/*

* jQuery UI Tag-it!

*

* @version v2.0 (06/2011)

*

* Copyright 2011, Levy Carneiro Jr.

* Released under the MIT license.

* http://aehlke.github.com/tag-it/LICENSE

*

* Homepage:

*   http://aehlke.github.com/tag-it/

*

* Authors:

*   Levy Carneiro Jr.

*   Martin Rehfeld

*   Tobias Schmidt

*   Skylar Challand

*   Alex Ehlke

*

* Maintainer:

*   Alex Ehlke - Twitter: @aehlke

*

* Dependencies:

*   jQuery v1.4+

*   jQuery UI v1.8+

*/

(function($) {

    $.widget('ui.tagit', {

        options: {

            itemName          : 'item',

            fieldName         : 'tags',

            availableTags     : [],

            tagSource         : null,

            removeConfirmation: false,

            caseSensitive     : true,

            placeholderText   : null,

            // When enabled, quotes are not neccesary

            // for inputting multi-word tags.

            allowSpaces: false,

            // Whether to animate tag removals or not.

            animate: true,

            // The below options are for using a single field instead of several

            // for our form values.

            //

            // When enabled, will use a single hidden field for the form,

            // rather than one per tag. It will delimit tags in the field

            // with singleFieldDelimiter.

            //

            // The easiest way to use singleField is to just instantiate tag-it

            // on an INPUT element, in which case singleField is automatically

            // set to true, and singleFieldNode is set to that element. This 

            // way, you don't need to fiddle with these options.

            singleField: false,

            singleFieldDelimiter: ',',

            // Set this to an input DOM node to use an existing form field.

            // Any text in it will be erased on init. But it will be

            // populated with the text of tags as they are created,

            // delimited by singleFieldDelimiter.

            //

            // If this is not set, we create an input node for it,

            // with the name given in settings.fieldName, 

            // ignoring settings.itemName.

            singleFieldNode: null,

            // Optionally set a tabindex attribute on the input that gets

            // created for tag-it.

            tabIndex: null,

            // Event callbacks.

            onTagAdded  : null,

            onTagRemoved: null,

            onTagClicked: null

        },

        _create: function() {

            // for handling static scoping inside callbacks

            var that = this;

            // There are 2 kinds of DOM nodes this widget can be instantiated on:

            //     1. UL, OL, or some element containing either of these.

            //     2. INPUT, in which case 'singleField' is overridden to true,

            //        a UL is created and the INPUT is hidden.

            if (this.element.is('input')) {

                this.tagList = $('<ul></ul>').insertAfter(this.element);

                this.options.singleField = true;

                this.options.singleFieldNode = this.element;

                this.element.css('display', 'none');

            } else {

                this.tagList = this.element.find('ul, ol').andSelf().last();

            }

            this._tagInput = $('<input type="text" />').addClass('ui-widget-content');

            if (this.options.tabIndex) {

                this._tagInput.attr('tabindex', this.options.tabIndex);

            }

            if (this.options.placeholderText) {

                this._tagInput.attr('placeholder', this.options.placeholderText);

            }

            this.options.tagSource = this.options.tagSource || function(search, showChoices) {

                var filter = search.term.toLowerCase();

                var choices = $.grep(this.options.availableTags, function(element) {

                    // Only match autocomplete options that begin with the search term.

                    // (Case insensitive.)

                    return (element.toLowerCase().indexOf(filter) === 0);

                });

                showChoices(this._subtractArray(choices, this.assignedTags()));

            };

            // Bind tagSource callback functions to this context.

            if ($.isFunction(this.options.tagSource)) {

                this.options.tagSource = $.proxy(this.options.tagSource, this);

            }

            this.tagList

                .addClass('tagit')

                .addClass('ui-widget ui-widget-content ui-corner-all')

                // Create the input field.

                .append($('<li class="tagit-new"></li>').append(this._tagInput))

                .click(function(e) {

                    var target = $(e.target);

                    if (target.hasClass('tagit-label')) {

                        that._trigger('onTagClicked', e, target.closest('.tagit-choice'));

                    } else {

                        // Sets the focus() to the input field, if the user

                        // clicks anywhere inside the UL. This is needed

                        // because the input field needs to be of a small size.

                        that._tagInput.focus();

                    }

                });

            // Add existing tags from the list, if any.

            this.tagList.children('li').each(function() {

                if (!$(this).hasClass('tagit-new')) {

                    that.createTag($(this).html(), $(this).attr('class'));

                    $(this).remove();

                }

            });

            // Single field support.

            if (this.options.singleField) {

                if (this.options.singleFieldNode) {

                    // Add existing tags from the input field.

                    var node = $(this.options.singleFieldNode);

                    var tags = node.val().split(this.options.singleFieldDelimiter);

                    node.val('');

                    $.each(tags, function(index, tag) {

                        that.createTag(tag);

                    });

                } else {

                    // Create our single field input after our list.

                    this.options.singleFieldNode = this.tagList.after('<input type="hidden" style="display:none;" value="" name="' + this.options.fieldName + '" />');

                }

            }

            // Events.

            this._tagInput

                .keydown(function(event) {

                    // Backspace is not detected within a keypress, so it must use keydown.

                    if (event.which == $.ui.keyCode.BACKSPACE && that._tagInput.val() === '') {

                        var tag = that._lastTag();

                        if (!that.options.removeConfirmation || tag.hasClass('remove')) {

                            // When backspace is pressed, the last tag is deleted.

                            that.removeTag(tag);

                        } else if (that.options.removeConfirmation) {

                            tag.addClass('remove ui-state-highlight');

                        }

                    } else if (that.options.removeConfirmation) {

                        that._lastTag().removeClass('remove ui-state-highlight');

                    }

                    // Comma/Space/Enter are all valid delimiters for new tags,

                    // except when there is an open quote or if setting allowSpaces = true.

                    // Tab will also create a tag, unless the tag input is empty, in which case it isn't caught.

                    if (

                        event.which == $.ui.keyCode.COMMA ||

                        event.which == $.ui.keyCode.ENTER ||

                        (

                            event.which == $.ui.keyCode.TAB &&

                            that._tagInput.val() !== ''

                        ) ||

                        (

                            event.which == $.ui.keyCode.SPACE &&

                            that.options.allowSpaces !== true &&

                            (

                                $.trim(that._tagInput.val()).replace( /^s*/, '' ).charAt(0) != '"' ||

                                (

                                    $.trim(that._tagInput.val()).charAt(0) == '"' &&

                                    $.trim(that._tagInput.val()).charAt($.trim(that._tagInput.val()).length - 1) == '"' &&

                                    $.trim(that._tagInput.val()).length - 1 !== 0

                                )

                            )

                        )

                    ) {

                        event.preventDefault();

                        that.createTag(that._cleanedInput());

                        // The autocomplete doesn't close automatically when TAB is pressed.

                        // So let's ensure that it closes.

                        that._tagInput.autocomplete('close');

                    }

                }).blur(function(e){

                    // Create a tag when the element loses focus (unless it's empty).

                    that.createTag(that._cleanedInput());

                });

            // Autocomplete.

            if (this.options.availableTags || this.options.tagSource) {

                this._tagInput.autocomplete({

                    source: this.options.tagSource,

                    select: function(event, ui) {

                        // Delete the last tag if we autocomplete something despite the input being empty

                        // This happens because the input's blur event causes the tag to be created when

                        // the user clicks an autocomplete item.

                        // The only artifact of this is that while the user holds down the mouse button

                        // on the selected autocomplete item, a tag is shown with the pre-autocompleted text,

                        // and is changed to the autocompleted text upon mouseup.

                        if (that._tagInput.val() === '') {

                            that.removeTag(that._lastTag(), false);

                        }

                        that.createTag(ui.item.value);

                        // Preventing the tag input to be updated with the chosen value.

                        return false;

                    }

                });

            }

        },

        _cleanedInput: function() {

            // Returns the contents of the tag input, cleaned and ready to be passed to createTag

            return $.trim(this._tagInput.val().replace(/^"(.*)"$/, '$1'));

        },

        _lastTag: function() {

            return this.tagList.children('.tagit-choice:last');

        },

        assignedTags: function() {

            // Returns an array of tag string values

            var that = this;

            var tags = [];

            if (this.options.singleField) {

                tags = $(this.options.singleFieldNode).val().split(this.options.singleFieldDelimiter);

                if (tags[0] === '') {

                    tags = [];

                }

            } else {

                this.tagList.children('.tagit-choice').each(function() {

                    tags.push(that.tagLabel(this));

                });

            }

            return tags;

        },

        _updateSingleTagsField: function(tags) {

            // Takes a list of tag string values, updates this.options.singleFieldNode.val to the tags delimited by this.options.singleFieldDelimiter

            $(this.options.singleFieldNode).val(tags.join(this.options.singleFieldDelimiter));

        },

        _subtractArray: function(a1, a2) {

            var result = [];

            for (var i = 0; i < a1.length; i++) {

                if ($.inArray(a1[i], a2) == -1) {

                    result.push(a1[i]);

                }

            }

            return result;

        },

        tagLabel: function(tag) {

            // Returns the tag's string label.

            if (this.options.singleField) {

                return $(tag).children('.tagit-label').text();

            } else {

                return $(tag).children('input').val();

            }

        },

        _isNew: function(value) {

            var that = this;

            var isNew = true;

            this.tagList.children('.tagit-choice').each(function(i) {

                if (that._formatStr(value) == that._formatStr(that.tagLabel(this))) {

                    isNew = false;

                    return false;

                }

            });

            return isNew;

        },

        _formatStr: function(str) {

            if (this.options.caseSensitive) {

                return str;

            }

            return $.trim(str.toLowerCase());

        },

        createTag: function(value, additionalClass) {

            var that = this;

            // Automatically trims the value of leading and trailing whitespace.

            value = $.trim(value);

            if (!this._isNew(value) || value === '') {

                return false;

            }

            var label = $(this.options.onTagClicked ? '<a class="tagit-label"></a>' : '<span class="tagit-label"></span>').text(value);

            // Create tag.

            var tag = $('<li></li>')

                .addClass('tagit-choice ui-widget-content ui-state-default ui-corner-all')

                .addClass(additionalClass)

                .append(label);

            // Button for removing the tag.

            var removeTagIcon = $('<span></span>')

                .addClass('ui-icon ui-icon-close');

            var removeTag = $('<a><span class="text-icon">\xd7</span></a>') // \xd7 is an X

                .addClass('tagit-close')

                .append(removeTagIcon)

                .click(function(e) {

                    // Removes a tag when the little 'x' is clicked.

                    that.removeTag(tag);

                });

            tag.append(removeTag);

            // Unless options.singleField is set, each tag has a hidden input field inline.

            if (this.options.singleField) {

                var tags = this.assignedTags();

                tags.push(value);

                this._updateSingleTagsField(tags);

            } else {

                var escapedValue = label.html();

                tag.append('<input type="hidden" style="display:none;" value="' + escapedValue + '" name="' + this.options.itemName + '[' + this.options.fieldName + '][]" />');

            }

            this._trigger('onTagAdded', null, tag);

            // Cleaning the input.

            this._tagInput.val('');

            // insert tag

            this._tagInput.parent().before(tag);

        },

        removeTag: function(tag, animate) {

            animate = animate || this.options.animate;

            tag = $(tag);

            this._trigger('onTagRemoved', null, tag);

            if (this.options.singleField) {

                var tags = this.assignedTags();

                var removedTagLabel = this.tagLabel(tag);

                tags = $.grep(tags, function(el){

                    return el != removedTagLabel;

                });

                this._updateSingleTagsField(tags);

            }

            // Animate the removal.

            if (animate) {

                tag.fadeOut('fast').hide('blind', {direction: 'horizontal'}, 'fast', function(){