// Copyright 2010 Mike Brevoort http://mike.brevoort.com @mbrevoort
// 
// v1.0 jquery-facebook-multi-friend-selector
// 
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
// 
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
   
(function($) { 
    var JFMFS = function(element, options) {
        var elem = $(element),
            obj = this,
            uninitializedImagefriendElements = [], // for images that are initialized
            keyUpTimer,
            friends_per_row = 0,
            friend_height_px = 0,
            first_element_offset_px;
            
        var settings = $.extend({
            max_selected: -1,
            max_selected_message: "{0} of {1} selected",
			pre_selected_friends: [],
			exclude_friends: [],
			friend_fields: "id,name",
			sorter: function(a, b) {
                var x = a.name.toLowerCase();
                var y = b.name.toLowerCase();
                return ((x < y) ? -1 : ((x > y) ? 1 : 0));
            },
			labels: {
				selected: "Seleccionado",
				filter_default: "Empieza a escribir",
				filter_title: "Buscar amigos:",
				all: " ",
				max_selected_message: "{0}  seleccionado"
			}
        }, options || {});
        var lastSelected;  // used when shift-click is performed to know where to start from to select multiple elements
                
        var arrayToObjectGraph = function(a) {
			  var o = {};
			  for(var i=0, l=a.length; i<l; i++){
			    o[a[i]]='';
			  }
			  return o;
		};
		
        // ----------+----------+----------+----------+----------+----------+----------+
        // Initialization of container
        // ----------+----------+----------+----------+----------+----------+----------+
        elem.html(
            "<div id='jfmfs-friend-selector'>" +
            "    <div id='jfmfs-inner-header'>" +
            "        <span class='jfmfs-title'>" + settings.labels.filter_title + " </span><input type='text' id='jfmfs-friend-filter-text' value='" + settings.labels.filter_default + "'/>" +
            "        <a class='filter-link selected' id='jfmfs-filter-all' href='#'>" + settings.labels.all + "</a>" +
            "        <a class='filter-link' id='jfmfs-filter-selected' href='#'>" + settings.labels.selected + " (<span id='jfmfs-selected-count'>0</span>)</a>" +
            ((settings.max_selected > 0) ? "<div id='jfmfs-max-selected-wrapper'></div>" : "") +
            "    </div>" +
            "    <div id='jfmfs-friend-container'></div>" +
            "</div>" 
        );
        
        var friend_container = $("#jfmfs-friend-container"),
            container = $("#jfmfs-friend-selector"),
			preselected_friends_graph = arrayToObjectGraph(settings.pre_selected_friends),
			excluded_friends_graph = arrayToObjectGraph(settings.exclude_friends),
            all_friends;
            
        FB.api('/me/friends?fields=' + settings.friend_fields, function(response) {
            var sortedFriendData = response.data.sort(settings.sorter),
                preselectedFriends = {},
                buffer = [],
			    selectedClass = "";
            
            $.each(sortedFriendData, function(i, friend) {
				if(! (friend.id in excluded_friends_graph)) {
					selectedClass = (friend.id in preselected_friends_graph) ? "selected" : "";
	                buffer.push("<div class='jfmfs-friend " + selectedClass + " ' id='" + friend.id  +"'><img/><div class='friend-name'>" + friend.name + "</div></div>");            
				}
            });
            friend_container.append(buffer.join(""));
            
            uninitializedImagefriendElements = $(".jfmfs-friend", elem);            
            uninitializedImagefriendElements.bind('inview', function (event, visible) {
                if( $(this).attr('src') === undefined) {
                    $("img", $(this)).attr("src", "//graph.facebook.com/" + this.id + "/picture");
                }
                $(this).unbind('inview');
            });

            init();
        });
        
        
        // ----------+----------+----------+----------+----------+----------+----------+
        // Public functions
        // ----------+----------+----------+----------+----------+----------+----------+
        
        this.getSelectedIds = function() {
            var ids = [];
            $.each(elem.find(".jfmfs-friend.selected"), function(i, friend) {
                ids.push($(friend).attr("id"));
            });
            return ids;
        };
        
        this.getSelectedIdsAndNames = function() {
            var selected = [];
            $.each(elem.find(".jfmfs-friend.selected"), function(i, friend) {
                selected.push( {id: $(friend).attr("id"), name: $(friend).find(".friend-name").text()});
            });
            return selected;
        };
        
        this.clearSelected = function () {
            all_friends.removeClass("selected");
        };
        
        // ----------+----------+----------+----------+----------+----------+----------+
        // Private functions
        // ----------+----------+----------+----------+----------+----------+----------+
        
        var init = function() {
            all_friends = $(".jfmfs-friend", elem);
            
            // calculate friends per row
            first_element_offset_px = all_friends.first().offset().top;
            for(var i=0, l=all_friends.length; i < l; i++ ) {
                if($(all_friends[i]).offset().top === first_element_offset_px) {
                    friends_per_row++;
                } else {
                    friend_height_px = $(all_friends[i]).offset().top - first_element_offset_px;
                    break;
                }
            }
            
            // handle when a friend is clicked for selection
            elem.delegate(".jfmfs-friend", 'click', function(event) {
                
                // if the element is being selected, test if the max number of items have
                // already been selected, if so, just return
                if(!$(this).hasClass("selected") && 
                    maxSelectedEnabled() &&
                    $(".jfmfs-friend.selected").length >= settings.max_selected &&
                    settings.max_selected != 1) {
                        return;
                    }
                    
                // if the max is 1 then unselect the current and select the new    
                if(settings.max_selected == 1) {
                    elem.find(".selected").removeClass("selected");                    
                }
                    
                $(this).toggleClass("selected");
                $(this).removeClass("hover");
                
                // support shift-click operations to select multiple items at a time
                if( $(this).hasClass("selected")) {
                    if ( !lastSelected ) {
                        lastSelected = $(this);
                    } 
                    else {                        
                        if( event.shiftKey ) {
                            var selIndex = $(this).index();
                            var lastIndex = lastSelected.index();
                            var end = Math.max(selIndex,lastIndex);
                            var start = Math.min(selIndex,lastIndex);
                            for(var i=start; i<=end; i++) {
                                var aFriend = $( all_friends[i] );
                                if(!aFriend.hasClass("hide-non-selected") && !aFriend.hasClass("hide-filtered")) {
                                    if( maxSelectedEnabled() && $(".jfmfs-friend.selected").length < settings.max_selected ) {
                                        $( all_friends[i] ).addClass("selected");                                        
                                    }
                                }
                            }
                        }
                    }
                }
                
                // keep track of last selected, this is used for the shift-select functionality
                lastSelected = $(this);
                
                // update the count of the total number selected
                updateSelectedCount();

                if( maxSelectedEnabled() ) {
                    updateMaxSelectedMessage();
                }
                elem.trigger("jfmfs.selection.changed", [obj.getSelectedIdsAndNames()]);
            });

            // filter by selected, hide all non-selected
            $("#jfmfs-filter-selected").click(function(event) {
				event.preventDefault();
                all_friends.not(".selected").addClass("hide-non-selected");
                $(".filter-link").removeClass("selected");
                $(this).addClass("selected");
            });

            // remove filter, show all
            $("#jfmfs-filter-all").click(function(event) {
				event.preventDefault();
                all_friends.removeClass("hide-non-selected");
                $(".filter-link").removeClass("selected");
                $(this).addClass("selected");
            });

            // hover effect on friends
            elem.find(".jfmfs-friend:not(.selected)").live(
                'hover', function (ev) {
                    if (ev.type == 'mouseover') {
                        $(this).addClass("hover");
                    }
                    if (ev.type == 'mouseout') {
                        $(this).removeClass("hover");
                    }
                });

            // filter as you type 
            elem.find("#jfmfs-friend-filter-text")
                .keyup( function() {
                    var filter = $(this).val();
                    clearTimeout(keyUpTimer);
                    keyUpTimer = setTimeout( function() {
                        if(filter == '') {
                            all_friends.removeClass("hide-filtered");
                        }
                        else {
                            container.find(".friend-name:not(:Contains(" + filter +"))").parent().addClass("hide-filtered");
                            container.find(".friend-name:Contains(" + filter +")").parent().removeClass("hide-filtered");                         
                        }    
                        showImagesInViewPort();                        
                    }, 400);
                })
                .focus( function() {
                    if($.trim($(this).val()) == 'Empieza a escribir') {
                        $(this).val('');
                    }
                    })
                .blur(function() {
                    if($.trim($(this).val()) == '') {
                        $(this).val('Empieza a escribir');
                    }                        
                    });

            // hover states on the buttons        
            elem.find(".jfmfs-button").hover(
                function(){ $(this).addClass("jfmfs-button-hover");} , 
                function(){ $(this).removeClass("jfmfs-button-hover");}
            );      
            
            // manages lazy loading of images
            var getViewportHeight = function() {
                var height = window.innerHeight; // Safari, Opera
                var mode = document.compatMode;

                if ( (mode || !$.support.boxModel) ) { // IE, Gecko
                    height = (mode == 'CSS1Compat') ?
                    document.documentElement.clientHeight : // Standards
                    document.body.clientHeight; // Quirks
                }

                return height;
            };
            
            var showImagesInViewPort = function() {
                var container_height_px = friend_container.innerHeight(),
                    scroll_top_px = friend_container.scrollTop(),
                    container_offset_px = friend_container.offset().top,
                    $el, top_px,
                    elementVisitedCount = 0,
                    foundVisible = false,
                    allVisibleFriends = $(".jfmfs-friend:not(.hide-filtered )");

                $.each(allVisibleFriends, function(i, $el){
                    elementVisitedCount++;
                    if($el !== null) {
                        $el = $(allVisibleFriends[i]);
                        top_px = (first_element_offset_px + (friend_height_px * Math.ceil(elementVisitedCount/friends_per_row))) - scroll_top_px - container_offset_px; 
						if (top_px + friend_height_px >= -10 && 
                            top_px - friend_height_px < container_height_px) {  // give some extra padding for broser differences
                                $el.data('inview', true);
                                $el.trigger('inview', [ true ]);
                                foundVisible = true;
                        } 
                        else {                            
                            if(foundVisible) {
                                return false;
                            }
                        }                            
                    }              
                });
            };

			var updateSelectedCount = function() {
				$("#jfmfs-selected-count").html( selectedCount() );
			};

            friend_container.bind('scroll', $.debounce( 250, showImagesInViewPort ));

            updateMaxSelectedMessage();                      
            showImagesInViewPort();
			updateSelectedCount();
            elem.trigger("jfmfs.friendload.finished");
        };

        var selectedCount = function() {
            return $(".jfmfs-friend.selected").length;
        };

        var maxSelectedEnabled = function () {
            return settings.max_selected > 0;
        };
        
        var updateMaxSelectedMessage = function() {
            var message = settings.labels.max_selected_message.replace("{0}", selectedCount()).replace("{1}", settings.max_selected);
            $("#jfmfs-max-selected-wrapper").html( message );
        };
        
    };
    

    
    $.fn.jfmfs = function(options) {
        return this.each(function() {
            var element = $(this);
            
            // Return early if this element already has a plugin instance
            if (element.data('jfmfs')) { return; }
            
            // pass options to plugin constructor
            var jfmfs = new JFMFS(this, options);
            
            // Store plugin object in this element's data
            element.data('jfmfs', jfmfs);
            
        });
    };
    
    // todo, make this more ambiguous
    jQuery.expr[':'].Contains = function(a, i, m) { 
        return jQuery(a).text().toUpperCase().indexOf(m[3].toUpperCase()) >= 0; 
    };
        

})(jQuery);

if($.debounce === undefined) {
    /*
     * jQuery throttle / debounce - v1.1 - 3/7/2010
     * http://benalman.com/projects/jquery-throttle-debounce-plugin/
     * 
     * Copyright (c) 2010 "Cowboy" Ben Alman
     * Dual licensed under the MIT and GPL licenses.
     * http://benalman.com/about/license/
     */
    (function(b,c){var $=b.jQuery||b.Cowboy||(b.Cowboy={}),a;$.throttle=a=function(e,f,j,i){var h,d=0;if(typeof f!=="boolean"){i=j;j=f;f=c}function g(){var o=this,m=+new Date()-d,n=arguments;function l(){d=+new Date();j.apply(o,n)}function k(){h=c}if(i&&!h){l()}h&&clearTimeout(h);if(i===c&&m>e){l()}else{if(f!==true){h=setTimeout(i?k:l,i===c?e-m:e)}}}if($.guid){g.guid=j.guid=j.guid||$.guid++}return g};$.debounce=function(d,e,f){return f===c?a(d,e,false):a(d,f,e!==false)}})(this);
}