import Foundation
import Display
import AsyncDisplayKit
import SwiftSignalKit

enum ItemListSwitchItemNodeType {
    case regular
    case icon
}

class ItemListSwitchItem: ListViewItem, ItemListItem {
    let theme: PresentationTheme
    let title: String
    let value: Bool
    let type: ItemListSwitchItemNodeType
    let enableInteractiveChanges: Bool
    let enabled: Bool
    let sectionId: ItemListSectionId
    let style: ItemListStyle
    let updated: (Bool) -> Void
    
    init(theme: PresentationTheme, title: String, value: Bool, type: ItemListSwitchItemNodeType = .regular, enableInteractiveChanges: Bool = true, enabled: Bool = true, sectionId: ItemListSectionId, style: ItemListStyle, updated: @escaping (Bool) -> Void) {
        self.theme = theme
        self.title = title
        self.value = value
        self.type = type
        self.enableInteractiveChanges = enableInteractiveChanges
        self.enabled = enabled
        self.sectionId = sectionId
        self.style = style
        self.updated = updated
    }
    
    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 = ItemListSwitchItemNode(type: self.type)
            let (layout, apply) = node.asyncLayout()(self, params, itemListNeighbors(item: self, topItem: previousItem as? ItemListItem, bottomItem: nextItem as? ItemListItem))
            
            node.contentSize = layout.contentSize
            node.insets = layout.insets
            
            Queue.mainQueue().async {
                completion(node, {
                    return (nil, { _ in apply(false) })
                })
            }
        }
    }
    
    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 {
            if let nodeValue = node() as? ItemListSwitchItemNode {
                let makeLayout = nodeValue.asyncLayout()
                
                async {
                    let (layout, apply) = makeLayout(self, params, itemListNeighbors(item: self, topItem: previousItem as? ItemListItem, bottomItem: nextItem as? ItemListItem))
                    Queue.mainQueue().async {
                        completion(layout, { _ in
                            var animated = true
                            if case .None = animation {
                                animated = false
                            }
                            apply(animated)
                        })
                    }
                }
            }
        }
    }
}

private let titleFont = Font.regular(17.0)

private protocol ItemListSwitchNodeImpl {
    var frameColor: UIColor { get set }
    var contentColor: UIColor { get set }
    var handleColor: UIColor { get set }
    var positiveContentColor: UIColor { get set }
    var negativeContentColor: UIColor { get set }
}

extension SwitchNode: ItemListSwitchNodeImpl {
    var positiveContentColor: UIColor {
        get {
            return .white
        } set(value) {
            
        }
    }
    var negativeContentColor: UIColor {
        get {
            return .white
        } set(value) {
            
        }
    }
}

extension IconSwitchNode: ItemListSwitchNodeImpl {
}

class ItemListSwitchItemNode: ListViewItemNode {
    private let backgroundNode: ASDisplayNode
    private let topStripeNode: ASDisplayNode
    private let bottomStripeNode: ASDisplayNode
    
    private let titleNode: TextNode
    private var switchNode: ASDisplayNode & ItemListSwitchNodeImpl
    private let switchGestureNode: ASDisplayNode
    private var disabledOverlayNode: ASDisplayNode?
    
    private var item: ItemListSwitchItem?
    
    init(type: ItemListSwitchItemNodeType) {
        self.backgroundNode = ASDisplayNode()
        self.backgroundNode.isLayerBacked = true
        self.backgroundNode.backgroundColor = .white
        
        self.topStripeNode = ASDisplayNode()
        self.topStripeNode.isLayerBacked = true
        
        self.bottomStripeNode = ASDisplayNode()
        self.bottomStripeNode.isLayerBacked = true
        
        self.titleNode = TextNode()
        self.titleNode.isUserInteractionEnabled = false
        switch type {
            case .regular:
                self.switchNode = SwitchNode()
            case .icon:
                self.switchNode = IconSwitchNode()
        }
        
        self.switchGestureNode = ASDisplayNode()
        
        super.init(layerBacked: false, dynamicBounce: false)
        
        self.addSubnode(self.titleNode)
        self.addSubnode(self.switchNode)
        self.addSubnode(self.switchGestureNode)
    }
    
    override func didLoad() {
        super.didLoad()
        
        (self.switchNode.view as? UISwitch)?.addTarget(self, action: #selector(self.switchValueChanged(_:)), for: .valueChanged)
        self.switchGestureNode.view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.tapGesture(_:))))
    }
    
    func asyncLayout() -> (_ item: ItemListSwitchItem, _ params: ListViewItemLayoutParams, _ insets: ItemListNeighbors) -> (ListViewItemNodeLayout, (Bool) -> Void) {
        let makeTitleLayout = TextNode.asyncLayout(self.titleNode)
        
        let currentItem = self.item
        var currentDisabledOverlayNode = self.disabledOverlayNode
        
        return { item, params, neighbors in
            let contentSize: CGSize
            let insets: UIEdgeInsets
            let separatorHeight = UIScreenPixel
            let itemBackgroundColor: UIColor
            let itemSeparatorColor: UIColor
            
            var updatedTheme: PresentationTheme?
            
            if currentItem?.theme !== item.theme {
                updatedTheme = item.theme
            }
            
            switch item.style {
                case .plain:
                    itemBackgroundColor = item.theme.list.plainBackgroundColor
                    itemSeparatorColor = item.theme.list.itemPlainSeparatorColor
                    contentSize = CGSize(width: params.width, height: 44.0)
                    insets = itemListNeighborsPlainInsets(neighbors)
                case .blocks:
                    itemBackgroundColor = item.theme.list.itemBlocksBackgroundColor
                    itemSeparatorColor = item.theme.list.itemBlocksSeparatorColor
                    contentSize = CGSize(width: params.width, height: 44.0)
                    insets = itemListNeighborsGroupedInsets(neighbors)
            }
            
            let (titleLayout, titleApply) = makeTitleLayout(TextNodeLayoutArguments(attributedString: NSAttributedString(string: item.title, font: titleFont, textColor: item.theme.list.itemPrimaryTextColor), backgroundColor: nil, maximumNumberOfLines: 1, truncationType: .end, constrainedSize: CGSize(width: params.width - params.leftInset - params.rightInset - 80.0, height: CGFloat.greatestFiniteMagnitude), alignment: .natural, cutout: nil, insets: UIEdgeInsets()))
            
            if !item.enabled {
                if currentDisabledOverlayNode == nil {
                    currentDisabledOverlayNode = ASDisplayNode()
                    currentDisabledOverlayNode?.backgroundColor = itemBackgroundColor.withAlphaComponent(0.5)
                }
            } else {
                currentDisabledOverlayNode = nil
            }
            
            let layout = ListViewItemNodeLayout(contentSize: contentSize, insets: insets)
            let layoutSize = layout.size
            
            return (ListViewItemNodeLayout(contentSize: contentSize, insets: insets), { [weak self] animated in
                if let strongSelf = self {
                    strongSelf.item = item
                    
                    let transition: ContainedViewLayoutTransition
                    if animated {
                        transition = ContainedViewLayoutTransition.animated(duration: 0.4, curve: .spring)
                    } else {
                        transition = .immediate
                    }
                    
                    if let currentDisabledOverlayNode = currentDisabledOverlayNode {
                        if currentDisabledOverlayNode != strongSelf.disabledOverlayNode {
                            strongSelf.disabledOverlayNode = currentDisabledOverlayNode
                            strongSelf.addSubnode(currentDisabledOverlayNode)
                            currentDisabledOverlayNode.alpha = 0.0
                            transition.updateAlpha(node: currentDisabledOverlayNode, alpha: 1.0)
                            currentDisabledOverlayNode.frame = CGRect(origin: CGPoint(), size: CGSize(width: layout.contentSize.width, height: layout.contentSize.height - separatorHeight))
                        } else {
                            transition.updateFrame(node: currentDisabledOverlayNode, frame: CGRect(origin: CGPoint(), size: CGSize(width: layout.contentSize.width, height: layout.contentSize.height - separatorHeight)))
                        }
                    } else if let disabledOverlayNode = strongSelf.disabledOverlayNode {
                        transition.updateAlpha(node: disabledOverlayNode, alpha: 0.0, completion: { [weak disabledOverlayNode] _ in
                            disabledOverlayNode?.removeFromSupernode()
                        })
                        strongSelf.disabledOverlayNode = nil
                    }
                    
                    if let _ = updatedTheme {
                        strongSelf.topStripeNode.backgroundColor = itemSeparatorColor
                        strongSelf.bottomStripeNode.backgroundColor = itemSeparatorColor
                        strongSelf.backgroundNode.backgroundColor = itemBackgroundColor
                        
                        strongSelf.switchNode.frameColor = item.theme.list.itemSwitchColors.frameColor
                        strongSelf.switchNode.contentColor = item.theme.list.itemSwitchColors.contentColor
                        strongSelf.switchNode.handleColor = item.theme.list.itemSwitchColors.handleColor
                        strongSelf.switchNode.positiveContentColor = item.theme.list.itemSwitchColors.positiveColor
                        strongSelf.switchNode.negativeContentColor = item.theme.list.itemSwitchColors.negativeColor
                    }
                    
                    let _ = titleApply()
                    
                    let leftInset = 16.0 + params.leftInset
                    
                    switch item.style {
                        case .plain:
                            if strongSelf.backgroundNode.supernode != nil {
                                strongSelf.backgroundNode.removeFromSupernode()
                            }
                            if strongSelf.topStripeNode.supernode != nil {
                                strongSelf.topStripeNode.removeFromSupernode()
                            }
                            if strongSelf.bottomStripeNode.supernode == nil {
                                strongSelf.insertSubnode(strongSelf.bottomStripeNode, at: 0)
                            }
                            
                            strongSelf.bottomStripeNode.frame = CGRect(origin: CGPoint(x: leftInset, y: contentSize.height - separatorHeight), size: CGSize(width: params.width - leftInset, height: separatorHeight))
                        case .blocks:
                            if strongSelf.backgroundNode.supernode == nil {
                                strongSelf.insertSubnode(strongSelf.backgroundNode, at: 0)
                            }
                            if strongSelf.topStripeNode.supernode == nil {
                                strongSelf.insertSubnode(strongSelf.topStripeNode, at: 1)
                            }
                            if strongSelf.bottomStripeNode.supernode == nil {
                                strongSelf.insertSubnode(strongSelf.bottomStripeNode, at: 2)
                            }
                            switch neighbors.top {
                                case .sameSection(false):
                                    strongSelf.topStripeNode.isHidden = true
                                default:
                                    strongSelf.topStripeNode.isHidden = false
                            }
                            let bottomStripeInset: CGFloat
                            switch neighbors.bottom {
                                case .sameSection(false):
                                    bottomStripeInset = 16.0 + params.leftInset
                                default:
                                    bottomStripeInset = 0.0
                            }
                            
                            strongSelf.backgroundNode.frame = CGRect(origin: CGPoint(x: 0.0, y: -min(insets.top, separatorHeight)), size: CGSize(width: params.width, height: contentSize.height + min(insets.top, separatorHeight) + min(insets.bottom, separatorHeight)))
                            strongSelf.topStripeNode.frame = CGRect(origin: CGPoint(x: 0.0, y: -min(insets.top, separatorHeight)), size: CGSize(width: layoutSize.width, height: separatorHeight))
                            strongSelf.bottomStripeNode.frame = CGRect(origin: CGPoint(x: bottomStripeInset, y: contentSize.height - separatorHeight), size: CGSize(width: layoutSize.width - bottomStripeInset, height: separatorHeight))
                    }
                    
                    strongSelf.titleNode.frame = CGRect(origin: CGPoint(x: leftInset, y: 11.0), size: titleLayout.size)
                    if let switchView = strongSelf.switchNode.view as? UISwitch {
                        if strongSelf.switchNode.bounds.size.width.isZero {
                            switchView.sizeToFit()
                        }
                        let switchSize = switchView.bounds.size
                        
                        strongSelf.switchNode.frame = CGRect(origin: CGPoint(x: params.width - params.rightInset - switchSize.width - 15.0, y: 6.0), size: switchSize)
                        strongSelf.switchGestureNode.frame = strongSelf.switchNode.frame
                        if switchView.isOn != item.value {
                            switchView.setOn(item.value, animated: animated)
                        }
                        switchView.isUserInteractionEnabled = item.enableInteractiveChanges
                    }
                    strongSelf.switchGestureNode.isHidden = item.enableInteractiveChanges
                }
            })
        }
    }
    
    override func animateInsertion(_ currentTimestamp: Double, duration: Double, short: Bool) {
        self.layer.animateAlpha(from: 0.0, to: 1.0, duration: 0.4)
    }
    
    override func animateRemoved(_ currentTimestamp: Double, duration: Double) {
        self.layer.animateAlpha(from: 1.0, to: 0.0, duration: 0.15, removeOnCompletion: false)
    }
    
    @objc func switchValueChanged(_ switchView: UISwitch) {
        if let item = self.item {
            let value = switchView.isOn
            item.updated(value)
        }
    }
    
    @objc func tapGesture(_ recognizer: UITapGestureRecognizer) {
        if let item = self.item, let switchView = self.switchNode.view as? UISwitch, case .ended = recognizer.state {
            let value = switchView.isOn
            item.updated(!value)
        }
    }
}