//
//  SlideMenuController.swift
//  Gasteizko Margolariak
//
//  Created by Inigo Valentin on 2016-08-23
//  Copyright © 2016 Inigo Valentin. All rights reserved.
//
//  Based on the work of Yuji Hato.
//

import Foundation
import UIKit

@objc public protocol SlideMenuControllerDelegate {
    optional func leftWillOpen()
    optional func leftDidOpen()
    optional func leftWillClose()
    optional func leftDidClose()
    optional func rightWillOpen()
    optional func rightDidOpen()
    optional func rightWillClose()
    optional func rightDidClose()
}

public struct SlideMenuOptions {
    public static var leftViewWidth: CGFloat = 270.0
    public static var leftBezelWidth: CGFloat? = 16.0
    public static var contentViewScale: CGFloat = 0.96
    public static var contentViewOpacity: CGFloat = 0.5
    public static var contentViewDrag: Bool = false
    public static var shadowOpacity: CGFloat = 0.0
    public static var shadowRadius: CGFloat = 0.0
    public static var shadowOffset: CGSize = CGSizeMake(0,0)
    public static var panFromBezel: Bool = true
    public static var animationDuration: CGFloat = 0.4
    public static var rightViewWidth: CGFloat = 270.0
    public static var rightBezelWidth: CGFloat? = 16.0
    public static var rightPanFromBezel: Bool = true
    public static var hideStatusBar: Bool = true
    public static var pointOfNoReturnWidth: CGFloat = 44.0
    public static var simultaneousGestureRecognizers: Bool = true
    public static var opacityViewBackgroundColor: UIColor = UIColor.blackColor()
}

public class SlideMenuController: UIViewController, UIGestureRecognizerDelegate {
    
    
    public enum SlideAction {
        case Open
        case Close
    }
    
    public enum TrackAction {
        case LeftTapOpen
        case LeftTapClose
        case LeftFlickOpen
        case LeftFlickClose
        case RightTapOpen
        case RightTapClose
        case RightFlickOpen
        case RightFlickClose
    }
    
    
    struct PanInfo {
        var action: SlideAction
        var shouldBounce: Bool
        var velocity: CGFloat
    }
    
    public weak var delegate: SlideMenuControllerDelegate?
    
    public var opacityView = UIView()
    public var mainContainerView = UIView()
    public var leftContainerView = UIView()
    public var rightContainerView =  UIView()
    public var mainViewController: UIViewController?
    public var leftViewController: UIViewController?
    public var leftPanGesture: UIPanGestureRecognizer?
    public var leftTapGesture: UITapGestureRecognizer?
    public var rightViewController: UIViewController?
    public var rightPanGesture: UIPanGestureRecognizer?
    public var rightTapGesture: UITapGestureRecognizer?
    
    public required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    
    public override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: NSBundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    }
    
    public convenience init(mainViewController: UIViewController, leftMenuViewController: UIViewController) {
        self.init()
        self.mainViewController = mainViewController
        leftViewController = leftMenuViewController
        initView()
    }
    
    
    public convenience init(mainViewController: UIViewController, leftMenuViewController: UIViewController, rightMenuViewController: UIViewController) {
        self.init()
        self.mainViewController = mainViewController
        leftViewController = leftMenuViewController
        initView()
    }
    
    public override func awakeFromNib() {
        initView()
    }
    
    deinit { }
    
    public func initView() {
        mainContainerView = UIView(frame: view.bounds)
        mainContainerView.backgroundColor = UIColor.clearColor()
        mainContainerView.autoresizingMask = [.FlexibleHeight, .FlexibleWidth]
        view.insertSubview(mainContainerView, atIndex: 0)
        
        var opacityframe: CGRect = view.bounds
        let opacityOffset: CGFloat = 0
        opacityframe.origin.y = opacityframe.origin.y + opacityOffset
        opacityframe.size.height = opacityframe.size.height - opacityOffset
        opacityView = UIView(frame: opacityframe)
        opacityView.backgroundColor = SlideMenuOptions.opacityViewBackgroundColor
        opacityView.autoresizingMask = [UIViewAutoresizing.FlexibleHeight, UIViewAutoresizing.FlexibleWidth]
        opacityView.layer.opacity = 0.0
        view.insertSubview(opacityView, atIndex: 1)
        
        if leftViewController != nil {
            var leftFrame: CGRect = view.bounds
            leftFrame.size.width = SlideMenuOptions.leftViewWidth
            leftFrame.origin.x = leftMinOrigin();
            let leftOffset: CGFloat = 0
            leftFrame.origin.y = leftFrame.origin.y + leftOffset
            leftFrame.size.height = leftFrame.size.height - leftOffset
            leftContainerView = UIView(frame: leftFrame)
            leftContainerView.backgroundColor = UIColor.clearColor()
            leftContainerView.autoresizingMask = UIViewAutoresizing.FlexibleHeight
            view.insertSubview(leftContainerView, atIndex: 2)
            addLeftGestures()
        }
        
    }
    
    public override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
        mainContainerView.transform = CGAffineTransformMakeScale(1.0, 1.0)
        leftContainerView.hidden = true
        rightContainerView.hidden = true
        
        coordinator.animateAlongsideTransition(nil, completion: { (context: UIViewControllerTransitionCoordinatorContext!) -> Void in
            self.closeLeftNonAnimation()
            self.closeRightNonAnimation()
            self.leftContainerView.hidden = false
            self.rightContainerView.hidden = false
            
            if self.leftPanGesture != nil && self.leftPanGesture != nil {
                self.removeLeftGestures()
                self.addLeftGestures()
            }
            
            if self.rightPanGesture != nil && self.rightPanGesture != nil {
                self.removeRightGestures()
                self.addRightGestures()
            }
        })
    }
    
    public override func viewDidLoad() {
        super.viewDidLoad()
        edgesForExtendedLayout = UIRectEdge.None
    }
    
    public override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
        if let mainController = self.mainViewController{
            return mainController.supportedInterfaceOrientations()
        }
        return UIInterfaceOrientationMask.All
    }
    
    public override func shouldAutorotate() -> Bool {
        return mainViewController?.shouldAutorotate() ?? false
    }
    
    public override func viewWillLayoutSubviews() {
        // topLayoutGuideの値が確定するこのタイミングで各種ViewControllerをセットする
        setUpViewController(mainContainerView, targetViewController: mainViewController)
        setUpViewController(leftContainerView, targetViewController: leftViewController)
        setUpViewController(rightContainerView, targetViewController: rightViewController)
    }
    
    public override func openLeft() {
        guard let _ = leftViewController else { // If leftViewController is nil, then return
            return
        }
        
        self.delegate?.leftWillOpen?()
        
        setOpenWindowLevel()
        // for call viewWillAppear of leftViewController
        leftViewController?.beginAppearanceTransition(isLeftHidden(), animated: true)
        openLeftWithVelocity(0.0)
        
        track(.LeftTapOpen)
    }
    
    public override func openRight() {
        guard let _ = rightViewController else { // If rightViewController is nil, then return
            return
        }
        
        self.delegate?.rightWillOpen?()
        
        setOpenWindowLevel()
        rightViewController?.beginAppearanceTransition(isRightHidden(), animated: true)
        openRightWithVelocity(0.0)
        
        track(.RightTapOpen)
    }
    
    public override func closeLeft() {
        guard let _ = leftViewController else { // If leftViewController is nil, then return
            return
        }
        
        self.delegate?.leftWillClose?()
        
        leftViewController?.beginAppearanceTransition(isLeftHidden(), animated: true)
        closeLeftWithVelocity(0.0)
        setCloseWindowLevel()
    }
    
    public override func closeRight() {
        guard let _ = rightViewController else { // If rightViewController is nil, then return
            return
        }
        
        self.delegate?.rightWillClose?()
        
        rightViewController?.beginAppearanceTransition(isRightHidden(), animated: true)
        closeRightWithVelocity(0.0)
        setCloseWindowLevel()
    }
    
    
    public func addLeftGestures() {
        
        if (leftViewController != nil) {
            if leftPanGesture == nil {
                leftPanGesture = UIPanGestureRecognizer(target: self, action: #selector(self.handleLeftPanGesture(_:)))
                leftPanGesture!.delegate = self
                view.addGestureRecognizer(leftPanGesture!)
            }
            
            if leftTapGesture == nil {
                leftTapGesture = UITapGestureRecognizer(target: self, action: #selector(self.toggleLeft))
                leftTapGesture!.delegate = self
                view.addGestureRecognizer(leftTapGesture!)
            }
        }
    }
    
    public func addRightGestures() {
        
        if (rightViewController != nil) {
            if rightPanGesture == nil {
                rightPanGesture = UIPanGestureRecognizer(target: self, action: #selector(self.handleRightPanGesture(_:)))
                rightPanGesture!.delegate = self
                view.addGestureRecognizer(rightPanGesture!)
            }
            
            if rightTapGesture == nil {
                rightTapGesture = UITapGestureRecognizer(target: self, action: #selector(self.toggleRight))
                rightTapGesture!.delegate = self
                view.addGestureRecognizer(rightTapGesture!)
            }
        }
    }
    
    public func removeLeftGestures() {
        
        if leftPanGesture != nil {
            view.removeGestureRecognizer(leftPanGesture!)
            leftPanGesture = nil
        }
        
        if leftTapGesture != nil {
            view.removeGestureRecognizer(leftTapGesture!)
            leftTapGesture = nil
        }
    }
    
    public func removeRightGestures() {
        
        if rightPanGesture != nil {
            view.removeGestureRecognizer(rightPanGesture!)
            rightPanGesture = nil
        }
        
        if rightTapGesture != nil {
            view.removeGestureRecognizer(rightTapGesture!)
            rightTapGesture = nil
        }
    }
    
    public func isTagetViewController() -> Bool {
        // Function to determine the target ViewController
        // Please to override it if necessary
        return true
    }
    
    public func track(trackAction: TrackAction) {
        // function is for tracking
        // Please to override it if necessary
    }
    
    struct LeftPanState {
        static var frameAtStartOfPan: CGRect = CGRectZero
        static var startPointOfPan: CGPoint = CGPointZero
        static var wasOpenAtStartOfPan: Bool = false
        static var wasHiddenAtStartOfPan: Bool = false
        static var lastState : UIGestureRecognizerState = .Ended
    }
    
    func handleLeftPanGesture(panGesture: UIPanGestureRecognizer) {
        
        if !isTagetViewController() {
            return
        }
        
        if isRightOpen() {
            return
        }
        
        switch panGesture.state {
        case UIGestureRecognizerState.Began:
            if LeftPanState.lastState != .Ended &&  LeftPanState.lastState != .Cancelled &&  LeftPanState.lastState != .Failed {
                return
            }
            
            if isLeftHidden() {
                self.delegate?.leftWillOpen?()
            } else {
                self.delegate?.leftWillClose?()
            }
            
            LeftPanState.frameAtStartOfPan = leftContainerView.frame
            LeftPanState.startPointOfPan = panGesture.locationInView(view)
            LeftPanState.wasOpenAtStartOfPan = isLeftOpen()
            LeftPanState.wasHiddenAtStartOfPan = isLeftHidden()
            
            leftViewController?.beginAppearanceTransition(LeftPanState.wasHiddenAtStartOfPan, animated: true)
            addShadowToView(leftContainerView)
            setOpenWindowLevel()
        case UIGestureRecognizerState.Changed:
            if LeftPanState.lastState != .Began && LeftPanState.lastState != .Changed {
                return
            }
            
            let translation: CGPoint = panGesture.translationInView(panGesture.view!)
            leftContainerView.frame = applyLeftTranslation(translation, toFrame: LeftPanState.frameAtStartOfPan)
            applyLeftOpacity()
            applyLeftContentViewScale()
        case UIGestureRecognizerState.Ended, UIGestureRecognizerState.Cancelled:
            if LeftPanState.lastState != .Changed {
                setCloseWindowLevel()
                return
            }
            
            let velocity:CGPoint = panGesture.velocityInView(panGesture.view)
            let panInfo: PanInfo = panLeftResultInfoForVelocity(velocity)
            
            if panInfo.action == .Open {
                if !LeftPanState.wasHiddenAtStartOfPan {
                    leftViewController?.beginAppearanceTransition(true, animated: true)
                }
                openLeftWithVelocity(panInfo.velocity)
                
                track(.LeftFlickOpen)
            } else {
                if LeftPanState.wasHiddenAtStartOfPan {
                    leftViewController?.beginAppearanceTransition(false, animated: true)
                }
                closeLeftWithVelocity(panInfo.velocity)
                setCloseWindowLevel()
                
                track(.LeftFlickClose)
                
            }
        case UIGestureRecognizerState.Failed, UIGestureRecognizerState.Possible:
            break
        }
        
        LeftPanState.lastState = panGesture.state
    }
    
    struct RightPanState {
        static var frameAtStartOfPan: CGRect = CGRectZero
        static var startPointOfPan: CGPoint = CGPointZero
        static var wasOpenAtStartOfPan: Bool = false
        static var wasHiddenAtStartOfPan: Bool = false
        static var lastState : UIGestureRecognizerState = .Ended
    }
    
    func handleRightPanGesture(panGesture: UIPanGestureRecognizer) {
        
        if !isTagetViewController() {
            return
        }
        
        if isLeftOpen() {
            return
        }
        
        switch panGesture.state {
        case UIGestureRecognizerState.Began:
            if RightPanState.lastState != .Ended &&  RightPanState.lastState != .Cancelled &&  RightPanState.lastState != .Failed {
                return
            }
            
            if isRightHidden() {
                self.delegate?.rightWillOpen?()
            } else {
                self.delegate?.rightWillClose?()
            }
            
            RightPanState.frameAtStartOfPan = rightContainerView.frame
            RightPanState.startPointOfPan = panGesture.locationInView(view)
            RightPanState.wasOpenAtStartOfPan =  isRightOpen()
            RightPanState.wasHiddenAtStartOfPan = isRightHidden()
            
            rightViewController?.beginAppearanceTransition(RightPanState.wasHiddenAtStartOfPan, animated: true)
            
            addShadowToView(rightContainerView)
            setOpenWindowLevel()
        case UIGestureRecognizerState.Changed:
            if RightPanState.lastState != .Began && RightPanState.lastState != .Changed {
                return
            }
            
            let translation: CGPoint = panGesture.translationInView(panGesture.view!)
            rightContainerView.frame = applyRightTranslation(translation, toFrame: RightPanState.frameAtStartOfPan)
            applyRightOpacity()
            applyRightContentViewScale()
            
        case UIGestureRecognizerState.Ended, UIGestureRecognizerState.Cancelled:
            if RightPanState.lastState != .Changed {
                setCloseWindowLevel()
                return
            }
            
            let velocity: CGPoint = panGesture.velocityInView(panGesture.view)
            let panInfo: PanInfo = panRightResultInfoForVelocity(velocity)
            
            if panInfo.action == .Open {
                if !RightPanState.wasHiddenAtStartOfPan {
                    rightViewController?.beginAppearanceTransition(true, animated: true)
                }
                openRightWithVelocity(panInfo.velocity)
                
                track(.RightFlickOpen)
            } else {
                if RightPanState.wasHiddenAtStartOfPan {
                    rightViewController?.beginAppearanceTransition(false, animated: true)
                }
                closeRightWithVelocity(panInfo.velocity)
                setCloseWindowLevel()
                
                track(.RightFlickClose)
            }
        case UIGestureRecognizerState.Failed, UIGestureRecognizerState.Possible:
            break
        }
        
        RightPanState.lastState = panGesture.state
    }
    
    public func openLeftWithVelocity(velocity: CGFloat) {
        let xOrigin: CGFloat = leftContainerView.frame.origin.x
        let finalXOrigin: CGFloat = 0.0
        
        var frame = leftContainerView.frame;
        frame.origin.x = finalXOrigin;
        
        var duration: NSTimeInterval = Double(SlideMenuOptions.animationDuration)
        if velocity != 0.0 {
            duration = Double(fabs(xOrigin - finalXOrigin) / velocity)
            duration = Double(fmax(0.1, fmin(1.0, duration)))
        }
        
        addShadowToView(leftContainerView)
        
        UIView.animateWithDuration(duration, delay: 0.0, options: UIViewAnimationOptions.CurveEaseInOut, animations: { [weak self]() -> Void in
            if let strongSelf = self {
                strongSelf.leftContainerView.frame = frame
                strongSelf.opacityView.layer.opacity = Float(SlideMenuOptions.contentViewOpacity)
                
                SlideMenuOptions.contentViewDrag == true ? (strongSelf.mainContainerView.transform = CGAffineTransformMakeTranslation(SlideMenuOptions.leftViewWidth, 0)) : (strongSelf.mainContainerView.transform = CGAffineTransformMakeScale(SlideMenuOptions.contentViewScale, SlideMenuOptions.contentViewScale))
                
            }
        }) { [weak self](Bool) -> Void in
            if let strongSelf = self {
                strongSelf.disableContentInteraction()
                strongSelf.leftViewController?.endAppearanceTransition()
                strongSelf.delegate?.leftDidOpen?()
            }
        }
    }
    
    public func openRightWithVelocity(velocity: CGFloat) {
        let xOrigin: CGFloat = rightContainerView.frame.origin.x
        
        //	CGFloat finalXOrigin = SlideMenuOptions.rightViewOverlapWidth;
        let finalXOrigin: CGFloat = CGRectGetWidth(view.bounds) - rightContainerView.frame.size.width
        
        var frame = rightContainerView.frame
        frame.origin.x = finalXOrigin
        
        var duration: NSTimeInterval = Double(SlideMenuOptions.animationDuration)
        if velocity != 0.0 {
            duration = Double(fabs(xOrigin - CGRectGetWidth(view.bounds)) / velocity)
            duration = Double(fmax(0.1, fmin(1.0, duration)))
        }
        
        addShadowToView(rightContainerView)
        
        UIView.animateWithDuration(duration, delay: 0.0, options: UIViewAnimationOptions.CurveEaseInOut, animations: { [weak self]() -> Void in
            if let strongSelf = self {
                strongSelf.rightContainerView.frame = frame
                strongSelf.opacityView.layer.opacity = Float(SlideMenuOptions.contentViewOpacity)
                
                SlideMenuOptions.contentViewDrag == true ? (strongSelf.mainContainerView.transform = CGAffineTransformMakeTranslation(-SlideMenuOptions.rightViewWidth, 0)) : (strongSelf.mainContainerView.transform = CGAffineTransformMakeScale(SlideMenuOptions.contentViewScale, SlideMenuOptions.contentViewScale))
            }
        }) { [weak self](Bool) -> Void in
            if let strongSelf = self {
                strongSelf.disableContentInteraction()
                strongSelf.rightViewController?.endAppearanceTransition()
                strongSelf.delegate?.rightDidOpen?()
            }
        }
    }
    
    public func closeLeftWithVelocity(velocity: CGFloat) {
        
        let xOrigin: CGFloat = leftContainerView.frame.origin.x
        let finalXOrigin: CGFloat = leftMinOrigin()
        
        var frame: CGRect = leftContainerView.frame;
        frame.origin.x = finalXOrigin
        
        var duration: NSTimeInterval = Double(SlideMenuOptions.animationDuration)
        if velocity != 0.0 {
            duration = Double(fabs(xOrigin - finalXOrigin) / velocity)
            duration = Double(fmax(0.1, fmin(1.0, duration)))
        }
        
        UIView.animateWithDuration(duration, delay: 0.0, options: UIViewAnimationOptions.CurveEaseInOut, animations: { [weak self]() -> Void in
            if let strongSelf = self {
                strongSelf.leftContainerView.frame = frame
                strongSelf.opacityView.layer.opacity = 0.0
                strongSelf.mainContainerView.transform = CGAffineTransformMakeScale(1.0, 1.0)
            }
        }) { [weak self](Bool) -> Void in
            if let strongSelf = self {
                strongSelf.removeShadow(strongSelf.leftContainerView)
                strongSelf.enableContentInteraction()
                strongSelf.leftViewController?.endAppearanceTransition()
                strongSelf.delegate?.leftDidClose?()
            }
        }
    }
    
    
    public func closeRightWithVelocity(velocity: CGFloat) {
        
        let xOrigin: CGFloat = rightContainerView.frame.origin.x
        let finalXOrigin: CGFloat = CGRectGetWidth(view.bounds)
        
        var frame: CGRect = rightContainerView.frame
        frame.origin.x = finalXOrigin
        
        var duration: NSTimeInterval = Double(SlideMenuOptions.animationDuration)
        if velocity != 0.0 {
            duration = Double(fabs(xOrigin - CGRectGetWidth(view.bounds)) / velocity)
            duration = Double(fmax(0.1, fmin(1.0, duration)))
        }
        
        UIView.animateWithDuration(duration, delay: 0.0, options: UIViewAnimationOptions.CurveEaseInOut, animations: { [weak self]() -> Void in
            if let strongSelf = self {
                strongSelf.rightContainerView.frame = frame
                strongSelf.opacityView.layer.opacity = 0.0
                strongSelf.mainContainerView.transform = CGAffineTransformMakeScale(1.0, 1.0)
            }
        }) { [weak self](Bool) -> Void in
            if let strongSelf = self {
                strongSelf.removeShadow(strongSelf.rightContainerView)
                strongSelf.enableContentInteraction()
                strongSelf.rightViewController?.endAppearanceTransition()
                strongSelf.delegate?.rightDidClose?()
            }
        }
    }
    
    
    public override func toggleLeft() {
        if isLeftOpen() {
            closeLeft()
            setCloseWindowLevel()
            // Tracking of close tap is put in here. Because closeMenu is due to be call even when the menu tap.
            
            track(.LeftTapClose)
        } else {
            openLeft()
        }
    }
    
    public func isLeftOpen() -> Bool {
        return leftViewController != nil && leftContainerView.frame.origin.x == 0.0
    }
    
    public func isLeftHidden() -> Bool {
        return leftContainerView.frame.origin.x <= leftMinOrigin()
    }
    
    public override func toggleRight() {
        if isRightOpen() {
            closeRight()
            setCloseWindowLevel()
            
            // Tracking of close tap is put in here. Because closeMenu is due to be call even when the menu tap.
            track(.RightTapClose)
        } else {
            openRight()
        }
    }
    
    public func isRightOpen() -> Bool {
        return rightViewController != nil && rightContainerView.frame.origin.x == CGRectGetWidth(view.bounds) - rightContainerView.frame.size.width
    }
    
    public func isRightHidden() -> Bool {
        return rightContainerView.frame.origin.x >= CGRectGetWidth(view.bounds)
    }
    
    public func changeMainViewController(mainViewController: UIViewController,  close: Bool) {
        
        removeViewController(self.mainViewController)
        self.mainViewController = mainViewController
        setUpViewController(mainContainerView, targetViewController: mainViewController)
        if (close) {
            closeLeft()
            closeRight()
        }
    }
    
    public func changeLeftViewWidth(width: CGFloat) {
        
        SlideMenuOptions.leftViewWidth = width;
        var leftFrame: CGRect = view.bounds
        leftFrame.size.width = width
        leftFrame.origin.x = leftMinOrigin();
        let leftOffset: CGFloat = 0
        leftFrame.origin.y = leftFrame.origin.y + leftOffset
        leftFrame.size.height = leftFrame.size.height - leftOffset
        leftContainerView.frame = leftFrame;
    }
    
    public func changeRightViewWidth(width: CGFloat) {
        
        SlideMenuOptions.rightBezelWidth = width;
        var rightFrame: CGRect = view.bounds
        rightFrame.size.width = width
        rightFrame.origin.x = rightMinOrigin()
        let rightOffset: CGFloat = 0
        rightFrame.origin.y = rightFrame.origin.y + rightOffset;
        rightFrame.size.height = rightFrame.size.height - rightOffset
        rightContainerView.frame = rightFrame;
    }
    
    public func changeLeftViewController(leftViewController: UIViewController, closeLeft:Bool) {
        
        removeViewController(self.leftViewController)
        self.leftViewController = leftViewController
        setUpViewController(leftContainerView, targetViewController: leftViewController)
        if closeLeft {
            self.closeLeft()
        }
    }
    
    public func changeRightViewController(rightViewController: UIViewController, closeRight:Bool) {
        removeViewController(self.rightViewController)
        self.rightViewController = rightViewController;
        setUpViewController(rightContainerView, targetViewController: rightViewController)
        if closeRight {
            self.closeRight()
        }
    }
    
    private func leftMinOrigin() -> CGFloat {
        return  -SlideMenuOptions.leftViewWidth
    }
    
    private func rightMinOrigin() -> CGFloat {
        return CGRectGetWidth(view.bounds)
    }
    
    
    private func panLeftResultInfoForVelocity(velocity: CGPoint) -> PanInfo {
        
        let thresholdVelocity: CGFloat = 1000.0
        let pointOfNoReturn: CGFloat = CGFloat(floor(leftMinOrigin())) + SlideMenuOptions.pointOfNoReturnWidth
        let leftOrigin: CGFloat = leftContainerView.frame.origin.x
        
        var panInfo: PanInfo = PanInfo(action: .Close, shouldBounce: false, velocity: 0.0)
        
        panInfo.action = leftOrigin <= pointOfNoReturn ? .Close : .Open;
        
        if velocity.x >= thresholdVelocity {
            panInfo.action = .Open
            panInfo.velocity = velocity.x
        } else if velocity.x <= (-1.0 * thresholdVelocity) {
            panInfo.action = .Close
            panInfo.velocity = velocity.x
        }
        
        return panInfo
    }
    
    private func panRightResultInfoForVelocity(velocity: CGPoint) -> PanInfo {
        
        let thresholdVelocity: CGFloat = -1000.0
        let pointOfNoReturn: CGFloat = CGFloat(floor(CGRectGetWidth(view.bounds)) - SlideMenuOptions.pointOfNoReturnWidth)
        let rightOrigin: CGFloat = rightContainerView.frame.origin.x
        
        var panInfo: PanInfo = PanInfo(action: .Close, shouldBounce: false, velocity: 0.0)
        
        panInfo.action = rightOrigin >= pointOfNoReturn ? .Close : .Open
        
        if velocity.x <= thresholdVelocity {
            panInfo.action = .Open
            panInfo.velocity = velocity.x
        } else if (velocity.x >= (-1.0 * thresholdVelocity)) {
            panInfo.action = .Close
            panInfo.velocity = velocity.x
        }
        
        return panInfo
    }
    
    private func applyLeftTranslation(translation: CGPoint, toFrame:CGRect) -> CGRect {
        
        var newOrigin: CGFloat = toFrame.origin.x
        newOrigin += translation.x
        
        let minOrigin: CGFloat = leftMinOrigin()
        let maxOrigin: CGFloat = 0.0
        var newFrame: CGRect = toFrame
        
        if newOrigin < minOrigin {
            newOrigin = minOrigin
        } else if newOrigin > maxOrigin {
            newOrigin = maxOrigin
        }
        
        newFrame.origin.x = newOrigin
        return newFrame
    }
    
    private func applyRightTranslation(translation: CGPoint, toFrame: CGRect) -> CGRect {
        
        var  newOrigin: CGFloat = toFrame.origin.x
        newOrigin += translation.x
        
        let minOrigin: CGFloat = rightMinOrigin()
        let maxOrigin: CGFloat = rightMinOrigin() - rightContainerView.frame.size.width
        var newFrame: CGRect = toFrame
        
        if newOrigin > minOrigin {
            newOrigin = minOrigin
        } else if newOrigin < maxOrigin {
            newOrigin = maxOrigin
        }
        
        newFrame.origin.x = newOrigin
        return newFrame
    }
    
    private func getOpenedLeftRatio() -> CGFloat {
        
        let width: CGFloat = leftContainerView.frame.size.width
        let currentPosition: CGFloat = leftContainerView.frame.origin.x - leftMinOrigin()
        return currentPosition / width
    }
    
    private func getOpenedRightRatio() -> CGFloat {
        
        let width: CGFloat = rightContainerView.frame.size.width
        let currentPosition: CGFloat = rightContainerView.frame.origin.x
        return -(currentPosition - CGRectGetWidth(view.bounds)) / width
    }
    
    private func applyLeftOpacity() {
        
        let openedLeftRatio: CGFloat = getOpenedLeftRatio()
        let opacity: CGFloat = SlideMenuOptions.contentViewOpacity * openedLeftRatio
        opacityView.layer.opacity = Float(opacity)
    }
    
    
    private func applyRightOpacity() {
        let openedRightRatio: CGFloat = getOpenedRightRatio()
        let opacity: CGFloat = SlideMenuOptions.contentViewOpacity * openedRightRatio
        opacityView.layer.opacity = Float(opacity)
    }
    
    private func applyLeftContentViewScale() {
        let openedLeftRatio: CGFloat = getOpenedLeftRatio()
        let scale: CGFloat = 1.0 - ((1.0 - SlideMenuOptions.contentViewScale) * openedLeftRatio);
        let drag: CGFloat = SlideMenuOptions.leftViewWidth + leftContainerView.frame.origin.x
        
        SlideMenuOptions.contentViewDrag == true ? (mainContainerView.transform = CGAffineTransformMakeTranslation(drag, 0)) : (mainContainerView.transform = CGAffineTransformMakeScale(scale, scale))
    }
    
    private func applyRightContentViewScale() {
        let openedRightRatio: CGFloat = getOpenedRightRatio()
        let scale: CGFloat = 1.0 - ((1.0 - SlideMenuOptions.contentViewScale) * openedRightRatio)
        let drag: CGFloat = rightContainerView.frame.origin.x - mainContainerView.frame.size.width
        
        SlideMenuOptions.contentViewDrag == true ? (mainContainerView.transform = CGAffineTransformMakeTranslation(drag, 0)) : (mainContainerView.transform = CGAffineTransformMakeScale(scale, scale))
    }
    
    private func addShadowToView(targetContainerView: UIView) {
        targetContainerView.layer.masksToBounds = false
        targetContainerView.layer.shadowOffset = SlideMenuOptions.shadowOffset
        targetContainerView.layer.shadowOpacity = Float(SlideMenuOptions.shadowOpacity)
        targetContainerView.layer.shadowRadius = SlideMenuOptions.shadowRadius
        targetContainerView.layer.shadowPath = UIBezierPath(rect: targetContainerView.bounds).CGPath
    }
    
    private func removeShadow(targetContainerView: UIView) {
        targetContainerView.layer.masksToBounds = true
        mainContainerView.layer.opacity = 1.0
    }
    
    private func removeContentOpacity() {
        opacityView.layer.opacity = 0.0
    }
    
    
    private func addContentOpacity() {
        opacityView.layer.opacity = Float(SlideMenuOptions.contentViewOpacity)
    }
    
    private func disableContentInteraction() {
        mainContainerView.userInteractionEnabled = false
    }
    
    private func enableContentInteraction() {
        mainContainerView.userInteractionEnabled = true
    }
    
    private func setOpenWindowLevel() {
        if (SlideMenuOptions.hideStatusBar) {
            dispatch_async(dispatch_get_main_queue(), {
                if let window = UIApplication.sharedApplication().keyWindow {
                    window.windowLevel = UIWindowLevelStatusBar + 1
                }
            })
        }
    }
    
    private func setCloseWindowLevel() {
        if (SlideMenuOptions.hideStatusBar) {
            dispatch_async(dispatch_get_main_queue(), {
                if let window = UIApplication.sharedApplication().keyWindow {
                    window.windowLevel = UIWindowLevelNormal
                }
            })
        }
    }
    
    private func setUpViewController(targetView: UIView, targetViewController: UIViewController?) {
        if let viewController = targetViewController {
            addChildViewController(viewController)
            viewController.view.frame = targetView.bounds
            targetView.addSubview(viewController.view)
            viewController.didMoveToParentViewController(self)
        }
    }
    
    
    private func removeViewController(viewController: UIViewController?) {
        if let _viewController = viewController {
            _viewController.view.layer.removeAllAnimations()
            _viewController.willMoveToParentViewController(nil)
            _viewController.view.removeFromSuperview()
            _viewController.removeFromParentViewController()
        }
    }
    
    public func closeLeftNonAnimation(){
        setCloseWindowLevel()
        let finalXOrigin: CGFloat = leftMinOrigin()
        var frame: CGRect = leftContainerView.frame;
        frame.origin.x = finalXOrigin
        leftContainerView.frame = frame
        opacityView.layer.opacity = 0.0
        mainContainerView.transform = CGAffineTransformMakeScale(1.0, 1.0)
        removeShadow(leftContainerView)
        enableContentInteraction()
    }
    
    public func closeRightNonAnimation(){
        setCloseWindowLevel()
        let finalXOrigin: CGFloat = CGRectGetWidth(view.bounds)
        var frame: CGRect = rightContainerView.frame
        frame.origin.x = finalXOrigin
        rightContainerView.frame = frame
        opacityView.layer.opacity = 0.0
        mainContainerView.transform = CGAffineTransformMakeScale(1.0, 1.0)
        removeShadow(rightContainerView)
        enableContentInteraction()
    }
    
    // MARK: UIGestureRecognizerDelegate
    public func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
        
        let point: CGPoint = touch.locationInView(view)
        
        if gestureRecognizer == leftPanGesture {
            return slideLeftForGestureRecognizer(gestureRecognizer, point: point)
        } else if gestureRecognizer == rightPanGesture {
            return slideRightViewForGestureRecognizer(gestureRecognizer, withTouchPoint: point)
        } else if gestureRecognizer == leftTapGesture {
            return isLeftOpen() && !isPointContainedWithinLeftRect(point)
        } else if gestureRecognizer == rightTapGesture {
            return isRightOpen() && !isPointContainedWithinRightRect(point)
        }
        
        return true
    }
    
    // returning true here helps if the main view is fullwidth with a scrollview
    public func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return SlideMenuOptions.simultaneousGestureRecognizers
    }
    
    private func slideLeftForGestureRecognizer( gesture: UIGestureRecognizer, point:CGPoint) -> Bool{
        return isLeftOpen() || SlideMenuOptions.panFromBezel && isLeftPointContainedWithinBezelRect(point)
    }
    
    private func isLeftPointContainedWithinBezelRect(point: CGPoint) -> Bool{
        if let bezelWidth = SlideMenuOptions.leftBezelWidth {
            var leftBezelRect: CGRect = CGRectZero
            var tempRect: CGRect = CGRectZero
            
            CGRectDivide(view.bounds, &leftBezelRect, &tempRect, bezelWidth, CGRectEdge.MinXEdge)
            return CGRectContainsPoint(leftBezelRect, point)
        } else {
            return true
        }
    }
    
    private func isPointContainedWithinLeftRect(point: CGPoint) -> Bool {
        return CGRectContainsPoint(leftContainerView.frame, point)
    }
    
    
    
    private func slideRightViewForGestureRecognizer(gesture: UIGestureRecognizer, withTouchPoint point: CGPoint) -> Bool {
        return isRightOpen() || SlideMenuOptions.rightPanFromBezel && isRightPointContainedWithinBezelRect(point)
    }
    
    private func isRightPointContainedWithinBezelRect(point: CGPoint) -> Bool {
        if let rightBezelWidth = SlideMenuOptions.rightBezelWidth {
            var rightBezelRect: CGRect = CGRectZero
            var tempRect: CGRect = CGRectZero
            let bezelWidth: CGFloat = CGRectGetWidth(view.bounds) - rightBezelWidth
            
            CGRectDivide(view.bounds, &tempRect, &rightBezelRect, bezelWidth, CGRectEdge.MinXEdge)
            
            return CGRectContainsPoint(rightBezelRect, point)
        } else {
            return true
        }
    }
    
    private func isPointContainedWithinRightRect(point: CGPoint) -> Bool {
        return CGRectContainsPoint(rightContainerView.frame, point)
    }
    
}


extension UIViewController {
    
    public func slideMenuController() -> SlideMenuController? {
        var viewController: UIViewController? = self
        while viewController != nil {
            if viewController is SlideMenuController {
                return viewController as? SlideMenuController
            }
            viewController = viewController?.parentViewController
        }
        return nil;
    }
    
    public func addLeftBarButtonWithImage(buttonImage: UIImage) {
        let leftButton: UIBarButtonItem = UIBarButtonItem(image: buttonImage, style: UIBarButtonItemStyle.Plain, target: self, action: #selector(self.toggleLeft))
        navigationItem.leftBarButtonItem = leftButton;
    }
    
    public func addRightBarButtonWithImage(buttonImage: UIImage) {
        let rightButton: UIBarButtonItem = UIBarButtonItem(image: buttonImage, style: UIBarButtonItemStyle.Plain, target: self, action: #selector(self.toggleRight))
        navigationItem.rightBarButtonItem = rightButton;
    }
    
    public func toggleLeft() {
        slideMenuController()?.toggleLeft()
    }
    
    public func toggleRight() {
        slideMenuController()?.toggleRight()
    }
    
    public func openLeft() {
        slideMenuController()?.openLeft()
    }
    
    public func openRight() {
        slideMenuController()?.openRight()    }
    
    public func closeLeft() {
        slideMenuController()?.closeLeft()
    }
    
    public func closeRight() {
        slideMenuController()?.closeRight()
    }
    
    // Please specify if you want menu gesuture give priority to than targetScrollView
    public func addPriorityToMenuGesuture(targetScrollView: UIScrollView) {
        guard let slideController = slideMenuController(), let recognizers = slideController.view.gestureRecognizers else {
            return
        }
        for recognizer in recognizers where recognizer is UIPanGestureRecognizer {
            targetScrollView.panGestureRecognizer.requireGestureRecognizerToFail(recognizer)
        }
    }
}