import types = require("utils/types");
import viewCommon = require("./view-common");
import viewDefinition = require("ui/core/view");
import trace = require("trace");
import utils = require("utils/utils");
import dependencyObservable = require("ui/core/dependency-observable");
import proxy = require("ui/core/proxy");
import style = require("ui/styling/style");
import enums = require("ui/enums");
import * as backgroundModule from "ui/styling/background";

global.moduleMerge(viewCommon, exports);

function onAutomationTextPropertyChanged(data: dependencyObservable.PropertyChangeData) {
    var view = <View>data.object;
    view._nativeView.accessibilityIdentifier = data.newValue + "";
    view._nativeView.accessibilityLabel = data.newValue + "";
}
(<proxy.PropertyMetadata>viewCommon.View.automationTextProperty.metadata).onSetNativeValue = onAutomationTextPropertyChanged;

function onOriginPropertyChanged(data: dependencyObservable.PropertyChangeData) {
    var view = <View>data.object;
    view._updateOriginPoint();
}
(<proxy.PropertyMetadata>viewCommon.View.originXProperty.metadata).onSetNativeValue = onOriginPropertyChanged;
(<proxy.PropertyMetadata>viewCommon.View.originYProperty.metadata).onSetNativeValue = onOriginPropertyChanged;

function onIsEnabledPropertyChanged(data: dependencyObservable.PropertyChangeData) {
    var view = <View>data.object;
    if (!view._nativeView) {
        return;
    }

    if (view._nativeView instanceof UIControl) {
        (<UIControl>view._nativeView).enabled = data.newValue;
    }
}
(<proxy.PropertyMetadata>viewCommon.View.isEnabledProperty.metadata).onSetNativeValue = onIsEnabledPropertyChanged;

function onIsUserInteractionEnabledPropertyChanged(data: dependencyObservable.PropertyChangeData) {
    var view = <View>data.object;
    if (!view._nativeView) {
        return;
    }

    view._nativeView.userInteractionEnabled = data.newValue;
}
(<proxy.PropertyMetadata>viewCommon.View.isUserInteractionEnabledProperty.metadata).onSetNativeValue = onIsUserInteractionEnabledPropertyChanged;

var PFLAG_FORCE_LAYOUT = 1;
var PFLAG_MEASURED_DIMENSION_SET = 1 << 1;
var PFLAG_LAYOUT_REQUIRED = 1 << 2;

export class View extends viewCommon.View {
    private _hasTransfrom = false;
    private _privateFlags: number;
    private _cachedFrame: CGRect;
    private _suspendCATransaction = false;

    constructor() {
        super();
        this._privateFlags = PFLAG_LAYOUT_REQUIRED | PFLAG_FORCE_LAYOUT;
    }

    public _addViewCore(view: viewCommon.View, atIndex?: number) {
        super._addViewCore(view, atIndex);
        this.requestLayout();
    }

    public _removeViewCore(view: viewCommon.View) {
        super._removeViewCore(view);
        // TODO: Detach from the context?
        view._onDetached();
        this.requestLayout();
    }

    get _nativeView(): UIView {
        return this.ios;
    }

    get isLayoutRequired(): boolean {
        return (this._privateFlags & PFLAG_LAYOUT_REQUIRED) === PFLAG_LAYOUT_REQUIRED;
    }

    get isLayoutRequested(): boolean {
        return (this._privateFlags & PFLAG_FORCE_LAYOUT) === PFLAG_FORCE_LAYOUT;
    }

    public requestLayout(): void {
        super.requestLayout();
        this._privateFlags |= PFLAG_FORCE_LAYOUT;

        var parent = <View>this.parent;
        if (parent && !parent.isLayoutRequested) {
            parent.requestLayout();
        }
    }

    public measure(widthMeasureSpec: number, heightMeasureSpec: number): void {
        var measureSpecsChanged = this._setCurrentMeasureSpecs(widthMeasureSpec, heightMeasureSpec);
        var forceLayout = (this._privateFlags & PFLAG_FORCE_LAYOUT) === PFLAG_FORCE_LAYOUT;
        if (forceLayout || measureSpecsChanged) {

            // first clears the measured dimension flag
            this._privateFlags &= ~PFLAG_MEASURED_DIMENSION_SET;

            // measure ourselves, this should set the measured dimension flag back
            this.onMeasure(widthMeasureSpec, heightMeasureSpec);
            this._privateFlags |= PFLAG_LAYOUT_REQUIRED;

            // flag not set, setMeasuredDimension() was not invoked, we raise
            // an exception to warn the developer
            if ((this._privateFlags & PFLAG_MEASURED_DIMENSION_SET) !== PFLAG_MEASURED_DIMENSION_SET) {
                throw new Error("onMeasure() did not set the measured dimension by calling setMeasuredDimension() " + this);
            }
        }
    }

    public layout(left: number, top: number, right: number, bottom: number): void {
        var { boundsChanged, sizeChanged } = this._setCurrentLayoutBounds(left, top, right, bottom);
        this.layoutNativeView(left, top, right, bottom);
        if (boundsChanged || (this._privateFlags & PFLAG_LAYOUT_REQUIRED) === PFLAG_LAYOUT_REQUIRED) {
            this.onLayout(left, top, right, bottom);
            this._privateFlags &= ~PFLAG_LAYOUT_REQUIRED;
        }

        if (sizeChanged) {
            this._onSizeChanged();
        }

        this._privateFlags &= ~PFLAG_FORCE_LAYOUT;
    }

    public setMeasuredDimension(measuredWidth: number, measuredHeight: number): void {
        super.setMeasuredDimension(measuredWidth, measuredHeight);
        this._privateFlags |= PFLAG_MEASURED_DIMENSION_SET;
    }

    public onMeasure(widthMeasureSpec: number, heightMeasureSpec: number): void {
        var view = this._nativeView;
        let nativeWidth = 0;
        let nativeHeight = 0;

        if (view) {
            var width = utils.layout.getMeasureSpecSize(widthMeasureSpec);
            var widthMode = utils.layout.getMeasureSpecMode(widthMeasureSpec);

            var height = utils.layout.getMeasureSpecSize(heightMeasureSpec);
            var heightMode = utils.layout.getMeasureSpecMode(heightMeasureSpec);

            if (widthMode === utils.layout.UNSPECIFIED) {
                width = Number.POSITIVE_INFINITY;
            }

            if (heightMode === utils.layout.UNSPECIFIED) {
                height = Number.POSITIVE_INFINITY;
            }

            var nativeSize = view.sizeThatFits(CGSizeMake(width, height));
            nativeWidth = nativeSize.width;
            nativeHeight = nativeSize.height;
        }

        var measureWidth = Math.max(nativeWidth, this.minWidth);
        var measureHeight = Math.max(nativeHeight, this.minHeight);

        var widthAndState = View.resolveSizeAndState(measureWidth, width, widthMode, 0);
        var heightAndState = View.resolveSizeAndState(measureHeight, height, heightMode, 0);

        this.setMeasuredDimension(widthAndState, heightAndState);
    }

    public onLayout(left: number, top: number, right: number, bottom: number): void {
        //
    }

    public _setNativeViewFrame(nativeView: any, frame: any) {
        if (!CGRectEqualToRect(nativeView.frame, frame)) {
            if (trace.enabled) {
                trace.write(this + ", Native setFrame: = " + NSStringFromCGRect(frame), trace.categories.Layout);
            }
            this._cachedFrame = frame;
            if (this._hasTransfrom) {
                // Always set identity transform before setting frame;
                let transform = nativeView.transform;
                nativeView.transform = CGAffineTransformIdentity;
                nativeView.frame = frame;
                nativeView.transform = transform;
            }
            else {
                nativeView.frame = frame;
            }
            var boundsOrigin = nativeView.bounds.origin;
            nativeView.bounds = CGRectMake(boundsOrigin.x, boundsOrigin.y, frame.size.width, frame.size.height);
        }
    }

    public layoutNativeView(left: number, top: number, right: number, bottom: number): void {
        if (!this._nativeView) {
            return;
        }

        // This is done because when rotated in iOS7 there is rotation applied on the first subview on the Window which is our frame.nativeView.view.
        // If we set it it should be transformed so it is correct.
        // When in landscape in iOS 7 there is transformation on the first subview of the window so we set frame to its subview.
        // in iOS 8 we set frame to subview again otherwise we get clipped.
        var nativeView: UIView;
        if (!this.parent && this._nativeView.subviews.count > 0 && utils.ios.MajorVersion < 8) {
            if (trace.enabled) {
                trace.write(this + " has no parent. Setting frame to first child instead.", trace.categories.Layout);
            }
            nativeView = (<UIView>this._nativeView.subviews[0]);
        }
        else {
            nativeView = this._nativeView;
        }

        var frame = CGRectMake(left, top, right - left, bottom - top);
        this._setNativeViewFrame(nativeView, frame);
    }

    public _updateLayout() {
        var oldBounds = this._getCurrentLayoutBounds();
        this.layoutNativeView(oldBounds.left, oldBounds.top, oldBounds.right, oldBounds.bottom);
    }

    public focus(): boolean {
        if (this.ios) {
            return this.ios.becomeFirstResponder();
        }

        return false;
    }

    public getLocationInWindow(): viewDefinition.Point {
        if (!this._nativeView || !this._nativeView.window) {
            return undefined;
        }

        var pointInWindow = this._nativeView.convertPointToView(this._nativeView.bounds.origin, null);
        return {
            x: utils.layout.toDeviceIndependentPixels(pointInWindow.x),
            y: utils.layout.toDeviceIndependentPixels(pointInWindow.y),
        };
    }

    public getLocationOnScreen(): viewDefinition.Point {
        if (!this._nativeView || !this._nativeView.window) {
            return undefined;
        }

        var pointInWindow = this._nativeView.convertPointToView(this._nativeView.bounds.origin, null);
        var pointOnScreen = this._nativeView.window.convertPointToWindow(pointInWindow, null);
        return {
            x: utils.layout.toDeviceIndependentPixels(pointOnScreen.x),
            y: utils.layout.toDeviceIndependentPixels(pointOnScreen.y),
        };
    }

    public getLocationRelativeTo(otherView: viewDefinition.View): viewDefinition.Point {
        if (!this._nativeView || !this._nativeView.window ||
            !otherView._nativeView || !otherView._nativeView.window ||
            this._nativeView.window !== otherView._nativeView.window) {
            return undefined;
        }

        var myPointInWindow = this._nativeView.convertPointToView(this._nativeView.bounds.origin, null);
        var otherPointInWindow = otherView._nativeView.convertPointToView(otherView._nativeView.bounds.origin, null);
        return {
            x: utils.layout.toDeviceIndependentPixels(myPointInWindow.x - otherPointInWindow.x),
            y: utils.layout.toDeviceIndependentPixels(myPointInWindow.y - otherPointInWindow.y),
        };
    }

    private _onSizeChanged() {
        this.style._sizeChanged();
    }

    public _updateNativeTransform() {
        let translateX = this.translateX || 0;
        let translateY = this.translateY || 0;
        let scaleX = this.scaleX || 1;
        let scaleY = this.scaleY || 1;
        let rotate = this.rotate || 0;
        let newTransform = CGAffineTransformIdentity;
        newTransform = CGAffineTransformTranslate(newTransform, translateX, translateY);
        newTransform = CGAffineTransformRotate(newTransform, rotate * Math.PI / 180);
        newTransform = CGAffineTransformScale(newTransform, scaleX === 0 ? 0.001 : scaleX, scaleY === 0 ? 0.001 : scaleY);
        if (!CGAffineTransformEqualToTransform(this._nativeView.transform, newTransform)) {
            this._nativeView.transform = newTransform;
            this._hasTransfrom = this._nativeView && !CGAffineTransformEqualToTransform(this._nativeView.transform, CGAffineTransformIdentity);
        }
    }

    public _updateOriginPoint() {
        let newPoint = CGPointMake(this.originX, this.originY);
        this._nativeView.layer.anchorPoint = newPoint;
        if (this._cachedFrame) {
            this._setNativeViewFrame(this._nativeView, this._cachedFrame);
        }
    }

    public _addToSuperview(superview: any, atIndex?: number): boolean {
        if (superview && this._nativeView) {
            if (types.isNullOrUndefined(atIndex) || atIndex >= superview.subviews.count) {
                superview.addSubview(this._nativeView);
            } else {
                superview.insertSubviewAtIndex(this._nativeView, atIndex);
            }

            return true;
        }

        return false;
    }

    public _removeFromSuperview() {
        if (this._nativeView) {
            this._nativeView.removeFromSuperview();
        }
    }

    // By default we update the view's presentation layer when setting backgroundColor and opacity properties.
    // This is done by calling CATransaction begin and commit methods.
    // This action should be disabled when updating those properties during an animation.
    public _suspendPresentationLayerUpdates() {
        this._suspendCATransaction = true;
    }

    public _resumePresentationLayerUpdates() {
        this._suspendCATransaction = false;
    }

    public _isPresentationLayerUpdateSuspeneded() {
        return this._suspendCATransaction;
    }
}

export class CustomLayoutView extends View {

    private _view: UIView;

    constructor() {
        super();
        this._view = UIView.new();
    }

    get ios(): UIView {
        return this._view;
    }

    get _nativeView(): UIView {
        return this._view;
    }

    public onMeasure(widthMeasureSpec: number, heightMeasureSpec: number): void {
        // Don't call super because it will set MeasureDimension. This method must be overriden and calculate its measuredDimensions.
    }

    public _addViewToNativeVisualTree(child: View, atIndex: number): boolean {
        super._addViewToNativeVisualTree(child, atIndex);

        return child._addToSuperview(this._nativeView, atIndex);
    }

    public _removeViewFromNativeVisualTree(child: View): void {
        super._removeViewFromNativeVisualTree(child);

        child._removeFromSuperview();
    }
}

export class ViewStyler implements style.Styler {
    // Background methods
    private static setBackgroundInternalProperty(view: View, newValue: any) {
        var nativeView: UIView = <UIView>view._nativeView;
        if (nativeView) {
            var updateSuspended = view._isPresentationLayerUpdateSuspeneded();
            if (!updateSuspended) {
                CATransaction.begin();
            }
            nativeView.backgroundColor = backgroundModule.ios.createBackgroundUIColor(view);
            
            if (!updateSuspended) {
                CATransaction.commit();
            }
        }
    }

    private static resetBackgroundInternalProperty(view: View, nativeValue: any) {
        var nativeView: UIView = <UIView>view._nativeView;
        if (nativeView) {
            nativeView.backgroundColor = nativeValue;
        }
    }

    private static getNativeBackgroundInternalValue(view: View): any {
        var nativeView: UIView = <UIView>view._nativeView;
        if (nativeView) {
            return nativeView.backgroundColor;
        }
        return undefined;
    }

    // Visibility methods
    private static setVisibilityProperty(view: View, newValue: any) {
        var nativeView: UIView = <UIView>view._nativeView;
        if (nativeView) {
            return nativeView.hidden = (newValue !== enums.Visibility.visible);
        }
    }

    private static resetVisibilityProperty(view: View, nativeValue: any) {
        var nativeView: UIView = <UIView>view._nativeView;
        if (nativeView) {
            return nativeView.hidden = false;
        }
    }

    // Opacity methods
    private static setOpacityProperty(view: View, newValue: any) {
        var nativeView: UIView = <UIView>view._nativeView;
        if (nativeView) {
            var updateSuspended = view._isPresentationLayerUpdateSuspeneded();
            if (!updateSuspended) {
                CATransaction.begin();
            }
            var alpha = nativeView.alpha = newValue;
            if (!updateSuspended) {
                CATransaction.commit();
            }
            return alpha;
        }
    }

    private static resetOpacityProperty(view: View, nativeValue: any) {
        var nativeView: UIView = <UIView>view._nativeView;
        if (nativeView) {
            return nativeView.alpha = 1.0;
        }
    }
    
    // Rotate
    private static setRotateProperty(view: View, newValue: any) {
        view._updateNativeTransform();
    }

    private static resetRotateProperty(view: View, nativeValue: any) {
        view._updateNativeTransform();
    }

    private static getRotateProperty(view: View): any {
        if (view._nativeView instanceof UIView) {
            let t: CGAffineTransform = (<UIView>view._nativeView).transform;
            return Math.atan2(t.b, t.a);
        }
        return 0;
    }

    // ScaleX
    private static setScaleXProperty(view: View, newValue: any) {
        view._updateNativeTransform();
    }

    private static resetScaleXProperty(view: View, nativeValue: any) {
        view._updateNativeTransform();
    }

    private static getScaleXProperty(view: View): any {
        if (view._nativeView instanceof UIView) {
            let t: CGAffineTransform = (<UIView>view._nativeView).transform;
            return Math.sqrt(t.a * t.a + t.c * t.c);
        }
        return 0;
    }

    // ScaleY
    private static setScaleYProperty(view: View, newValue: any) {
        view._updateNativeTransform();
    }

    private static resetScaleYProperty(view: View, nativeValue: any) {
        view._updateNativeTransform();
    }

    private static getScaleYProperty(view: View): any {
        if (view._nativeView instanceof UIView) {
            let t: CGAffineTransform = (<UIView>view._nativeView).transform;
            return Math.sqrt(t.b * t.b + t.d * t.d);
        }
        return 0;
    }

    // TranslateX
    private static setTranslateXProperty(view: View, newValue: any) {
        view._updateNativeTransform();
    }

    private static resetTranslateXProperty(view: View, nativeValue: any) {
        view._updateNativeTransform();
    }

    private static getTranslateXProperty(view: View): any {
        if (view._nativeView instanceof UIView) {
            let t: CGAffineTransform = (<UIView>view._nativeView).transform;
            return t.tx;
        }
        return 0;
    }

    // TranslateY
    private static setTranslateYProperty(view: View, newValue: any) {
        view._updateNativeTransform();
    }

    private static resetTranslateYProperty(view: View, nativeValue: any) {
        view._updateNativeTransform();
    }

    private static getTranslateYProperty(view: View): any {
        if (view._nativeView instanceof UIView) {
            let t: CGAffineTransform = (<UIView>view._nativeView).transform;
            return t.ty;
        }
        return 0;
    }

    // z-index
    private static setZIndexProperty(view: View, newValue: any) {
        view.ios.layer.zPosition = newValue;
    }

    private static resetZIndexProperty(view: View, nativeValue: any) {
        view.ios.layer.zPosition = nativeValue;
    }

    private static getZIndexProperty(view: View): any {
        return view.ios.layer.zPosition;
    }

    public static registerHandlers() {
        style.registerHandler(style.backgroundInternalProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setBackgroundInternalProperty,
            ViewStyler.resetBackgroundInternalProperty,
            ViewStyler.getNativeBackgroundInternalValue));

        style.registerHandler(style.visibilityProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setVisibilityProperty,
            ViewStyler.resetVisibilityProperty));

        style.registerHandler(style.opacityProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setOpacityProperty,
            ViewStyler.resetOpacityProperty));
        style.registerHandler(style.rotateProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setRotateProperty,
            ViewStyler.resetRotateProperty,
            ViewStyler.getRotateProperty));

        style.registerHandler(style.scaleXProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setScaleXProperty,
            ViewStyler.resetScaleXProperty,
            ViewStyler.getScaleXProperty));

        style.registerHandler(style.scaleYProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setScaleYProperty,
            ViewStyler.resetScaleYProperty,
            ViewStyler.getScaleYProperty));

        style.registerHandler(style.translateXProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setTranslateXProperty,
            ViewStyler.resetTranslateXProperty,
            ViewStyler.getTranslateXProperty));

        style.registerHandler(style.translateYProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setTranslateYProperty,
            ViewStyler.resetTranslateYProperty,
            ViewStyler.getTranslateYProperty));

        style.registerHandler(style.zIndexProperty, new style.StylePropertyChangedHandler(
            ViewStyler.setZIndexProperty,
            ViewStyler.resetZIndexProperty,
            ViewStyler.getZIndexProperty));
    }
}

ViewStyler.registerHandlers();