/*
 * Treeview 1.2 - jQuery plugin to hide and show branches of a tree
 *
 * Copyright (c) 2006 Jörn Zaefferer, Myles Angell
 *
 * Dual licensed under the MIT and GPL licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
 *
 * Revision: $Id$
 *
 */

/**
 *
 * @example $("ul").Treeview();
 * @before <ul>
 *   <li>Item 1
 *     <ul>
 *       <li>Item 1.1</li>
 *     </ul>
 *   </li>
 *   <li class="closed">Item 2 (starts closed)
 *     <ul>
 *       <li>Item 2.1
 *         <ul>
 *           <li>Item 2.1.1</li>
 *           <li>Item 2.1.2</li>
 *         </ul>
 *       </li>
 *       <li>Item 2.2</li>
 *     </ul>
 *   </li>
 *   <li>Item 3</li>
 * </ul>
 * @desc Basic usage example
 *
 * @example $("ul").Treeview({ animated: "fast", collapsed: true});
 * @before <ul>
 *   <li class="open">Item 1 (starts open)
 *     <ul>
 *       <li>Item 1.1</li>
 *     </ul>
 *   </li>
 *   <li>Item 2
 *     <ul>
 *       <li>Item 2.1</li>
 *       <li>Item 2.2</li>
 *     </ul>
 *   </li>
 * </ul>
 * @desc Create a treeview that starts collapsed. Toggling branches is animated.
 *
 * @example $("ul").Treeview({ control: #treecontrol });
 * @before <div id="treecontrol">
 *   <a href="#">Collapse All</a>
 *   <a href="#">Expand All</a>
 *   <a href="#">Toggle All</a>
 * </div>
 * @desc Creates a treeview that can be controlled with a few links.
 * Very likely to be changed/improved in future versions.
 */

(function($) {

    // classes used by the plugin
    // need to be styled via external stylesheet, see first example
    var CLASSES = {
        open: "open",
        closed: "closed",
        expandable: "expandable",
        collapsable: "collapsable",
        lastCollapsable: "lastCollapsable",
        lastExpandable: "lastExpandable",
        last: "last",
        hitarea: "hitarea"
    };

    // styles for hitareas
    var hitareaCSS = {
        height: 15,
        width: 15,
        marginLeft: "-15px",
        "float": "left",
        cursor: "pointer"
    };

    // ie specific styles for hitareas
    if( $.browser.msie )
        $.extend( hitareaCSS, {
            background: "#fff",
            filter: "alpha(opacity=0)",
            display: "inline"
        });

    $.extend($.fn, {
        swapClass: function(c1, c2) {
            return this.each(function() {
                var $this = $(this);
                if ( $.className.has(this, c1) )
                    $this.removeClass(c1).addClass(c2);
                else if ( $.className.has(this, c2) )
                    $this.removeClass(c2).addClass(c1);
            });
        },
        replaceClass: function(c1, c2) {
            return this.each(function() {
                var $this = $(this);
                if ( $.className.has(this, c1) )
                    $this.removeClass(c1).addClass(c2);
            });
        },
        hoverClass: function(className) {
            className = className || "hover";
            return this.hover(function() {
                $(this).addClass(className);
            }, function() {
                $(this).removeClass(className);
            });
        },
        heightToggle: function(animated, callback) {
            animated ?
                this.animate({ height: "toggle" }, animated, callback) :
                this.each(function(){
                    jQuery(this)[ jQuery(this).is(":hidden") ? "show" : "hide" ]();
                    if(callback)
                        callback.apply(this, arguments);
                });
        },
        heightHide: function(animated, callback) {
            if (animated) {
                this.animate({ height: "hide" }, animated, callback)
            } else {
                this.hide();
                if (callback)
                    this.each(callback);
            }
        },
        prepareBranches: function(settings) {
            // mark last tree items
            this.filter(":last-child").addClass(CLASSES.last);
            // collapse whole tree, or only those marked as closed, anyway except those marked as open
            this.filter((settings.collapsed ? "" : "." + CLASSES.closed) + ":not(." + CLASSES.open + ")").find(">ul").hide();
            // return all items with sublists
            return this.filter(":has(>ul)");
        },
        applyClasses: function(settings, toggler) {
            this.filter(":has(ul):not(:has(>a))").find(">span").click(function(event) {
                if ( this == event.target ) {
                    toggler.apply($(this).next());
                }
            }).add( $("a", this) ).hoverClass();

            // handle closed ones first
            this.filter(":has(>ul:hidden)")
                    .addClass(CLASSES.expandable)
                    .replaceClass(CLASSES.last, CLASSES.lastExpandable);

            // handle open ones
            this.not(":has(>ul:hidden)")
                    .addClass(CLASSES.collapsable)
                    .replaceClass(CLASSES.last, CLASSES.lastCollapsable);

            // append hitarea
            this.prepend("<div class=\"" + CLASSES.hitarea + "\">")
                // find hitarea
                .find("div." + CLASSES.hitarea)
                // apply styles to hitarea
                .css(hitareaCSS)
                // apply click event to hitarea
                .click( toggler );
        },
        Treeview: function(settings) {

            // currently no defaults necessary, all implicit
            settings = $.extend({}, settings);

            if (settings.add) {
                return this.trigger("add", [settings.add]);
            }

            if (settings.toggle ) {
                var callback = settings.toggle;
                settings.toggle = function() {
                    return callback.apply($(this).parent()[0], arguments);
                }
            }

            // factory for treecontroller
            function treeController(tree, control) {
                // factory for click handlers
                function handler(filter) {
                    return function() {
                        // reuse toggle event handler, applying the elements to toggle
                        // start searching for all hitareas
                        toggler.apply( $("div." + CLASSES.hitarea, tree).filter(function() {
                            // for plain toggle, no filter is provided, otherwise we need to check the parent element
                            return filter ? $(this).parent("." + filter).length : true;
                        }) );
                        return false;
                    }
                }
                // click on first element to collapse tree
                $(":eq(0)", control).click( handler(CLASSES.collapsable) );
                // click on second to expand tree
                $(":eq(1)", control).click( handler(CLASSES.expandable) );
                // click on third to toggle tree
                $(":eq(2)", control).click( handler() );
            }

            // handle toggle event
            function toggler() {
                // this refers to hitareas, we need to find the parent lis first
                $(this).parent()
                    // swap classes
                    .swapClass( CLASSES.collapsable, CLASSES.expandable )
                    .swapClass( CLASSES.lastCollapsable, CLASSES.lastExpandable )
                    // find child lists
                    .find( ">ul" )
                    // toggle them
                    .heightToggle( settings.animated, settings.toggle );
                if ( settings.unique ) {
                    $(this).parent()
                        .siblings()
                        .replaceClass( CLASSES.collapsable, CLASSES.expandable )
                        .replaceClass( CLASSES.lastCollapsable, CLASSES.lastExpandable )
                        .find( ">ul" )
                        .heightHide( settings.animated, settings.toggle );
                }
            }

            function serialize() {
                function binary(arg) {
                    return arg ? 1 : 0;
                }
                var data = [];
                branches.each(function(i, e) {
                    data[i] = $(e).is(":has(>ul:visible)") ? 1 : 0;
                });
                $.cookie("treeview", data.join("") );
            }

            function deserialize() {
                var stored = $.cookie("treeview");
                if ( stored ) {
                    var data = stored.split("");
                    branches.each(function(i, e) {
                        $(e).find(">ul")[ parseInt(data[i]) ? "show" : "hide" ]();
                    });
                }
            }

            // add treeview class to activate styles
            this.addClass("treeview");

            // prepare branches and find all tree items with child lists
            var branches = this.find("li").prepareBranches(settings);

            switch(settings.persist) {
            case "cookie":
                var toggleCallback = settings.toggle;
                settings.toggle = function() {
                    serialize();
                    if (toggleCallback) {
                        toggleCallback.apply(this, arguments);
                    }
                };
                deserialize();
                break;
            case "location":
                var current = this.find("a").filter(function() { return this.href == location.href; });
                if ( current.length ) {
                    current.addClass("selected").parents("ul, li").add( current.next() ).show();
                }
                break;
            }

            branches.applyClasses(settings, toggler);

            // if control option is set, create the treecontroller
            if ( settings.control )
                treeController(this, settings.control);

            return this.bind("add", function(event, branches) {
                $(branches).prev().removeClass(CLASSES.last).removeClass(CLASSES.lastCollapsable).removeClass(CLASSES.lastExpandable);
                $(branches).find("li").andSelf().prepareBranches(settings).applyClasses(settings, toggler);
            });
        }
    });
})(jQuery);