//
// Created by Jake Lin on 2/24/16.
// Copyright (c) 2016 IBAnimatable. All rights reserved.
//

import UIKit

/**
 Navigator for `UINavigationController` or `UITabBarController` to support custom transition animation
 */
public class Navigator: NSObject {
  var transitionAnimationType: TransitionAnimationType
  var transitionDuration: Duration = defaultTransitionDuration

  // animation controller
  fileprivate var animator: AnimatedTransitioning?
  // interaction controller
  fileprivate var interactiveAnimator: InteractiveAnimator?

  public init(transitionAnimationType: TransitionAnimationType,
              transitionDuration: Duration = defaultTransitionDuration,
              interactiveGestureType: InteractiveGestureType? = nil) {
    self.transitionAnimationType = transitionAnimationType
    self.transitionDuration = transitionDuration
    super.init()

    animator = AnimatorFactory.makeAnimator(transitionAnimationType: transitionAnimationType, transitionDuration: transitionDuration)

    // If interactiveGestureType has been set
    if let interactiveGestureType = interactiveGestureType {
      // If configured as `.Default` then use the default interactive gesture type from the Animator
      switch interactiveGestureType {
      case .default:
        if let interactiveGestureType = animator?.interactiveGestureType {
          interactiveAnimator = InteractiveAnimatorFactory.makeInteractiveAnimator(interactiveGestureType: interactiveGestureType,
                                                                                   transitionType: .navigationTransition(.pop))
        }
      default:
        interactiveAnimator = InteractiveAnimatorFactory.makeInteractiveAnimator(interactiveGestureType: interactiveGestureType,
                                                                                 transitionType: .navigationTransition(.pop))
      }
    }
  }
}

// MARK: - navigation controller delegate
extension Navigator: UINavigationControllerDelegate {
  // MARK: - animation controller
  public func navigationController(_ navigationController: UINavigationController,
                                   animationControllerFor operation: UINavigationController.Operation,
                                   from fromVC: UIViewController,
                                   to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    interactiveAnimator?.connectGestureRecognizer(to: toVC)

    if operation == .push {
      animator?.transitionDuration = transitionDuration
      return animator
    } else if operation == .pop {
      // Use the reverse animation
      if let reverseTransitionAnimationType = animator?.reverseAnimationType {
        return AnimatorFactory.makeAnimator(transitionAnimationType: reverseTransitionAnimationType, transitionDuration: transitionDuration)
      }
    }
    return nil
  }

  // MARK: - interaction controller
  public func navigationController(_ navigationController: UINavigationController,
                                   interactionControllerFor animationController: UIViewControllerAnimatedTransitioning)
                                          -> UIViewControllerInteractiveTransitioning? {
    if let interactiveAnimator = interactiveAnimator, interactiveAnimator.interacting {
      return interactiveAnimator
    }
    return nil
  }
}

// MARK: - tabbar controller delegate
extension Navigator: UITabBarControllerDelegate {

  // MARK: - animation controller
  public func tabBarController(_ tabBarController: UITabBarController,
                               animationControllerForTransitionFrom fromVC: UIViewController,
                               to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {

    interactiveAnimator?.connectGestureRecognizer(to: toVC)

    #if swift(>=4.2)
    guard let viewControllers = tabBarController.viewControllers,
      let fromVCIndex = viewControllers.firstIndex(of: fromVC),
      let toVCIndex = viewControllers.firstIndex(of: toVC) else {
        return nil
    }

    #else
    guard let viewControllers = tabBarController.viewControllers,
      let fromVCIndex = viewControllers.index(of: fromVC),
      let toVCIndex = viewControllers.index(of: toVC) else {
        return nil
    }

    #endif

    if toVCIndex > fromVCIndex, let reverseTransitionAnimationType = animator?.reverseAnimationType {
      return AnimatorFactory.makeAnimator(transitionAnimationType: reverseTransitionAnimationType, transitionDuration: transitionDuration)
    }
    animator?.transitionDuration = transitionDuration
    return animator
  }

  // MARK: - interaction controller
  public func tabBarController(_ tabBarController: UITabBarController,
                               interactionControllerFor animationController: UIViewControllerAnimatedTransitioning)
    -> UIViewControllerInteractiveTransitioning? {
      if let interactiveAnimator = interactiveAnimator, interactiveAnimator.interacting {
        return interactiveAnimator
      }
      return nil
  }
}