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

/**
 * @summary     AlphabetSearch
 * @description Show an set of alphabet buttons alongside a table providing
 *     search input options
 * @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.
 * 
 * License      MIT - http://datatables.net/license/mit
 *
 * For more detailed information please see:
 *     http://datatables.net/blog/2014-09-22
 */
(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 ( searchData[0].charAt(0) === context.alphabetSearch ) {
		return true;
	}

	return false;
} );


// Private support methods
function bin ( data ) {
	var letter, bins = {};

	for ( var i=0, ien=data.length ; i<ien ; i++ ) {
		letter = data[i].charAt(0).toUpperCase();

		if ( bins[letter] ) {
			bins[letter]++;
		}
		else {
			bins[letter] = 1;
		}
	}

	return bins;
}

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

	var columnData = table.column(0).data();
	var bins = bin( columnData );

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


}());