//
//  Virgil_PagedView.swift
//  轮播图片
//
//  Created by virgil on 16/3/31.
//  Copyright © 2016年 virgil. All rights reserved.
//

import UIKit

class Virgil_PagedView: UIView, UIScrollViewDelegate {

    private var tapItemClosure: TapItemClosure?

    private var scrollView: UIScrollView!

    weak var delegate: Virgil_PagedViewDelegate?

    private var imageViewCount = 0
    var imgs: NSMutableArray!

    var titles: NSArray = ["爱跑腿", "青城校园", "青城校园", "爱跑腿", "爱跑腿"]

    var titleLabel: UILabel?

    var pageControl = UIPageControl()

    ///初始化方法
    ///
    /// - parameter frame    :frame
    /// - parameter images  :UIImage数组
    /// - parameter timeInterval  :循环时间

    init(frame: CGRect, images: [UIImage], timeInterval: Double) {
        super.init(frame: frame)
        scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height))
        initializeImageViews(images: images as NSArray?, timeInterval: timeInterval, imageURLStrings: nil, placeholderImage: nil)
    }

    ///初始化方法closure
    ///
    /// - parameter frame    :frame
    /// - parameter images  :UIImage数组
    /// - parameter timeInterval  :循环时间
    /// - parameter tapItemClosure  :closure实现点击事件

    init(frame: CGRect, images: [UIImage], timeInterval: Double, tapItemClosure:@escaping TapItemClosure) {
        super.init(frame: frame)
        self.tapItemClosure = tapItemClosure
        scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height))
        initializeImageViews(images: images as NSArray?, timeInterval: timeInterval, imageURLStrings: nil, placeholderImage: nil)

    }

    ///初始化方法URL
    ///
    /// - parameter frame    :frame
    /// - parameter imageURLStrings  :url字符串数组
    /// - parameter timeInterval  :循环时间

    init(frame: CGRect, imageURLStrings: [String], timeInterval: Double) {
        super.init(frame: frame)
        scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height))
        initializeImageViews(images: nil, timeInterval: timeInterval, imageURLStrings: imageURLStrings as NSArray?, placeholderImage: nil)
    }

    ///初始化方法URL&Closure
    ///
    /// - parameter frame    :frame
    /// - parameter imageURLStrings  :url字符串数组
    /// - parameter timeInterval  :循环时间
    /// - parameter tapItemClosure  :closure实现点击事件

    init(frame: CGRect, imageURLStrings: [String], timeInterval: Double, tapItemClosure:@escaping TapItemClosure) {
        super.init(frame: frame)
        self.tapItemClosure = tapItemClosure
        scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height))
        initializeImageViews(images: nil, timeInterval: timeInterval, imageURLStrings: imageURLStrings as NSArray?, placeholderImage: nil)
    }

    ///初始化方法URL
    ///
    /// - parameter frame    :frame
    /// - parameter imageURLStrings  :url字符串数组
    /// - parameter placeholderImage  :加载中图片
    /// - parameter timeInterval  :循环时间

    init(frame: CGRect, imageURLStrings: [String], placeholderImage: UIImage, timeInterval: Double) {
        super.init(frame: frame)
        scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height))
        initializeImageViews(images: nil, timeInterval: timeInterval, imageURLStrings: imageURLStrings as NSArray?, placeholderImage: placeholderImage)
    }

    ///初始化方法URL&Closure
    ///
    /// - parameter frame    :frame
    /// - parameter imageURLStrings  :url字符串数组
    /// - parameter placeholderImage  :加载中图片
    /// - parameter timeInterval  :循环时间
    /// - parameter tapItemClosure  :closure实现点击事件

    init(frame: CGRect, imageURLStrings: [String], placeholderImage: UIImage, timeInterval: Double, tapItemClosure:@escaping TapItemClosure) {
        super.init(frame: frame)
        self.tapItemClosure = tapItemClosure
        scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height))
        initializeImageViews(images: nil, timeInterval: timeInterval, imageURLStrings: imageURLStrings as NSArray?, placeholderImage: placeholderImage)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // MARK: 初始化

    private func initializeImageViews(images: NSArray?, timeInterval: Double, imageURLStrings: NSArray?, placeholderImage: UIImage?) {

        self.scrollView.isPagingEnabled = true
        self.scrollView.delegate = self
        self.scrollView.showsHorizontalScrollIndicator = false
        self.scrollView.showsVerticalScrollIndicator = false

        //view宽度&高度
        let viewWidth = self.scrollView.frame.size.width
        let viewHeight = self.scrollView.frame.size.height

        var count = 0

        if images != nil {
            imageViewCount = images!.count
            //计算设置view的总内容宽度
            self.scrollView.contentSize = CGSize(width: viewWidth * CGFloat(images!.count + 2), height: viewHeight)
            count = images!.count
        } else {
            imageViewCount = imageURLStrings!.count
            //计算设置view的总内容宽度
            self.scrollView.contentSize = CGSize(width: viewWidth * CGFloat(imageURLStrings!.count + 2), height: viewHeight)
            count = imageURLStrings!.count
        }

        //将数组数据加入到view中
        //第一张图片位置放最后一张
        //最后一张图片位置放第一张

        for i in 0 ..< count + 2 {
            if i == 0 {
                //第一个位置，放最后一张图片

                let imageView: UIImageView
                if images != nil {
                    imageView = UIImageView(image: images!.lastObject as? UIImage)
                } else {
                    imageView = UIImageView(image: placeholderImage)

                    imageView.sd_setImage(with: NSURL(string: imageURLStrings!.lastObject as! String)! as URL, placeholderImage: placeholderImage!)
                }
                imageView.frame = CGRect(x: 0, y: 0, width: viewWidth, height: viewHeight)
                self.scrollView.addSubview(imageView)

                let btn = UIButton(type: .custom)
                btn.frame = CGRect(x: 0, y: 0, width: viewWidth, height: viewHeight)
                btn.tag = i
                btn.addTarget(self, action: #selector(Virgil_PagedView.btnClick), for: .touchUpInside)
                self.scrollView.addSubview(btn)
            } else if i == count + 1 {
                //最后一个位置，放第一张图片

                let imageView: UIImageView
                if images != nil {
                    imageView = UIImageView(image: images!.firstObject as? UIImage)
                } else {
                    imageView = UIImageView(image: placeholderImage)
                    imageView.sd_setImage(with: NSURL(string: imageURLStrings!.firstObject as! String)! as URL, placeholderImage: placeholderImage!)
                }

                imageView.frame = CGRect(x: viewWidth * CGFloat(i), y: 0, width: viewWidth, height: viewHeight)
                self.scrollView.addSubview(imageView)

                let btn = UIButton(type: .custom)
                btn.frame = CGRect(x: viewWidth * CGFloat(i), y: 0, width: viewWidth, height: viewHeight)
                btn.tag = i
                btn.addTarget(self, action: #selector(Virgil_PagedView.btnClick), for: .touchUpInside)
                self.scrollView.addSubview(btn)
            } else {
                //如果i ＝ 1，则为第二个位置，放第一张图片，以此类推

                let imageView: UIImageView
                if images != nil {
                    imageView = UIImageView(image: images![i - 1] as? UIImage)
                } else {
                    imageView = UIImageView(image: placeholderImage)
                    imageView.sd_setImage(with: (NSURL(string: imageURLStrings![i - 1] as! String)! as NSURL) as URL, placeholderImage: placeholderImage!)
                }

                imageView.frame = CGRect(x: viewWidth * CGFloat(i), y: 0, width: viewWidth, height: viewHeight)
                self.scrollView.addSubview(imageView)

                let btn = UIButton(type: .custom)
                btn.frame = CGRect(x: viewWidth * CGFloat(i), y: 0, width: viewWidth, height: viewHeight)
                btn.tag = i
                btn.addTarget(self, action: #selector(Virgil_PagedView.btnClick), for: .touchUpInside)
                self.scrollView.addSubview(btn)

            }
        }

        //设置view默认显示第二张图片的位置
        self.scrollView.setContentOffset(CGPoint(x: viewWidth, y: 0), animated: false)

        self.addSubview(scrollView)

        //计时器
        let timer = Timer(timeInterval: timeInterval, target: self, selector: #selector(Virgil_PagedView.loop), userInfo: nil, repeats: true)
        RunLoop.current.add(timer, forMode: RunLoop.Mode.default)

        addBottomView()
    }

    func addBottomView() {

        let view = UIView(frame: CGRect(x: 0, y: self.frame.size.height - 20, width: self.frame.size.width, height: 20))
//        view.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.4)
//        
        self.addSubview(view)
//        

        pageControl.frame = CGRect(x: (view.frame.size.width - CGFloat(imageViewCount * 20)) / 2, y: 0, width: CGFloat(imageViewCount * 20), height: 20)
        pageControl.numberOfPages = imageViewCount
        pageControl.currentPage = 0
        pageControl.currentPageIndicatorTintColor = CommonUntils.getUIColorFromRGB(rgbValue: 0xffffff, alpha: 1.0)
        pageControl.pageIndicatorTintColor = CommonUntils.getUIColorFromRGB(rgbValue: 0xffffff, alpha: 0.6)

        view.addSubview(pageControl)

    }

    // MARK: 计时器方法
    @objc func loop() {
        let width = scrollView.frame.size.width
        let page = floor((scrollView.contentOffset.x - width/2)/width) + 1
        self.pageControl.currentPage = NSInteger(page)
        scrollView.setContentOffset(CGPoint(x: width * CGFloat(page + 1), y: 0), animated: true)
    }

    // MARK: - scrollView Delegate

    func scrollViewDidScroll(_ scrollView: UIScrollView) {

        if (Int(scrollView.contentOffset.x) % Int(scrollView.frame.size.width)) == 0 {
            let width = scrollView.frame.size.width
            let page = floor((scrollView.contentOffset.x - width/2)/width) + 1

            if page == 0 {
                scrollView.setContentOffset(CGPoint(x: width * CGFloat(imageViewCount), y: 0), animated: false)
                self.pageControl.currentPage = imageViewCount - 1
                titleLabel?.text = titles[imageViewCount - 1] as? String
            } else if page >= CGFloat(imageViewCount + 1) {
                scrollView.setContentOffset(CGPoint(x: width, y: 0), animated: false)
                self.pageControl.currentPage = NSInteger(0)
                titleLabel?.text = titles[0] as? String
            } else {
                self.pageControl.currentPage = NSInteger(page - 1)
                titleLabel?.text = titles[Int(page - 1)] as? String
            }

        }
    }

    // MARK: btn点击

    @objc internal func btnClick(btn: AnyObject) {

        if btn.tag == 0 {
            //第一按钮对应最后一个

            if delegate != nil {
                delegate?.didTapItem?(item: imageViewCount - 1)
            }

            if tapItemClosure != nil {
                tapItemClosure!(imageViewCount - 1)
            }

        } else if btn.tag == imageViewCount + 1 {
            //最后一个按钮对应第一个
            if delegate != nil {
                delegate?.didTapItem?(item: 0)
            }

            if tapItemClosure != nil {
                tapItemClosure!(0)
            }

        } else {
            //正常对应 tag - 1 == i
            if delegate != nil {
                delegate?.didTapItem?(item: btn.tag - 1)
            }

            if tapItemClosure != nil {
                tapItemClosure!(btn.tag - 1)
            }
        }

    }

}

@objc
public protocol Virgil_PagedViewDelegate {
    @objc optional func didTapItem(item: Int)
}