import transition = require("ui/transition");
import platform = require("platform");

let screenWidth = platform.screen.mainScreen.widthDIPs;
let screenHeight = platform.screen.mainScreen.heightDIPs;
let leftEdge = CGAffineTransformMakeTranslation(-screenWidth, 0);
let rightEdge = CGAffineTransformMakeTranslation(screenWidth, 0);
let topEdge = CGAffineTransformMakeTranslation(0, -screenHeight);
let bottomEdge = CGAffineTransformMakeTranslation(0, screenHeight);

export class SlideTransition extends transition.Transition {
    private _direction: string;

    constructor(direction: string, duration: number, curve: any) {
        super(duration, curve);
        this._direction = direction;
    }

    public animateIOSTransition(containerView: UIView, fromView: UIView, toView: UIView, operation: UINavigationControllerOperation, completion: (finished: boolean) => void): void {
        let originalToViewTransform = toView.transform;
        let originalFromViewTransform = fromView.transform;

        let fromViewEndTransform: CGAffineTransform;
        let toViewBeginTransform: CGAffineTransform;
        let push = (operation === UINavigationControllerOperation.UINavigationControllerOperationPush);

        switch (this._direction) {
            case "left":
                toViewBeginTransform = push ? rightEdge : leftEdge;
                fromViewEndTransform = push ? leftEdge : rightEdge;
                break;
            case "right":
                toViewBeginTransform = push ? leftEdge : rightEdge;
                fromViewEndTransform = push ? rightEdge : leftEdge;
                break;
            case "top":
                toViewBeginTransform = push ? bottomEdge : topEdge;
                fromViewEndTransform = push ? topEdge : bottomEdge;
                break;
            case "bottom":
                toViewBeginTransform = push ? topEdge : bottomEdge;
                fromViewEndTransform = push ? bottomEdge : topEdge;
                break;
        }

        toView.transform = toViewBeginTransform;
        fromView.transform = CGAffineTransformIdentity;

        switch (operation) {
            case UINavigationControllerOperation.UINavigationControllerOperationPush:
                containerView.insertSubviewAboveSubview(toView, fromView);
                break;
            case UINavigationControllerOperation.UINavigationControllerOperationPop:
                containerView.insertSubviewBelowSubview(toView, fromView);
                break;
        }

        let duration = this.getDuration();
        let curve = this.getCurve();
        UIView.animateWithDurationAnimationsCompletion(duration, () => {
            UIView.setAnimationCurve(curve);
            toView.transform = CGAffineTransformIdentity;
            fromView.transform = fromViewEndTransform;
        }, (finished: boolean) => {
            toView.transform = originalToViewTransform; 
            fromView.transform = originalFromViewTransform; 
            completion(finished);   
        });
    }
}