import Foundation
import Display
import AsyncDisplayKit
import TelegramCore

class InstantPageReferenceControllerNode: ViewControllerTracingNode, UIScrollViewDelegate {
    private var presentationData: PresentationData

    private var containerLayout: (ContainerViewLayout, CGFloat)?
    
    private let dimNode: ASDisplayNode

    private let wrappingScrollNode: ASScrollNode
    private let contentContainerNode: ASDisplayNode
    private let contentBackgroundNode: ASImageNode
    
    private let titleNode: ASTextNode
    private let separatorNode: ASDisplayNode
    
    private let closeButton: HighlightableButtonNode
    
    var dismiss: (() -> Void)?
    var close: (() -> Void)?
    
    init(account: Account, item: InstantPageTextItem) {
        self.presentationData = account.telegramApplicationContext.currentPresentationData.with { $0 }
        
        self.wrappingScrollNode = ASScrollNode()
        self.wrappingScrollNode.view.alwaysBounceVertical = true
        self.wrappingScrollNode.view.delaysContentTouches = false
        self.wrappingScrollNode.view.canCancelContentTouches = true
        
        self.dimNode = ASDisplayNode()
        self.dimNode.backgroundColor = UIColor(white: 0.0, alpha: 0.5)
        
        let roundedBackground = generateStretchableFilledCircleImage(radius: 16.0, color: self.presentationData.theme.actionSheet.opaqueItemBackgroundColor)
        
        self.contentContainerNode = ASDisplayNode()
        self.contentContainerNode.isOpaque = false
        self.contentContainerNode.clipsToBounds = true
        
        self.contentBackgroundNode = ASImageNode()
        self.contentBackgroundNode.displaysAsynchronously = false
        self.contentBackgroundNode.displayWithoutProcessing = true
        self.contentBackgroundNode.image = roundedBackground
        
        self.titleNode = ASTextNode()
        self.titleNode.attributedText = NSAttributedString(string: self.presentationData.strings.ShareMenu_ShareTo, font: Font.medium(20.0), textColor: self.presentationData.theme.actionSheet.primaryTextColor)
        
        self.separatorNode = ASDisplayNode()
        self.separatorNode.backgroundColor = self.presentationData.theme.actionSheet.opaqueItemSeparatorColor
        
        self.closeButton = HighlightableButtonNode()
            
        super.init()
        
        self.backgroundColor = nil
        self.isOpaque = false
        
        self.dimNode.view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.dimTapGesture(_:))))
        self.addSubnode(self.dimNode)
        
        self.wrappingScrollNode.view.delegate = self
        self.addSubnode(self.wrappingScrollNode)
        
        self.wrappingScrollNode.addSubnode(self.contentBackgroundNode)
        self.wrappingScrollNode.addSubnode(self.contentContainerNode)
    }
    
    override func didLoad() {
        super.didLoad()
        
        if #available(iOSApplicationExtension 11.0, *) {
            self.wrappingScrollNode.view.contentInsetAdjustmentBehavior = .never
        }
    }
    
    @objc func closeButtonPressed() {
        self.close?()
    }
    
    @objc func dimTapGesture(_ recognizer: UITapGestureRecognizer) {
        if case .ended = recognizer.state {
            self.closeButtonPressed()
        }
    }
    
    func animateIn() {
        self.dimNode.layer.animateAlpha(from: 0.0, to: 1.0, duration: 0.4)
        
        let offset = self.bounds.size.height - self.contentBackgroundNode.frame.minY
        
        let dimPosition = self.dimNode.layer.position
        self.dimNode.layer.animatePosition(from: CGPoint(x: dimPosition.x, y: dimPosition.y - offset), to: dimPosition, duration: 0.3, timingFunction: kCAMediaTimingFunctionSpring)
        self.layer.animateBoundsOriginYAdditive(from: -offset, to: 0.0, duration: 0.3, timingFunction: kCAMediaTimingFunctionSpring)
    }
    
    func animateOut(completion: (() -> Void)? = nil) {
        var dimCompleted = false
        var offsetCompleted = false
        
        let internalCompletion: () -> Void = { [weak self] in
            if let strongSelf = self, dimCompleted && offsetCompleted {
                strongSelf.dismiss?()
            }
            completion?()
        }
        
        self.dimNode.layer.animateAlpha(from: 1.0, to: 0.0, duration: 0.3, removeOnCompletion: false, completion: { _ in
            dimCompleted = true
            internalCompletion()
        })
        
        let offset = self.bounds.size.height - self.contentBackgroundNode.frame.minY
        let dimPosition = self.dimNode.layer.position
        self.dimNode.layer.animatePosition(from: dimPosition, to: CGPoint(x: dimPosition.x, y: dimPosition.y - offset), duration: 0.3, timingFunction: kCAMediaTimingFunctionSpring, removeOnCompletion: false)
        self.layer.animateBoundsOriginYAdditive(from: 0.0, to: -offset, duration: 0.3, timingFunction: kCAMediaTimingFunctionSpring, removeOnCompletion: false, completion: { _ in
            offsetCompleted = true
            internalCompletion()
        })
    }
    
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        if self.bounds.contains(point) {
            if !self.contentBackgroundNode.bounds.contains(self.convert(point, to: self.contentBackgroundNode)) {
                return self.dimNode.view
            }
        }
        return super.hitTest(point, with: event)
    }
    
    func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
        let contentOffset = scrollView.contentOffset
        let additionalTopHeight = max(0.0, -contentOffset.y)
        
        if additionalTopHeight >= 30.0 {
            self.closeButtonPressed()
        }
    }
    
    func containerLayoutUpdated(_ layout: ContainerViewLayout, navigationBarHeight: CGFloat, transition: ContainedViewLayoutTransition) {
        var insets = layout.insets(options: [.statusBar, .input])
        let cleanInsets = layout.insets(options: [.statusBar])
        insets.top = max(10.0, insets.top)
        
        var bottomInset: CGFloat = 10.0 + cleanInsets.bottom
        if insets.bottom > 0 {
            bottomInset -= 12.0
        }
        
        let titleAreaHeight: CGFloat = 54.0
        
        let buttonHeight: CGFloat = 57.0
        let sectionSpacing: CGFloat = 8.0
        
        let maximumContentHeight = layout.size.height - insets.top - max(bottomInset + buttonHeight, insets.bottom) - sectionSpacing
        
        let width = horizontalContainerFillingSizeForLayout(layout: layout, sideInset: 10.0 + layout.safeInsets.left)
        
        let sideInset = floor((layout.size.width - width) / 2.0)
        
        let contentContainerFrame = CGRect(origin: CGPoint(x: sideInset, y: insets.top), size: CGSize(width: width, height: maximumContentHeight))
        let contentFrame = contentContainerFrame.insetBy(dx: 0.0, dy: 0.0)
        
        self.containerLayout = (layout, navigationBarHeight)
    
        transition.updateFrame(node: self.wrappingScrollNode, frame: CGRect(origin: CGPoint(), size: layout.size))
        
        transition.updateFrame(node: self.dimNode, frame: CGRect(origin: CGPoint(), size: layout.size))
        
        let titleSize = self.titleNode.measure(CGSize(width: width, height: titleAreaHeight))
        let titleFrame = CGRect(origin: CGPoint(x: floor((width - titleSize.width) / 2.0), y: 15.0), size: titleSize)
        transition.updateFrame(node: self.titleNode, frame: titleFrame)
        
        //transition.updateFrame(node: self.closeButtonNode, frame: CGRect(origin: CGPoint(x: sideInset, y: layout.size.height - bottomInset - buttonHeight), size: CGSize(width: width, height: buttonHeight)))
        
        transition.updateFrame(node: self.contentContainerNode, frame: contentContainerFrame)
        transition.updateFrame(node: self.separatorNode, frame: CGRect(origin: CGPoint(x: 0.0, y: titleAreaHeight), size: CGSize(width: contentContainerFrame.size.width, height: UIScreenPixel)))
    }
}