/**
 * This plugin provides a generic way to add suggestions to a text box.
 *
 * Set options:
 *
 *		$( '#textbox' ).suggestions( { option1: value1, option2: value2 } );
 *		$( '#textbox' ).suggestions( option, value );
 *
 * Get option:
 *
 *		value = $( '#textbox' ).suggestions( option );
 *
 * Initialize:
 *
 *		$( '#textbox' ).suggestions();
 *
 * Uses jQuery.suggestions singleton internally.
 *
 * @class jQuery.plugin.suggestions
 */

/**
 * @method suggestions
 * @chainable
 * @return {jQuery}
 *
 * @param {Object} options
 *
 * @param {Function} [options.fetch] Callback that should fetch suggestions and set the suggestions
 *  property. Called in context of the text box.
 * @param {string} options.fetch.query
 * @param {Function} options.fetch.response Callback to receive the suggestions with
 * @param {Array} options.fetch.response.suggestions
 * @param {number} options.fetch.maxRows
 *
 * @param {Function} [options.cancel] Callback function to call when any pending asynchronous
 *  suggestions fetches. Called in context of the text box.
 *
 * @param {Object} [options.special] Set of callbacks for rendering and selecting.
 *
 * @param {Function} options.special.render Called in context of the suggestions-special element.
 * @param {string} options.special.render.query
 * @param {Object} options.special.render.context
 *
 * @param {Function} options.special.select Called in context of the suggestions-result-current element.
 * @param {jQuery} options.special.select.$textbox
 *
 * @param {Object} [options.result] Set of callbacks for rendering and selecting
 *
 * @param {Function} options.result.render Called in context of the suggestions-result element.
 * @param {string} options.result.render.suggestion
 * @param {Object} options.result.render.context
 *
 * @param {Function} options.result.select Called in context of the suggestions-result-current element.
 * @param {jQuery} options.result.select.$textbox
 *
 * @param {Object} [options.update] Set of callbacks for listening to a change in the text input.
 *
 * @param {Function} options.update.before Called right after the user changes the textbox text.
 * @param {Function} options.update.after Called after results are updated either from the cache or
 * the API as a result of the user input.
 *
 * @param {jQuery} [options.$region=this] The element to place the suggestions below and match width of.
 *
 * @param {string[]} [options.suggestions] Array of suggestions to display.
 *
 * @param {number} [options.maxRows=10] Maximum number of suggestions to display at one time.
 *  Must be between 1 and 100.
 *
 * @param {number} [options.delay=120] Number of milliseconds to wait for the user to stop typing.
 *  Must be between 0 and 1200.
 *
 * @param {boolean} [options.cache=false] Whether to cache results from a fetch.
 *
 * @param {number} [options.cacheMaxAge=60000] Number of milliseconds to cache results from a fetch.
 *  Must be higher than 1. Defaults to 1 minute.
 *
 * @param {boolean} [options.submitOnClick=false] Whether to submit the form containing the textbox
 *  when a suggestion is clicked.
 *
 * @param {number} [options.maxExpandFactor=3] Maximum suggestions box width relative to the textbox
 *  width. If set to e.g. 2, the suggestions box will never be grown beyond 2 times the width of
 *  the textbox. Must be higher than 1.
 *
 * @param {string} [options.expandFrom=auto] Which direction to offset the suggestion box from.
 *  Values 'start' and 'end' translate to left and right respectively depending on the directionality
 *   of the current document, according to `$( 'html' ).css( 'direction' )`.
 *   Valid values: "left", "right", "start", "end", and "auto".
 *
 * @param {boolean} [options.positionFromLeft] Sets `expandFrom=left`, for backwards
 *  compatibility.
 *
 * @param {boolean} [options.highlightInput=false] Whether to highlight matched portions of the
 *  input or not.
 */

( function ( $, mw ) {

	var hasOwn = Object.hasOwnProperty;

	/**
	 * Used by jQuery.plugin.suggestions.
	 *
	 * @class jQuery.suggestions
	 * @singleton
	 * @private
	 */
	$.suggestions = {
		/**
		 * Cancel any delayed maybeFetch() call and callback the context so
		 * they can cancel any async fetching if they use AJAX or something.
		 *
		 * @param {Object} context
		 */
		cancel: function ( context ) {
			if ( context.data.timerID !== null ) {
				clearTimeout( context.data.timerID );
			}
			if ( $.isFunction( context.config.cancel ) ) {
				context.config.cancel.call( context.data.$textbox );
			}
		},

		/**
		 * Hide the element with suggestions and clean up some state.
		 *
		 * @param {Object} context
		 */
		hide: function ( context ) {
			// Remove any highlights, including on "special" items
			context.data.$container.find( '.suggestions-result-current' ).removeClass( 'suggestions-result-current' );
			// Hide the container
			context.data.$container.hide();
		},

		/**
		 * Restore the text the user originally typed in the textbox, before it
		 * was overwritten by highlight(). This restores the value the currently
		 * displayed suggestions are based on, rather than the value just before
		 * highlight() overwrote it; the former is arguably slightly more sensible.
		 *
		 * @param {Object} context
		 */
		restore: function ( context ) {
			context.data.$textbox.val( context.data.prevText );
		},

		/**
		 * Ask the user-specified callback for new suggestions. Any previous delayed
		 * call to this function still pending will be canceled. If the value in the
		 * textbox is empty or hasn't changed since the last time suggestions were fetched,
		 * this function does nothing.
		 *
		 * @param {Object} context
		 * @param {boolean} delayed Whether or not to delay this by the currently configured amount of time
		 */
		update: function ( context, delayed ) {
			function maybeFetch() {
				var val = context.data.$textbox.val(),
					cache = context.data.cache,
					cacheHit;

				if ( typeof context.config.update.before === 'function' ) {
					context.config.update.before.call( context.data.$textbox );
				}

				// Only fetch if the value in the textbox changed and is not empty, or if the results were hidden
				// if the textbox is empty then clear the result div, but leave other settings intouched
				if ( val.length === 0 ) {
					$.suggestions.hide( context );
					context.data.prevText = '';
				} else if (
					val !== context.data.prevText ||
					!context.data.$container.is( ':visible' )
				) {
					context.data.prevText = val;
					// Try cache first
					if ( context.config.cache && hasOwn.call( cache, val ) ) {
						if ( mw.now() - cache[ val ].timestamp < context.config.cacheMaxAge ) {
							context.data.$textbox.suggestions( 'suggestions', cache[ val ].suggestions );
							if ( typeof context.config.update.after === 'function' ) {
								context.config.update.after.call( context.data.$textbox, cache[ val ].metadata );
							}
							cacheHit = true;
						} else {
							// Cache expired
							delete cache[ val ];
						}
					}
					if ( !cacheHit && typeof context.config.fetch === 'function' ) {
						context.config.fetch.call(
							context.data.$textbox,
							val,
							function ( suggestions, metadata ) {
								suggestions = suggestions.slice( 0, context.config.maxRows );
								context.data.$textbox.suggestions( 'suggestions', suggestions );
								if ( typeof context.config.update.after === 'function' ) {
									context.config.update.after.call( context.data.$textbox, metadata );
								}
								if ( context.config.cache ) {
									cache[ val ] = {
										suggestions: suggestions,
										metadata: metadata,
										timestamp: mw.now()
									};
								}
							},
							context.config.maxRows
						);
					}
				}

				// Always update special rendering
				$.suggestions.special( context );
			}

			// Cancels any delayed maybeFetch call, and invokes context.config.cancel.
			$.suggestions.cancel( context );

			if ( delayed ) {
				// To avoid many started/aborted requests while typing, we're gonna take a short
				// break before trying to fetch data.
				context.data.timerID = setTimeout( maybeFetch, context.config.delay );
			} else {
				maybeFetch();
			}
		},

		/**
		 * @param {Object} context
		*/
		special: function ( context ) {
			// Allow custom rendering - but otherwise don't do any rendering
			if ( typeof context.config.special.render === 'function' ) {
				// Wait for the browser to update the value
				setTimeout( function () {
					// Render special
					var $special = context.data.$container.find( '.suggestions-special' );
					context.config.special.render.call( $special, context.data.$textbox.val(), context );
				}, 1 );
			}
		},

		/**
		 * Sets the value of a property, and updates the widget accordingly
		 *
		 * @param {Object} context
		 * @param {string} property Name of property
		 * @param {Mixed} value Value to set property with
		 */
		configure: function ( context, property, value ) {
			var newCSS,
				$result, $results, $spanForWidth, childrenWidth,
				i, expWidth, maxWidth, text;

			// Validate creation using fallback values
			switch ( property ) {
				case 'fetch':
				case 'cancel':
				case 'special':
				case 'result':
				case 'update':
				case '$region':
				case 'expandFrom':
					context.config[ property ] = value;
					break;
				case 'suggestions':
					context.config[ property ] = value;
					// Update suggestions
					if ( context.data !== undefined ) {
						if ( context.data.$textbox.val().length === 0 ) {
							// Hide the div when no suggestion exist
							$.suggestions.hide( context );
						} else {
							// Rebuild the suggestions list
							context.data.$container.show();
							// Update the size and position of the list
							newCSS = {
								top: context.config.$region.offset().top + context.config.$region.outerHeight(),
								bottom: 'auto',
								width: context.config.$region.outerWidth(),
								height: 'auto'
							};

							// Process expandFrom, after this it is set to left or right.
							context.config.expandFrom = ( function ( expandFrom ) {
								var regionWidth, docWidth, regionCenter, docCenter,
									docDir = $( document.documentElement ).css( 'direction' ),
									$region = context.config.$region;

								// Backwards compatible
								if ( context.config.positionFromLeft ) {
									expandFrom = 'left';

								// Catch invalid values, default to 'auto'
								} else if ( [ 'left', 'right', 'start', 'end', 'auto' ].indexOf( expandFrom ) === -1 ) {
									expandFrom = 'auto';
								}

								if ( expandFrom === 'auto' ) {
									if ( $region.data( 'searchsuggest-expand-dir' ) ) {
										// If the markup explicitly contains a direction, use it.
										expandFrom = $region.data( 'searchsuggest-expand-dir' );
									} else {
										regionWidth = $region.outerWidth();
										docWidth = $( document ).width();
										if ( regionWidth > ( 0.85 * docWidth ) ) {
											// If the input size takes up more than 85% of the document horizontally
											// expand the suggestions to the writing direction's native end.
											expandFrom = 'start';
										} else {
											// Calculate the center points of the input and document
											regionCenter = $region.offset().left + regionWidth / 2;
											docCenter = docWidth / 2;
											if ( Math.abs( regionCenter - docCenter ) < ( 0.10 * docCenter ) ) {
												// If the input's center is within 10% of the document center
												// use the writing direction's native end.
												expandFrom = 'start';
											} else {
												// Otherwise expand the input from the closest side of the page,
												// towards the side of the page with the most free open space
												expandFrom = regionCenter > docCenter ? 'right' : 'left';
											}
										}
									}
								}

								if ( expandFrom === 'start' ) {
									expandFrom = docDir === 'rtl' ? 'right' : 'left';

								} else if ( expandFrom === 'end' ) {
									expandFrom = docDir === 'rtl' ? 'left' : 'right';
								}

								return expandFrom;

							}( context.config.expandFrom ) );

							if ( context.config.expandFrom === 'left' ) {
								// Expand from left
								newCSS.left = context.config.$region.offset().left;
								newCSS.right = 'auto';
							} else {
								// Expand from right
								newCSS.left = 'auto';
								newCSS.right = $( 'body' ).width() - ( context.config.$region.offset().left + context.config.$region.outerWidth() );
							}

							context.data.$container.css( newCSS );
							$results = context.data.$container.children( '.suggestions-results' );
							$results.empty();
							expWidth = -1;
							for ( i = 0; i < context.config.suggestions.length; i++ ) {
								text = context.config.suggestions[ i ];
								$result = $( '<div>' )
									.addClass( 'suggestions-result' )
									.attr( 'rel', i )
									.data( 'text', context.config.suggestions[ i ] )
									.mousemove( function () {
										context.data.selectedWithMouse = true;
										$.suggestions.highlight(
											context,
											$( this ).closest( '.suggestions-results .suggestions-result' ),
											false
										);
									} )
									.appendTo( $results );
								// Allow custom rendering
								if ( typeof context.config.result.render === 'function' ) {
									context.config.result.render.call( $result, context.config.suggestions[ i ], context );
								} else {
									$result.text( text );
								}

								if ( context.config.highlightInput ) {
									$result.highlightText( context.data.prevText, { method: 'prefixHighlight' } );
								}

								// Widen results box if needed (new width is only calculated here, applied later).

								// The monstrosity below accomplishes two things:
								// * Wraps the text contents in a DOM element, so that we can know its width. There is
								//   no way to directly access the width of a text node, and we can't use the parent
								//   node width as it has text-overflow: ellipsis; and overflow: hidden; applied to
								//   it, which trims it to a smaller width.
								// * Temporarily applies position: absolute; to the wrapper to pull it out of normal
								//   document flow. Otherwise the CSS text-overflow: ellipsis; and overflow: hidden;
								//   rules would cause some browsers (at least all versions of IE from 6 to 11) to
								//   still report the "trimmed" width. This should not be done in regular CSS
								//   stylesheets as we don't want this rule to apply to other <span> elements, like
								//   the ones generated by jquery.highlightText.
								$spanForWidth = $result.wrapInner( '<span>' ).children();
								childrenWidth = $spanForWidth.css( 'position', 'absolute' ).outerWidth();
								$spanForWidth.contents().unwrap();

								if ( childrenWidth > $result.width() && childrenWidth > expWidth ) {
									// factor in any padding, margin, or border space on the parent
									expWidth = childrenWidth + ( context.data.$container.width() - $result.width() );
								}
							}

							// Apply new width for results box, if any
							if ( expWidth > context.data.$container.width() ) {
								maxWidth = context.config.maxExpandFactor * context.data.$textbox.width();
								context.data.$container.width( Math.min( expWidth, maxWidth ) );
							}
						}
					}
					break;
				case 'maxRows':
					context.config[ property ] = Math.max( 1, Math.min( 100, value ) );
					break;
				case 'delay':
					context.config[ property ] = Math.max( 0, Math.min( 1200, value ) );
					break;
				case 'cacheMaxAge':
					context.config[ property ] = Math.max( 1, value );
					break;
				case 'maxExpandFactor':
					context.config[ property ] = Math.max( 1, value );
					break;
				case 'cache':
				case 'submitOnClick':
				case 'positionFromLeft':
				case 'highlightInput':
					context.config[ property ] = !!value;
					break;
			}
		},

		/**
		 * Highlight a result in the results table
		 *
		 * @param {Object} context
		 * @param {jQuery|string} result `<tr>` to highlight, or 'prev' or 'next'
		 * @param {boolean} updateTextbox If true, put the suggestion in the textbox
		 */
		highlight: function ( context, result, updateTextbox ) {
			var selected = context.data.$container.find( '.suggestions-result-current' );
			if ( !result.get || selected.get( 0 ) !== result.get( 0 ) ) {
				if ( result === 'prev' ) {
					if ( selected.hasClass( 'suggestions-special' ) ) {
						result = context.data.$container.find( '.suggestions-result:last' );
					} else {
						result = selected.prev();
						if ( !( result.length && result.hasClass( 'suggestions-result' ) ) ) {
							// there is something in the DOM between selected element and the wrapper, bypass it
							result = selected.parents( '.suggestions-results > *' ).prev().find( '.suggestions-result' ).eq( 0 );
						}

						if ( selected.length === 0 ) {
							// we are at the beginning, so lets jump to the last item
							if ( context.data.$container.find( '.suggestions-special' ).html() !== '' ) {
								result = context.data.$container.find( '.suggestions-special' );
							} else {
								result = context.data.$container.find( '.suggestions-results .suggestions-result:last' );
							}
						}
					}
				} else if ( result === 'next' ) {
					if ( selected.length === 0 ) {
						// No item selected, go to the first one
						result = context.data.$container.find( '.suggestions-results .suggestions-result:first' );
						if ( result.length === 0 && context.data.$container.find( '.suggestions-special' ).html() !== '' ) {
							// No suggestion exists, go to the special one directly
							result = context.data.$container.find( '.suggestions-special' );
						}
					} else {
						result = selected.next();
						if ( !( result.length && result.hasClass( 'suggestions-result' ) ) ) {
							// there is something in the DOM between selected element and the wrapper, bypass it
							result = selected.parents( '.suggestions-results > *' ).next().find( '.suggestions-result' ).eq( 0 );
						}

						if ( selected.hasClass( 'suggestions-special' ) ) {
							result = $( [] );
						} else if (
							result.length === 0 &&
							context.data.$container.find( '.suggestions-special' ).html() !== ''
						) {
							// We were at the last item, jump to the specials!
							result = context.data.$container.find( '.suggestions-special' );
						}
					}
				}
				selected.removeClass( 'suggestions-result-current' );
				result.addClass( 'suggestions-result-current' );
			}
			if ( updateTextbox ) {
				if ( result.length === 0 || result.is( '.suggestions-special' ) ) {
					$.suggestions.restore( context );
				} else {
					context.data.$textbox.val( result.data( 'text' ) );
					// .val() doesn't call any event handlers, so
					// let the world know what happened
					context.data.$textbox.change();
				}
				context.data.$textbox.trigger( 'change' );
			}
		},

		/**
		 * Respond to keypress event
		 *
		 * @param {jQuery.Event} e
		 * @param {Object} context
		 * @param {number} key Code of key pressed
		 */
		keypress: function ( e, context, key ) {
			var selected,
				wasVisible = context.data.$container.is( ':visible' ),
				preventDefault = false;

			switch ( key ) {
				// Arrow down
				case 40:
					if ( wasVisible ) {
						$.suggestions.highlight( context, 'next', true );
						context.data.selectedWithMouse = false;
					} else {
						$.suggestions.update( context, false );
					}
					preventDefault = true;
					break;
				// Arrow up
				case 38:
					if ( wasVisible ) {
						$.suggestions.highlight( context, 'prev', true );
						context.data.selectedWithMouse = false;
					}
					preventDefault = wasVisible;
					break;
				// Escape
				case 27:
					$.suggestions.hide( context );
					$.suggestions.restore( context );
					$.suggestions.cancel( context );
					context.data.$textbox.trigger( 'change' );
					preventDefault = wasVisible;
					break;
				// Enter
				case 13:
					preventDefault = wasVisible;
					selected = context.data.$container.find( '.suggestions-result-current' );
					$.suggestions.hide( context );
					if ( selected.length === 0 || context.data.selectedWithMouse ) {
						// If nothing is selected or if something was selected with the mouse
						// cancel any current requests and allow the form to be submitted
						// (simply don't prevent default behavior).
						$.suggestions.cancel( context );
						preventDefault = false;
					} else if ( selected.is( '.suggestions-special' ) ) {
						if ( typeof context.config.special.select === 'function' ) {
							// Allow the callback to decide whether to prevent default or not
							if ( context.config.special.select.call( selected, context.data.$textbox, 'keyboard' ) === true ) {
								preventDefault = false;
							}
						}
					} else {
						if ( typeof context.config.result.select === 'function' ) {
							// Allow the callback to decide whether to prevent default or not
							if ( context.config.result.select.call( selected, context.data.$textbox, 'keyboard' ) === true ) {
								preventDefault = false;
							}
						}
					}
					break;
				default:
					$.suggestions.update( context, true );
					break;
			}
			if ( preventDefault ) {
				e.preventDefault();
				e.stopPropagation();
			}
		}
	};

	// See file header for method documentation
	$.fn.suggestions = function () {

		// Multi-context fields
		var returnValue,
			args = arguments;

		$( this ).each( function () {
			var context, key;

			/* Construction and Loading */

			context = $( this ).data( 'suggestions-context' );
			if ( context === undefined || context === null ) {
				context = {
					config: {
						fetch: function () {},
						cancel: function () {},
						special: {},
						result: {},
						update: {},
						$region: $( this ),
						suggestions: [],
						maxRows: 10,
						delay: 120,
						cache: false,
						cacheMaxAge: 60000,
						submitOnClick: false,
						maxExpandFactor: 3,
						expandFrom: 'auto',
						highlightInput: false
					}
				};
			}

			/* API */

			// Handle various calling styles
			if ( args.length > 0 ) {
				if ( typeof args[ 0 ] === 'object' ) {
					// Apply set of properties
					for ( key in args[ 0 ] ) {
						$.suggestions.configure( context, key, args[ 0 ][ key ] );
					}
				} else if ( typeof args[ 0 ] === 'string' ) {
					if ( args.length > 1 ) {
						// Set property values
						$.suggestions.configure( context, args[ 0 ], args[ 1 ] );
					} else if ( returnValue === null || returnValue === undefined ) {
						// Get property values, but don't give access to internal data - returns only the first
						returnValue = ( args[ 0 ] in context.config ? undefined : context.config[ args[ 0 ] ] );
					}
				}
			}

			/* Initialization */

			if ( context.data === undefined ) {
				context.data = {
					// ID of running timer
					timerID: null,

					// Text in textbox when suggestions were last fetched
					prevText: null,

					// Cache of fetched suggestions
					cache: {},

					// Number of results visible without scrolling
					visibleResults: 0,

					// Suggestion the last mousedown event occurred on
					mouseDownOn: $( [] ),
					$textbox: $( this ),
					selectedWithMouse: false
				};

				context.data.$container = $( '<div>' )
					.css( 'display', 'none' )
					.addClass( 'suggestions' )
					.append(
						$( '<div>' ).addClass( 'suggestions-results' )
							// Can't use click() because the container div is hidden when the
							// textbox loses focus. Instead, listen for a mousedown followed
							// by a mouseup on the same div.
							.mousedown( function ( e ) {
								context.data.mouseDownOn = $( e.target ).closest( '.suggestions-results .suggestions-result' );
							} )
							.mouseup( function ( e ) {
								var $result = $( e.target ).closest( '.suggestions-results .suggestions-result' ),
									$other = context.data.mouseDownOn;

								context.data.mouseDownOn = $( [] );
								if ( $result.get( 0 ) !== $other.get( 0 ) ) {
									return;
								}
								$.suggestions.highlight( context, $result, true );
								if ( typeof context.config.result.select === 'function' ) {
									context.config.result.select.call( $result, context.data.$textbox, 'mouse' );
								}
								// Don't interfere with special clicks (e.g. to open in new tab)
								if ( !( e.which !== 1 || e.altKey || e.ctrlKey || e.shiftKey || e.metaKey ) ) {
									// This will hide the link we're just clicking on, which causes problems
									// when done synchronously in at least Firefox 3.6 (T64858).
									setTimeout( function () {
										$.suggestions.hide( context );
									}, 0 );
								}
								// Always bring focus to the textbox, as that's probably where the user expects it
								// if they were just typing.
								context.data.$textbox.focus();
							} )
					)
					.append(
						$( '<div>' ).addClass( 'suggestions-special' )
							// Can't use click() because the container div is hidden when the
							// textbox loses focus. Instead, listen for a mousedown followed
							// by a mouseup on the same div.
							.mousedown( function ( e ) {
								context.data.mouseDownOn = $( e.target ).closest( '.suggestions-special' );
							} )
							.mouseup( function ( e ) {
								var $special = $( e.target ).closest( '.suggestions-special' ),
									$other = context.data.mouseDownOn;

								context.data.mouseDownOn = $( [] );
								if ( $special.get( 0 ) !== $other.get( 0 ) ) {
									return;
								}
								if ( typeof context.config.special.select === 'function' ) {
									context.config.special.select.call( $special, context.data.$textbox, 'mouse' );
								}
								// Don't interfere with special clicks (e.g. to open in new tab)
								if ( !( e.which !== 1 || e.altKey || e.ctrlKey || e.shiftKey || e.metaKey ) ) {
									// This will hide the link we're just clicking on, which causes problems
									// when done synchronously in at least Firefox 3.6 (T64858).
									setTimeout( function () {
										$.suggestions.hide( context );
									}, 0 );
								}
								// Always bring focus to the textbox, as that's probably where the user expects it
								// if they were just typing.
								context.data.$textbox.focus();
							} )
							.mousemove( function ( e ) {
								context.data.selectedWithMouse = true;
								$.suggestions.highlight(
									context, $( e.target ).closest( '.suggestions-special' ), false
								);
							} )
					)
					.appendTo( $( 'body' ) );

				$( this )
					// Stop browser autocomplete from interfering
					.attr( 'autocomplete', 'off' )
					.keydown( function ( e ) {
						// Store key pressed to handle later
						context.data.keypressed = e.which;
						context.data.keypressedCount = 0;
					} )
					.keypress( function ( e ) {
						context.data.keypressedCount++;
						$.suggestions.keypress( e, context, context.data.keypressed );
					} )
					.keyup( function ( e ) {
						// The keypress event is fired when a key is pressed down and that key normally
						// produces a character value. We also want to handle some keys that don't
						// produce a character value so we also attach to the keydown/keyup events.
						// List of codes sourced from
						// https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode
						var allowed = [
							40, // up arrow
							38, // down arrow
							27, // escape
							13, // enter
							46, // delete
							8 //   backspace
						];
						if ( context.data.keypressedCount === 0 &&
							e.which === context.data.keypressed &&
							allowed.indexOf( e.which ) !== -1
						) {
							$.suggestions.keypress( e, context, context.data.keypressed );
						}
					} )
					.blur( function () {
						// When losing focus because of a mousedown
						// on a suggestion, don't hide the suggestions
						if ( context.data.mouseDownOn.length > 0 ) {
							return;
						}
						$.suggestions.hide( context );
						$.suggestions.cancel( context );
					} );
			}

			// Store the context for next time
			$( this ).data( 'suggestions-context', context );
		} );
		return returnValue !== undefined ? returnValue : $( this );
	};

	/**
	 * @class jQuery
	 * @mixins jQuery.plugin.suggestions
	 */

}( jQuery, mediaWiki ) );