//
//  FFPageView.swift
//  FFPage
//
//  Created by FFIB on 2017/10/19.
//  Copyright © 2017年 FFIB. All rights reserved.
//

import UIKit

public protocol FFPageViewDataSource {
    func pageView(pageView: FFPageView, cellForItemAt index: Int) -> FFPageContentViewCell
}

public protocol FFPageViewDelegate {
    func pageViewWithClickMenu(pageView: FFPageView)
}

@IBDesignable
public class FFPageView: UIView {
    private var pageMenuView = FFPageMenuView()
    private var pageContentView = FFPageContentView()
    private var needlayout = true
    private var rootVC: UIViewController?
    private var ffConstraints = [NSLayoutConstraint]()

    //configuratable parameter

    public var dataSource: FFPageViewDataSource?
    public var delegate: FFPageViewDelegate?

    var isNavigationMenu = true {
        willSet {
            if newValue != isNavigationMenu {
                needlayout = true
                setNeedsLayout()
            }

        }
    }

    public var sliderView = UIView() {
        willSet {
            if sliderView != newValue {
                pageMenuView.sliderView = newValue
            }
        }
    }

    public var selectedColor = UIColor.blue {
        willSet {
            if selectedColor != newValue {
                pageMenuView.selectedColor = newValue
            }
        }
    }
    public var normalColor = UIColor.black {
        willSet {
            if normalColor != newValue {
                pageMenuView.normalColor = newValue
            }
        }
    }
    public var pageMenuContentMode = FFPageMenuContentMode.scaleAspectFill {
        willSet {
            pageMenuView.pageMenuContentMode = newValue
        }
    }
    public var font = UIFont.systemFont(ofSize: 17) {
        willSet {
            if font != newValue {
                pageMenuView.font = newValue
            }
        }
    }

    public var titles = [String]() {
        willSet {
            if titles != newValue {
                pageMenuView.titles = newValue
                pageContentView.needLayout = true
                pageMenuView.setNeedsLayout()
                pageContentView.setNeedsLayout()
            }
        }
    }

    public override func layoutSubviews() {
        super.layoutSubviews()
        if needlayout {
            initSubViews()
        }
    }

    func initSubViews() {
        needlayout = false
        pageContentView.removeFromSuperview()
        pageMenuView.removeFromSuperview()
        NSLayoutConstraint.deactivate(ffConstraints)
        ffConstraints.removeAll()
        pageMenuView.pageDelegate = self
        pageContentView.dataSource = self
        pageContentView.pageDelegate = self
        addSubview(pageContentView)

        pageContentView.translatesAutoresizingMaskIntoConstraints = false
        pageMenuView.translatesAutoresizingMaskIntoConstraints = false
        let contentTopConstraint: NSLayoutConstraint

        var responder = self.next
        while responder != nil {
            if let targetVC = responder as? UIViewController {
                rootVC = targetVC
                break
            }
            responder = responder?.next
        }

        if #available(iOS 11.0, *) {
            pageContentView.contentInsetAdjustmentBehavior = .never
        } else {
            rootVC?.automaticallyAdjustsScrollViewInsets = false
        }

        switch isNavigationMenu {
        case false:
            addSubview(pageMenuView)

            let menuConstraints = [NSLayoutConstraint(item: pageMenuView,
                                                      attribute: .top,
                                                      relatedBy: .equal,
                                                      toItem: self,
                                                      attribute: .top,
                                                      multiplier: 1,
                                                      constant: 0),
                                   NSLayoutConstraint(item: pageMenuView,
                                                      attribute: .leading,
                                                      relatedBy: .equal,
                                                      toItem: self,
                                                      attribute: .leading,
                                                      multiplier: 1,
                                                      constant: 0),
                                   NSLayoutConstraint(item: pageMenuView,
                                                      attribute: .trailing,
                                                      relatedBy: .equal,
                                                      toItem: self,
                                                      attribute: .trailing,
                                                      multiplier: 1,
                                                      constant: 0),
                                   NSLayoutConstraint(item: pageMenuView,
                                                      attribute: .height,
                                                      relatedBy: .equal,
                                                      toItem: nil,
                                                      attribute: .height,
                                                      multiplier: 1,
                                                      constant: 44)]
            contentTopConstraint = NSLayoutConstraint(item: pageContentView,
                                                      attribute: .top,
                                                      relatedBy: .equal,
                                                      toItem: pageMenuView,
                                                      attribute: .bottom,
                                                      multiplier: 1,
                                                      constant: 0)
            ffConstraints += menuConstraints
        case true:
            var barContentView: UIView?
            if #available(iOS 11, *) {
                barContentView = rootVC?
                    .navigationController?
                    .navigationBar
                    .subviews
                    .filter { NSStringFromClass($0.classForCoder).contains("NavigationBarContentView") }
                    .first
            } else {
                barContentView  = rootVC?.navigationController?.navigationBar
            }

            contentTopConstraint = NSLayoutConstraint(item: pageContentView,
                                                      attribute: .top,
                                                      relatedBy: .equal,
                                                      toItem: self,
                                                      attribute: .top,
                                                      multiplier: 1,
                                                      constant: 0)


            let menuConstraints = [NSLayoutConstraint(item: pageMenuView,
                                                      attribute: .top,
                                                      relatedBy: .equal,
                                                      toItem: barContentView,
                                                      attribute: .top,
                                                      multiplier: 1,
                                                      constant: 0),
                                   NSLayoutConstraint(item: pageMenuView,
                                                      attribute: .bottom,
                                                      relatedBy: .equal,
                                                      toItem: barContentView,
                                                      attribute: .bottom,
                                                      multiplier: 1,
                                                      constant: 0),
                                   NSLayoutConstraint(item: pageMenuView,
                                                      attribute: .centerX,
                                                      relatedBy: .equal,
                                                      toItem: barContentView,
                                                      attribute: .centerX,
                                                      multiplier: 1,
                                                      constant: 0)]
            ffConstraints += menuConstraints
            NotificationCenter.default.addObserver(forName: NSNotification.Name.init("UINavigationController.willShow"), object: nil, queue: nil, using: { (notification) in
                if let userInfo = notification.userInfo,
                    let vc = userInfo["targetController"] as? UIViewController,
                    self.rootVC == vc {
                    self.pageMenuView.isHidden = false
                } else {
                    self.pageMenuView.isHidden = true
                }
            })
        }

        let contentConstraints = [contentTopConstraint,
                                  NSLayoutConstraint(item: pageContentView,
                                                     attribute: .leading,
                                                     relatedBy: .equal,
                                                     toItem: self,
                                                     attribute: .leading,
                                                     multiplier: 1,
                                                     constant: 0),
                                  NSLayoutConstraint(item: pageContentView,
                                                     attribute: .trailing,
                                                     relatedBy: .equal,
                                                     toItem: self,
                                                     attribute: .trailing,
                                                     multiplier: 1,
                                                     constant: 0),
                                  NSLayoutConstraint(item: pageContentView,
                                                     attribute: .bottom,
                                                     relatedBy: .equal,
                                                     toItem: self,
                                                     attribute: .bottom,
                                                     multiplier: 1,
                                                     constant: 0),
                                  NSLayoutConstraint(item: pageContentView,
                                                     attribute: .width,
                                                     relatedBy: .equal,
                                                     toItem: self,
                                                     attribute: .width,
                                                     multiplier: 1,
                                                     constant: 0)]
        ffConstraints += contentConstraints
        NSLayoutConstraint.activate(ffConstraints)
    }

    public func dequeue(with identifier: String) -> FFPageContentViewCell {
        return pageContentView.dequeue(with: identifier)
    }

    public func register(nib: UINib, with identifier: String) {
        pageContentView.register(nib: nib, with: identifier)
    }

    public func register(cell: AnyClass, with identifier: String) {
        pageContentView.register(cell: cell, with: identifier)
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }
}

extension FFPageView: FFPageMenuViewDelegate {
    public func pageMenuView(pageMenuView: FFPageMenuView, didSelectItemAt index: Int) {
        pageContentView.scrollRectToVisible(CGRect(x: CGFloat(index) * frame.width, y: 0, width: frame.width, height: frame.height), animated: true)
        if let delegate = delegate {
            delegate.pageViewWithClickMenu(pageView: self)
        }
    }
}

extension FFPageView: FFPageContentViewDelegate {
    public func pageContentView(pageContentView: FFPageContentView, didSelectItemAt index: Int) {
        let offset = pageContentView.contentOffset.x / pageContentView.frame.width
        pageMenuView.scroll(offset: offset)
    }
}

extension FFPageView: FFPageContentViewDataSource {
    public func pageContentView(pageContentView: FFPageContentView, cellForItemAt index: Int) -> FFPageContentViewCell {
        guard let dataSource = dataSource else {
            fatalError("\(self) did not set up FFPageViewDataSource")
        }
        return dataSource.pageView(pageView: self, cellForItemAt: index)
    }

    public func numberOfSections(in pageContentView: FFPageContentView) -> Int {
        return titles.count
    }
}

extension UIViewController: UINavigationControllerDelegate {
    public func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
        NotificationCenter.default.post(name: NSNotification.Name("UINavigationController.willShow"), object: nil, userInfo: ["targetController": viewController])
    }
}