<?php

/**
 *
 *
 * Class: Pagination
 *
 * Description: Extended pagination class
 * Version: 1.0
 *
 * @author: iamfake @ flashback
 *
 *
 *
 * Usage:
 *
 * //new pagination object
 * //params ( number_of_results, current_page/offset, limited_results_per_page, (optional|defaults to true)show_numeric_links )
 * $paging = new Pagination( count( $contents ), $offset, $limit, true );
 *
 * //setters
 * //set a unique identifier for this object (optional)
 * //will concatenated '_133t' to the end of the class identifier strings. (! to your own set with the chained method ->addClass())
 * $paging->uniqueIdentifier( '_1337' );
 *
 * //set some custom quicklinks (optional)
 * //addClass chains to the current array item
 * $paging->first( '&larr;' )->addClass( 'first' );
 * $paging->last( '&rarr;' )->addClass( 'last' );
 * $paging->next( '&raquo;' )->addClass( 'next' );
 * $paging->previous( '&laquo;' )->addClass( 'previous' );
 *
 * //args( number_to_jump, label/key (optional | defaults to int value of the jump) )
 * $paging->quickJump( 10, '&hellip;' )->addClass( 'quickJump' );
 *
 * //optional
 * $paging->limitedNumberOfLinks( 3 );
 * //if set to false quicklinks will be static
 * //and always visible on the page
 * //remove or set to true to make it dynamic (optional | defaults to true)
 * $paging->useDynamicQuickLinks( false );
 *
 *
 * //getters
 * //does what the method name suggest, returns set values
 * $paging->currentOffset()
 * $paging->limit()
 * $paging->currentPage()
 * $paging->totalNumberOfPages()
 * $paging->hasResults()
 *
 *
 * //return array of pagination links, takes 1 (optional) argument.
 * a classname for all the numeric links.
 * $paging->links( 'paging_default' )
 *
 *
 *
 * HTML Usage:
 *
 * <ul class="pagination">
 *  <?php foreach( $links as $link ): ?>
 *  <li class="<?php print $link['class']; ?>"><a href="?page=<?php print $link['value']; ?>"><?php print $link['key']; ?></a></li>
 *  <?php endforeach; ?>
 * </ul>
 *
 *
 *
 *
 */
final class Pagination
{

    private $_totalNumberOfResults,
            $_numberOfResultsPerPage,
            $_totalNumberOfPages,
            $_currentPage,
            $_showNumeric,
            $_currentItem       = null,
            $_uniqueIdentifier  = '',
            $_dynamicQuickLinks = true,
            $_links             = array(),
            $_gutter            = null,
            $_quickJump         = null,
            $_first             = null,
            $_last              = null,
            $_next              = null,
            $_previous          = null,
            $_iterator          = 1,
            $_limit;

    /**
     * construct
     *
     * @param $totalNumberOfResults, $currentPage, $numberOfResultsPerPage, $showNumeric
     * @return void
     */
    public function __construct( $totalNumberOfResults, $currentPage, $numberOfResultsPerPage, $showNumeric = true )
    {
        //validate inputtypes
        if( !is_integer( $totalNumberOfResults ) || !is_numeric( $currentPage ) || !is_integer( $numberOfResultsPerPage ) || !is_bool( $showNumeric ) )
        {
            throw new PaginationException( 'Please insert valid types.' );
        }

        //set class properties
        $this->_totalNumberOfResults    = $totalNumberOfResults;
        $this->_currentPage             = (int)$currentPage;
        $this->_numberOfResultsPerPage  = $numberOfResultsPerPage;
        $this->_showNumeric             = $showNumeric;

        //set the total amount of pages
        $this->_totalNumberOfPages      = (int)ceil( $totalNumberOfResults / $numberOfResultsPerPage );
        $this->_limit                   = $this->_totalNumberOfPages;
    }

    /**
     * if there are results to show
     *
     * @param
     * @return (bool) true|false
     */
    public function isValid()
    {
        if( $this->_totalNumberOfPages < $this->_currentPage )
        {
            return false;
        }

        return true;

    }

    /**
     * set unique identifier
     *
     * @param
     * @return void
     */
    public function uniqueIdentifier( $id = null )
    {
        if( !$id )
        {
            return $this->_uniqueIdentifier;
        }

        return $this->_uniqueIdentifier = $id;
    }

    /**
     * construct
     *
     * @param
     * @return void
     */
    public function currentPage()
    {
        return $this->_currentPage;
    }

    /**
     * construct
     *
     * @param
     * @return void
     */
    public function currentOffset()
    {
        return ( ( $this->_currentPage - 1 ) * $this->_numberOfResultsPerPage );
    }

    /**
     * construct
     *
     * @param
     * @return void
     */
    public function totalNumberOfPages()
    {
        return $this->_totalNumberOfPages;
    }

    /**
     * construct
     *
     * @param
     * @return void
     */
    public function limit()
    {
        return $this->_numberOfResultsPerPage;
    }

    /**
     * quickjump
     *
     * @param
     * @return void
     */
    public function quickJump( $value, $key = null )
    {

        if( !is_integer( $value ) )
        {
            throw new TemplateException( 'Please insert a valid INTEGER in method ' . __METHOD__ . ' for jump : "' . $value . '"' );
        }

        //calculate jump value
        $value = ( ( $this->_currentPage + $value ) <= $this->_totalNumberOfPages ) ? ( $this->_currentPage + $value ) : $this->_totalNumberOfPages;


        //if key is set use it else use value
        $key = ( $key ) ? $key : $value;

        $this->_quickJump = array( 'value' => $value, 'key' => $key, 'class' => '' );
        $this->_currentItem = &$this->_quickJump;
        return $this;
    }

    /**
     * limit pagination links
     *
     * @param $gutter
     * @return void
     */
    public function limitedNumberOfLinks( $gutter )
    {
        //validate input param.
        if( !is_integer( $gutter ) )
        {
            throw new PaginationException( 'Calling method : ' . __METHOD__ . ' with $gutter of type : ' . gettype( $gutter ) . ' expected INTEGER.' );
        }

        $this->_gutter = $gutter;
    }

    /**
     * setter for next link
     *
     * @param
     * @return self
     */
    public function next( $key )
    {
        $this->_next = array( 'key' => $key, 'value' => ( ( ($this->_currentPage + 1 ) < $this->_totalNumberOfPages ) ? ($this->_currentPage + 1 ) : $this->_totalNumberOfPages ) );
        $this->_currentItem     = &$this->_next;
        return $this;
    }

    /**
     * setter for previous link
     *
     * @param
     * @return self
     */
    public function previous( $key )
    {
        $this->_previous        = array( 'key' => $key, 'value' => ( ( ( $this->_currentPage - 1 ) >= 1 ) ? ( $this->_currentPage - 1 ) : 1 ) );
        $this->_currentItem     = &$this->_previous;
        return $this;
    }

    /**
     * setter for first link
     *
     * @param
     * @return self
     */
    public function first( $key )
    {
        $this->_first       = array( 'key' => $key, 'value' => 1 );
        $this->_currentItem = &$this->_first;
        return $this;
    }

    /**
     * setter for last link
     *
     * @param
     * @return self
     */
    public function last( $key )
    {
        $this->_last        = array( 'key' => $key, 'value' => $this->_totalNumberOfPages );
        $this->_currentItem = &$this->_last;
        return $this;
    }

    /**
     * Setter method to define if quicklinks should be static or dynamic.
     *
     * option to set quicklinks to be static or dynamic(default).
     *
     * @param (bool) $bool
     * @return void
     */
    public function useDynamicQuickLinks( $bool )
    {
        if( !is_bool( $bool ) )
        {
            throw new PaginationException( 'Value passed to method : ' . __METHOD__ . ' needs to be a boolean value.' );
        }

        $this->_dynamicQuickLinks = $bool;
    }

    /**
     * set class for specific item.
     *
     * chains to first, last, next, previous, jump
     *
     * @param
     * @return void
     */
    public function addClass( $classname )
    {
        if( !$this->_currentItem )
            throw new PaginationException( 'Please chain your class methods properly.' );
        $this->_currentItem[ 'class' ] = $classname . $this->_uniqueIdentifier;
    }

    /**
     * building the gutters
     *
     * set new iterator values
     *
     * @param
     * @return void
     */
    private function _defineNewGutters()
    {
        //total number of valid links
        $totalNumberOfValidLinks = ( $this->_gutter * 2 ) + 1;

        //
        if( $this->_currentPage <= $this->_gutter ){
            $this->_iterator = 1;
        }else if( $this->_currentPage + $this->_gutter >= $this->_totalNumberOfPages ){
            $this->_iterator = $this->_totalNumberOfPages - ($this->_gutter * 2);
        }else{
            $this->_iterator = $this->_currentPage - $this->_gutter;
        }

        //build limit based on gutters
        $this->_limit = ( ($this->_currentPage + $this->_gutter) <= $this->_totalNumberOfPages ) ? $this->_iterator + ($this->_gutter * 2) : ( $this->_totalNumberOfPages );
    }

    /**
     * build (array)$_links
     *
     * @param
     * @return void
     */
    private function _buildLinks( $classname )
    {
        //build dynamic links
        if( $this->_gutter && ( ( $this->_gutter * 2) + 1 ) < $this->_totalNumberOfPages )
        {
            $this->_defineNewGutters();
        }

        //set first link
        //check to see if isn't set, if so check to that it is available for showing.
        if( $this->_first && !$this->_dynamicQuickLinks || $this->_first && ( ( $this->_currentPage - $this->_gutter ) > 1 ) )
        {
            if( !$this->_dynamicQuickLinks && ( $this->_currentPage - $this->_gutter) <= 1 )
                $this->_first[ 'class' ] .= ' deactive firstDeactive' . $this->_uniqueIdentifier;

            $this->_links[] = $this->_first;
        }

        //set previous link
        //check to see if isn't set, if so check to that it is available for showing.
        if( $this->_previous && !$this->_dynamicQuickLinks || $this->_previous && ( $this->_currentPage > 1 ) )
        {
            if( !$this->_dynamicQuickLinks && ( $this->_currentPage <= 1 ) )
                $this->_previous[ 'class' ] .= ' deactive previousDeactive' . $this->_uniqueIdentifier;
            $this->_links[] = $this->_previous;
        }

        //create numerical links
        if( $this->_showNumeric )
        {

            for( $this->_iterator; $this->_iterator <= $this->_limit; $this->_iterator++ )
            {
                $this->_links[] = array( 'key' => $this->_iterator, 'value' => $this->_iterator ,'class' => $classname . $this->_uniqueIdentifier . ( ($this->_iterator == $this->_currentPage ) ? ' active' : '' ) );
            }

            //quick jump to page
            if( $this->_quickJump && !$this->_dynamicQuickLinks || $this->_quickJump && ( ( $this->_currentPage + $this->_gutter ) < $this->_totalNumberOfPages ) )
            {
                if( !$this->_dynamicQuickLinks && ( ( $this->_currentPage + $this->_gutter ) >= $this->_totalNumberOfPages ) )
                    $this->_quickJump[ 'class' ] .= ' deactive quickJumpDeactive' . $this->_uniqueIdentifier;
                $this->_links[] = $this->_quickJump;
            }
        }

        //set next page
        if( $this->_next && !$this->_dynamicQuickLinks || $this->_next && ( $this->_currentPage < $this->_totalNumberOfPages ) )
        {
            if( !$this->_dynamicQuickLinks && ( $this->_currentPage >= $this->_totalNumberOfPages ) )
                $this->_next[ 'class' ] .= ' deactive nextDeactive' . $this->_uniqueIdentifier;
            $this->_links[] = $this->_next;
        }

        //set lastpage
        if( $this->_last && !$this->_dynamicQuickLinks || $this->_last && ( ( $this->_currentPage + $this->_gutter ) < $this->_totalNumberOfPages ) )
        {
            if( !$this->_dynamicQuickLinks && ( ( $this->_currentPage + $this->_gutter ) >= $this->_totalNumberOfPages ) )
                $this->_last[ 'class' ] .= ' deactive lastDeactive' . $this->_uniqueIdentifier;
            $this->_links[] = $this->_last;
        }

    }

    /**
     * output links
     *
     * @param
     * @return (array) $links
     */
    public function links( $classname = '' )
    {
        //build links
        $this->_buildLinks( $classname );
        return $this->_links;
    }

}

class PaginationException extends Exception{}