//
//  JSNavigationController.swift
//  JSNavigationController
//

import AppKit

protocol JSNavigationControllerViewDelegate: AnyObject {
    
    var contentView: NSView { get }
    var navigationBarView: NSView? { get }
    var leadingConstraint: NSLayoutConstraint? { get set}
    
    func hasNavigationBar(_ hasBar: Bool)
}

final class JSNavigationController: NSViewController, JSViewControllersStackManager {
    
    private struct Constants {
        static let segueTemplatesKey = "segueTemplates"
        static let segueIdentifierKey = "identifier"
        static let segueIdentifier = "rootViewController"
    }
    
    weak var controllerViewDelegate: JSNavigationControllerViewDelegate?
    
	weak var contentView: NSView?
    var viewControllers: [NSViewController] = []
    var navigationBarController: JSNavigationBarController?
    weak var delegate: JSNavigationControllerDelegate?

	// MARK: - Creating Navigation Controllers
    init(rootViewController: NSViewController, viewDelegate: JSNavigationControllerViewDelegate) {
        self.contentView = viewDelegate.contentView
        self.navigationBarController = JSNavigationBarController(view: viewDelegate.navigationBarView)
        self.controllerViewDelegate = viewDelegate
		super.init(nibName: nil, bundle: nil)
		self.push(viewController: rootViewController, animated: false)
	}

    init(viewControllers: [NSViewController], viewDelegate: JSNavigationControllerViewDelegate) {
		self.contentView = viewDelegate.contentView
		self.navigationBarController = JSNavigationBarController(view: viewDelegate.navigationBarView)
        self.controllerViewDelegate = viewDelegate
		super.init(nibName: nil, bundle: nil)
		self.set(viewControllers: viewControllers, animated: false)
	}
	
	required public init?(coder: NSCoder) {
		super.init(coder: coder)
	}

	// MARK: - View Lifecycle
    override func loadView() {
        if self.nibName.isExist {
			super.loadView()
		} else {
            let v = NSView(frame: .zero)
            v.translatesAutoresizingMaskIntoConstraints = false
            v.wantsLayer = true
			self.view = v
		}
	}

    override func viewDidAppear() {
		super.viewDidAppear()
        
		guard self.nibName != nil else { return }
        guard let segues = self.value(forKey: Constants.segueTemplatesKey) as? [NSObject] else { return } // Undocumented
        
		for segue in segues {
            if let id = segue.value(forKey: Constants.segueIdentifierKey) as? String {
				self.performSegue(withIdentifier: id, sender: self)
			}
		}
	}

	// MARK: - Pushing
    func push(viewController: NSViewController, contentAnimation: AnimationBlock?, navigationBarAnimation: AnimationBlock?) {
		guard !Set(self.viewControllers).contains(viewController) else { return }

		self.viewControllers.append(viewController)
		self.delegate?.navigationController(self, willShowViewController: viewController, animated: (contentAnimation != nil))

		// Remove old view
		if let previousViewController = self.previousViewController
            , contentAnimation == nil {
			previousViewController.view.removeFromSuperview()
		}

		// Add the new view
		self.contentView?.addSubview(viewController.view, positioned: .above, relativeTo: self.previousViewController?.view)

		// NavigationBar
		if let vc = viewController as? JSNavigationBarViewControllerProvider {
			vc.navigationController = self
			self.navigationBarController?.push(viewController: vc.navigationBarViewController(), animation: navigationBarAnimation)
		} else {
			self.navigationBarController?.push(viewController: EmptyViewController(), animation: navigationBarAnimation)
		}
        
        self.controllerViewDelegate?.hasNavigationBar(viewController is JSNavigationBarViewControllerProvider)

		if let contentAnimation = contentAnimation {
			CATransaction.begin()
			CATransaction.setCompletionBlock { [weak self] in
				self?.previousViewController?.view.removeFromSuperview()
				self?.previousViewController?.view.layer?.removeAllAnimations()
				self?.delegate?.navigationController(self!, didShowViewController: viewController, animated: true)
			}
			self.animatePush(contentAnimation)
			CATransaction.commit()
		} else {
			self.delegate?.navigationController(self, didShowViewController: viewController, animated: false)
		}
	}

    func push(viewController: NSViewController, animation: AnimationBlock?) {
		let navBarAnimation: AnimationBlock? = animation != nil ? navigationBarController?.defaultPushAnimation() : nil
		self.push(viewController: viewController, contentAnimation: animation, navigationBarAnimation: navBarAnimation)
	}

    func push(viewController: NSViewController, animated: Bool, offsetContentView: Bool = false) {
        if let contentView = self.contentView, let delegate = self.controllerViewDelegate, let leadingConstraint = delegate.leadingConstraint, let applicationView = contentView.superview, offsetContentView {
            applicationView.removeConstraint(leadingConstraint)
            let updatedConstraint = contentView.leadingAnchor.constraint(equalTo: applicationView.leadingAnchor, constant: 60)
            delegate.leadingConstraint = updatedConstraint
            applicationView.addConstraint(updatedConstraint)
        }
		if animated {
			self.push(viewController: viewController, animation: self.defaultPushAnimation())
		} else {
			self.push(viewController: viewController, animation: nil)
		}
	}

	// MARK: - Popping
    func pop(toViewController viewController: NSViewController, contentAnimation: AnimationBlock?, navigationBarAnimation: AnimationBlock?) {
		guard Set(self.viewControllers).contains(viewController) else { return }
		guard let rootViewController = self.viewControllers.first else { return }
		guard let topViewController = self.topViewController else { return }
		guard topViewController != rootViewController else { return }

		self.delegate?.navigationController(self, willShowViewController: viewController, animated: (contentAnimation != nil))
		
        let viewControllerPosition = self.viewControllers.firstIndex(of: viewController)

		// Add the new view
		self.contentView?.addSubview(viewController.view, positioned: .below, relativeTo: topViewController.view)

		// NavigationBar
		if let vc = viewController as? JSNavigationBarViewControllerProvider {
			self.navigationBarController?.pop(toViewController: vc.navigationBarViewController(), animation: navigationBarAnimation)
		}
        
        self.controllerViewDelegate?.hasNavigationBar(viewController is JSNavigationBarViewControllerProvider)

		if let contentAnimation = contentAnimation {
			CATransaction.begin()
			CATransaction.setCompletionBlock { [unowned self] in
				self.topViewController?.view.removeFromSuperview()
				self.topViewController?.view.layer?.removeAllAnimations()
				let range = (viewControllerPosition! + 1)..<self.viewControllers.count
				self.viewControllers.removeSubrange(range)
				self.delegate?.navigationController(self, didShowViewController: viewController, animated: true)
			}
			self.animatePop(toView: viewController.view, animation: contentAnimation)
			CATransaction.commit()
		} else {
			topViewController.view.removeFromSuperview()
			let range = (viewControllerPosition! + 1)..<self.viewControllers.count
			self.viewControllers.removeSubrange(range)
			self.delegate?.navigationController(self, didShowViewController: viewController, animated: false)
		}
	}

    func pop(toViewController viewController: NSViewController, animation: AnimationBlock?) {
		let navBarAnimation: AnimationBlock? = animation != nil ? self.navigationBarController?.defaultPopAnimation() : nil
		self.pop(toViewController: viewController, contentAnimation: animation, navigationBarAnimation: navBarAnimation)
	}

    func pop(toViewController viewController: NSViewController, animated: Bool) {
		if animated {
			self.pop(toViewController: viewController, animation: defaultPopAnimation())
		} else {
			self.pop(toViewController: viewController, animation: nil)
		}
	}

    func popViewController(contentAnimation: AnimationBlock?, navigationBarAnimation: AnimationBlock?) {
		guard let previousViewController = self.previousViewController else { return }
		self.pop(toViewController: previousViewController, contentAnimation: contentAnimation, navigationBarAnimation: navigationBarAnimation)
	}

    func popViewController(animation: AnimationBlock?) {
		let navBarAnimation: AnimationBlock? = animation != nil ? self.navigationBarController?.defaultPopAnimation() : nil
		self.popViewController(contentAnimation: animation, navigationBarAnimation: navBarAnimation)
	}

    func popViewController(animated: Bool) {
		if animated {
			self.popViewController(animation: self.defaultPopAnimation())
		} else {
			self.popViewController(animation: nil)
		}
	}

    func popToRootViewController(contentAnimation: AnimationBlock?, navigationBarAnimation: AnimationBlock?) {
		guard let rootViewController = self.viewControllers.first else { return }
		guard let topViewController = self.topViewController else { return }
		guard topViewController != rootViewController else { return }

		self.pop(toViewController: rootViewController, contentAnimation: contentAnimation, navigationBarAnimation: navigationBarAnimation)
	}

    func popToRootViewController(animation: AnimationBlock?) {
		let navBarAnimation: AnimationBlock? = animation != nil ? self.navigationBarController?.defaultPopAnimation() : nil
		self.popToRootViewController(contentAnimation: animation, navigationBarAnimation: navBarAnimation)
	}

    func popToRootViewController(animated: Bool, moveContentViewBack: Bool = false) {
        if let contentView = self.contentView, let delegate = self.controllerViewDelegate, let leadingConstraint = delegate.leadingConstraint, let applicationView = contentView.superview, moveContentViewBack {
            applicationView.removeConstraint(leadingConstraint)
            let updatedConstraint = contentView.leadingAnchor.constraint(equalTo: applicationView.leadingAnchor)
            delegate.leadingConstraint = updatedConstraint
            applicationView.addConstraint(updatedConstraint)
        }
		if animated {
			self.popToRootViewController(animation: self.defaultPopAnimation())
		} else {
			self.popToRootViewController(animation: nil)
		}
	}

	// MARK: - Animations
	func defaultPushAnimation() -> AnimationBlock {
		return { [weak self] (_, _) in
			let containerViewBounds = self?.contentView?.bounds ?? .zero

			let slideToLeftTransform = CATransform3DMakeTranslation(-containerViewBounds.width / 2, 0, 0)
			let slideToLeftAnimation = CABasicAnimation(keyPath: #keyPath(CALayer.transform))
			slideToLeftAnimation.fromValue = NSValue(caTransform3D: CATransform3DIdentity)
			slideToLeftAnimation.toValue = NSValue(caTransform3D: slideToLeftTransform)
            slideToLeftAnimation.duration = 0.25
			slideToLeftAnimation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeOut)
			slideToLeftAnimation.fillMode = CAMediaTimingFillMode.forwards
			slideToLeftAnimation.isRemovedOnCompletion = false

			let slideFromRightTransform = CATransform3DMakeTranslation(containerViewBounds.width, 0, 0)
			let slideFromRightAnimation = CABasicAnimation(keyPath: #keyPath(CALayer.transform))
			slideFromRightAnimation.fromValue = NSValue(caTransform3D: slideFromRightTransform)
			slideFromRightAnimation.toValue = NSValue(caTransform3D: CATransform3DIdentity)
            slideFromRightAnimation.duration = 0.25
			slideFromRightAnimation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeOut)
			slideFromRightAnimation.fillMode = CAMediaTimingFillMode.forwards
			slideFromRightAnimation.isRemovedOnCompletion = false

			return ([slideToLeftAnimation], [slideFromRightAnimation])
		}
	}

	func defaultPopAnimation() -> AnimationBlock {
		return { [weak self] (_, _) in
			let containerViewBounds = self?.contentView?.bounds ?? .zero

			let slideToRightTransform = CATransform3DMakeTranslation(-containerViewBounds.width / 2, 0, 0)
			let slideToRightAnimation = CABasicAnimation(keyPath: #keyPath(CALayer.transform))
			slideToRightAnimation.fromValue = NSValue(caTransform3D: slideToRightTransform)
			slideToRightAnimation.toValue = NSValue(caTransform3D: CATransform3DIdentity)
            slideToRightAnimation.duration = 0.25
			slideToRightAnimation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeOut)
			slideToRightAnimation.fillMode = CAMediaTimingFillMode.forwards
			slideToRightAnimation.isRemovedOnCompletion = false

			let slideToRightFromCenterTransform = CATransform3DMakeTranslation(containerViewBounds.width, 0, 0)
			let slideToRightFromCenterAnimation = CABasicAnimation(keyPath: #keyPath(CALayer.transform))
			slideToRightFromCenterAnimation.fromValue = NSValue(caTransform3D: CATransform3DIdentity)
			slideToRightFromCenterAnimation.toValue = NSValue(caTransform3D: slideToRightFromCenterTransform)
            slideToRightFromCenterAnimation.duration = 0.25
			slideToRightFromCenterAnimation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.easeOut)
			slideToRightFromCenterAnimation.fillMode = CAMediaTimingFillMode.forwards
			slideToRightFromCenterAnimation.isRemovedOnCompletion = false

			return ([slideToRightFromCenterAnimation], [slideToRightAnimation])
		}
	}

	// MARK: - Storyboard
	override func prepare(for segue: NSStoryboardSegue, sender: Any?) {
        guard segue.identifier == Constants.segueIdentifier else { return }
		guard let destinationController = segue.destinationController as? NSViewController else { return }

		self.push(viewController: destinationController, animated: false)
	}
}