import Foundation
import UIKit
import Display
import AsyncDisplayKit
import SwiftSignalKit
import TelegramCore
import TelegramPresentationData
import LegacyComponents
import ItemListUI
import PresentationDataUtils

private let textFont = Font.with(size: 17.0, traits: .monospacedNumbers)
private let smallTextFont = Font.with(size: 13.0, traits: .monospacedNumbers)

public final class MessagePriceItem: ListViewItem, ItemListItem {
    let theme: PresentationTheme
    let strings: PresentationStrings
    let minValue: Int64
    let maxValue: Int64
    let value: Int64
    let price: String
    public let sectionId: ItemListSectionId
    let updated: (Int64) -> Void
    
    public init(theme: PresentationTheme, strings: PresentationStrings, minValue: Int64, maxValue: Int64, value: Int64, price: String, sectionId: ItemListSectionId, updated: @escaping (Int64) -> Void) {
        self.theme = theme
        self.strings = strings
        self.minValue = minValue
        self.maxValue = maxValue
        self.value = value
        self.price = price
        self.sectionId = sectionId
        self.updated = updated
    }
    
    public 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 = MessagePriceItemNode()
            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() })
                })
            }
        }
    }
    
    public 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? MessagePriceItemNode {
                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
                            apply()
                        })
                    }
                }
            }
        }
    }
}

private class MessagePriceItemNode: ListViewItemNode {
    private struct Amount: Equatable {
        private let sliderSteps: [Int]
        private let maxRealValue: Int
        let maxSliderValue: Int
        private let isLogarithmic: Bool
        
        private(set) var realValue: Int
        private(set) var sliderValue: Int
        
        private static func makeSliderSteps(maxRealValue: Int, isLogarithmic: Bool) -> [Int] {
            if isLogarithmic {
                var sliderSteps: [Int] = [ 1, 10, 50, 100, 500, 1_000, 2_000, 5_000, 7_500, 10_000 ]
                sliderSteps.removeAll(where: { $0 >= maxRealValue })
                sliderSteps.append(maxRealValue)
                return sliderSteps
            } else {
                return [1, maxRealValue]
            }
        }
        
        private static func remapValueToSlider(realValue: Int, maxSliderValue: Int, steps: [Int]) -> Int {
            guard realValue >= steps.first!, realValue <= steps.last! else { return 0 }

            for i in 0 ..< steps.count - 1 {
                if realValue >= steps[i] && realValue <= steps[i + 1] {
                    let range = steps[i + 1] - steps[i]
                    let relativeValue = realValue - steps[i]
                    let stepFraction = Float(relativeValue) / Float(range)
                    return Int(Float(i) * Float(maxSliderValue) / Float(steps.count - 1)) + Int(stepFraction * Float(maxSliderValue) / Float(steps.count - 1))
                }
            }
            return maxSliderValue
        }

        private static func remapSliderToValue(sliderValue: Int, maxSliderValue: Int, steps: [Int]) -> Int {
            guard sliderValue >= 0, sliderValue <= maxSliderValue else { return steps.first! }

            let stepIndex = Int(Float(sliderValue) / Float(maxSliderValue) * Float(steps.count - 1))
            let fraction = Float(sliderValue) / Float(maxSliderValue) * Float(steps.count - 1) - Float(stepIndex)
            
            if stepIndex >= steps.count - 1 {
                return steps.last!
            } else {
                let range = steps[stepIndex + 1] - steps[stepIndex]
                return steps[stepIndex] + Int(fraction * Float(range))
            }
        }
        
        init(realValue: Int, maxRealValue: Int, maxSliderValue: Int, isLogarithmic: Bool) {
            self.sliderSteps = Amount.makeSliderSteps(maxRealValue: maxRealValue, isLogarithmic: isLogarithmic)
            self.maxRealValue = maxRealValue
            self.maxSliderValue = maxSliderValue
            self.isLogarithmic = isLogarithmic
            
            self.realValue = realValue
            self.sliderValue = Amount.remapValueToSlider(realValue: self.realValue, maxSliderValue: self.maxSliderValue, steps: self.sliderSteps)
        }
        
        init(sliderValue: Int, maxRealValue: Int, maxSliderValue: Int, isLogarithmic: Bool) {
            self.sliderSteps = Amount.makeSliderSteps(maxRealValue: maxRealValue, isLogarithmic: isLogarithmic)
            self.maxRealValue = maxRealValue
            self.maxSliderValue = maxSliderValue
            self.isLogarithmic = isLogarithmic
            
            self.sliderValue = sliderValue
            self.realValue = Amount.remapSliderToValue(sliderValue: self.sliderValue, maxSliderValue: self.maxSliderValue, steps: self.sliderSteps)
        }
        
        func withRealValue(_ realValue: Int) -> Amount {
            return Amount(realValue: realValue, maxRealValue: self.maxRealValue, maxSliderValue: self.maxSliderValue, isLogarithmic: self.isLogarithmic)
        }
        
        func withSliderValue(_ sliderValue: Int) -> Amount {
            return Amount(sliderValue: sliderValue, maxRealValue: self.maxRealValue, maxSliderValue: self.maxSliderValue, isLogarithmic: self.isLogarithmic)
        }
    }
    
    private let backgroundNode: ASDisplayNode
    private let topStripeNode: ASDisplayNode
    private let bottomStripeNode: ASDisplayNode
    private let maskNode: ASImageNode
    
    private var sliderView: TGPhotoEditorSliderView?
    private let leftTextNode: ImmediateTextNode
    private let rightTextNode: ImmediateTextNode
    private let centerLeftTextNode: ImmediateTextNode
    private let centerRightTextNode: ImmediateTextNode
    
    private var amount: Amount = Amount(realValue: 1, maxRealValue: 1000, maxSliderValue: 1000, isLogarithmic: true)
    
    private var item: MessagePriceItem?
    private var layoutParams: ListViewItemLayoutParams?
    
    init() {
        self.backgroundNode = ASDisplayNode()
        self.backgroundNode.isLayerBacked = true
        
        self.topStripeNode = ASDisplayNode()
        self.topStripeNode.isLayerBacked = true
        
        self.bottomStripeNode = ASDisplayNode()
        self.bottomStripeNode.isLayerBacked = true
        
        self.maskNode = ASImageNode()
        
        self.leftTextNode = ImmediateTextNode()
        self.rightTextNode = ImmediateTextNode()
        self.centerLeftTextNode = ImmediateTextNode()
        self.centerRightTextNode = ImmediateTextNode()
        
        super.init(layerBacked: false, dynamicBounce: false)
        
        self.addSubnode(self.leftTextNode)
        self.addSubnode(self.rightTextNode)
        self.addSubnode(self.centerLeftTextNode)
        self.addSubnode(self.centerRightTextNode)
    }
    
    override func didLoad() {
        super.didLoad()
        
        let sliderView = TGPhotoEditorSliderView()
        sliderView.enableEdgeTap = true
        sliderView.enablePanHandling = true
        sliderView.trackCornerRadius = 1.0
        sliderView.lineSize = 4.0
        sliderView.disablesInteractiveTransitionGestureRecognizer = true
        if let item = self.item, let params = self.layoutParams {
            self.amount = Amount(realValue: Int(item.value), maxRealValue: Int(item.maxValue), maxSliderValue: 999, isLogarithmic: true)
            
            sliderView.minimumValue = 0
            sliderView.startValue = 0
            sliderView.maximumValue = CGFloat(self.amount.maxSliderValue)
            sliderView.displayEdges = true
            sliderView.value = CGFloat(self.amount.sliderValue)
            sliderView.backgroundColor = item.theme.list.itemBlocksBackgroundColor
            sliderView.backColor = item.theme.list.itemSwitchColors.frameColor
            sliderView.trackColor = item.theme.list.itemAccentColor
            sliderView.knobImage = PresentationResourcesItemList.knobImage(item.theme)
            
            sliderView.frame = CGRect(origin: CGPoint(x: params.leftInset + 18.0, y: 36.0), size: CGSize(width: params.width - params.leftInset - params.rightInset - 18.0 * 2.0, height: 44.0))
        }
        self.view.addSubview(sliderView)
        sliderView.addTarget(self, action: #selector(self.sliderValueChanged), for: .valueChanged)
        self.sliderView = sliderView
    }
        
    func asyncLayout() -> (_ item: MessagePriceItem, _ params: ListViewItemLayoutParams, _ neighbors: ItemListNeighbors) -> (ListViewItemNodeLayout, () -> Void) {
        let currentItem = self.item
        
        return { item, params, neighbors in
            var themeUpdated = false
            if currentItem?.theme !== item.theme {
                themeUpdated = true
            }
            
            let contentSize: CGSize
            let insets: UIEdgeInsets
            let separatorHeight = UIScreenPixel
            
            contentSize = CGSize(width: params.width, height: 88.0)
            insets = itemListNeighborsGroupedInsets(neighbors, params)
            
            let layout = ListViewItemNodeLayout(contentSize: contentSize, insets: insets)
            let layoutSize = layout.size
            
            return (layout, { [weak self] in
                if let strongSelf = self {
                    strongSelf.item = item
                    strongSelf.layoutParams = params
                    
                    strongSelf.backgroundNode.backgroundColor = item.theme.list.itemBlocksBackgroundColor
                    strongSelf.topStripeNode.backgroundColor = item.theme.list.itemBlocksSeparatorColor
                    strongSelf.bottomStripeNode.backgroundColor = item.theme.list.itemBlocksSeparatorColor
                    
                    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)
                    }
                    if strongSelf.maskNode.supernode == nil {
                        strongSelf.insertSubnode(strongSelf.maskNode, at: 3)
                    }
                    
                    let hasCorners = itemListHasRoundedBlockLayout(params)
                    var hasTopCorners = false
                    var hasBottomCorners = false
                    switch neighbors.top {
                    case .sameSection(false):
                        strongSelf.topStripeNode.isHidden = true
                    default:
                        hasTopCorners = true
                        strongSelf.topStripeNode.isHidden = hasCorners
                    }
                    let bottomStripeInset: CGFloat
                    let bottomStripeOffset: CGFloat
                    switch neighbors.bottom {
                        case .sameSection(false):
                            bottomStripeInset = params.leftInset + 16.0
                            bottomStripeOffset = -separatorHeight
                            strongSelf.bottomStripeNode.isHidden = false
                        default:
                            bottomStripeInset = 0.0
                            bottomStripeOffset = 0.0
                            hasBottomCorners = true
                            strongSelf.bottomStripeNode.isHidden = hasCorners
                    }
                    
                    strongSelf.maskNode.image = hasCorners ? PresentationResourcesItemList.cornersImage(item.theme, top: hasTopCorners, bottom: hasBottomCorners) : nil
                    
                    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.maskNode.frame = strongSelf.backgroundNode.frame.insetBy(dx: params.leftInset, dy: 0.0)
                    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 + bottomStripeOffset), size: CGSize(width: layoutSize.width - bottomStripeInset, height: separatorHeight))
                    
                    strongSelf.leftTextNode.attributedText = NSAttributedString(string: "\(item.minValue)", font: Font.regular(13.0), textColor: item.theme.list.itemSecondaryTextColor)
                    strongSelf.rightTextNode.attributedText = NSAttributedString(string: "\(item.maxValue)", font: Font.regular(13.0), textColor: item.theme.list.itemSecondaryTextColor)
                    
                    //TODO:localize
                    let centralLeftText = "\(item.value) Stars"
                    strongSelf.centerLeftTextNode.attributedText = NSAttributedString(string: centralLeftText, font: textFont, textColor: item.theme.list.itemPrimaryTextColor)
                    strongSelf.centerRightTextNode.attributedText = NSAttributedString(string: item.price, font: smallTextFont, textColor: item.theme.list.itemSecondaryTextColor)
                    
                    let leftTextSize = strongSelf.leftTextNode.updateLayout(CGSize(width: 100.0, height: 100.0))
                    let rightTextSize = strongSelf.rightTextNode.updateLayout(CGSize(width: 100.0, height: 100.0))
                    let centerLeftTextSize = strongSelf.centerLeftTextNode.updateLayout(CGSize(width: 200.0, height: 100.0))
                    let centerRightTextSize = strongSelf.centerRightTextNode.updateLayout(CGSize(width: 200.0, height: 100.0))
                    let centerSpacing: CGFloat = 6.0
                    
                    let sideInset: CGFloat = 18.0
                    
                    strongSelf.leftTextNode.frame = CGRect(origin: CGPoint(x: params.leftInset + sideInset, y: 15.0), size: leftTextSize)
                    strongSelf.rightTextNode.frame = CGRect(origin: CGPoint(x: params.width - params.leftInset - sideInset - rightTextSize.width, y: 15.0), size: rightTextSize)
                    
                    let totalCenterWidth = centerLeftTextSize.width + centerSpacing + centerRightTextSize.width
                    let centerLeftFrame = CGRect(origin: CGPoint(x: floorToScreenPixels((params.width - totalCenterWidth) / 2.0), y: 11.0), size: centerLeftTextSize)
                    strongSelf.centerLeftTextNode.frame = centerLeftFrame
                    
                    let centerRightFrame = CGRect(origin: CGPoint(x: floorToScreenPixels((params.width - totalCenterWidth) / 2.0) + totalCenterWidth - centerRightTextSize.width, y: 14.0 - UIScreenPixel), size: centerRightTextSize)
                    strongSelf.centerRightTextNode.frame = centerRightFrame
                    
                    if let sliderView = strongSelf.sliderView {
                        if themeUpdated {
                            sliderView.backgroundColor = item.theme.list.itemBlocksBackgroundColor
                            sliderView.backColor = item.theme.list.itemSecondaryTextColor
                            sliderView.trackColor = item.theme.list.itemAccentColor.withAlphaComponent(0.45)
                            sliderView.knobImage = PresentationResourcesItemList.knobImage(item.theme)
                        }
                        
                        sliderView.frame = CGRect(origin: CGPoint(x: params.leftInset + 18.0, y: 36.0), size: CGSize(width: params.width - params.leftInset - params.rightInset - 18.0 * 2.0, height: 44.0))
                    }
                }
            })
        }
    }
    
    override func animateInsertion(_ currentTimestamp: Double, duration: Double, options: ListViewItemAnimationOptions) {
        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 sliderValueChanged() {
        guard let sliderView = self.sliderView else {
            return
        }
        var updatedAmount = self.amount.withSliderValue(Int(sliderView.value))
        if updatedAmount.realValue > 50 {
            if updatedAmount.realValue < 100 {
                updatedAmount = updatedAmount.withRealValue(Int(round(Double(updatedAmount.realValue) / 1.0) * 1.0))
            } else if updatedAmount.realValue < 500 {
                updatedAmount = updatedAmount.withRealValue(Int(round(Double(updatedAmount.realValue) / 5.0) * 5.0))
            } else if updatedAmount.realValue < 1000 {
                updatedAmount = updatedAmount.withRealValue(Int(round(Double(updatedAmount.realValue) / 10.0) * 10.0))
            } else if updatedAmount.realValue < 5000 {
                updatedAmount = updatedAmount.withRealValue(Int(round(Double(updatedAmount.realValue) / 25.0) * 25.0))
            } else {
                updatedAmount = updatedAmount.withRealValue(Int(round(Double(updatedAmount.realValue) / 50.0) * 50.0))
            }
        }
        self.amount = updatedAmount
        
        self.item?.updated(Int64(self.amount.realValue))
    }
}