            require_once 'Zend/Paginator/Adapter/Array.php';
            
            $paginator = new self(new Zend_Paginator_Adapter_Array($data));
        } else if ($data instanceof Zend_Db_Select) {
            /**
             * @see Zend_Paginator_Adapter_DbSelect
             */
            require_once 'Zend/Paginator/Adapter/DbSelect.php';
            
            $paginator = new self(new Zend_Paginator_Adapter_DbSelect($data));
        } else if ($data instanceof Iterator) {
            /**
             * @see Zend_Paginator_Adapter_Iterator
             */
            require_once 'Zend/Paginator/Adapter/Iterator.php';
            
            $paginator = new self(new Zend_Paginator_Adapter_Iterator($data));
        } else if (is_int($data)) {
            /**
             * @see Zend_Paginator_Adapter_Null
             */
            require_once 'Zend/Paginator/Adapter/Null.php';
            
            $paginator = new self(new Zend_Paginator_Adapter_Null($data));
        } else {
            $type = (is_object($data)) ? get_class($data) : gettype($data);
            
            /**
             * @see Zend_Paginator_Exception
             */
            require_once 'Zend/Paginator/Exception.php';
            
            throw new Zend_Paginator_Exception('No adapter for type ' . $type);
        }

        return $paginator;
    }
    
    /**
     * Set a global config
     *
     * @param Zend_Config $config
     */
    public static function setConfig(Zend_Config $config)
    {
        self::$_config = $config;
        
        $scrollingStyle = $config->get('scrollingstyle');
        
        if ($scrollingStyle != null) {
            self::setDefaultScrollingStyle($scrollingStyle);
        }
        
        $prefixPaths = $config->get('prefixpaths');
        
        if ($prefixPaths != null) {
            self::addScrollingStylePrefixPaths($prefixPaths->prefixpath->toArray());
        }
    }

    /**
     * Gets the default scrolling style.
     *
     * @return  string
     */
    public static function getDefaultScrollingStyle()
    {
        return self::$_defaultScrollingStyle;
    }
    
    /**
     * Sets the default scrolling style.
     *
     * @param  string $scrollingStyle
     */
    public static function setDefaultScrollingStyle($scrollingStyle = 'Sliding')
    {
        self::$_defaultScrollingStyle = $scrollingStyle;
    }

    /**
     * Constructor.
     */
    public function __construct(Zend_Paginator_Adapter_Interface $adapter)
    {
        $this->_adapter = $adapter;
        
        $config = self::$_config;
        
        if ($config != null) {
            $setupMethods = array('ItemCountPerPage', 'PageRange');
            
            foreach ($setupMethods as $setupMethod) {
                $value = $config->get(strtolower($setupMethod));
                
                if ($value != null) {
                    $setupMethod = 'set' . $setupMethod;
                    $this->$setupMethod($value);
                }
            }
        }
    }
    
    /**
     * Serialize as string
     *
     * Proxies to {@link render()}.
     * 
     * @return string
     */
    public function __toString()
    {
        try {
            $return = $this->render();
            return $return;
        } catch (Exception $e) {
            trigger_error($e->getMessage(), E_USER_WARNING);
        }
        
        return '';
    }
    
    /**
     * Returns the number of pages.
     *
     * @return integer
     */
    public function count()
    {
        if (!$this->_pageCount) {
            $this->_pageCount = $this->_calculatePageCount();
        }
        
        return $this->_pageCount;
    }
    
    /**
     * Get the absolute item number for the specified item
     *
     * @param int $relativeItemNumber
     * @param int $pageNumber
     * @return int
     */
    public function getAbsoluteItemNumber($relativeItemNumber, $pageNumber = null)
    {
        $relativeItemNumber = $this->normalizeItemNumber($relativeItemNumber);
        
        if ($pageNumber == null) {
            $pageNumber = $this->getCurrentPageNumber();
        }
        
        $pageNumber = $this->normalizePageNumber($pageNumber);
        
        return (($pageNumber - 1) * $this->getItemCountPerPage()) + $relativeItemNumber;
    }
    
    /**
     * Get the adapter
     *
     * @return Zend_Paginator_Adapter_Interface
     */
    public function getAdapter()
    {
        return $this->_adapter;
    }
    
    /**
     * Returns the number of items for the current page.
     *
     * @return integer
     */
    public function getCurrentItemCount()
    {
        if ($this->_currentItemCount === null) {
            $this->_currentItemCount = $this->getItemCount($this->getCurrentItems());
        }
        
        return $this->_currentItemCount;
    }
    
    /**
     * Returns the items for the current page.
     *
     * @return ArrayIterator
     */
    public function getCurrentItems()
    {
        if ($this->_currentItems === null) {
            $this->_currentItems = $this->getItemsByPage($this->getCurrentPageNumber());
        }
        
        return $this->_currentItems;
    }

    /**
     * Returns the current page number.
     *
     * @return integer
     */
    public function getCurrentPageNumber()
    {
        return $this->normalizePageNumber($this->_currentPageNumber);
    }
    
    /**
     * Sets the current page number.
     *
     * @param  integer $pageNumber Page number
     * @return Zend_Paginator $this
     */
    public function setCurrentPageNumber($pageNumber)
    {
        $this->_currentPageNumber = $pageNumber;
        $this->_currentItems      = null;
        $this->_currentItemCount  = null;
        
        return $this;
    }
    
    /**
     * Get an item from a page. The current page is used if there's no page sepcified.
     *
     * @param int $itemNumber Item number. Valid range: 1 - itemCountPerPage
     * @param int $pageNumber
     * @return ArrayIterator
     */
    public function getItem($itemNumber, $pageNumber = null)
    {
        $itemNumber = $this->normalizeItemNumber($itemNumber);
        
        if ($pageNumber == null) {
            $pageNumber = $this->getCurrentPageNumber();
        }
        
        $page = $this->getItemsByPage($pageNumber);
        $itemCount = $this->getItemCount($page);
        
        if ($itemCount == 0) {
            /**
             * @see Zend_Paginator_Exception
             */
            require_once 'Zend/Paginator/Exception.php';
            
            throw new Zend_Paginator_Exception('Page ' . $pageNumber . ' is empty. '
                                             . 'Probably no data to paginate.');
        }
        
        if ($itemNumber > $itemCount) {
            /**
             * @see Zend_Paginator_Exception
             */
            require_once 'Zend/Paginator/Exception.php';
            
            throw new Zend_Paginator_Exception('Page ' . $pageNumber . ' does not'
                                             . ' contain item number ' . $itemNumber);
        }
        
        return $page[$itemNumber - 1];
    }

    /**
     * Returns the number of items per page.
     *
     * @return integer
     */
    public function getItemCountPerPage()
    {
        return $this->_itemCountPerPage;
    }
    
    /**
     * Sets the number of items per page.
     *
     * @param  integer $itemCountPerPage
     * @return Zend_Paginator $this
     */
    public function setItemCountPerPage($itemCountPerPage)
    {
        $this->_itemCountPerPage = $itemCountPerPage;
        $this->_pageCount        = $this->_calculatePageCount();
        $this->_pageItems        = array();
        $this->_currentItems     = null;
        $this->_currentItemCount = null;
        
        return $this;
    }

    /**
     * Returns the number of items in a collection.
     *
     * @param  mixed $items Items
     * @return integer
     */
    public function getItemCount($items)
    {
        $itemCount = 0;
        
        if (is_array($items) || $items instanceof Countable) {
            $itemCount = count($items);
        } else { // $items is something like LimitIterator
            foreach ($items as $item) {
                $itemCount++;
            }
        }

        return $itemCount;
    }

    /**
     * Returns the items for a given page.
     *
     * @return ArrayIterator
     */
    public function getItemsByPage($pageNumber)
    {
        $pageNumber = $this->normalizePageNumber($pageNumber);
        
        if (isset($this->_pageItems[$pageNumber])) {
            return $this->_pageItems[$pageNumber];
        }
        
        $offset = ($pageNumber - 1) * $this->_itemCountPerPage;
        
        $items = $this->_adapter->getItems($offset, $this->_itemCountPerPage);
        
        if (!$items instanceof Iterator) {
            $items = new ArrayIterator($items);
        }
        
        $this->_pageItems[$pageNumber] = $items;
        
        return $items;
    }

    /**
     * Returns a foreach-compatible iterator.
     *
     * @return ArrayIterator
     */
    public function getIterator()
    {
        return $this->getCurrentItems();
    }
    
    /**
     * Returns the page range (see property declaration above).
     *
     * @return integer
     */
    public function getPageRange()
    {
        return $this->_pageRange;
    }
    
    /**
     * Sets the page range (see property declaration above).
     *
     * @param  integer $pageRange
     * @return Zend_Paginator $this
     */
    public function setPageRange($pageRange)
    {
        $this->_pageRange = $pageRange;
        
        return $this;
    }

    /**
     * Returns the page collection.
     *
     * @param  string $scrollingStyle Scrolling style
     * @return array
     */
    public function getPages($scrollingStyle = null)
    {
        if ($this->_pages === null) {
            $this->_pages = $this->_createPages($scrollingStyle);
        }
        
        return $this->_pages;
    }

    /**
     * Returns a subset of pages within a given range.
     *
     * @param  integer $lowerBound Lower bound of the range
     * @param  integer $upperBound Upper bound of the range
     * @return array
     */
    public function getPagesInRange($lowerBound, $upperBound)
    {
        $lowerBound = $this->normalizePageNumber($lowerBound);
        $upperBound = $this->normalizePageNumber($upperBound);
        
        $pages = array();
        
        for ($pageNumber = $lowerBound; $pageNumber <= $upperBound; $pageNumber++) {
            $pages[$pageNumber] = $pageNumber;
        }
        
        return $pages;
    }
    
    /**
     * Retrieve view object
     *
     * If none registered, attempts to pull from ViewRenderer.
     * 
     * @return Zend_View_Interface|null
     */
    public function getView()
    {
        if (null === $this->_view) {
            /**
             * @see Zend_Controller_Action_HelperBroker
             */
            require_once 'Zend/Controller/Action/HelperBroker.php';
            
            $viewRenderer = Zend_Controller_Action_HelperBroker::getStaticHelper('viewRenderer');
            if (null === $viewRenderer->view) {
                $viewRenderer->initView();
            }
            $this->_view = $viewRenderer->view;
        }

        return $this->_view;
    }
    
    /**
     * Set view object
     * 
     * @param  Zend_View_Interface $view 
     * @return Zend_Paginator
     */
    public function setView(Zend_View_Interface $view = null)
    {
        $this->_view = $view;
        
        return $this;
    }
    
    /**
     * Bring the item number in range of the page
     *
     * @param int $itemNumber
     * @return int
     */
    public function normalizeItemNumber($itemNumber)
    {
        if ($itemNumber < 1) {
            $itemNumber = 1;
        }
        
        if ($itemNumber > $this->_itemCountPerPage) {
            $itemNumber = $this->_itemCountPerPage;
        }
        
        return $itemNumber;
    }
    
    /**
     * Bring the page number in range of the paginator
     *
     * @param int $pageNumber
     * @return int
     */
    public function normalizePageNumber($pageNumber)
    {
        if ($pageNumber < 1) {
            $pageNumber = 1;
        }
        
        $pageCount = $this->count();
        
        if ($pageCount > 0 && $pageNumber > $pageCount) {
            $pageNumber = $pageCount;
        }
        
        return $pageNumber;
    }
    
    /**
     * Render the paginator
     * 
     * @param  Zend_View_Interface $view 
     * @return string
     */
    public function render(Zend_View_Interface $view = null)
    {
        if (null !== $view) {
            $this->setView($view);
        }

        $view = $this->getView();
        
        return $view->paginationControl($this);
    }

    /**
     * Calculate the page count
     *
     * @return int
     */
    protected function _calculatePageCount()
    {
        return (int) ceil($this->_adapter->count() / $this->_itemCountPerPage);
    }

    /**
     * Creates the page collection.
     *
     * @param  string $scrollingStyle Scrolling style
     * @return stdClass
     */
    protected function _createPages($scrollingStyle = null)
    {
        $pageCount = $this->count();
        $currentPageNumber = $this->getCurrentPageNumber();
        
        $pages = new stdClass();
        $pages->pageCount        = $pageCount;
        $pages->itemCountPerPage = $this->getItemCountPerPage();
        $pages->first            = 1;
        $pages->current          = $currentPageNumber;
        $pages->last             = $pageCount;

        // Previous and next
        if ($currentPageNumber - 1 > 0) {
            $pages->previous = $currentPageNumber - 1;
        }

        if ($currentPageNumber + 1 <= $pageCount) {
            $pages->next = $currentPageNumber + 1;
        }

        // Pages in range
        $scrollingStyle = $this->_loadScrollingStyle($scrollingStyle);
        $pages->pagesInRange     = $scrollingStyle->getPages($this);
        $pages->firstPageInRange = min($pages->pagesInRange);
        $pages->lastPageInRange  = max($pages->pagesInRange);

        // Item numbers
        if ($this->getCurrentItems() !== null) {
            $pages->currentItemCount = $this->getCurrentItemCount();
            $pages->totalItemCount   = $this->_adapter->count();
            $pages->firstItemNumber  = (($currentPageNumber - 1) * $this->_itemCountPerPage) + 1;
            $pages->lastItemNumber   = $pages->firstItemNumber + $pages->currentItemCount - 1;
        }

        return $pages;
    }
    
    /**
     * Load a ScrollingStyle
     *
     * @param string $scrollingStyle
     * @return Zend_Paginator_ScrollingStyle_Interface
     */
    protected function _loadScrollingStyle($scrollingStyle = null)
    {
        if ($scrollingStyle === null) {
            $scrollingStyle = self::$_defaultScrollingStyle;
        }
        
        $className = self::getScrollingStyleLoader()->load($scrollingStyle);
        
        return new $className();
    }
}