jQuery(function ($) {
    // default shape window height when first opened
    var defaultHeight = 200;

    // append the shape tracing window container at the end of the document
    $('<div id="shape-tracing-container"> ' +
            '<div id="shape-tracing-resize-handle" ></div>' +
            '<div id="shape-tracing-toolbar">' +
                '<div id="shape-tracing-toolbar-switch"></div>' +
            '</div>' +
            '<div id="shape-tracing-window">' +
                '<div id="shape-tracing-window-tree"></div>' +
                '<div id="shape-tracing-window-content"></div>' +
            '</div>' +
        '</div>' +
        '<div id="shape-tracing-container-ghost"></div>' +
        '<div id="shape-tracing-overlay"></div>'
    ).appendTo('body');

    // preload main objects
    var shapeTracingContainer = $('#shape-tracing-container');
    var shapeTracingResizeHandle = $('#shape-tracing-resize-handle');
    var shapeTracingToolbar = $('#shape-tracing-toolbar');
    var shapeTracingToolbarSwitch = $('#shape-tracing-toolbar-switch');
    var shapeTracingWindow = $('#shape-tracing-window');
    var shapeTracingWindowTree = $('#shape-tracing-window-tree');
    var shapeTracingWindowContent = $('#shape-tracing-window-content');
    var shapeTracingGhost = $('#shape-tracing-container-ghost');
    var shapeTracingOverlay = $('#shape-tracing-overlay');

    var shapeTracingEnabled = false;

    // store the size of the container when it is closed (default in css)
    var initialContainerSize = shapeTracingContainer.height();
    var previousSize = 0;

    // ensure the ghost has always the same size as the container
    // and the container is always positionned correctly
    var syncResize = function () {
        var _window = $(window);
        var containerHeight = shapeTracingContainer.outerHeight();
        var containerWidth = shapeTracingContainer.outerWidth();
        var toolbarHeight = shapeTracingToolbar.outerHeight();
        var resizeHandleHeight = shapeTracingResizeHandle.outerHeight();

        shapeTracingGhost.height(containerHeight);

        var windowHeight = _window.height();
        var scrollTop = _window.scrollTop();
        var containerWindowHeight = containerHeight - toolbarHeight - resizeHandleHeight;

        shapeTracingContainer.offset({ top: windowHeight - containerHeight + scrollTop, left: 0 });
        shapeTracingWindow.height(containerWindowHeight);
        shapeTracingWindowTree.height(containerWindowHeight);
        shapeTracingWindowContent.height(containerWindowHeight);
        shapeTracingContainer.width('100%');

        syncResizeMeta();
    };

    // forces the content meta zone's height to enable scrollbar
    var syncResizeMeta = function () {
        var containerHeight = shapeTracingContainer.outerHeight();
        var containerWidth = shapeTracingContainer.outerWidth();
        var toolbarHeight = shapeTracingToolbar.outerHeight();
        var resizeHandleHeight = shapeTracingResizeHandle.outerHeight();

        var tabsHeight = $('.shape-tracing-tabs:visible').outerHeight();
        var breadcrumbHeight = $('.shape-tracing-breadcrumb:visible').outerHeight();
        if (tabsHeight) {
            var metaContent = $('.shape-tracing-meta-content:visible');
            padding = parseInt(metaContent.css('padding-bottom') + metaContent.css('padding-top'));
            metaContent.height(containerHeight - toolbarHeight - resizeHandleHeight - tabsHeight - breadcrumbHeight - padding);
        }
    };

    // ensure the size/position is correct whenver the container or the browser is resized
    shapeTracingContainer.resize(syncResize);
    $(window).resize(syncResize);
    $(window).resize();

    // removes the position flickering by hiding it first, then showing when ready
    shapeTracingContainer.show();

    // expand/collapse behavior
    // ensure the container has always a valid size when expanded
    shapeTracingToolbarSwitch.click(function () {
        var _this = $(this);
        _this.toggleClass('expanded');
        if (_this.hasClass('expanded')) {
            shapeTracingContainer.height(Math.max(previousSize, defaultHeight, shapeTracingContainer.height()));
            enableShapeTracing();
        }
        else {
            // save previous height
            previousSize = shapeTracingContainer.height();
            shapeTracingContainer.height(initialContainerSize);
            disableShapeTracing();
        }

        syncResize();
    });

    var disableShapeTracing = function () {
        shapeTracingEnabled = false;
        selectShape();
    }

    var enableShapeTracing = function () {
        shapeTracingEnabled = true;
    }

    // add a resizable handle to the container
    $('#shape-tracing-resize-handle').addClass('ui-resizable-handle ui-resizable-n');
    shapeTracingContainer.resizable({
        handles: { n: '#shape-tracing-resize-handle' },
        grid: 20, // mitigates the number of calls to syncResize(), and aligns to the line height
        resize: function () { shapeTracingEnabled = false },
        stop: function () { shapeTracingEnabled = true }
    });

    var shapeNodes = {}; // represents the main index of shape nodes, indexed by id

    // projects the shape ids to each DOM element
    var startShapeTracingBeacons = $('.shape-tracing-wrapper[shape-id]');
    startShapeTracingBeacons.each(function () {
        var _this = $(this);

        var shapeNode = {
            id: _this.attr('shape-id'),
            type: _this.attr('shape-type'),
            hint: _this.attr('shape-hint'),
            parent: null,
            children: {}
        };

        // register the new shape node into the main shape nodes index
        shapeNodes[shapeNode.id] = shapeNode;

        // assign the shape-id attribute to all direct children, except wrappers themselves (it would erase their own shape-id)
        var found = false;
        _this
            .nextUntil('[end-of="' + shapeNode.id + '"]') // all elements between the script beacons
            .find(':not(.shape-tracing-wrapper)') // all children but not inner beacons
            .andSelf() // add the first level items
            .attr('shape-id', shapeNode.id) // add the shape-id attribute
            .each(function () {
                // assign a shapeNode instance to the DOM element
                this.shapeNode = shapeNode;
                found = true;
            });

        // if the shape is empty, add a hint
        if (!found) {
            shapeNode.hint = 'empty';
        }
        this.shapeNode = shapeNode;
    });

    // construct the shape tree based on all current nodes
    // for each start beacon, search for the first parent beacon, and create nodes if they don't exist
    startShapeTracingBeacons.each(function () {
        var _this = $(this);
        var shapeNode = this.shapeNode;
        var parent = _this.parents('[shape-id!=' + shapeNode.id + ']').get(0);

        shapeNodes[shapeNode.id] = shapeNode;

        if (parent.shapeNode) {
            var parentShapeNode = parent.shapeNode;
            shapeNodes[parentShapeNode.id] = parentShapeNode;
            shapeNode.parent = parentShapeNode;
            parentShapeNode.children[shapeNode.id] = shapeNode;
        }
    });

    // removes all beacons as we don't need them anymore
    $('.shape-tracing-wrapper').remove();

    // add first level shapes tree nodes
    var shapes = $('<ul></ul>');
    for (var shapeId in shapeNodes) {
        if (!shapeNodes[shapeId].parent) {
            shapes.append(createTreeNode(shapeNodes[shapeId]));
        }
    }

    shapeTracingWindowTree.append(shapes);

    // add the expand/collapse logic to the shapes tree
    var glyph = $('<span class="expando-glyph-container closed"><span class="expando-glyph"></span>&#8203;</span>');
    shapeTracingWindowTree.find('li:has(ul:has(li))').prepend(glyph);

    // collapse all sub uls
    shapeTracingWindowTree.find('ul ul').toggle(false);

    // expands a list of shapes in the tree
    var openExpando = function (expando) {
        if (expando.hasClass("closed") || expando.hasClass("closing")) {
            expando.siblings('ul').slideDown(100, function () { expando.removeClass("opening").removeClass("closed").addClass("open"); });
            expando.addClass("opening");
        }
    }

    // collapses a list of shapes in the tree
    var closeExpando = function (expando) {
        if (!expando.hasClass("closed") && !expando.hasClass("closing")) {
            expando.siblings('ul').slideUp(100, function () { expando.removeClass("closing").removeClass("open").addClass("closed"); });
            expando.addClass("closing");
        }
    }

    //create an overlay on shapes' descendants
    var overlayTarget = null;
    $('[shape-id]').add(shapeTracingOverlay).mousemove(
        function (event) {
            if (!shapeTracingEnabled) {
                return;
            }

            event.stopPropagation();

            if ($(this).get(0) == shapeTracingOverlay.get(0)) {
                shapeTracingOverlay.hide();
            }

            var element = document.elementFromPoint(event.pageX - $(window).scrollLeft(), event.pageY - $(window).scrollTop());
            shapeTracingOverlay.show();


            while (element && !element.shapeNode)
                element = element.parentNode;

            if (!element || (overlayTarget != null && overlayTarget.get(0) == element)) {
                return;
            }

            element = $(element);
            shapeTracingOverlay.offset(element.offset());
            shapeTracingOverlay.width(element.outerWidth()); // include border and padding 
            shapeTracingOverlay.height(element.outerHeight()); // include border and padding 

            overlayTarget = element;
        }
    );

    // selects a specific shape in the tree, highlight its elements, and display the information
    var selectShape = function (shapeId) {
        if (!shapeId) {
            // remove selection ?
            shapeTracingOverlay.hide();
            $('.shape-tracing-selected').removeClass('shape-tracing-selected');
            shapeTracingWindowTree.find('.shape-tracing-selected').removeClass('shape-tracing-selected');
            $('[shape-id-meta]:visible').toggle(false);
            return;
        }

        $('.shape-tracing-selected').removeClass('shape-tracing-selected');
        $('li[tree-shape-id="' + shapeId + '"] > div').add('[shape-id="' + shapeId + '"]').addClass('shape-tracing-selected');
        shapeTracingOverlay.hide();

        // show the properties for the selected shape
        $('[shape-id-meta]:visible').toggle(false);
        var target = $('[shape-id-meta="' + shapeId + '"]"');
        target.toggle(true);

        // enable codemirror for the current tab
        enableCodeMirror(target);

        syncResizeMeta();
    }

    // select shapes when clicked
    shapeTracingOverlay.click(function () {
        var shapeNode = overlayTarget.get(0).shapeNode;
        selectShape(shapeNode.id);

        var lastExpanded = null;
        // open the tree until the selected element
        $('li[tree-shape-id="' + shapeNode.id + '"]').parents('li').andSelf().find('> .expando-glyph-container').each(function () {
            openExpando($(this));
        }).each(function () {
            shapeTracingWindowTree.scrollTo(this, 0, { margin: true });
        });

        refreshBreadcrumb();

        return false;
    });

    //create an overlay on shape tree nodes
    shapeTracingWindowTree.find('[tree-shape-id] > div')
    .hover(
        function () {
            var _this = $(this);
            $('.shape-tracing-overlay').removeClass('shape-tracing-overlay');
            _this.addClass('shape-tracing-overlay');
        },
        function () {
            $('.shape-tracing-overlay').removeClass('shape-tracing-overlay');
        })
    .click(function (event) {
        var shapeId = $(this).parent().get(0).shapeNode.id;
        selectShape(shapeId);

        var element = $('[shape-id="' + shapeId + '"]').get(0);
        // there might be no DOM element if the shape was empty, or is not displayed
        if (element) {
            $(window).scrollTo(element, 500, { margin: true });
        }

        event.stopPropagation();
    });

    // move all shape tracing meta blocks to the content window
    $("[shape-id-meta]").detach().prependTo(shapeTracingWindowContent);

    // add the expand/collapse logic to the shape model
    shapeTracingWindowContent.find('li:has(ul:has(li))').prepend(glyph);

    // collapse all sub uls
    shapeTracingWindowContent.find('ul ul').toggle(false);

    // tabs events
    shapeTracingWindowContent.find('.shape-tracing-tabs > li').click(function () {
        var _this = $(this);
        var tabName = this.className.split(/\s/)[0];

        // toggle the selected class on the tab li
        $('.shape-tracing-tabs > li.selected').removeClass('selected');
        $('.shape-tracing-tabs > li.' + tabName).addClass('selected');

        // hide all tabs and display the selected one
        $('.shape-tracing-meta-content > div').toggle(false);
        $('.shape-tracing-meta-content > div.' + tabName).toggle(true);

        // look for the targetted panel
        var wrapper = _this.parent().parent().first();
        var panel = wrapper.find('div.' + tabName);

        refreshBreadcrumb();
        syncResizeMeta();

        // enable codemirror for the current tab
        enableCodeMirror(panel);
    });

    var refreshBreadcrumb = function () {
        var container = shapeTracingWindowContent.find('.shape-tracing-meta:visible');
        var breadcrumb = container.find('.shape-tracing-breadcrumb');
        var tab = container.find('.shape-tracing-meta-content > div:visible');

        if (tab.hasClass('shape')) {
            breadcrumb.text('');
        }
        else if (tab.hasClass('model')) {
            breadcrumb.text('');
        }
        else if (tab.hasClass('placement')) {
            breadcrumb.text(container.find('.sgd-pl > .value').text());
        }
        else if (tab.hasClass('template')) {
            breadcrumb.text(container.find('.sgd-t > .value').text());
        }
        else if (tab.hasClass('html')) {
            breadcrumb.text('');
        }
    };

    // template link opens template tab
    shapeTracingWindowContent.find('.sgd-t a').click(function () {
        $(this).parents('.shape-tracing-meta').find('.shape-tracing-tabs > .template').click()
    });

    // activates codemirror on specific textareas
    var enableCodeMirror = function (target) {
        // if there is a script, and colorization is not enabled yet, turn it on
        // code mirror seems to work only if the textarea is visible
        target.find('textarea:visible').each(function () {
            if ($(this).next('.CodeMirror').length == 0) {
                CodeMirror.fromTextArea(this, { mode: "razor", tabMode: "indent", readOnly: true, lineNumbers: true });
            }
        });
    }

    // automatically expand or collapse shapes in the tree
    shapeTracingWindow.find('.expando-glyph-container').click(function () {
        var _this = $(this);
        if (_this.hasClass("closed") || _this.hasClass("closing")) {
            openExpando(_this);
        }
        else {
            closeExpando(_this);
        }

        return false;
    });

    //create an overlay on model nodes
    shapeTracingWindowContent.find('.model div.name')
    .hover(
        function () {
            var _this = $(this);
            $('.shape-tracing-overlay').removeClass('shape-tracing-overlay');
            _this.addClass('shape-tracing-overlay');
        },
        function () {
            $('.shape-tracing-overlay').removeClass('shape-tracing-overlay');
        })
    .click(function (event) {
        // model node is selected
        var _this = $(this);
        shapeTracingWindowContent.find('.shape-tracing-selected').removeClass('shape-tracing-selected');
        _this.addClass('shape-tracing-selected');

        // display breadcrumb
        var breadcrumb = null;
        _this.parentsUntil('.model').children('.name').each(function () {
            if (breadcrumb != null) {
                breadcrumb = $(this).text() + '.' + breadcrumb;
            }
            else {
                breadcrumb = $(this).text();
            }
        });

        // fix enumerable properties display
        breadcrumb = breadcrumb.replace('.[', '[');

        _this.parents('.shape-tracing-meta').find('.shape-tracing-breadcrumb').text('@' + breadcrumb);
        event.stopPropagation();
    });

    // recursively create a node for the shapes tree
    function createTreeNode(shapeNode) {
        var node = $('<li></li>');
        node.attr('tree-shape-id', shapeNode.id);
        node.get(0).shapeNode = shapeNode;

        var text = shapeNode.type;
        // add the hint to the tree node if available
        if (shapeNode.hint != '') {
            text += ' [' + shapeNode.hint + ']';
        }

        node.append('<div>' + text + '</div>');
        var list = $('<ul></ul>');
        node.append(list);
        if (shapeNode.children) {
            for (var shapeId in shapeNode.children) {
                var child = createTreeNode(shapeNode.children[shapeId]);
                list.append(child);
            }
        }
        return node;
    }

});