import Foundation
import UIKit
import Postbox
import AsyncDisplayKit
import Display
import SwiftSignalKit
import TelegramPresentationData

private let titleFont = UIFont.systemFont(ofSize: 13.0)

class ChatHoleItem: ListViewItem {
    let index: MessageIndex
    let presentationData: ChatPresentationData
    //let header: ChatMessageDateHeader
    
    init(index: MessageIndex, presentationData: ChatPresentationData) {
        self.index = index
        self.presentationData = presentationData
        //self.header = ChatMessageDateHeader(timestamp: index.timestamp, theme: theme, strings: strings)
    }
    
    func nodeConfiguredForParams(async: @escaping (@escaping () -> Void) -> Void, params: ListViewItemLayoutParams, synchronousLoads: Bool, previousItem: ListViewItem?, nextItem: ListViewItem?, completion: @escaping (ListViewItemNode, @escaping () -> (Signal<Void, NoError>?, (ListViewItemApply) -> Void)) -> Void) {
        async {
            let node = ChatHoleItemNode()
            node.layoutForParams(params, item: self, previousItem: previousItem, nextItem: nextItem)
            Queue.mainQueue().async {
                completion(node, {
                    return (nil, { _ in })
                })
            }
        }
    }
    
    func updateNode(async: @escaping (@escaping () -> Void) -> Void, node: @escaping () -> ListViewItemNode, params: ListViewItemLayoutParams, previousItem: ListViewItem?, nextItem: ListViewItem?, animation: ListViewItemUpdateAnimation, completion: @escaping (ListViewItemNodeLayout, @escaping (ListViewItemApply) -> Void) -> Void) {
        Queue.mainQueue().async {
            completion(ListViewItemNodeLayout(contentSize: node().contentSize, insets: node().insets), { _ in
            })
        }
    }
}

class ChatHoleItemNode: ListViewItemNode {
    var item: ChatHoleItem?
    let backgroundNode: ASImageNode
    let labelNode: TextNode
    
    private let layoutConstants = ChatMessageItemLayoutConstants.default
    
    init() {
        self.backgroundNode = ASImageNode()
        self.backgroundNode.isLayerBacked = true
        self.backgroundNode.displayWithoutProcessing = true
        self.backgroundNode.displaysAsynchronously = false
        
        self.labelNode = TextNode()
        self.labelNode.isUserInteractionEnabled = false
        
        super.init(layerBacked: false)
        
        self.addSubnode(self.backgroundNode)
        
        self.addSubnode(self.labelNode)
        
        self.transform = CATransform3DMakeRotation(CGFloat.pi, 0.0, 0.0, 1.0)
    }
    
    override func layoutForParams(_ params: ListViewItemLayoutParams, item: ListViewItem, previousItem: ListViewItem?, nextItem: ListViewItem?) {
        if let item = item as? ChatHoleItem {
            let dateAtBottom = false//!chatItemsHaveCommonDateHeader(item, nextItem)
            let (layout, apply) = self.asyncLayout()(item, params, dateAtBottom)
            apply()
            self.contentSize = layout.contentSize
            self.insets = layout.insets
        }
    }
    
    func asyncLayout() -> (_ item: ChatHoleItem, _ params: ListViewItemLayoutParams, _ dateAtBottom: Bool) -> (ListViewItemNodeLayout, () -> Void) {
        let labelLayout = TextNode.asyncLayout(self.labelNode)
        let layoutConstants = self.layoutConstants
        let currentItem = self.item
        return { item, params, dateAtBottom in
            var updatedBackground: UIImage?
            if item.presentationData.theme !== currentItem?.presentationData.theme {
                let graphics = PresentationResourcesChat.additionalGraphics(item.presentationData.theme.theme, wallpaper: item.presentationData.theme.wallpaper, bubbleCorners: item.presentationData.chatBubbleCorners)
                updatedBackground = graphics.chatServiceBubbleFillImage
            }
            
            let serviceColor = serviceMessageColorComponents(theme: item.presentationData.theme.theme, wallpaper: item.presentationData.theme.wallpaper)
            
            let (size, apply) = labelLayout(TextNodeLayoutArguments(attributedString: NSAttributedString(string: item.presentationData.strings.Channel_NotificationLoading, font: titleFont, textColor: serviceColor.primaryText), backgroundColor: nil, maximumNumberOfLines: 1, truncationType: .end, constrainedSize: CGSize(width: params.width, height: CGFloat.greatestFiniteMagnitude), alignment: .natural, cutout: nil, insets: UIEdgeInsets()))
            
            let backgroundSize = CGSize(width: size.size.width + 8.0 + 8.0, height: 20.0)
            
            return (ListViewItemNodeLayout(contentSize: CGSize(width: params.width, height: 20.0), insets: UIEdgeInsets(top: 4.0 + (dateAtBottom ? layoutConstants.timestampHeaderHeight : 0.0), left: 0.0, bottom: 4.0, right: 0.0)), { [weak self] in
                if let strongSelf = self {
                    strongSelf.item = item
                    
                    if let updatedBackground = updatedBackground {
                        strongSelf.backgroundNode.image = updatedBackground
                    }
                    
                    let _ = apply()
                    
                    strongSelf.backgroundNode.frame = CGRect(origin: CGPoint(x: floorToScreenPixels((params.width - backgroundSize.width) / 2.0), y: 0.0), size: backgroundSize)
                    strongSelf.labelNode.frame = CGRect(origin: CGPoint(x: strongSelf.backgroundNode.frame.origin.x + 8.0, y: floorToScreenPixels((backgroundSize.height - size.size.height) / 2.0)), size: size.size)
                }
            })
        }
    }
    
    override public func animateAdded(_ currentTimestamp: Double, duration: Double) {
        self.layer.animateAlpha(from: 0.0, to: 1.0, duration: 0.2)
    }
    
    override public func animateRemoved(_ currentTimestamp: Double, duration: Double) {
        self.layer.animateAlpha(from: 1.0, to: 0.0, duration: duration * 0.5, removeOnCompletion: false)
    }
}