module INSPECTOR {
    export class Inspector {

        private _c2diwrapper: HTMLElement;
        // private _detailsPanel: DetailPanel;
        /** The panel displayed at the top of the inspector */
        private _topPanel: HTMLElement;
        /** The div containing the content of the active tab */
        private _tabPanel: HTMLElement;
        /** The panel containing the list if items */
        // private _treePanel   : HTMLElement;
        private _tabbar: TabBar;
        private _scene: BABYLON.Scene;
        /** The HTML document relative to this inspector (the window or the popup depending on its mode) */
        public static DOCUMENT: HTMLDocument;
        /** The HTML window. In popup mode, it's the popup itself. Otherwise, it's the current tab */
        public static WINDOW: Window;
        /** True if the inspector is built as a popup tab */
        private _popupMode: boolean = false;
        /** The original canvas style, before applying the inspector*/
        private _canvasStyle: any;

        private _initialTab: number;

        private _parentElement: BABYLON.Nullable<HTMLElement>;

        /** The inspector is created with the given engine.
         * If the parameter 'popup' is false, the inspector is created as a right panel on the main window.
         * If the parameter 'popup' is true, the inspector is created in another popup.
         */
        constructor(scene: BABYLON.Scene, popup?: boolean, initialTab: number = 0, parentElement: BABYLON.Nullable<HTMLElement> = null, newColors?: {
            backgroundColor?: string,
            backgroundColorLighter?: string,
            backgroundColorLighter2?: string,
            backgroundColorLighter3?: string,
            color?: string,
            colorTop?: string,
            colorBot?: string
        }) {

            // Load GUI library if not already done
            if (!BABYLON.GUI) {
                BABYLON.Tools.LoadScript("https://preview.babylonjs.com/gui/babylon.gui.js", () => {
                    //Load properties of GUI objects now as BABYLON.GUI has to be declared before 
                    loadGUIProperties();
                }, () => {
                    console.warn('Error : loading "babylon.gui.js". Please add script https://preview.babylonjs.com/gui/babylon.gui.js to the HTML file.');
                });
            }
            else {
                //Load properties of GUI objects now as BABYLON.GUI has to be declared before 
                loadGUIProperties();
            }

            //get Tabbar initialTab
            this._initialTab = initialTab;

            //get parentElement of our Inspector
            this._parentElement = parentElement;

            // get canvas parent only if needed.
            this._scene = scene;

            // Save HTML document and window
            Inspector.DOCUMENT = window.document;
            Inspector.WINDOW = window;

            // POPUP MODE
            if (popup) {
                // Build the inspector in the given parent
                this.openPopup(true);// set to true in order to NOT dispose the inspector (done in openPopup), as it's not existing yet
            } else {
                // Get canvas and its DOM parent
                let canvas = <HTMLElement>this._scene.getEngine().getRenderingCanvas();
                let canvasParent = canvas.parentElement;

                // get canvas style                
                let canvasComputedStyle = Inspector.WINDOW.getComputedStyle(canvas);

                this._canvasStyle = {
                    width: Helpers.Css(canvas, 'width'),
                    height: Helpers.Css(canvas, 'height'),

                    position: canvasComputedStyle.position,
                    top: canvasComputedStyle.top,
                    bottom: canvasComputedStyle.bottom,
                    left: canvasComputedStyle.left,
                    right: canvasComputedStyle.right,

                    padding: canvasComputedStyle.padding,
                    paddingBottom: canvasComputedStyle.paddingBottom,
                    paddingLeft: canvasComputedStyle.paddingLeft,
                    paddingTop: canvasComputedStyle.paddingTop,
                    paddingRight: canvasComputedStyle.paddingRight,

                    margin: canvasComputedStyle.margin,
                    marginBottom: canvasComputedStyle.marginBottom,
                    marginLeft: canvasComputedStyle.marginLeft,
                    marginTop: canvasComputedStyle.marginTop,
                    marginRight: canvasComputedStyle.marginRight

                };

                if (this._parentElement) {
                    // Build the inspector wrapper
                    this._c2diwrapper = Helpers.CreateDiv('insp-wrapper', this._parentElement);
                    this._c2diwrapper.style.width = '100%';
                    this._c2diwrapper.style.height = '100%';
                    this._c2diwrapper.style.paddingLeft = '5px';

                    // add inspector     
                    let inspector = Helpers.CreateDiv('insp-right-panel', this._c2diwrapper);
                    inspector.style.width = '100%';
                    inspector.style.height = '100%';
                    // and build it in the popup  
                    this._buildInspector(inspector);
                } else {
                    // Create c2di wrapper
                    this._c2diwrapper = Helpers.CreateDiv('insp-wrapper');

                    // copy style from canvas to wrapper
                    for (let prop in this._canvasStyle) {
                        (<any>this._c2diwrapper.style)[prop] = this._canvasStyle[prop];
                    }

                    if (!canvasComputedStyle.width || !canvasComputedStyle.height || !canvasComputedStyle.left) {
                        return;
                    }

                    // Convert wrapper size in % (because getComputedStyle returns px only)
                    let widthPx = parseFloat(canvasComputedStyle.width.substr(0, canvasComputedStyle.width.length - 2)) || 0;
                    let heightPx = parseFloat(canvasComputedStyle.height.substr(0, canvasComputedStyle.height.length - 2)) || 0;

                    // If the canvas position is absolute, restrain the wrapper width to the window width + left positionning
                    if (canvasComputedStyle.position === "absolute" || canvasComputedStyle.position === "relative") {
                        // compute only left as it takes predominance if right is also specified (and it will be for the wrapper)
                        let leftPx = parseFloat(canvasComputedStyle.left.substr(0, canvasComputedStyle.left.length - 2)) || 0;
                        if (widthPx + leftPx >= Inspector.WINDOW.innerWidth) {
                            this._c2diwrapper.style.maxWidth = `${widthPx - leftPx}px`;
                        }
                    }


                    // Check if the parent of the canvas is the body page. If yes, the size ratio is computed
                    let parent = this._getRelativeParent(canvas);

                    let parentWidthPx = parent.clientWidth;
                    let parentHeightPx = parent.clientHeight;

                    let pWidth = widthPx / parentWidthPx * 100;
                    let pheight = heightPx / parentHeightPx * 100;

                    this._c2diwrapper.style.width = pWidth + "%";
                    this._c2diwrapper.style.height = pheight + "%";

                    // reset canvas style
                    canvas.style.position = "static";
                    canvas.style.width = "100%";
                    canvas.style.height = "100%";
                    canvas.style.paddingBottom = "0";
                    canvas.style.paddingLeft = "0";
                    canvas.style.paddingTop = "0";
                    canvas.style.paddingRight = "0";

                    canvas.style.margin = "0";
                    canvas.style.marginBottom = "0";
                    canvas.style.marginLeft = "0";
                    canvas.style.marginTop = "0";
                    canvas.style.marginRight = "0";

                    // Replace canvas with the wrapper...
                    if (canvasParent) {
                        canvasParent.replaceChild(this._c2diwrapper, canvas);
                    }
                    // ... and add canvas to the wrapper
                    this._c2diwrapper.appendChild(canvas);

                    // add inspector
                    let inspector = Helpers.CreateDiv('insp-right-panel', this._c2diwrapper);

                    // Add split bar
                    if (!this._parentElement) {
                        Split([canvas, inspector], {
                            direction: 'horizontal',
                            sizes: [75, 25],
                            onDrag: () => {
                                Helpers.SEND_EVENT('resize');
                                if (this._tabbar) {
                                    this._tabbar.updateWidth()
                                }
                            }
                        });
                    }

                    // Build the inspector
                    this._buildInspector(inspector);
                }
                // Send resize event to the window
                Helpers.SEND_EVENT('resize');
                this._tabbar.updateWidth();
            }

            /*
            * Refresh the inspector if the browser is not edge
            *   Why not ?! Condition commented on 180525
            *   To be tested
            */
            // if (!Helpers.IsBrowserEdge()) {
                this.refresh();
            // }

            // Check custom css colors
            if (newColors) {

                let bColor = newColors.backgroundColor || '#242424';
                let bColorl1 = newColors.backgroundColorLighter || '#2c2c2c';
                let bColorl2 = newColors.backgroundColorLighter2 || '#383838';
                let bColorl3 = newColors.backgroundColorLighter3 || '#454545';

                let color = newColors.color || '#ccc';
                let colorTop = newColors.colorTop || '#f29766';
                let colorBot = newColors.colorBot || '#5db0d7';

                let styles = Inspector.DOCUMENT.querySelectorAll('style');
                for (let s = 0; s < styles.length; s++) {
                    let style = styles[s];

                    if (style.innerHTML.indexOf('insp-wrapper') != -1) {

                        styles[s].innerHTML = styles[s].innerHTML
                            .replace(/#242424/g, bColor) // background color
                            .replace(/#2c2c2c/g, bColorl1) // background-lighter
                            .replace(/#383838/g, bColorl2) // background-lighter2
                            .replace(/#454545/g, bColorl3) // background-lighter3
                            .replace(/#ccc/g, color) // color
                            .replace(/#f29766/g, colorTop) // color-top
                            .replace(/#5db0d7/g, colorBot) // color-bot
                    }
                }
            }
        }

        /**
         * If the given element has a position 'asbolute' or 'relative', 
         * returns the first parent of the given element that has a position 'relative' or 'absolute'.
         * If the given element has no position, returns the first parent
         * 
         */
        private _getRelativeParent(elem: HTMLElement, lookForAbsoluteOrRelative?: boolean): HTMLElement {
            // If the elem has no parent, returns himself
            if (!elem.parentElement) {
                return elem;
            }
            let computedStyle = Inspector.WINDOW.getComputedStyle(elem);
            // looking for the first element absolute or relative
            if (lookForAbsoluteOrRelative) {
                // if found, return this one
                if (computedStyle.position === "relative" || computedStyle.position === "absolute") {
                    return elem;
                } else {
                    // otherwise keep looking
                    return this._getRelativeParent(elem.parentElement, true);
                }
            }
            // looking for the relative parent of the element 
            else {
                if (computedStyle.position == "static") {
                    return elem.parentElement;
                } else {
                    // the elem has a position relative or absolute, look for the closest relative/absolute parent
                    return this._getRelativeParent(elem.parentElement, true);
                }
            }
        }

        /** Build the inspector panel in the given HTML element */
        private _buildInspector(parent: HTMLElement) {
            // tabbar
            this._tabbar = new TabBar(this, this._initialTab);

            // Top panel
            this._topPanel = Helpers.CreateDiv('top-panel', parent);
            // Add tabbar
            this._topPanel.appendChild(this._tabbar.toHtml());
            this._tabbar.updateWidth();

            // Tab panel
            this._tabPanel = Helpers.CreateDiv('tab-panel-content', this._topPanel);

        }

        public get scene(): BABYLON.Scene {
            return this._scene;
        }
        public get popupMode(): boolean {
            return this._popupMode;
        }

        /**  
         * Filter the list of item present in the tree.
         * All item returned should have the given filter contained in the item id.
        */
        public filterItem(filter: string) {
            let tab = this._tabbar.getActiveTab();

            if (tab) {
                tab.filter(filter);
            }
        }

        /** Display the mesh tab on the given object */
        public displayObjectDetails(mesh: BABYLON.AbstractMesh) {
            this._tabbar.switchMeshTab(mesh);
        }

        /** Clean the whole tree of item and rebuilds it */
        public refresh() {
            // Clean top panel
            Helpers.CleanDiv(this._tabPanel);

            // Get the active tab and its items
            let activeTab = this._tabbar.getActiveTab();

            if (!activeTab) {
                return;
            }
            activeTab.update();
            this._tabPanel.appendChild(activeTab.getPanel());
            Helpers.SEND_EVENT('resize');

        }

        /** Remove the inspector panel when it's built as a right panel:
         * remove the right panel and remove the wrapper
         */
        public dispose() {
            if (!this._popupMode) {
                let activeTab = this._tabbar.getActiveTab();
                if (activeTab) {
                    activeTab.dispose();
                }

                // Get canvas
                let canvas = <HTMLElement>this._scene.getEngine().getRenderingCanvas();

                // restore canvas style
                for (let prop in this._canvasStyle) {
                    (<any>canvas.style)[prop] = this._canvasStyle[prop];
                }
                // Get parent of the wrapper 
                if (canvas.parentElement) {
                    let canvasParent = canvas.parentElement.parentElement;

                    if (canvasParent) {
                        canvasParent.insertBefore(canvas, this._c2diwrapper);
                        // Remove wrapper
                        Helpers.CleanDiv(this._c2diwrapper);
                        this._c2diwrapper.remove();
                        // Send resize event to the window
                        Helpers.SEND_EVENT('resize');
                    }
                }
            }
            Scheduler.getInstance().dispose();
        }

        /** Open the inspector in a new popup
         * Set 'firstTime' to true if there is no inspector created beforehands
         */
        public openPopup(firstTime?: boolean) {

            // Create popup
            let popup = window.open('', 'Babylon.js INSPECTOR', 'toolbar=no,resizable=yes,menubar=no,width=750,height=1000');
            if (!popup) {
                alert("Please update your browser to open the Babylon.js inspector in an external view.");
                return;
            }
            popup.document.title = "Babylon.js INSPECTOR";
            // Get the inspector style      
            let styles = Inspector.DOCUMENT.querySelectorAll('style');
            for (let s = 0; s < styles.length; s++) {
                popup.document.body.appendChild(styles[s].cloneNode(true));
            }
            let links = document.querySelectorAll('link');
            for (let l = 0; l < links.length; l++) {
                let link = popup.document.createElement("link");
                link.rel = "stylesheet";
                link.href = (links[l] as HTMLLinkElement).href;
                popup.document.head.appendChild(link);
            }
            // Dispose the right panel if existing
            if (!firstTime) {
                this.dispose();
            }
            // set the mode as popup
            this._popupMode = true;
            // Save the HTML document
            Inspector.DOCUMENT = popup.document;
            Inspector.WINDOW = popup;
            // Build the inspector wrapper
            this._c2diwrapper = Helpers.CreateDiv('insp-wrapper', popup.document.body);
            // add inspector     
            let inspector = Helpers.CreateDiv('insp-right-panel', this._c2diwrapper);
            inspector.classList.add('popupmode');
            // and build it in the popup  
            this._buildInspector(inspector);
            // Rebuild it
            this.refresh();

            popup.addEventListener('resize', () => {
                if (this._tabbar) {
                    this._tabbar.updateWidth()
                }
            });
        }

        public getActiveTabIndex(): number {
            return this._tabbar.getActiveTabIndex();
        }
    }
}