// tipsy, facebook style tooltips for jquery
// version 1.0.0a
// (c) 2008-2010 jason frame [jason@onehackoranother.com]
// released under the MIT license
// Modified by Justin Donaldson [donaldson@bigml.com]
// Added:
// 1) Correctly handle svg elements (title children and/or xlink:title attr)
// 2) Add some new dynamic gravity placement functions autoNWNE and autoSWSE
// 3) z-index override for tipsies on top of tipsies
// 4) Custom className argument that allows adding classes to the tipsy popup
// 5) Add custom cancelHide function argument that can override a tipsy hide
//    behavior. This is useful when you wish to keep a parent tipsy open while
//    its child is still active.
(function($) {

    function maybeCall(thing, ctx) {
        return (typeof thing == 'function') ? (thing.call(ctx)) : thing;
    }

    // CAUTION the current implementation does not allow for tipsied elements to stay out of DOM (in between events)
    // i.e. don't remove, store, then re-insert tipsied elements (and why would you want to do that anyway?)
    var garbageCollect = (function() {
        var currentInterval;
        var to = null;
        var tipsies = [];

        function _do() {
            for (var i = 0; i < tipsies.length;) {
                var t = tipsies[i];
                // FIXME? the 2nd (non-paranoid) check is from the link below, it should be replaced if a better way is found
                // http://stackoverflow.com/questions/4040715/check-if-cached-jquery-object-is-still-in-dom
                if (t.options.gcInterval === 0 || t.$element.closest('body').length === 0) {
                    t.hoverState = 'out';
                    t.hide();
                    tipsies.splice(i,1);
                } else {
                    i++;
                }
            }
        }
        function _loop() {
            to = setTimeout(function() { _do(); _loop(); }, currentInterval);
        }

        return function(t) {
            if (t.options.gcInterval === 0) return;

            if (to && t.options.gcInterval < currentInterval) {
                clearTimeout(to); to = null;
                currentInterval = t.options.gcInterval;
            }
            tipsies.push(t);
            if (!to) _loop();
        };
    })();

    function Tipsy(element, options) {
        this.$element = $(element);
        this.options = options;
        this.enabled = true;
        this.fixTitle();
        garbageCollect(this);
    }


    Tipsy.prototype = {
        show: function() {
            var title = this.getTitle();
            if (title && this.enabled) {
                var $tip = this.tip();

                $tip.find('.tipsy-inner')[this.options.html ? 'html' : 'text'](title);
                $tip[0].className = 'tipsy'; // reset classname in case of dynamic gravity
                $tip.remove().css({top: 0, left: 0, visibility: 'hidden', display: 'block'}).prependTo(document.body);

                var pos = $.extend({}, this.$element.offset(), {
                    width: this.$element[0].offsetWidth || 0,
                    height: this.$element[0].offsetHeight || 0
                });

                if (typeof this.$element[0].nearestViewportElement == 'object') {
                    // SVG
					var el = this.$element[0];
                    var rect = el.getBoundingClientRect();
					pos.width = rect.width;
					pos.height = rect.height;
                }


                var actualWidth = $tip[0].offsetWidth,
                    actualHeight = $tip[0].offsetHeight,
                    gravity = maybeCall(this.options.gravity, this.$element[0]);

                var tp;
                switch (gravity.charAt(0)) {
                    case 'n':
                        tp = {top: pos.top + pos.height + this.options.offset, left: pos.left + pos.width / 2 - actualWidth / 2};
                        break;
                    case 's':
                        tp = {top: pos.top - actualHeight - this.options.offset, left: pos.left + pos.width / 2 - actualWidth / 2};
                        break;
                    case 'e':
                        tp = {top: pos.top + pos.height / 2 - actualHeight / 2, left: pos.left - actualWidth - this.options.offset};
                        break;
                    case 'w':
                        tp = {top: pos.top + pos.height / 2 - actualHeight / 2, left: pos.left + pos.width + this.options.offset};
                        break;
                }

                if (gravity.length == 2) {
                    if (gravity.charAt(1) == 'w') {
                        tp.left = pos.left + pos.width / 2 - 15;
                    } else {
                        tp.left = pos.left + pos.width / 2 - actualWidth + 15;
                    }
                }

                $tip.css(tp).addClass('tipsy-' + gravity);
                $tip.find('.tipsy-arrow')[0].className = 'tipsy-arrow tipsy-arrow-' + gravity.charAt(0);
                if (this.options.className) {
                    $tip.addClass(maybeCall(this.options.className, this.$element[0]));
                }

                if (this.options.fade) {
                    $tip.stop().css({opacity: 0, display: 'block', visibility: 'visible'}).animate({opacity: this.options.opacity});
                } else {
                    $tip.css({visibility: 'visible', opacity: this.options.opacity});
                }

                $tip.css({'z-index':this.options.zIndex});

                var t = this;
                var set_hovered  = function(set_hover){
                    return function(){
                        t.$tip.stop();
                        t.tipHovered = set_hover;
                        if (!set_hover){
                            if (t.options.delayOut === 0 && t.options.trigger != 'manual') {
                                t.hide();
                            } else {
                                setTimeout(function() {
                                    if (t.hoverState == 'out') t.hide(); }, t.options.delayOut);
                            }
                        }
                    };
                };
               $tip.hover(set_hovered(true), set_hovered(false));
            }
        },

        hide: function() {
            if (this.options.fade) {
                this.tip().stop().fadeOut(function() { $(this).remove(); });
            } else {
                if (this.options.cancelHide == null || !this.options.cancelHide()){
                        this.tip().remove();
                }
            }
        },

        fixTitle: function() {
            var $e = this.$element;

            if ($e.attr('title') || typeof($e.attr('original-title')) != 'string') {
                $e.attr('original-title', $e.attr('title') || '').removeAttr('title');
            }
            if (typeof $e.context.nearestViewportElement == 'object'){
                if ($e.children('title').length){
                    $e.append('<original-title>' + ($e.children('title').text() || '') + '</original-title>')
                        .children('title').remove();
                }
            }
        },

        getTitle: function() {

            var title, $e = this.$element, o = this.options;
            this.fixTitle();

            if (typeof o.title == 'string') {
                var title_name = o.title == 'title' ? 'original-title' : o.title;
                if ($e.children(title_name).length){
                    title = $e.children(title_name).html();
                } else{
                    title = $e.attr(title_name);
                    if (typeof title == 'undefined') title = ''
                }

            } else if (typeof o.title == 'function') {
                title = o.title.call($e[0]);
            }
            title = ('' + title).replace(/(^\s*|\s*$)/, "");
            return title || o.fallback;
        },

        tip: function() {
            if (!this.$tip) {
                this.$tip = $('<div class="tipsy"></div>').html('<div class="tipsy-arrow"></div><div class="tipsy-inner"></div>');
            }
            return this.$tip;
        },

        validate: function() {
            if (!this.$element[0].parentNode) {
                this.hide();
                this.$element = null;
                this.options = null;
            }
        },

        enable: function() { this.enabled = true; },
        disable: function() { this.enabled = false; },
        toggleEnabled: function() { this.enabled = !this.enabled; }
    };

    $.fn.tipsy = function(options) {

        if (options === true) {
            return this.data('tipsy');
        } else if (typeof options == 'string') {
            $(this).each(function(i,el){
              if ($(el).data('tipsy')) {
                  tipsy = $(el).data('tipsy')
                  tipsy[options]();
              }
            });
            return this;
        }

        options = $.extend({}, $.fn.tipsy.defaults, options);

        if (options.hoverlock && options.delayOut === 0) {
            options.delayOut = 100;
        }

        function get(ele) {
            var tipsy = $.data(ele, 'tipsy');
            if (!tipsy) {
                tipsy = new Tipsy(ele, $.fn.tipsy.elementOptions(ele, options));
                $.data(ele, 'tipsy', tipsy);
            }
            return tipsy;
        }

        function enter() {
            var tipsy = get(this);
            tipsy.hoverState = 'in';
            if (options.delayIn === 0) {
                tipsy.show();
            } else {
                tipsy.fixTitle();
                setTimeout(function() { if (tipsy.hoverState == 'in') tipsy.show(); }, options.delayIn);
            }
        }

        function leave() {
            var tipsy = get(this);
            tipsy.hoverState = 'out';
            if (options.delayOut === 0) {
                tipsy.hide();
            } else {
                var to = function() {
                    if (!tipsy.tipHovered || !options.hoverlock){
                        if (tipsy.hoverState == 'out') tipsy.hide();
                    }
                };
                setTimeout(to, options.delayOut);
            }
        }

        if (!options.live) this.each(function() { get(this); });

        if (options.trigger != 'manual') {
            var binder = options.live ? 'live' : 'bind',
                eventIn = options.trigger == 'hover' ? 'mouseenter' : 'focus',
                eventOut = options.trigger == 'hover' ? 'mouseleave' : 'blur';
            this[binder](eventIn, enter)[binder](eventOut, leave);
        }

        return this;

    };

    $.fn.tipsy.defaults = {
        className: null,
        delayIn: 0,
        delayOut: 0,
        fade: false,
        'zIndex': 100000,
        fallback: '',
        cancelHide: null,
        gcInterval: 0,
        gravity: 'n',
        html: false,
        live: false,
        offset: 0,
        opacity: 0.8,
        title: 'title',
        trigger: 'hover',
        hoverlock: false
    };

    // Overwrite this method to provide options on a per-element basis.
    // For example, you could store the gravity in a 'tipsy-gravity' attribute:
    // return $.extend({}, options, {gravity: $(ele).attr('tipsy-gravity') || 'n' });
    // (remember - do not modify 'options' in place!)
    $.fn.tipsy.elementOptions = function(ele, options) {
        return $.metadata ? $.extend({}, options, $(ele).metadata()) : options;
    };

    $.fn.tipsy.autoNS = function() {
        return $(this).offset().top > ($(document).scrollTop() + $(window).height() / 2) ? 's' : 'n';
    };

    $.fn.tipsy.autoWE = function() {
        return $(this).offset().left > ($(document).scrollLeft() + $(window).width() / 2) ? 'e' : 'w';
    };
    $.fn.tipsy.autoNWNE = function() {
        return $(this).offset().left > ($(document).scrollLeft() + $(window).width() / 2) ? 'ne' : 'nw';
    };
    $.fn.tipsy.autoSWSE = function() {
        return $(this).offset().left > ($(document).scrollLeft() + $(window).width() / 2) ? 'se' : 'sw';
    };


    /**
     * yields a closure of the supplied parameters, producing a function that takes
     * no arguments and is suitable for use as an autogravity function like so:
     *
     * @param margin (int) - distance from the viewable region edge that an
     *        element should be before setting its tooltip's gravity to be away
     *        from that edge.
     * @param prefer (string, e.g. 'n', 'sw', 'w') - the direction to prefer
     *        if there are no viewable region edges effecting the tooltip's
     *        gravity. It will try to vary from this minimally, for example,
     *        if 'sw' is preferred and an element is near the right viewable
     *        region edge, but not the top edge, it will set the gravity for
     *        that element's tooltip to be 'se', preserving the southern
     *        component.
     */
     $.fn.tipsy.autoBounds = function(margin, prefer) {
		return function() {
			var dir = {ns: prefer[0], ew: (prefer.length > 1 ? prefer[1] : false)},
                boundTop = $(document).scrollTop() + margin,
                boundLeft = $(document).scrollLeft() + margin,
                $this = $(this);

			if ($this.offset().top < boundTop) dir.ns = 'n';
			if ($this.offset().left < boundLeft) dir.ew = 'w';
			if ($(window).width() + $(document).scrollLeft() - $this.offset().left < margin) dir.ew = 'e';
			if ($(window).height() + $(document).scrollTop() - $this.offset().top < margin) dir.ns = 's';

			return dir.ns + (dir.ew ? dir.ew : '');
		};
    };
})(jQuery);