!(function () {
    var scale = 1, transformY = 0, selected = false;
    var html = document.getElementsByTagName('html')[0];

    var jQuery = $ || window.jQuery;
    var injectOffset = jQuery.fn.offset;
    var injectEventFix = jQuery.event.fix;
    var injectMouseInBounds = jQuery.fn.__isMouseInBounds__;

    // 修正事件偏移
    function correctEvent(e) {
        if (e && !e.corrected) {
            e.pageX = e.pageX / scale;
            e.pageY = (e.pageY - transformY) / scale;
            e.clientX = e.clientX / scale;
            e.clientY = (e.clientY - transformY) / scale;
            e.corrected = true;
        }
        return e;
    }

    // 进行缩放
    function transformScale() {
        var bounds = getScaleBounds();
        scale = bounds.scale;
        document.body.style.width = bounds.width + "px";
        document.body.style.height = bounds.height + "px";
        document.body.style.transform = "scale(" + bounds.scale+ ")";
        document.body.style.transformOrigin = "top left";
        document.body.style["-ms-transform"] = "scale(" + bounds.scale+ ")";
        document.body.style["-ms-transform-origin"] = "top left";
        html.style.overflowY = "auto";
        html.style.backgroundColor = "#2c3d59";

        if (bounds.height * bounds.scale < html.clientHeight) {
            transformY = (html.clientHeight - bounds.height * bounds.scale) / 2;
            document.body.style.top = transformY + "px";
            html.style.overflowY = "hidden";
        } else {
            transformY = 0;
        }


        window.scale = window.devicePixelRatio * scale;
    }

    // 取消缩放
    function removeScale() {
        document.body.style.width = "100%";
        document.body.style.height = "100%";
        document.body.style.transform = "";
        document.body.style.transformOrigin = "";
        document.body.style["-ms-transform"] = "";
        document.body.style["-ms-transform-origin"] = "";
        document.body.style.overflowY = "hidden";
        document.body.style.top = "0px";
        html.style.backgroundColor = "#ffffff";

        window.scale = window.devicePixelRatio / scale;
        scale = 1;
    }

    // 获取缩放倍数，原模板宽高
    function getScaleBounds() {
        var widgts = BI.designConfigure.widgets,
            layoutRatio = BI.designConfigure.layoutRatio,
            freeLayoutRatio = BI.designConfigure.freeLayoutRatio,
            freeWidgets = BI.designConfigure.freeWidgetIds;
        var left = null, right = null, top = null, bottom = null,
            freeLeft = null, freeRight = null, freeTop = null, freeBottom = null;
        BI.each(widgts, function (wId, widget) {
            var bounds = widget.bounds || {};
            if (BI.contains(freeWidgets, wId)) {
                freeLeft = BI.isNull(freeLeft) ? bounds.left : Math.min(freeLeft, bounds.left);
                freeRight = Math.max(freeRight, bounds.left + bounds.width);
                freeTop = BI.isNull(freeTop) ? bounds.top : Math.min(freeTop, bounds.top);
                freeBottom = Math.max(freeBottom, bounds.top + bounds.height);
            } else {
                left = BI.isNull(left) ? bounds.left : Math.min(left, bounds.left);
                right = Math.max(right, bounds.left + bounds.width);
                top = BI.isNull(top) ? bounds.top : Math.min(top, bounds.top);
                bottom = Math.max(bottom, bounds.top + bounds.height);
            }
        });

        var templateWidth = Math.round((right / (layoutRatio.x || 1)) || (freeRight / (freeLayoutRatio.x || 1)));
        var templateHeight = Math.round((bottom / (layoutRatio.y || 1)) || (freeBottom / (freeLayoutRatio.y || 1)));
        var scaleRatio = parseFloat((html.clientWidth / templateWidth).toFixed(1));
        return {
            scale: scaleRatio,
            width: html.clientWidth / scaleRatio,
            height: templateHeight
        };
    }

    // 准备环境，主要是纠正事件偏移
    function prepareEnv() {
        // IE的fixed元素不受transform：scale影响
        if (!BI.isIE()) {
            jQuery.fn.__isMouseInBounds__ = function (e) {
                var offset2Body = this.get(0).getBoundingClientRect ? this.get(0).getBoundingClientRect() : this.offset();
                var width = offset2Body.width || this.outerWidth();
                var height = offset2Body.height || this.outerHeight();
                var pageX = e.pageX * scale,
                    pageY = e.pageY * scale + transformY;
                return !(pageX < Math.floor(offset2Body.left) || pageX > offset2Body.left + width
                    || pageY < Math.floor(offset2Body.top) || pageY > offset2Body.top + height);
            };
            jQuery.fn.offset = function( options ) {
                function getWindow( elem ) {
                    return jQuery.isWindow( elem ) ?
                        elem :
                        elem.nodeType === 9 ?
                            elem.defaultView || elem.parentWindow :
                            false;
                }

                if ( arguments.length ) {
                    return options === undefined ?
                        this :
                        this.each(function( i ) {
                            jQuery.offset.setOffset( this, options, i );
                        });
                }

                var docElem, win,
                    box = { top: 0, left: 0 },
                    elem = this[ 0 ],
                    doc = elem && elem.ownerDocument;

                if ( !doc ) {
                    return;
                }

                docElem = doc.documentElement;

                // Make sure it's not a disconnected DOM node
                if ( !jQuery.contains( docElem, elem ) ) {
                    return box;
                }

                var el = elem,
                    offsetLeft = 0,
                    offsetTop  = 0;

                do{
                    offsetLeft += el.offsetLeft;
                    offsetTop  += el.offsetTop;
                    el = el.offsetParent;
                } while( el );

                var elm = elem;
                do{
                    offsetLeft -= elm.scrollLeft || 0;
                    offsetTop  -= elm.scrollTop || 0;
                    elm = elm.parentNode;
                } while( elm );
                win = getWindow( doc );
                return {
                    top: offsetTop  + ( win.pageYOffset || docElem.scrollTop )  - ( docElem.clientTop  || 0 ),
                    left: offsetLeft + ( win.pageXOffset || docElem.scrollLeft ) - ( docElem.clientLeft || 0 )
                };
            };
            jQuery.event.fix = function ( e ) {
                return correctEvent(injectEventFix.call(this, e));
            };
        }

        window.addEventListener('resize', updateScale);
    }

    function restoreEnv() {
        if (!BI.isIE()) {
            jQuery.fn.__isMouseInBounds__ = injectMouseInBounds;
            jQuery.fn.offset = injectOffset;
            jQuery.event.fix = injectEventFix;
        }

        window.removeEventListener('resize', updateScale);
    }

    function selectHandler () {
        selected && prepareEnv();
        selected ? transformScale() : removeScale();
        !selected && restoreEnv();
    }

    function updateScale () {
        if (html.getBoundingClientRect().width !== document.body.getBoundingClientRect().width) {
            selectHandler();
        }
    }

    var injectCaptureMouseMoves = BI.MouseMoveTracker.prototype.captureMouseMoves;
    var injectOnMouseMove = BI.MouseMoveTracker.prototype._onMouseMove;
    // 用jQEvent代替MouseEvent
    function injectMouseMoveTracker() {
        BI.MouseMoveTracker.prototype.captureMouseMoves = function (e) {
            var jQEvent = e.originalEvent ? e : jQuery.event.fix(e);
            injectCaptureMouseMoves.call(this, correctEvent(jQEvent));
        };
        BI.MouseMoveTracker.prototype._onMouseMove = function (e) {
            var jQEvent = e.originalEvent ? e : jQuery.event.fix(e);
            injectOnMouseMove.call(this, correctEvent(jQEvent));
        }
    }
    injectMouseMoveTracker();

    BI.config("bi.constant.dashboard.toolbar.left.items", function (config) {
        return BI.concat(config, [{
            type: "bi.multi_select_item",
            text: BI.i18nText("BI-Plugin-Scale_Adaptive"),
            selected: false,
            listeners: [{
                eventName: BI.MultiSelectItem.EVENT_CHANGE,
                action: function () {
                    selected = this.isSelected();
                    selectHandler();
                }
            }]
        }])
    });
}());