/*
 * jQuery multiSuggeset Plugin v.01
 *
 * Copyright 2012, Rob Moen
 * http://sane.ly
 * This document is licensed as free software under the terms of the
 * MIT License: http://www.opensource.org/licenses/mit-license.php
 *
 * Example:
 *
	// Input element.
	var $input = $( '#exampleInput' );
	// Multi Suggest configuration.
	var options = {
		'parent': $input.parent(),
		'prefix': 'example-multi',

		// Build suggestion groups in order.
		'suggestions': function ( params ) {
			// Generic params object.
			var example = params.example,
				example2 = params.example2,
				query = params.query;
				groups = {
					// Set 1
					'query': {
						'label': 'Query',
						'items': [query],
						'itemClass': 'query-class'
					},
					// Set 2
					'exampleGroup': {
						'label': 'Example 1',
						'items': example,
						'itemClass': 'example-class'
					},
					// Set 3
					'exampleGroup2': {
						'label': 'Example 2',
						'items': example2,
						'itemClass': 'example-class'
					}
				};
			// Return the groups object.
			return groups;
		},
		// Called on succesfull input.
		'input': function ( callback ) {
			var query = $input.val();
			// Example params object.
			var params = {
					'query': query,
					'example': ['example item 1', 'example item 2', 'example item 3', 'example item 4'],
					'example2': ['example item 5', 'example item 6']
			};
			// Build with params.
			callback( params );
		}
	};

	// Setup
	$input.multiSuggest( options );

 */
( function ( $ ) {
	$.fn.multiSuggest = function ( options ) {
		return this.each( function () {
			// Private members.
			var inputTimer = null,
				visible = false,
				focused = false,
				$input = $( this ),
				currentInput = '',
				$multiSuggest;

			// Merge options with default configuration.
			$.extend( {
				'doc': document,
				'prefix': 'multi',
				'cssEllipsis': true
			}, options );

			// DOM Setup.
			$multiSuggest = $( '<div>', options.doc )
				.addClass( options.prefix + '-suggest-select' )
				.hide();
			$( options.parent ).append( $multiSuggest );

			/* Methods */

			// Hides & Show MultiSuggest.
			function toggle() {
				if ( visible ) {
					close();
				} else {
					open();
				}
			}
			// Call configured input method and supply the private build method as callback.
			function onInput() {
				// Throttle
				clearTimeout( inputTimer );
				inputTimer = setTimeout( function () {
					var txt = $input.val();
					if ( txt !== '' ) {
						// Be sure that input has changed.
						if (
							txt !== currentInput &&
							typeof options.input === 'function'
						) {
							options.input.call( $input, function ( params, callback ) {
								build( params );
							} );
						}
					} else {
						// No Text, close.
						if ( visible ) {
							close();
						}
					}
					// Set current input.
					currentInput = txt;

				}, 250 );
			}
			// Opens the MultiSuggest dropdown.
			function open() {
				if ( !visible ) {
					// Call input method if cached value is stale
					if (
						$input.val() !== '' &&
						$input.val() !== currentInput
					) {
						onInput();
					} else {
						// Show if there are suggestions.
						if ( $multiSuggest.children().length > 0 ) {
							visible = true;
							$multiSuggest.show();
						}
					}
				}
			}
			// Closes the dropdown.
			function close() {
				if ( visible ) {
					setTimeout( function () {
						visible = false;
						$multiSuggest.hide();
					}, 100 );
				}
			}
			// When an item is selected in the dropdown.
			function select( text ) {
				// Cache input.
				currentInput = text;
				$input.val( text );
				close();
				if ( typeof options.select === 'function' ) {
					options.select.call( this );
				}
			}
			// When an item is "clicked".
			// Use of mousedown to prevent blur.
			function onItemMousedown ( e ) {
				e.preventDefault();
				$multiSuggest
					.find( '.' + options.prefix + '-suggest-item' )
					.removeClass( 'selected' );
				$( this ).addClass( 'selected' );
				select.call( this, $( this ).data( 'text' ) );
			}
			// Adds a group to the dropdown.
			function addGroup( name, group ) {
				var $groupWrap,
					$group,
					$item,
					i;
				// Add a container with a label for this group.
				$group = $( '<div>', options.doc )
					.addClass( options.prefix + '-suggest-container' )
					.append(
						$( '<div>', options.doc )
							.addClass( options.prefix + '-suggest-label' )
							.text( group.label )
					)
					.append(
						$( '<div>', options.doc ).addClass( options.prefix + '-suggest-wrap' )
					)
					// Add a clear break.
					.append( $( '<div style="clear: both;">', options.doc ) );
				// Add group
				$multiSuggest.append( $group );

				// Find the group wrapper element.
				$groupWrap = $group.find( '.' + options.prefix + '-suggest-wrap' );
				// If no items, add a dummy element to take up space.
				if ( group.items.length === 0 ) {
					$groupWrap.append(
						$( '<div>&nbsp;</div>', options.doc )
							.addClass( options.prefix + '-suggest-dummy-item' )
					);
				}
				// Add each item.
				for( i = 0; i < group.items.length; i++ ) {
					$item = $( '<div>', options.doc )
						.addClass( options.prefix + '-suggest-item' )
						.data( 'text', group.items[i] )
						.on( 'mousedown', onItemMousedown );
					if ( 'itemClass' in group ) {
						$item.addClass( group.itemClass );
					}
					$groupWrap.append( $item );
					// Wrap in span
					$item.append( $( '<span>' )
						.css( 'whiteSpace', 'nowrap' )
						.text( group.items[i] )
					);
					// Select this item by default
					if ( group.items[i].toLowerCase() === $input.val().toLowerCase() ) {
						$item.addClass( 'selected' );
					}
					// CSS Ellipsis
					if ( options.cssEllipsis ) {
						$item.css( {
							'white-space': 'nowrap',
							'overflow': 'hidden',
							'-o-text-overflow': 'ellipsis',
							'text-overflow': 'ellipsis'
						} );
					}
				}
			}
			// Build the dropdown.
			// Fired as callback in configured input event.
			function build( params ) {
				var suggestions = options.suggestions( params ),
					group;
				// Setup groups
				$multiSuggest.empty();
				if ( suggestions !== undefined ) {
					for ( group in suggestions ) {
						if ( $.isPlainObject( suggestions[group] ) ) {
							addGroup( group, suggestions[group] );
						}
					}
					// Open dropdown.
					open();
					// Run update method supplied in configuration.
					if ( typeof options.update === 'function' ) {
						options.update();
					}
				}
			}
			// Bind target input events
			$input.on( {
				// Handle any change to the input.
				'keydown cut paste': function ( e ) {
					var $item,
						$items = $multiSuggest
							.find( '.' + options.prefix + '-suggest-item' ),
						selected = 0;

					// Find the selected index.
					$.each( $items, function ( i, e ) {
						if( $( this ).hasClass( 'selected' ) ) {
							selected = i;
						}
					});
					// Down arrow
					if ( e.which === 40 ) {
						e.preventDefault();
						// If not visible, open and do nothing.
						if ( !visible ) {
							open();
							return;
						}
						selected = ( selected + 1 ) % $items.length;
						$items.removeClass( 'selected' );
						$( $items[selected] ).addClass( 'selected' );
					// Up Arrow
					} else if ( e.which === 38 ) {
						e.preventDefault();
						// If not visible, open and do nothing.
						if ( !visible ) {
							open();
							return;
						}
						selected = ( selected + $items.length - 1 ) % $items.length;
						$items.removeClass( 'selected' );
						$( $items[selected] ).addClass( 'selected' );
					// Enter key.
					} else if ( e.which === 13 ) {
						// Only if the dropdown is open.
						if ( visible ) {
							e.preventDefault();
							$item = $multiSuggest
								.find( '.' + options.prefix + '-suggest-item.selected' );
							if ( $item.length > 0 ) {
								select.call( this, $item.data( 'text' ) );
							} else {
								close();
							}
							return;
						}
					}
					// Handle normal input.
					onInput();
				},
				'focus': function () {
					focused = true;
					open();
				},
				'blur': function () {
					focused = false;
					close();
				},
				'mousedown': function () {
					if ( focused ) {
						toggle();
					}
				}
			} );
			return this;
		} );
	};
}( jQuery ) );