Swiftgram/submodules/MediaPickerUI/Sources/MediaPickerScreen.swift

import Foundation
import UIKit
import Display
import AsyncDisplayKit
import Postbox
import TelegramCore
import SwiftSignalKit
import AccountContext
import TelegramPresentationData
import TelegramUIPreferences
import TelegramStringFormatting
import MergeLists
import Photos
import PhotosUI
import LegacyComponents
import LegacyMediaPickerUI
import AttachmentUI
import ContextUI
import WebSearchUI

final class MediaPickerInteraction {
    let openMedia: (PHFetchResult<PHAsset>, Int, UIImage?) -> Void
    let openSelectedMedia: (TGMediaSelectableItem, UIImage?) -> Void
    let toggleSelection: (TGMediaSelectableItem, Bool) -> Void
    let sendSelected: (TGMediaSelectableItem?, Bool, Int32?, Bool) -> Void
    let schedule: () -> Void
    let dismissInput: () -> Void
    let selectionState: TGMediaSelectionContext?
    let editingState: TGMediaEditingContext
    var hiddenMediaId: String?
    
    init(openMedia: @escaping (PHFetchResult<PHAsset>, Int, UIImage?) -> Void, openSelectedMedia: @escaping (TGMediaSelectableItem, UIImage?) -> Void, toggleSelection: @escaping (TGMediaSelectableItem, Bool) -> Void, sendSelected: @escaping (TGMediaSelectableItem?, Bool, Int32?, Bool) -> Void, schedule: @escaping  () -> Void, dismissInput: @escaping () -> Void, selectionState: TGMediaSelectionContext?, editingState: TGMediaEditingContext) {
        self.openMedia = openMedia
        self.openSelectedMedia = openSelectedMedia
        self.toggleSelection = toggleSelection
        self.sendSelected = sendSelected
        self.schedule = schedule
        self.dismissInput = dismissInput
        self.selectionState = selectionState
        self.editingState = editingState
    }
}

private struct MediaPickerGridEntry: Comparable, Identifiable {
    let stableId: Int
    let content: MediaPickerGridItemContent
    
    static func <(lhs: MediaPickerGridEntry, rhs: MediaPickerGridEntry) -> Bool {
        return lhs.stableId < rhs.stableId
    }
    
    func item(account: Account, interaction: MediaPickerInteraction, theme: PresentationTheme) -> MediaPickerGridItem {
        return MediaPickerGridItem(content: self.content, interaction: interaction, theme: theme)
    }
}

private struct MediaPickerGridTransaction {
    let deletions: [Int]
    let insertions: [GridNodeInsertItem]
    let updates: [GridNodeUpdateItem]
    let scrollToItem: GridNodeScrollToItem?
    
    init(previousList: [MediaPickerGridEntry], list: [MediaPickerGridEntry], account: Account, interaction: MediaPickerInteraction, theme: PresentationTheme, scrollToItem: GridNodeScrollToItem?) {
         let (deleteIndices, indicesAndItems, updateIndices) = mergeListsStableWithUpdates(leftList: previousList, rightList: list)
        
        self.deletions = deleteIndices
        self.insertions = indicesAndItems.map { GridNodeInsertItem(index: $0.0, item: $0.1.item(account: account, interaction: interaction, theme: theme), previousIndex: $0.2) }
        self.updates = updateIndices.map { GridNodeUpdateItem(index: $0.0, previousIndex: $0.2, item: $0.1.item(account: account, interaction: interaction, theme: theme)) }
        
        self.scrollToItem = scrollToItem
    }
}

public final class MediaPickerScreen: ViewController, AttachmentContainable {
    private let context: AccountContext
    private var presentationData: PresentationData
    private var presentationDataDisposable: Disposable?
    private let updatedPresentationData: (initial: PresentationData, signal: Signal<PresentationData, NoError>)?
    
    fileprivate var interaction: MediaPickerInteraction?
    
    private let peer: EnginePeer?
    private let chatLocation: ChatLocation?
    private let bannedSendMedia: (Int32, Bool)?
    private let collection: PHAssetCollection?
    
    private let titleView: MediaPickerTitleView
    private let moreButtonNode: MediaPickerMoreButtonNode
    
    public weak var webSearchController: WebSearchController?
    
    public var openCamera: ((TGAttachmentCameraView?) -> Void)?
    public var presentStickers: ((@escaping (TelegramMediaFile, Bool, UIView, CGRect) -> Void) -> TGPhotoPaintStickersScreen?)?
    public var presentSchedulePicker: (Bool, @escaping (Int32) -> Void) -> Void = { _, _ in }
    public var presentTimerPicker: (@escaping (Int32) -> Void) -> Void = { _ in }
    public var presentWebSearch: (MediaGroupsScreen) -> Void = { _ in }
    public var getCaptionPanelView: () -> TGCaptionPanelView? = { return nil }
    
    public var legacyCompletion: (_ signals: [Any], _ silently: Bool, _ scheduleTime: Int32?) -> Void = { _, _, _ in }
    
    public var requestAttachmentMenuExpansion: () -> Void = { }
    public var updateNavigationStack: (@escaping ([AttachmentContainable]) -> [AttachmentContainable]) -> Void = { _ in }
    public var updateTabBarAlpha: (CGFloat, ContainedViewLayoutTransition) -> Void  = { _, _ in }
    public var cancelPanGesture: () -> Void = { }
    
    private class Node: ViewControllerTracingNode, UIGestureRecognizerDelegate {
        enum DisplayMode {
            case all
            case selected
        }
        
        enum State {
            case noAccess(cameraAccess: AVAuthorizationStatus?)
            case assets(fetchResult: PHFetchResult<PHAsset>?, preload: Bool, mediaAccess: PHAuthorizationStatus, cameraAccess: AVAuthorizationStatus?)
        }
        
        private weak var controller: MediaPickerScreen?
        private var presentationData: PresentationData
        fileprivate let mediaAssetsContext: MediaAssetsContext
        
        private var requestedMediaAccess = false
        private var requestedCameraAccess = false
        
        private let containerNode: ASDisplayNode
        private let backgroundNode: NavigationBackgroundNode
        private let gridNode: GridNode
        fileprivate var cameraView: TGAttachmentCameraView?
        private var placeholderNode: MediaPickerPlaceholderNode?
        private var manageNode: MediaPickerManageNode?
        
        private var selectionNode: MediaPickerSelectedListNode?
        
        private var nextStableId: Int = 1
        private var currentEntries: [MediaPickerGridEntry] = []
        private var enqueuedTransactions: [MediaPickerGridTransaction] = []
        private var state: State?
        
        private var preloadPromise = ValuePromise<Bool>(true)
        
        private var itemsDisposable: Disposable?
        private var selectionChangedDisposable: Disposable?
        private var itemsDimensionsUpdatedDisposable: Disposable?
        private var hiddenMediaDisposable: Disposable?
        
        private let hiddenMediaId = Promise<String?>(nil)
        
        private var didSetReady = false
        private let _ready = Promise<Bool>()
        var ready: Promise<Bool> {
            return self._ready
        }
        
        private var validLayout: (ContainerViewLayout, CGFloat)?
        
        init(controller: MediaPickerScreen) {
            self.controller = controller
            self.presentationData = controller.presentationData
            
            let mediaAssetsContext = MediaAssetsContext()
            self.mediaAssetsContext = mediaAssetsContext
            
            self.containerNode = ASDisplayNode()
            self.backgroundNode = NavigationBackgroundNode(color: self.presentationData.theme.rootController.tabBar.backgroundColor)
            self.backgroundNode.backgroundColor = self.presentationData.theme.list.plainBackgroundColor
            self.gridNode = GridNode()

            super.init()
                        
            self.addSubnode(self.containerNode)
            self.containerNode.addSubnode(self.backgroundNode)
            self.containerNode.addSubnode(self.gridNode)
                         
            let collection = controller.collection
            let preloadPromise = self.preloadPromise
            let updatedState = combineLatest(mediaAssetsContext.mediaAccess(), mediaAssetsContext.cameraAccess())
            |> mapToSignal { mediaAccess, cameraAccess -> Signal<State, NoError> in
                if case .notDetermined = mediaAccess {
                    return .single(.assets(fetchResult: nil, preload: false, mediaAccess: mediaAccess, cameraAccess: cameraAccess))
                } else if [.restricted, .denied].contains(mediaAccess) {
                    return .single(.noAccess(cameraAccess: cameraAccess))
                } else {
                    if let collection = collection {
                        return combineLatest(mediaAssetsContext.fetchAssets(collection), preloadPromise.get())
                        |> map { fetchResult, preload in
                            return .assets(fetchResult: fetchResult, preload: preload, mediaAccess: mediaAccess, cameraAccess: cameraAccess)
                        }
                    } else {
                        return combineLatest(mediaAssetsContext.recentAssets(), preloadPromise.get())
                        |> map { fetchResult, preload in
                            return .assets(fetchResult: fetchResult, preload: preload, mediaAccess: mediaAccess, cameraAccess: cameraAccess)
                        }
                    }
                }
            }
            
            self.itemsDisposable = (updatedState
            |> deliverOnMainQueue).start(next: { [weak self] state in
                guard let strongSelf = self else {
                    return
                }
                strongSelf.updateState(state)
            })
            
            self.gridNode.scrollingInitiated = { [weak self] in
                self?.dismissInput()
            }
            
            self.gridNode.visibleContentOffsetChanged = { [weak self] _ in
                self?.updateNavigation(transition: .immediate)
            }
            
            self.hiddenMediaDisposable = (self.hiddenMediaId.get()
            |> deliverOnMainQueue).start(next: { [weak self] id in
                if let strongSelf = self {
                    strongSelf.controller?.interaction?.hiddenMediaId = id
                    
                    strongSelf.gridNode.forEachItemNode { itemNode in
                        if let itemNode = itemNode as? MediaPickerGridItemNode {
                            itemNode.updateHiddenMedia()
                        }
                    }
                    
                    strongSelf.selectionNode?.updateHiddenMedia()
                }
            })
            
            if let selectionState = self.controller?.interaction?.selectionState {
                func selectionChangedSignal(selectionState: TGMediaSelectionContext) -> Signal<Bool, NoError> {
                    return Signal { subscriber in
                        let disposable = selectionState.selectionChangedSignal()?.start(next: { next in
                            if let next = next as? TGMediaSelectionChange {
                                subscriber.putNext(next.animated)
                            }
                        }, completed: {})
                        return ActionDisposable {
                            disposable?.dispose()
                        }
                    }
                }
                
                self.selectionChangedDisposable = (selectionChangedSignal(selectionState: selectionState)
                |> deliverOnMainQueue).start(next: { [weak self] animated in
                    if let strongSelf = self {
                        strongSelf.updateSelectionState(animated: animated)
                    }
                })
            }
            
            if let editingState = self.controller?.interaction?.editingState {
                func itemsDimensionsUpdatedSignal(editingState: TGMediaEditingContext) -> Signal<Void, NoError> {
                    return Signal { subscriber in
                        let disposable = editingState.cropAdjustmentsUpdatedSignal()?.start(next: { next in
                            subscriber.putNext(Void())
                        }, completed: {})
                        return ActionDisposable {
                            disposable?.dispose()
                        }
                    }
                }
                
                self.itemsDimensionsUpdatedDisposable = (itemsDimensionsUpdatedSignal(editingState: editingState)
                |> deliverOnMainQueue).start(next: { [weak self] _ in
                    if let strongSelf = self {
                        strongSelf.updateSelectionState()
                    }
                })
            }
        }
        
        deinit {
            self.itemsDisposable?.dispose()
            self.hiddenMediaDisposable?.dispose()
            self.selectionChangedDisposable?.dispose()
            self.itemsDimensionsUpdatedDisposable?.dispose()
        }
        
        private var selectionGesture: MediaPickerGridSelectionGesture?
        override func didLoad() {
            super.didLoad()
            
            self.gridNode.scrollView.alwaysBounceVertical = true
            self.gridNode.scrollView.showsVerticalScrollIndicator = false
            
            if self.controller?.collection == nil {
                let cameraView = TGAttachmentCameraView(forSelfPortrait: false)!
                cameraView.clipsToBounds = true
                cameraView.removeCorners()
                cameraView.pressed = { [weak self] in
                    if let strongSelf = self, !strongSelf.openingMedia {
                        strongSelf.controller?.openCamera?(strongSelf.cameraView)
                    }
                }
                self.cameraView = cameraView
                cameraView.startPreview()
                
                self.gridNode.scrollView.addSubview(cameraView)
            } else {
                self.containerNode.clipsToBounds = true
            }
                    
            self.selectionGesture = MediaPickerGridSelectionGesture(target: nil, action: nil, gridNode: self.gridNode)
            self.selectionGesture?.delegate = self
            self.selectionGesture?.began = { [weak self] in
                self?.controller?.cancelPanGesture()
            }
            self.selectionGesture?.itemAt = { [weak self] point in
                if let strongSelf = self, let itemNode = strongSelf.gridNode.itemNodeAtPoint(point) as? MediaPickerGridItemNode, let asset = itemNode.asset.flatMap({ TGMediaAsset(phAsset: $0) }) {
                    return (asset, strongSelf.controller?.interaction?.selectionState?.isItemSelected(asset) ?? false)
                } else {
                    return nil
                }
            }
            self.selectionGesture?.updateSelection = { [weak self] asset, selected in
                if let strongSelf = self {
                    strongSelf.controller?.interaction?.selectionState?.setItem(asset, selected: selected, animated: true, sender: nil)
                }
            }
        }
        
        func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
            if otherGestureRecognizer.view is UIScrollView || otherGestureRecognizer is UIPanGestureRecognizer {
                return true
            } else {
                return false
            }
        }
                
        fileprivate func dismissInput() {
            self.view.window?.endEditing(true)
        }
        
        private func updateState(_ state: State) {
            guard let controller = self.controller, let interaction = controller.interaction else {
                return
            }
            
            let previousState = self.state
            self.state = state
            
            var stableId: Int = 0
            var entries: [MediaPickerGridEntry] = []
            
            var updateLayout = false
            
            switch state {
                case let .noAccess(cameraAccess):
                    if case .assets = previousState {
                        updateLayout = true
                    } else if case let .noAccess(previousCameraAccess) = previousState, previousCameraAccess != cameraAccess {
                        updateLayout = true
                    }
                    if case .notDetermined = cameraAccess, !self.requestedCameraAccess {
                        self.requestedCameraAccess = true
                        self.mediaAssetsContext.requestCameraAccess()
                    }
                case let .assets(fetchResult, preload, mediaAccess, cameraAccess):
                    if let fetchResult = fetchResult {
                        let totalCount = fetchResult.count
                        let count = preload ? min(10, totalCount) : totalCount
                        
                        for i in 0 ..< count {
                            entries.append(MediaPickerGridEntry(stableId: stableId, content: .asset(fetchResult, totalCount - i - 1)))
                            stableId += 1
                        }
                        
                        if case let .assets(previousFetchResult, _, _, previousCameraAccess) = previousState, previousFetchResult == nil || previousCameraAccess != cameraAccess {
                            updateLayout = true
                        }
                        
                        if case .notDetermined = cameraAccess, !self.requestedCameraAccess {
                            self.requestedCameraAccess = true
                            self.mediaAssetsContext.requestCameraAccess()
                        }
                    } else if case .notDetermined = mediaAccess, !self.requestedMediaAccess {
                        self.requestedMediaAccess = true
                        self.mediaAssetsContext.requestMediaAccess()
                    }
            }
        
            let previousEntries = self.currentEntries
            self.currentEntries = entries
            
            let transaction = MediaPickerGridTransaction(previousList: previousEntries, list: entries, account: controller.context.account, interaction: interaction, theme: self.presentationData.theme, scrollToItem: nil)
            self.enqueueTransaction(transaction)
            
            if updateLayout, let (layout, navigationBarHeight) = self.validLayout {
                self.containerLayoutUpdated(layout, navigationBarHeight: navigationBarHeight, transition: previousState == nil ? .immediate : .animated(duration: 0.2, curve: .easeInOut))
            }
            self.updateNavigation(transition: .immediate)
        }
        
        private func updateSelectionState(animated: Bool = false) {
            self.gridNode.forEachItemNode { itemNode in
                if let itemNode = itemNode as? MediaPickerGridItemNode {
                    itemNode.updateSelectionState(animated: animated)
                }
            }
            self.selectionNode?.updateSelectionState()
            
            let count = Int32(self.controller?.interaction?.selectionState?.count() ?? 0)
            self.controller?.updateSelectionState(count: count)
            
            if let (layout, navigationBarHeight) = self.validLayout {
                self.containerLayoutUpdated(layout, navigationBarHeight: navigationBarHeight, transition: .animated(duration: 0.3, curve: .spring))
            }
        }
        
        func updatePresentationData(_ presentationData: PresentationData) {
            self.presentationData = presentationData
            
            self.backgroundNode.backgroundColor = self.presentationData.theme.list.plainBackgroundColor
            self.backgroundNode.updateColor(color: self.presentationData.theme.rootController.tabBar.backgroundColor, transition: .immediate)
        }
        
        private var currentDisplayMode: DisplayMode = .all
        func updateMode(_ displayMode: DisplayMode) {
            let updated = self.currentDisplayMode != displayMode
            self.currentDisplayMode = displayMode
            
            if case .selected = displayMode, self.selectionNode == nil, let controller = self.controller {
                let selectionNode = MediaPickerSelectedListNode(context: controller.context)
                selectionNode.layer.allowsGroupOpacity = true
                selectionNode.alpha = 0.0
                selectionNode.isUserInteractionEnabled = false
                selectionNode.interaction = self.controller?.interaction
                self.containerNode.insertSubnode(selectionNode, aboveSubnode: self.gridNode)
                self.selectionNode = selectionNode
                
                if let (layout, navigationBarHeight) = self.validLayout {
                    self.containerLayoutUpdated(layout, navigationBarHeight: navigationBarHeight, transition: .immediate)
                }
            }
            
            let transition = ContainedViewLayoutTransition.animated(duration: 0.2, curve: .easeInOut)
            self.gridNode.isUserInteractionEnabled = displayMode == .all
            
            var completion: () -> Void = {}
            if updated && displayMode == .all {
                completion = {
                    self.updateNavigation(transition: .animated(duration: 0.1, curve: .easeInOut))
                }
            }
            
            if let selectionNode = self.selectionNode {
                transition.updateAlpha(node: selectionNode, alpha: displayMode == .selected ? 1.0 : 0.0, completion: { _ in
                    completion()
                })
                selectionNode.isUserInteractionEnabled = displayMode == .selected
            }
            
            if updated && displayMode == .selected {
                self.updateNavigation(transition: .immediate)
            }
        }
        
        var openingMedia = false
        fileprivate func openMedia(fetchResult: PHFetchResult<PHAsset>, index: Int, immediateThumbnail: UIImage?) {
            guard let controller = self.controller, let interaction = controller.interaction, let (layout, _) = self.validLayout, !self.openingMedia else {
                return
            }
            Queue.mainQueue().justDispatch {
                self.dismissInput()
            }
            
            var hasTimer = false
            if controller.chatLocation?.peerId != controller.context.account.peerId && controller.chatLocation?.peerId.namespace == Namespaces.Peer.CloudUser {
                hasTimer = true
            }
            
            self.openingMedia = true
            let index = fetchResult.count - index - 1
            presentLegacyMediaPickerGallery(context: controller.context, peer: controller.peer, chatLocation: controller.chatLocation, presentationData: self.presentationData, source: .fetchResult(fetchResult: fetchResult, index: index), immediateThumbnail: immediateThumbnail, selectionContext: interaction.selectionState, editingContext: interaction.editingState, hasSilentPosting: true, hasSchedule: true, hasTimer: hasTimer, updateHiddenMedia: { [weak self] id in
                self?.hiddenMediaId.set(.single(id))
            }, initialLayout: layout, transitionHostView: { [weak self] in
                return self?.gridNode.view
            }, transitionView: { [weak self] identifier in
                return self?.transitionView(for: identifier)
            }, completed: { [weak self] result, silently, scheduleTime in
                if let strongSelf = self {
                    strongSelf.controller?.interaction?.sendSelected(result, silently, scheduleTime, false)
                }
            }, presentStickers: controller.presentStickers, presentSchedulePicker: controller.presentSchedulePicker, presentTimerPicker: controller.presentTimerPicker, getCaptionPanelView: controller.getCaptionPanelView, present: { [weak self] c, a in
                self?.controller?.present(c, in: .window(.root), with: a)
            }, finishedTransitionIn: {
                self.openingMedia = false
            })
        }
        
        fileprivate func openSelectedMedia(item: TGMediaSelectableItem, immediateThumbnail: UIImage?) {
            guard let controller = self.controller, let interaction = controller.interaction, let (layout, _) = self.validLayout, !self.openingMedia else {
                return
            }
            Queue.mainQueue().justDispatch {
                self.dismissInput()
            }
            
            var hasTimer = false
            if controller.chatLocation?.peerId != controller.context.account.peerId && controller.chatLocation?.peerId.namespace == Namespaces.Peer.CloudUser {
                hasTimer = true
            }
            
            self.openingMedia = true
            presentLegacyMediaPickerGallery(context: controller.context, peer: controller.peer, chatLocation: controller.chatLocation, presentationData: self.presentationData, source: .selection(item: item), immediateThumbnail: immediateThumbnail, selectionContext: interaction.selectionState, editingContext: interaction.editingState, hasSilentPosting: true, hasSchedule: true, hasTimer: hasTimer, updateHiddenMedia: { [weak self] id in
                self?.hiddenMediaId.set(.single(id))
            }, initialLayout: layout, transitionHostView: { [weak self] in
                return self?.selectionNode?.view
            }, transitionView: { [weak self] identifier in
                return self?.transitionView(for: identifier)
            }, completed: { [weak self] result, silently, scheduleTime in
                if let strongSelf = self {
                    strongSelf.controller?.interaction?.sendSelected(result, silently, scheduleTime, false)
                }
            }, presentStickers: controller.presentStickers, presentSchedulePicker: controller.presentSchedulePicker, presentTimerPicker: controller.presentTimerPicker, getCaptionPanelView: controller.getCaptionPanelView, present: { [weak self] c, a in
                self?.controller?.present(c, in: .window(.root), with: a, blockInteraction: true)
            }, finishedTransitionIn: {
                self.openingMedia = false
            })
        }
        
        fileprivate func send(asFile: Bool = false, silently: Bool, scheduleTime: Int32?, animated: Bool) {
            var hasHeic = false
            let allItems = self.controller?.interaction?.selectionState?.selectedItems() ?? []
            for item in allItems {
                if item is TGCameraCapturedVideo {
                } else if let asset = item as? TGMediaAsset, asset.uniformTypeIdentifier.contains("heic") {
                    hasHeic = true
                    break
                }
            }
            
            let proceed: (Bool) -> Void = { convertToJpeg in
                guard let signals = TGMediaAssetsController.resultSignals(for: self.controller?.interaction?.selectionState, editingContext: self.controller?.interaction?.editingState, intent: asFile ? TGMediaAssetsControllerSendFileIntent : TGMediaAssetsControllerSendMediaIntent, currentItem: nil, storeAssets: true, convertToJpeg: false, descriptionGenerator: legacyAssetPickerItemGenerator(), saveEditedPhotos: true) else {
                    return
                }
                self.controller?.legacyCompletion(signals, silently, scheduleTime)
                self.controller?.dismiss(animated: animated)
            }
            
            if asFile && hasHeic {
                self.controller?.present(standardTextAlertController(theme: AlertControllerTheme(presentationData: self.presentationData), title: nil, text: self.presentationData.strings.MediaPicker_JpegConversionText, actions: [TextAlertAction(type: .defaultAction, title: self.presentationData.strings.MediaPicker_KeepHeic, action: {
                    proceed(false)
                }), TextAlertAction(type: .genericAction, title: self.presentationData.strings.MediaPicker_ConvertToJpeg, action: {
                    proceed(true)
                })], actionLayout: .vertical), in: .window(.root))
            } else {
                proceed(false)
            }
        }
        
        private func openLimitedMediaOptions() {
            let presentationData = self.presentationData
            let controller = ActionSheetController(presentationData: self.presentationData)
            let dismissAction: () -> Void = { [weak controller] in
                controller?.dismissAnimated()
            }
            controller.setItemGroups([
                ActionSheetItemGroup(items: [
                    ActionSheetButtonItem(title: presentationData.strings.Media_LimitedAccessSelectMore, color: .accent, action: { [weak self] in
                        dismissAction()
                        if #available(iOS 14.0, *), let strongController = self?.controller {
                            PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: strongController)
                        }
                    }),
                    ActionSheetButtonItem(title: presentationData.strings.Media_LimitedAccessChangeSettings, color: .accent, action: { [weak self] in
                        dismissAction()
                        self?.controller?.context.sharedContext.applicationBindings.openSettings()
                    })
                ]),
                ActionSheetItemGroup(items: [ActionSheetButtonItem(title: presentationData.strings.Common_Cancel, action: { dismissAction() })])
            ])
            self.controller?.present(controller, in: .window(.root))
        }
        
        private func transitionView(for identifier: String) -> UIView? {
            if let selectionNode = self.selectionNode, selectionNode.alpha > 0.0 {
                return selectionNode.transitionView(for: identifier)
            } else {
                var transitionNode: MediaPickerGridItemNode?
                self.gridNode.forEachItemNode { itemNode in
                    if let itemNode = itemNode as? MediaPickerGridItemNode, itemNode.identifier == identifier {
                        transitionNode = itemNode
                    }
                }
                return transitionNode?.transitionView()
            }
        }
        
        private func enqueueTransaction(_ transaction: MediaPickerGridTransaction) {
            self.enqueuedTransactions.append(transaction)
            
            if let _ = self.validLayout {
                self.dequeueTransaction()
            }
        }
        
        private func dequeueTransaction() {
            if self.enqueuedTransactions.isEmpty {
                return
            }
            let transaction = self.enqueuedTransactions.removeFirst()
            self.gridNode.transaction(GridNodeTransaction(deleteItems: transaction.deletions, insertItems: transaction.insertions, updateItems: transaction.updates, scrollToItem: transaction.scrollToItem, updateLayout: nil, itemTransition: .immediate, stationaryItems: .none, updateFirstIndexInSectionOffset: nil), completion: { _ in })
        }
        
        func scrollToTop(animated: Bool = false) {
            if let selectionNode = self.selectionNode, selectionNode.alpha > 0.0 {
                selectionNode.scrollToTop(animated: animated)
            } else {
                self.gridNode.scrollView.setContentOffset(CGPoint(x: 0.0, y: -self.gridNode.scrollView.contentInset.top), animated: animated)
            }
        }
        
        private var previousContentOffset: GridNodeVisibleContentOffset?
        
        func updateNavigation(transition: ContainedViewLayoutTransition) {
            if let selectionNode = self.selectionNode, selectionNode.alpha > 0.0 {
                self.controller?.navigationBar?.updateBackgroundAlpha(1.0, transition: .immediate)
                self.controller?.updateTabBarAlpha(1.0, transition)
            } else if self.placeholderNode != nil {
                self.controller?.navigationBar?.updateBackgroundAlpha(0.0, transition: .immediate)
                self.controller?.updateTabBarAlpha(0.0, transition)
            } else {
                var previousContentOffsetValue: CGFloat?
                if let previousContentOffset = self.previousContentOffset, case let .known(value) = previousContentOffset {
                    previousContentOffsetValue = value
                }
                
                let offset = self.gridNode.visibleContentOffset()
                switch offset {
                    case let .known(value):
                        let transition: ContainedViewLayoutTransition
                        if let previousContentOffsetValue = previousContentOffsetValue, value <= 0.0, previousContentOffsetValue > 2.0 {
                            transition = .animated(duration: 0.2, curve: .easeInOut)
                        } else {
                            transition = .immediate
                        }
                        self.controller?.navigationBar?.updateBackgroundAlpha(min(2.0, value) / 2.0, transition: transition)
                    case .unknown, .none:
                        self.controller?.navigationBar?.updateBackgroundAlpha(1.0, transition: .immediate)
                }
            }
            
            let count = Int32(self.controller?.interaction?.selectionState?.count() ?? 0)
            if count > 0 {
                self.controller?.updateTabBarAlpha(1.0, transition)
            }
        }
        
        func containerLayoutUpdated(_ layout: ContainerViewLayout, navigationBarHeight: CGFloat, transition: ContainedViewLayoutTransition) {
            let firstTime = self.validLayout == nil
            self.validLayout = (layout, navigationBarHeight)
            
            var insets = layout.insets(options: [])
            insets.top += navigationBarHeight
            
            let overflowInset: CGFloat = 70.0
            let bounds = CGRect(origin: CGPoint(), size: CGSize(width: layout.size.width, height: layout.size.height))
            let innerBounds = CGRect(origin: CGPoint(x: -overflowInset, y: 0.0), size: CGSize(width: layout.size.width, height: layout.size.height))
            
            let itemsPerRow: Int
            if case .compact = layout.metrics.widthClass {
                self._ready.set(.single(true))
                switch layout.orientation {
                    case .portrait:
                        itemsPerRow = 3
                    case .landscape:
                        itemsPerRow = 5
                }
            } else {
                itemsPerRow = 3
            }
            let width = layout.size.width - layout.safeInsets.left - layout.safeInsets.right
            let itemSpacing: CGFloat = 1.0
            let itemWidth = floorToScreenPixels((width - itemSpacing * CGFloat(itemsPerRow - 1)) / CGFloat(itemsPerRow))
            
            var cameraRect: CGRect? = CGRect(origin: CGPoint(x: layout.safeInsets.left, y: 0.0), size: CGSize(width: itemWidth, height: itemWidth * 2.0 + 1.0))
            if self.cameraView == nil {
                cameraRect = nil
            }
            
            var manageHeight: CGFloat = 0.0
            if case let .assets(_, _, mediaAccess, cameraAccess) = self.state {
                if cameraAccess == nil {
                    cameraRect = nil
                }
                if let (untilDate, personal) = self.controller?.bannedSendMedia {
                    self.gridNode.isHidden = true
                    
                    let banDescription: String
                    if untilDate != 0 && untilDate != Int32.max {
                        banDescription = self.presentationData.strings.Conversation_RestrictedMediaTimed(stringForFullDate(timestamp: untilDate, strings: self.presentationData.strings, dateTimeFormat: self.presentationData.dateTimeFormat)).string
                    } else if personal {
                        banDescription = self.presentationData.strings.Conversation_RestrictedMedia
                    } else {
                        banDescription = self.presentationData.strings.Conversation_DefaultRestrictedMedia
                    }
                    
                    var placeholderTransition = transition
                    let placeholderNode: MediaPickerPlaceholderNode
                    if let current = self.placeholderNode {
                        placeholderNode = current
                    } else {
                        placeholderNode = MediaPickerPlaceholderNode(content: .bannedSendMedia(banDescription))
                        self.containerNode.insertSubnode(placeholderNode, aboveSubnode: self.gridNode)
                        self.placeholderNode = placeholderNode
                        
                        placeholderTransition = .immediate
                    }
                    placeholderNode.update(layout: layout, theme: self.presentationData.theme, strings: self.presentationData.strings, hasCamera: false, transition: placeholderTransition)
                    placeholderTransition.updateFrame(node: placeholderNode, frame: innerBounds)
                    
                    self.updateNavigation(transition: .immediate)
                } else if case .notDetermined = mediaAccess {
                    
                } else {
                    if case .limited = mediaAccess {
                        let manageNode: MediaPickerManageNode
                        if let current = self.manageNode {
                            manageNode = current
                        } else {
                            manageNode = MediaPickerManageNode()
                            manageNode.pressed = { [weak self] in
                                if let strongSelf = self {
                                    strongSelf.openLimitedMediaOptions()
                                }
                            }
                            self.manageNode = manageNode
                            self.gridNode.addSubnode(manageNode)
                        }
                        manageHeight = manageNode.update(layout: layout, theme: self.presentationData.theme, strings: self.presentationData.strings, subject: .limitedMedia, transition: transition)
                        transition.updateFrame(node: manageNode, frame: CGRect(origin: CGPoint(x: 0.0, y: -manageHeight), size: CGSize(width: layout.size.width, height: manageHeight)))
                    } else if [.denied, .restricted].contains(cameraAccess) {
                        cameraRect = nil
                        
                        let manageNode: MediaPickerManageNode
                        if let current = self.manageNode {
                            manageNode = current
                        } else {
                            manageNode = MediaPickerManageNode()
                            manageNode.pressed = { [weak self] in
                                self?.controller?.context.sharedContext.applicationBindings.openSettings()
                            }
                            self.manageNode = manageNode
                            self.gridNode.addSubnode(manageNode)
                        }
                        manageHeight = manageNode.update(layout: layout, theme: self.presentationData.theme, strings: self.presentationData.strings, subject: .camera, transition: transition)
                        transition.updateFrame(node: manageNode, frame: CGRect(origin: CGPoint(x: 0.0, y: -manageHeight), size: CGSize(width: layout.size.width, height: manageHeight)))
                    } else if let manageNode = self.manageNode {
                        self.manageNode = nil
                        manageNode.removeFromSupernode()
                    }
                }
            } else {
                cameraRect = nil
            }
            
            let cleanGridInsets = UIEdgeInsets(top: insets.top, left: layout.safeInsets.left, bottom: layout.intrinsicInsets.bottom, right: layout.safeInsets.right)
            let gridInsets = UIEdgeInsets(top: insets.top + manageHeight, left: layout.safeInsets.left, bottom: layout.intrinsicInsets.bottom, right: layout.safeInsets.right)
            transition.updateFrame(node: self.gridNode, frame: innerBounds)
            
            transition.updateFrame(node: self.backgroundNode, frame: innerBounds)
            self.backgroundNode.update(size: bounds.size, transition: transition)
            
            transition.updateFrame(node: self.containerNode, frame: CGRect(origin: CGPoint(x: overflowInset, y: 0.0), size: CGSize(width: bounds.width - overflowInset * 2.0, height: bounds.height)))
            
            self.gridNode.transaction(GridNodeTransaction(deleteItems: [], insertItems: [], updateItems: [], scrollToItem: nil, updateLayout: GridNodeUpdateLayout(layout: GridNodeLayout(size: bounds.size, insets: gridInsets, scrollIndicatorInsets: nil, preloadSize: itemWidth, type: .fixed(itemSize: CGSize(width: itemWidth, height: itemWidth), fillWidth: true, lineSpacing: itemSpacing, itemSpacing: itemSpacing), cutout: cameraRect), transition: transition), itemTransition: .immediate, stationaryItems: .none, updateFirstIndexInSectionOffset: nil, updateOpaqueState: nil, synchronousLoads: false), completion: { [weak self] _ in
                guard let strongSelf = self else {
                    return
                }
                if !strongSelf.didSetReady && strongSelf.state != nil {
                    strongSelf.didSetReady = true
                    Queue.mainQueue().justDispatch {
                        strongSelf._ready.set(.single(true))
                        
                        Queue.mainQueue().after(0.5, {
                            strongSelf.preloadPromise.set(false)
                        })
                    }
                }
            })
            
            if let selectionNode = self.selectionNode {
                let selectedItems = self.controller?.interaction?.selectionState?.selectedItems() as? [TGMediaSelectableItem] ?? []
                let updateSelectionNode = {
                    selectionNode.updateLayout(size: bounds.size, insets: cleanGridInsets, items: selectedItems, grouped: self.controller?.groupedValue ?? true, theme: self.presentationData.theme, wallpaper: self.presentationData.chatWallpaper, bubbleCorners: self.presentationData.chatBubbleCorners, transition: transition)
                }
                
                if selectedItems.count < 1 && self.currentDisplayMode == .selected {
                    self.updateMode(.all)
                    Queue.mainQueue().after(0.3, updateSelectionNode)
                } else {
                    updateSelectionNode()
                }
                transition.updateFrame(node: selectionNode, frame: innerBounds)
            }
            
            if let cameraView = self.cameraView {
                if let cameraRect = cameraRect {
                    transition.updateFrame(view: cameraView, frame: cameraRect)
                    cameraView.isHidden = false
                } else {
                    cameraView.isHidden = true
                }
            }
            
            if firstTime {
                while !self.enqueuedTransactions.isEmpty {
                    self.dequeueTransaction()
                }
            }
            
            if case let .noAccess(cameraAccess) = self.state {
                var placeholderTransition = transition
                let placeholderNode: MediaPickerPlaceholderNode
                if let current = self.placeholderNode {
                    placeholderNode = current
                } else {
                    placeholderNode = MediaPickerPlaceholderNode(content: .intro)
                    placeholderNode.settingsPressed = { [weak self] in
                        self?.controller?.context.sharedContext.applicationBindings.openSettings()
                    }
                    placeholderNode.cameraPressed = { [weak self] in
                        self?.controller?.openCamera?(nil)
                    }
                    self.containerNode.insertSubnode(placeholderNode, aboveSubnode: self.gridNode)
                    self.placeholderNode = placeholderNode
                    
                    if transition.isAnimated {
                        placeholderNode.layer.animateAlpha(from: 0.0, to: 1.0, duration: 0.3)
                    }
                    placeholderTransition = .immediate
                    
                    self.updateNavigation(transition: .immediate)
                }
                placeholderNode.update(layout: layout, theme: self.presentationData.theme, strings: self.presentationData.strings, hasCamera: cameraAccess == .authorized, transition: placeholderTransition)
                placeholderTransition.updateFrame(node: placeholderNode, frame: innerBounds)
            } else if let placeholderNode = self.placeholderNode, self.controller?.bannedSendMedia == nil {
                self.placeholderNode = nil
                placeholderNode.removeFromSupernode()
            }
        }
    }
    
    private var validLayout: ContainerViewLayout?
    
    private var controllerNode: Node {
        return self.displayNode as! Node
    }
    
    private let _ready = Promise<Bool>()
    override public var ready: Promise<Bool> {
        return self._ready
    }
    
    private var groupedValue: Bool = true {
        didSet {
            self.groupedPromise.set(self.groupedValue)
            self.interaction?.selectionState?.grouping = self.groupedValue
            
            if let layout = self.validLayout {
                self.containerLayoutUpdated(layout, transition: .immediate)
            }
        }
    }
    private let groupedPromise = ValuePromise<Bool>(true)
    
    public init(context: AccountContext, updatedPresentationData: (initial: PresentationData, signal: Signal<PresentationData, NoError>)? = nil, peer: EnginePeer?, chatLocation: ChatLocation?, bannedSendMedia: (Int32, Bool)?, collection: PHAssetCollection? = nil, editingContext: TGMediaEditingContext? = nil, selectionContext: TGMediaSelectionContext? = nil) {
        self.context = context
        
        let presentationData = updatedPresentationData?.initial ?? context.sharedContext.currentPresentationData.with { $0 }
        self.presentationData = presentationData
        self.updatedPresentationData = updatedPresentationData
        self.peer = peer
        self.chatLocation = chatLocation
        self.bannedSendMedia = bannedSendMedia
        self.collection = collection
        
        self.titleView = MediaPickerTitleView(theme: self.presentationData.theme, segments: [self.presentationData.strings.Attachment_AllMedia, self.presentationData.strings.Attachment_SelectedMedia(1)], selectedIndex: 0)
        self.titleView.title = collection?.localizedTitle ?? presentationData.strings.Attachment_Gallery
        
        self.moreButtonNode = MediaPickerMoreButtonNode(theme: self.presentationData.theme)
                
        super.init(navigationBarPresentationData: NavigationBarPresentationData(presentationData: presentationData))
        
        self.statusBar.statusBarStyle = .Ignore
        
        self.presentationDataDisposable = ((updatedPresentationData?.signal ?? context.sharedContext.presentationData)
        |> deliverOnMainQueue).start(next: { [weak self] presentationData in
            if let strongSelf = self {
                let previousTheme = strongSelf.presentationData.theme
                let previousStrings = strongSelf.presentationData.strings
                
                strongSelf.presentationData = presentationData
                
                if previousTheme !== presentationData.theme || previousStrings !== presentationData.strings {
                    strongSelf.updateThemeAndStrings()
                }
            }
        })
        
        self.titleView.indexUpdated = { [weak self] index in
            if let strongSelf = self {
                strongSelf.controllerNode.updateMode(index == 0 ? .all : .selected)
            }
        }
        
        self.navigationItem.titleView = self.titleView
        
        if collection == nil {
            self.navigationItem.leftBarButtonItem = UIBarButtonItem(title: self.presentationData.strings.Common_Cancel, style: .plain, target: self, action: #selector(self.cancelPressed))
            self.navigationItem.rightBarButtonItem = UIBarButtonItem(customDisplayNode: self.moreButtonNode)
            self.navigationItem.rightBarButtonItem?.action = #selector(self.rightButtonPressed)
            self.navigationItem.rightBarButtonItem?.target = self
        } else {
            self.navigationItem.leftBarButtonItem = UIBarButtonItem(backButtonAppearanceWithTitle: self.presentationData.strings.Common_Back, target: self, action: #selector(self.backPressed))
        }
        
        self.moreButtonNode.action = { [weak self] _, gesture in
            if let strongSelf = self {
                strongSelf.searchOrMorePressed(node: strongSelf.moreButtonNode.contextSourceNode, gesture: gesture)
            }
        }
        
        self.scrollToTop = { [weak self] in
            if let strongSelf = self {
                if let webSearchController = strongSelf.webSearchController {
                    webSearchController.scrollToTop?()
                } else {
                    strongSelf.controllerNode.scrollToTop(animated: true)
                }
            }
        }
        
        self.scrollToTopWithTabBar = { [weak self] in
            if let strongSelf = self {
                if let webSearchController = strongSelf.webSearchController {
                    webSearchController.cancel()
                } else {
                    strongSelf.scrollToTop?()
                }
            }
        }
        
        self.interaction = MediaPickerInteraction(openMedia: { [weak self] fetchResult, index, immediateThumbnail in
            self?.controllerNode.openMedia(fetchResult: fetchResult, index: index, immediateThumbnail: immediateThumbnail)
        }, openSelectedMedia: { [weak self] item, immediateThumbnail in
            self?.controllerNode.openSelectedMedia(item: item, immediateThumbnail: immediateThumbnail)
        }, toggleSelection: { [weak self] item, value in
            if let strongSelf = self {
                strongSelf.interaction?.selectionState?.setItem(item, selected: value)
            }
        }, sendSelected: { [weak self] currentItem, silently, scheduleTime, animated in
            if let strongSelf = self, let selectionState = strongSelf.interaction?.selectionState {
                if let currentItem = currentItem {
                    selectionState.setItem(currentItem, selected: true)
                }
                strongSelf.controllerNode.send(silently: silently, scheduleTime: scheduleTime, animated: animated)
            }
        }, schedule: { [weak self] in
            if let strongSelf = self {
                strongSelf.presentSchedulePicker(false, { [weak self] time in
                    self?.interaction?.sendSelected(nil, false, time, true)
                })
            }
        }, dismissInput: { [weak self] in
            if let strongSelf = self {
                strongSelf.controllerNode.dismissInput()
            }
        }, selectionState: selectionContext ?? TGMediaSelectionContext(), editingState: editingContext ?? TGMediaEditingContext())
        self.interaction?.selectionState?.grouping = true
    }
    
    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    deinit {
        self.presentationDataDisposable?.dispose()
    }
    
    override public func loadDisplayNode() {
        self.displayNode = Node(controller: self)
        
        self._ready.set(self.controllerNode.ready.get())
        
        super.displayNodeDidLoad()
    }
    
    private var selectionCount: Int32 = 0
    fileprivate func updateSelectionState(count: Int32) {
        self.selectionCount = count
        if count > 0 {
            self.titleView.segments = [self.presentationData.strings.Attachment_AllMedia, self.presentationData.strings.Attachment_SelectedMedia(count)]
            self.titleView.segmentsHidden = false
            self.moreButtonNode.iconNode.enqueueState(.more, animated: true)
        } else {
            self.titleView.segmentsHidden = true
            self.moreButtonNode.iconNode.enqueueState(.search, animated: true)
            
            if self.titleView.index != 0 {
                Queue.mainQueue().after(0.3) {
                    self.titleView.index = 0
                }
            }
        }
    }
    
    private func updateThemeAndStrings() {
        self.navigationBar?.updatePresentationData(NavigationBarPresentationData(presentationData: self.presentationData))
        self.titleView.theme = self.presentationData.theme
        self.moreButtonNode.theme = self.presentationData.theme
        self.controllerNode.updatePresentationData(self.presentationData)
    }
    
    @objc private func backPressed() {
        self.updateNavigationStack { current in
            return current.filter { $0 !== self }
        }
    }
    
    @objc private func cancelPressed() {
        self.dismiss()
    }
    
    @objc private func rightButtonPressed() {
        self.moreButtonNode.action?(self.moreButtonNode.contextSourceNode, nil)
    }
    
    public func resetForReuse() {
        if let webSearchController = self.webSearchController {
            self.webSearchController = nil
            webSearchController.dismiss()
        }
        self.scrollToTop?()
        
        self.controllerNode.cameraView?.pausePreview()
    }
    
    public func prepareForReuse() {
        self.controllerNode.cameraView?.resumePreview()
        
        Queue.mainQueue().after(0.2, {
            self.controllerNode.updateNavigation(transition: .animated(duration: 0.15, curve: .easeInOut))
        })
    }
    
    @objc private func searchOrMorePressed(node: ContextReferenceContentNode, gesture: ContextGesture?) {
        switch self.moreButtonNode.iconNode.iconState {
            case .search:
                self.requestAttachmentMenuExpansion()
            self.presentWebSearch(MediaGroupsScreen(context: self.context, updatedPresentationData: self.updatedPresentationData, mediaAssetsContext: self.controllerNode.mediaAssetsContext, openGroup: { [weak self] collection in
                if let strongSelf = self {
                    if let webSearchController = strongSelf.webSearchController {
                        strongSelf.webSearchController = nil
                        if collection.assetCollectionSubtype != .smartAlbumUserLibrary {
                            Queue.mainQueue().after(0.5) {
                                webSearchController.cancel()
                            }
                        } else {
                            webSearchController.cancel()
                        }
                    }
                    if collection.assetCollectionSubtype != .smartAlbumUserLibrary {
                        let mediaPicker = MediaPickerScreen(context: strongSelf.context, updatedPresentationData: strongSelf.updatedPresentationData, peer: strongSelf.peer, chatLocation: strongSelf.chatLocation, bannedSendMedia: strongSelf.bannedSendMedia, collection: collection, editingContext: strongSelf.interaction?.editingState, selectionContext: strongSelf.interaction?.selectionState)
                        mediaPicker._presentedInModal = true
                        mediaPicker.updateNavigationStack = strongSelf.updateNavigationStack
                        strongSelf.updateNavigationStack({ _ in return [strongSelf, mediaPicker]})
                    }
                }
            }))
            case .more:
                let strings = self.presentationData.strings
                let selectionCount = self.selectionCount
            
                let items: Signal<ContextController.Items, NoError>  = self.groupedPromise.get()
                |> deliverOnMainQueue
                |> map { [weak self] grouped -> ContextController.Items in
                    var items: [ContextMenuItem] = []
                    items.append(.action(ContextMenuActionItem(text: selectionCount > 1 ? strings.Attachment_SendAsFiles : strings.Attachment_SendAsFile, icon: { theme in
                        return generateTintedImage(image: UIImage(bundleImageName: "Chat/Context Menu/File"), color: theme.contextMenu.primaryColor)
                    }, action: { [weak self] _, f in
                        f(.default)

                        self?.controllerNode.send(asFile: true, silently: false, scheduleTime: nil, animated: true)
                    })))
                
                    if selectionCount > 1 {
                        items.append(.separator)
                        
                        items.append(.action(ContextMenuActionItem(text: strings.Attachment_Grouped, icon: { theme in
                            if !grouped {
                                return nil
                            }
                            return generateTintedImage(image: UIImage(bundleImageName: "Chat/Context Menu/Check"), color: theme.contextMenu.primaryColor)
                        }, action: { [weak self] _, f in
                            f(.default)
                            
                            self?.groupedValue = true
                        })))
                        items.append(.action(ContextMenuActionItem(text: strings.Attachment_Ungrouped, icon: { theme in
                            if grouped {
                                return nil
                            }
                            return generateTintedImage(image: UIImage(bundleImageName: "Chat/Context Menu/Check"), color: theme.contextMenu.primaryColor)
                        }, action: {  [weak self] _, f in
                            f(.default)
                            
                            self?.groupedValue = false
                        })))
                    }
                    
                    return ContextController.Items(content: .list(items))
                }
            
                let contextController = ContextController(account: self.context.account, presentationData: self.presentationData, source: .reference(MediaPickerContextReferenceContentSource(controller: self, sourceNode: node)), items: items, gesture: gesture)
                self.presentInGlobalOverlay(contextController)
        }
    }
    
    override public func containerLayoutUpdated(_ layout: ContainerViewLayout, transition: ContainedViewLayoutTransition) {
        super.containerLayoutUpdated(layout, transition: transition)
        
        self.validLayout = layout
        self.controllerNode.containerLayoutUpdated(layout, navigationBarHeight: navigationLayout(layout: layout).navigationFrame.maxY, transition: transition)
    }
    
    public var mediaPickerContext: AttachmentMediaPickerContext? {
        if let interaction = self.interaction {
            return MediaPickerContext(interaction: interaction)
        } else {
            return nil
        }
    }
}

final class MediaPickerContext: AttachmentMediaPickerContext {
    private weak var interaction: MediaPickerInteraction?
    
    var selectionCount: Signal<Int, NoError> {
        return Signal { [weak self] subscriber in
            let disposable = self?.interaction?.selectionState?.selectionChangedSignal().start(next: { [weak self] value in
                subscriber.putNext(Int(self?.interaction?.selectionState?.count() ?? 0))
            }, error: { _ in }, completed: { })
            return ActionDisposable {
                disposable?.dispose()
            }
        }
    }
    
    var caption: Signal<NSAttributedString?, NoError> {
        return Signal { [weak self] subscriber in
            let disposable = self?.interaction?.editingState.forcedCaption().start(next: { caption in
                if let caption = caption as? NSAttributedString {
                    subscriber.putNext(caption)
                } else {
                    subscriber.putNext(nil)
                }
            }, error: { _ in }, completed: { })
            return ActionDisposable {
                disposable?.dispose()
            }
        }
    }
        
    init(interaction: MediaPickerInteraction) {
        self.interaction = interaction
    }
    
    func setCaption(_ caption: NSAttributedString) {
        self.interaction?.editingState.setForcedCaption(caption, skipUpdate: true)
    }
    
    func send(silently: Bool, mode: AttachmentMediaPickerSendMode) {
        self.interaction?.sendSelected(nil, silently, nil, true)
    }
    
    func schedule() {
        self.interaction?.schedule()
    }
}

private final class MediaPickerContextReferenceContentSource: ContextReferenceContentSource {
    private let controller: ViewController
    private let sourceNode: ContextReferenceContentNode
    
    init(controller: ViewController, sourceNode: ContextReferenceContentNode) {
        self.controller = controller
        self.sourceNode = sourceNode
    }
    
    func transitionInfo() -> ContextControllerReferenceViewInfo? {
        return ContextControllerReferenceViewInfo(referenceNode: self.sourceNode, contentAreaInScreenSpace: UIScreen.main.bounds)
    }
}

private class MediaPickerGridSelectionGesture: UIPanGestureRecognizer {
    var itemAt: (CGPoint) -> (TGMediaSelectableItem, Bool)? = { _ in return nil }
    var updateSelection: (TGMediaSelectableItem, Bool) -> Void = { _, _ in}
    var began: () -> Void = {}
    
    private weak var gridNode: GridNode?
    
    private var processing = false
    private var selecting = false
    
    private var initialLocation: CGPoint?
    
    init(target: Any?, action: Selector?, gridNode: GridNode) {
        self.gridNode = gridNode
        
        super.init(target: target, action: action)
        
        gridNode.view.addGestureRecognizer(self)
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesBegan(touches, with: event)
        
        guard let touch = touches.first, let gridNode = self.gridNode else {
            return
        }
        
        let location = touch.location(in: gridNode.view)
        self.initialLocation = location
    }
    
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesMoved(touches, with: event)
        
        guard let touch = touches.first, let gridNode = self.gridNode, let initialLocation = self.initialLocation else {
            self.state = .failed
            return
        }
        
        let location = touch.location(in: gridNode.view)
        let translation = CGPoint(x: location.x - initialLocation.x, y: location.y - initialLocation.y)
        
        var additionalLocation: CGPoint?
        if !self.processing {
            if abs(translation.y) > 5.0 {
                self.state = .failed
            } else if abs(translation.x) > 4.0 {
                self.processing = true
                self.gridNode?.scrollView.isScrollEnabled = false
                self.began()
                
                if let (_, selected) = self.itemAt(location) {
                    self.selecting = !selected
                }
                
                additionalLocation = self.initialLocation
            }
        }
        
        if self.processing {
            if let additionalLocation = additionalLocation {
                if let (item, selected) = self.itemAt(additionalLocation), selected != self.selecting {
                    self.updateSelection(item, self.selecting)
                }
            }
            
            if let (item, selected) = self.itemAt(location), selected != self.selecting {
                self.updateSelection(item, self.selecting)
            }
        }
    }
    
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesEnded(touches, with: event)
        
        self.state = .failed
        self.reset()
    }
    
    override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesCancelled(touches, with: event)
        
        self.state = .failed
        self.reset()
    }
    
    override func reset() {
        super.reset()
        
        self.processing = false
        self.initialLocation = nil
        self.gridNode?.scrollView.isScrollEnabled = true
    }
}