/*! AlphabetSearch for DataTables v1.0.0
 * 2014 SpryMedia Ltd - datatables.net/license
 */

/**
 * @summary     AlphabetSearch
 * @description Show an alphabet aloneside a table providing search input options 
 *              See http://datatables.net/blog/2014-09-22 for details 
 * @version     1.0.0   
 * @file        dataTables.alphabetSearch.js
 * @author      SpryMedia Ltd (www.sprymedia.co.uk)
 * @contact     www.sprymedia.co.uk/contact
 * @copyright   Copyright 2014 SpryMedia Ltd.
 *
 * This source file is free software, available under the following license:
 *   MIT license - http://datatables.net/license/mit
 *
 * This source file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the license files for details.
 *
 * For details please refer to: http://www.datatables.net
 */
(function(){


// Search function
$.fn.dataTable.Api.register( 'alphabetSearch()', function ( searchTerm ) {
        this.iterator( 'table', function ( context ) {
                context.alphabetSearch = searchTerm;
        } );    

        return this;
} );

// Recalculate the alphabet display for updated data
$.fn.dataTable.Api.register( 'alphabetSearch.recalc()', function ( searchTerm ) {
        this.iterator( 'table', function ( context ) {
                draw(   
                        new $.fn.dataTable.Api( context ),
                        $('div.alphabet', this.table().container())
                );      
        } );    

        return this;
} );


// Search plug-in 
$.fn.dataTable.ext.search.push( function ( context, searchData ) {
        // Ensure that there is a search applied to this table before running it
        if ( ! context.alphabetSearch ) {
                return true;
        }
        if ( context.alphabetSearch.match('nonalpha') && !(searchData[1].charAt(0).match(/^[a-zA-Z]/
                return true;
        }
        if ( searchData[1].charAt(0) === context.alphabetSearch ) {
                return true;
        }

        return false;
} );


// Private support methods
function bin ( data ) {
        var letter, bins = {};
        var nonalpha = 0;
        bins['nonalpha'] = 0;
        for ( var i=0, ien=data.length ; i<ien ; i++ ) {
                letter = data[i].charAt(13).toUpperCase();
                if ( !letter.match(/^[A-Z]/) ) {
                        bins['nonalpha']++;
                }
                else if ( bins[letter] ) {
                        bins[letter]++;
                }
                else {
                        bins[letter] = 1;
                }
        }
        return bins;
}

function draw ( table, alphabet )
{
        alphabet.empty();
        alphabet.append( 'Search: ' );

        var columnData = table.column(1).data();
        var bins = bin( columnData );

        $('<span class="clear active"/>')
                .data( 'letter', '' )
                .data( 'match-count', columnData.length )
                .html( 'None' )
                .appendTo( alphabet );

        $('<span class="clear active"/>')
                .data( 'letter', 'nonalpha' )
                .data( 'match-count', bins['nonalpha'] || 0 )
                .html( '0-9' )
                .appendTo( alphabet );

        for ( var i=0 ; i<26 ; i++ ) {
                var letter = String.fromCharCode( 65 + i );

                $('<span/>')
                        .data( 'letter', letter )
                        .data( 'match-count', bins[letter] || 0 )
                        .addClass( ! bins[letter] ? 'empty' : '' )
                        .html( letter )
                        .appendTo( alphabet );
        }

        $('<div class="alphabetInfo"></div>')
                .appendTo( alphabet );
}


$.fn.dataTable.AlphabetSearch = function ( context ) {
        var table = new $.fn.dataTable.Api( context );
        var alphabet = $('<div class="alphabet"/>');

        draw( table, alphabet );

        // Trigger a search
        alphabet.on( 'click', 'span', function () {
                alphabet.find( '.active' ).removeClass( 'active' );
                $(this).addClass( 'active' );

                table
                        .alphabetSearch( $(this).data('letter') )
                        .draw();
        } );

        // Mouse events to show helper information
        alphabet
                .on( 'mouseenter', 'span', function () {
                        alphabet
                                .find('div.alphabetInfo')
                                .css( {
                                        opacity: 1,
                                        left: $(this).position().left,
                                        width: $(this).width()
                                } )
                                .html( $(this).data('match-count') );
                } )
                .on( 'mouseleave', 'span', function () {
                        alphabet
                                .find('div.alphabetInfo')
                                .css('opacity', 0);
                } );

        // API method to get the alphabet container node
        this.node = function () {
                return alphabet;
        };
};

$.fn.DataTable.AlphabetSearch = $.fn.dataTable.AlphabetSearch;


// Register a search plug-in
$.fn.dataTable.ext.feature.push( {
        fnInit: function ( settings ) {
                var search = new $.fn.dataTable.AlphabetSearch( settings );
                return search.node();
        },
        cFeature: 'A'
} );


}());