import Foundation
import UIKit
import Photos
import Display
import AsyncDisplayKit
import SwiftSignalKit
import Postbox
import TelegramCore
import TelegramPresentationData
import TelegramUIPreferences
import PresentationDataUtils
import AccountContext
import ComponentFlow
import ViewControllerComponent
import MultilineTextComponent
import BalancedTextComponent
import BackButtonComponent
import ListSectionComponent
import ListActionItemComponent
import BundleIconComponent

final class BusinessSetupScreenComponent: Component {
    typealias EnvironmentType = ViewControllerComponentContainer.Environment
    
    let context: AccountContext

    init(
        context: AccountContext
    ) {
        self.context = context
    }

    static func ==(lhs: BusinessSetupScreenComponent, rhs: BusinessSetupScreenComponent) -> Bool {
        if lhs.context !== rhs.context {
            return false
        }

        return true
    }
    
    private final class ScrollView: UIScrollView {
        override func touchesShouldCancel(in view: UIView) -> Bool {
            return true
        }
    }
    
    final class View: UIView, UIScrollViewDelegate {
        private let topOverscrollLayer = SimpleLayer()
        private let scrollView: ScrollView
        
        private let navigationTitle = ComponentView<Empty>()
        private let title = ComponentView<Empty>()
        private let subtitle = ComponentView<Empty>()
        private let actionsSection = ComponentView<Empty>()
        
        private var isUpdating: Bool = false
        
        private var component: BusinessSetupScreenComponent?
        private(set) weak var state: EmptyComponentState?
        private var environment: EnvironmentType?
        
        override init(frame: CGRect) {
            self.scrollView = ScrollView()
            self.scrollView.showsVerticalScrollIndicator = true
            self.scrollView.showsHorizontalScrollIndicator = false
            self.scrollView.scrollsToTop = false
            self.scrollView.delaysContentTouches = false
            self.scrollView.canCancelContentTouches = true
            self.scrollView.contentInsetAdjustmentBehavior = .never
            if #available(iOS 13.0, *) {
                self.scrollView.automaticallyAdjustsScrollIndicatorInsets = false
            }
            self.scrollView.alwaysBounceVertical = true
            
            super.init(frame: frame)
            
            self.scrollView.delegate = self
            self.addSubview(self.scrollView)
            
            self.scrollView.layer.addSublayer(self.topOverscrollLayer)
        }
        
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
        
        deinit {
        }

        func scrollToTop() {
            self.scrollView.setContentOffset(CGPoint(), animated: true)
        }
        
        func attemptNavigation(complete: @escaping () -> Void) -> Bool {
            return true
        }
        
        func scrollViewDidScroll(_ scrollView: UIScrollView) {
            self.updateScrolling(transition: .immediate)
        }
        
        var scrolledUp = true
        private func updateScrolling(transition: Transition) {
            guard let environment = self.environment else {
                return
            }
            
            let navigationRevealOffsetY: CGFloat = -(environment.statusBarHeight + (environment.navigationHeight - environment.statusBarHeight) * 0.5) + (self.title.view?.frame.midY ?? 0.0)
            
            let navigationAlphaDistance: CGFloat = 16.0
            let navigationAlpha: CGFloat = max(0.0, min(1.0, (self.scrollView.contentOffset.y - navigationRevealOffsetY) / navigationAlphaDistance))
            if let controller = self.environment?.controller(), let navigationBar = controller.navigationBar {
                transition.setAlpha(layer: navigationBar.backgroundNode.layer, alpha: navigationAlpha)
                transition.setAlpha(layer: navigationBar.stripeNode.layer, alpha: navigationAlpha)
            }
            
            var scrolledUp = false
            if navigationAlpha < 0.5 {
                scrolledUp = true
            } else if navigationAlpha > 0.5 {
                scrolledUp = false
            }
            
            if self.scrolledUp != scrolledUp {
                self.scrolledUp = scrolledUp
                if !self.isUpdating {
                    self.state?.updated()
                }
            }
            
            if let navigationTitleView = self.navigationTitle.view {
                transition.setAlpha(view: navigationTitleView, alpha: navigationAlpha)
            }
        }
        
        func update(component: BusinessSetupScreenComponent, availableSize: CGSize, state: EmptyComponentState, environment: Environment<EnvironmentType>, transition: Transition) -> CGSize {
            self.isUpdating = true
            defer {
                self.isUpdating = false
            }
            
            let environment = environment[EnvironmentType.self].value
            let themeUpdated = self.environment?.theme !== environment.theme
            self.environment = environment
            
            self.component = component
            self.state = state
            
            if themeUpdated {
                self.backgroundColor = environment.theme.list.blocksBackgroundColor
            }
            
            let presentationData = component.context.sharedContext.currentPresentationData.with { $0 }
            
            //TODO:localize
            let navigationTitleSize = self.navigationTitle.update(
                transition: transition,
                component: AnyComponent(MultilineTextComponent(
                    text: .plain(NSAttributedString(string: "Telegram Business", font: Font.semibold(17.0), textColor: environment.theme.rootController.navigationBar.primaryTextColor)),
                    horizontalAlignment: .center
                )),
                environment: {},
                containerSize: CGSize(width: availableSize.width, height: 100.0)
            )
            let navigationTitleFrame = CGRect(origin: CGPoint(x: floor((availableSize.width - navigationTitleSize.width) / 2.0), y: environment.statusBarHeight + floor((environment.navigationHeight - environment.statusBarHeight - navigationTitleSize.height) / 2.0)), size: navigationTitleSize)
            if let navigationTitleView = self.navigationTitle.view {
                if navigationTitleView.superview == nil {
                    if let controller = self.environment?.controller(), let navigationBar = controller.navigationBar {
                        navigationBar.view.addSubview(navigationTitleView)
                    }
                }
                transition.setFrame(view: navigationTitleView, frame: navigationTitleFrame)
            }
            
            let bottomContentInset: CGFloat = 24.0
            let sideInset: CGFloat = 16.0 + environment.safeInsets.left
            let sectionSpacing: CGFloat = 32.0
            
            let _ = bottomContentInset
            let _ = sectionSpacing
            
            var contentHeight: CGFloat = 0.0
            
            contentHeight += environment.navigationHeight
            contentHeight += 16.0
            
            //TODO:localize
            let titleSize = self.title.update(
                transition: .immediate,
                component: AnyComponent(MultilineTextComponent(
                    text: .plain(NSAttributedString(string: "Telegram Business", font: Font.bold(29.0), textColor: environment.theme.list.itemPrimaryTextColor)),
                    horizontalAlignment: .center,
                    maximumNumberOfLines: 1
                )),
                environment: {},
                containerSize: CGSize(width: availableSize.width - sideInset * 2.0, height: 1000.0)
            )
            let titleFrame = CGRect(origin: CGPoint(x: floor((availableSize.width - titleSize.width) * 0.5), y: contentHeight), size: titleSize)
            if let titleView = self.title.view {
                if titleView.superview == nil {
                    self.scrollView.addSubview(titleView)
                }
                transition.setPosition(view: titleView, position: titleFrame.center)
                titleView.bounds = CGRect(origin: CGPoint(), size: titleFrame.size)
            }
            contentHeight += titleSize.height
            contentHeight += 17.0
            
            //TODO:localize
            let subtitleSize = self.subtitle.update(
                transition: .immediate,
                component: AnyComponent(BalancedTextComponent(
                    text: .plain(NSAttributedString(string: "You have now unlocked these additional business features.", font: Font.regular(15.0), textColor: environment.theme.list.itemPrimaryTextColor)),
                    horizontalAlignment: .center,
                    maximumNumberOfLines: 0,
                    lineSpacing: 0.25
                )),
                environment: {},
                containerSize: CGSize(width: availableSize.width - sideInset * 2.0, height: 1000.0)
            )
            let subtitleFrame = CGRect(origin: CGPoint(x: floor((availableSize.width - subtitleSize.width) * 0.5), y: contentHeight), size: subtitleSize)
            if let subtitleView = self.subtitle.view {
                if subtitleView.superview == nil {
                    self.scrollView.addSubview(subtitleView)
                }
                transition.setPosition(view: subtitleView, position: subtitleFrame.center)
                subtitleView.bounds = CGRect(origin: CGPoint(), size: subtitleFrame.size)
            }
            contentHeight += subtitleSize.height
            contentHeight += 21.0
            
            struct Item {
                var icon: String
                var title: String
                var subtitle: String
                var action: () -> Void
            }
            var items: [Item] = []
            //TODO:localize
            items.append(Item(
                icon: "Settings/Menu/AddAccount",
                title: "Location",
                subtitle: "Display the location of your business on your account.",
                action: { [weak self] in
                    guard let self else {
                        return
                    }
                    self.environment?.controller()?.push(component.context.sharedContext.makeBusinessLocationSetupScreen(context: component.context))
                }
            ))
            items.append(Item(
                icon: "Settings/Menu/DataVoice",
                title: "Opening Hours",
                subtitle: "Show to your customers when you are open for business.",
                action: { [weak self] in
                    guard let self else {
                        return
                    }
                    self.environment?.controller()?.push(component.context.sharedContext.makeBusinessHoursSetupScreen(context: component.context))
                }
            ))
            items.append(Item(
                icon: "Settings/Menu/Photos",
                title: "Quick Replies",
                subtitle: "Set up shortcuts with rich text and media to respond to messages faster.",
                action: { [weak self] in
                    guard let self, let component = self.component, let environment = self.environment else {
                        return
                    }
                    environment.controller()?.push(component.context.sharedContext.makeQuickReplySetupScreen(context: component.context))
                }
            ))
            items.append(Item(
                icon: "Settings/Menu/Stories",
                title: "Greeting Messages",
                subtitle: "Create greetings that will be automatically sent to new customers.",
                action: { [weak self] in
                    guard let self, let component = self.component, let environment = self.environment else {
                        return
                    }
                    environment.controller()?.push(component.context.sharedContext.makeGreetingMessageSetupScreen(context: component.context, isAwayMode: false))
                }
            ))
            items.append(Item(
                icon: "Settings/Menu/Trending",
                title: "Away Messages",
                subtitle: "Define messages that are automatically sent when you are off.",
                action: { [weak self] in
                    guard let self, let component = self.component, let environment = self.environment else {
                        return
                    }
                    environment.controller()?.push(component.context.sharedContext.makeGreetingMessageSetupScreen(context: component.context, isAwayMode: true))
                }
            ))
            items.append(Item(
                icon: "Settings/Menu/DataStickers",
                title: "Chatbots",
                subtitle: "Add any third-party chatbots that will process customer interactions.",
                action: { [weak self] in
                    guard let self, let component = self.component, let environment = self.environment else {
                        return
                    }
                    environment.controller()?.push(component.context.sharedContext.makeChatbotSetupScreen(context: component.context))
                }
            ))
            
            var actionsSectionItems: [AnyComponentWithIdentity<Empty>] = []
            for item in items {
                actionsSectionItems.append(AnyComponentWithIdentity(id: actionsSectionItems.count, component: AnyComponent(ListActionItemComponent(
                    theme: environment.theme,
                    title: AnyComponent(VStack([
                        AnyComponentWithIdentity(id: AnyHashable(0), component: AnyComponent(MultilineTextComponent(
                            text: .plain(NSAttributedString(
                                string: item.title,
                                font: Font.regular(presentationData.listsFontSize.baseDisplaySize),
                                textColor: environment.theme.list.itemPrimaryTextColor
                            )),
                            maximumNumberOfLines: 0
                        ))),
                        AnyComponentWithIdentity(id: AnyHashable(1), component: AnyComponent(MultilineTextComponent(
                            text: .plain(NSAttributedString(
                                string: item.subtitle,
                                font: Font.regular(floor(presentationData.listsFontSize.baseDisplaySize * 13.0 / 17.0)),
                                textColor: environment.theme.list.itemSecondaryTextColor
                            )),
                            maximumNumberOfLines: 0,
                            lineSpacing: 0.18
                        )))
                    ], alignment: .left, spacing: 2.0)),
                    leftIcon: AnyComponentWithIdentity(id: 0, component: AnyComponent(BundleIconComponent(
                        name: item.icon,
                        tintColor: nil
                    ))),
                    action: { _ in
                        item.action()
                    }
                ))))
            }
            
            let actionsSectionSize = self.actionsSection.update(
                transition: transition,
                component: AnyComponent(ListSectionComponent(
                    theme: environment.theme,
                    header: nil,
                    footer: nil,
                    items: actionsSectionItems
                )),
                environment: {},
                containerSize: CGSize(width: availableSize.width - sideInset * 2.0, height: 10000.0)
            )
            let actionsSectionFrame = CGRect(origin: CGPoint(x: sideInset, y: contentHeight), size: actionsSectionSize)
            if let actionsSectionView = self.actionsSection.view {
                if actionsSectionView.superview == nil {
                    self.scrollView.addSubview(actionsSectionView)
                }
                transition.setFrame(view: actionsSectionView, frame: actionsSectionFrame)
            }
            contentHeight += actionsSectionSize.height
            
            contentHeight += bottomContentInset
            contentHeight += environment.safeInsets.bottom
            
            let previousBounds = self.scrollView.bounds
            
            let contentSize = CGSize(width: availableSize.width, height: contentHeight)
            if self.scrollView.frame != CGRect(origin: CGPoint(), size: availableSize) {
                self.scrollView.frame = CGRect(origin: CGPoint(), size: availableSize)
            }
            if self.scrollView.contentSize != contentSize {
                self.scrollView.contentSize = contentSize
            }
            let scrollInsets = UIEdgeInsets(top: environment.navigationHeight, left: 0.0, bottom: 0.0, right: 0.0)
            if self.scrollView.scrollIndicatorInsets != scrollInsets {
                self.scrollView.scrollIndicatorInsets = scrollInsets
            }
                        
            if !previousBounds.isEmpty, !transition.animation.isImmediate {
                let bounds = self.scrollView.bounds
                if bounds.maxY != previousBounds.maxY {
                    let offsetY = previousBounds.maxY - bounds.maxY
                    transition.animateBoundsOrigin(view: self.scrollView, from: CGPoint(x: 0.0, y: offsetY), to: CGPoint(), additive: true)
                }
            }
            
            self.topOverscrollLayer.frame = CGRect(origin: CGPoint(x: 0.0, y: -3000.0), size: CGSize(width: availableSize.width, height: 3000.0))
            
            self.updateScrolling(transition: transition)
            
            return availableSize
        }
    }
    
    func makeView() -> View {
        return View()
    }
    
    func update(view: View, availableSize: CGSize, state: EmptyComponentState, environment: Environment<EnvironmentType>, transition: Transition) -> CGSize {
        return view.update(component: self, availableSize: availableSize, state: state, environment: environment, transition: transition)
    }
}

public final class BusinessSetupScreen: ViewControllerComponentContainer {
    private let context: AccountContext
    
    public init(context: AccountContext) {
        self.context = context
        
        super.init(context: context, component: BusinessSetupScreenComponent(
            context: context
        ), navigationBarAppearance: .default, theme: .default, updatedPresentationData: nil)
        
        let presentationData = context.sharedContext.currentPresentationData.with { $0 }
        self.title = ""
        self.navigationItem.backBarButtonItem = UIBarButtonItem(title: presentationData.strings.Common_Back, style: .plain, target: nil, action: nil)
        
        self.scrollToTop = { [weak self] in
            guard let self, let componentView = self.node.hostView.componentView as? BusinessSetupScreenComponent.View else {
                return
            }
            componentView.scrollToTop()
        }
        
        self.attemptNavigation = { [weak self] complete in
            guard let self, let componentView = self.node.hostView.componentView as? BusinessSetupScreenComponent.View else {
                return true
            }
            
            return componentView.attemptNavigation(complete: complete)
        }
    }
    
    required public init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    deinit {
    }
    
    @objc private func cancelPressed() {
        self.dismiss()
    }
    
    override public func containerLayoutUpdated(_ layout: ContainerViewLayout, transition: ContainedViewLayoutTransition) {
        super.containerLayoutUpdated(layout, transition: transition)
    }
}