space-ios/iOSClient/Offline/NCOffline.swift

//
//  NCOffline.swift
//  Nextcloud
//
//  Created by Marino Faggiana on 24/10/2018.
//  Copyright © 2018 Marino Faggiana. All rights reserved.
//
//  Author Marino Faggiana <marino.faggiana@nextcloud.com>
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//

import Foundation
import Sheeeeeeeeet

class NCOffline: UIViewController, UIGestureRecognizerDelegate, NCListCellDelegate, NCGridCellDelegate, NCSectionHeaderMenuDelegate, DropdownMenuDelegate, DZNEmptyDataSetSource, DZNEmptyDataSetDelegate, BKPasscodeViewControllerDelegate  {
    
    @IBOutlet fileprivate weak var collectionView: UICollectionView!

    var titleCurrentFolder = NSLocalizedString("_manage_file_offline_", comment: "")
    var serverUrl = ""
    
    private let appDelegate = UIApplication.shared.delegate as! AppDelegate
   
    private var metadataPush: tableMetadata?
    private var isEditMode = false
    private var selectFileID = [String]()
    
    private var sectionDatasource = CCSectionDataSourceMetadata()
    
    private var typeLayout = ""
    private var datasourceSorted = ""
    private var datasourceAscending = true
    private var datasourceGroupBy = ""
    private var datasourceDirectoryOnTop = false
    
    private var autoUploadFileName = ""
    private var autoUploadDirectory = ""
    
    private var listLayout: NCListLayout!
    private var gridLayout: NCGridLayout!
    
    private var actionSheet: ActionSheet?
    
    private let headerMenuHeight: CGFloat = 50
    private let sectionHeaderHeight: CGFloat = 20
    private let footerHeight: CGFloat = 50

    private let refreshControl = UIRefreshControl()
    
    //BKPasscodeViewController
    private var failedAttempts: Double = 0
    private var lockUntilDate: NSDate?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Cell
        collectionView.register(UINib.init(nibName: "NCListCell", bundle: nil), forCellWithReuseIdentifier: "listCell")
        collectionView.register(UINib.init(nibName: "NCGridCell", bundle: nil), forCellWithReuseIdentifier: "gridCell")
        
        // Header
        collectionView.register(UINib.init(nibName: "NCSectionHeaderMenu", bundle: nil), forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "sectionHeaderMenu")
        collectionView.register(UINib.init(nibName: "NCSectionHeader", bundle: nil), forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "sectionHeader")
        
        // Footer
        collectionView.register(UINib.init(nibName: "NCSectionFooter", bundle: nil), forSupplementaryViewOfKind: UICollectionView.elementKindSectionFooter, withReuseIdentifier: "sectionFooter")
        
        collectionView.alwaysBounceVertical = true

        listLayout = NCListLayout()
        gridLayout = NCGridLayout()
        
        // Add Refresh Control
        if #available(iOS 10.0, *) {
            collectionView.refreshControl = refreshControl
        } else {
            collectionView.addSubview(refreshControl)
        }
        
        // Configure Refresh Control
        refreshControl.tintColor = NCBrandColor.sharedInstance.brandText
        refreshControl.backgroundColor = NCBrandColor.sharedInstance.brand
        refreshControl.addTarget(self, action: #selector(loadDatasource), for: .valueChanged)
        
        // empty Data Source
        self.collectionView.emptyDataSetDelegate = self;
        self.collectionView.emptyDataSetSource = self;
        
        // 3D Touch peek and pop
        if traitCollection.forceTouchCapability == .available {
            registerForPreviewing(with: self, sourceView: view)
        }
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        // Color
        appDelegate.aspectNavigationControllerBar(self.navigationController?.navigationBar, online: appDelegate.reachability.isReachable(), hidden: false)
        appDelegate.aspectTabBar(self.tabBarController?.tabBar, hidden: false)
        
        self.navigationItem.title = titleCurrentFolder
        
        (typeLayout, datasourceSorted, datasourceAscending, datasourceGroupBy, datasourceDirectoryOnTop) = NCUtility.sharedInstance.getLayoutForView(key: k_layout_view_offline)
        
        // get auto upload folder
        autoUploadFileName = NCManageDatabase.sharedInstance.getAccountAutoUploadFileName()
        autoUploadDirectory = NCManageDatabase.sharedInstance.getAccountAutoUploadDirectory(appDelegate.activeUrl)
        
        if typeLayout == k_layout_list {
            collectionView.collectionViewLayout = listLayout
        } else {
            collectionView.collectionViewLayout = gridLayout
        }
        
        loadDatasource()
    }
    
    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)
        
        coordinator.animate(alongsideTransition: nil) { _ in
            self.collectionView.collectionViewLayout.invalidateLayout()
            self.actionSheet?.viewDidLayoutSubviews()
        }
    }
    
    // MARK: DZNEmpty
    
    func backgroundColor(forEmptyDataSet scrollView: UIScrollView) -> UIColor? {
        return NCBrandColor.sharedInstance.backgroundView
    }
    
    func image(forEmptyDataSet scrollView: UIScrollView) -> UIImage? {
        return CCGraphics.changeThemingColorImage(UIImage.init(named: "folder"), width: 300, height: 300, color: NCBrandColor.sharedInstance.brandElement)
    }
    
    func title(forEmptyDataSet scrollView: UIScrollView) -> NSAttributedString? {
        let text = "\n"+NSLocalizedString("_files_no_files_", comment: "")
        let attributes = [NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 20), NSAttributedString.Key.foregroundColor: UIColor.lightGray]
        return NSAttributedString.init(string: text, attributes: attributes)
    }
    
    func emptyDataSetShouldAllowScroll(_ scrollView: UIScrollView) -> Bool {
        return true
    }
    
    // MARK: BKPASSCODEVIEWCONTROLLER
    
    func passcodeViewController(_ aViewController: BKPasscodeViewController!, didFinishWithPasscode aPasscode: String!) {
        aViewController.dismiss(animated: true, completion: nil)
        performSegueDirectoryWithControlPasscode(controlPasscode: false)
    }
    
    func passcodeViewController(_ aViewController: BKPasscodeViewController!, authenticatePasscode aPasscode: String!, resultHandler aResultHandler: ((Bool) -> Void)!) {
        if aPasscode == CCUtility.getBlockCode() {
            failedAttempts = 0
            lockUntilDate = nil
            aResultHandler(true)
        } else {
            aResultHandler(false)
        }
    }
    
    func passcodeViewControllerDidFailAttempt(_ aViewController: BKPasscodeViewController!) {
        failedAttempts += 1
        if failedAttempts > 5 {
            var timeInterval: TimeInterval = 60
            if failedAttempts > 6 {
                let multiplier: Double = failedAttempts - 6
                timeInterval = (5 * 60) * multiplier
                if timeInterval > 3600 * 24 {
                    timeInterval = 3600 * 24
                }
            }
            lockUntilDate = NSDate.init(timeIntervalSinceNow: timeInterval)
        }
    }
    
    func passcodeViewControllerNumber(ofFailedAttempts aViewController: BKPasscodeViewController!) -> UInt {
        return UInt(failedAttempts)
    }
    
    func passcodeViewControllerLock(untilDate aViewController: BKPasscodeViewController!) -> Date? {
        return lockUntilDate as Date?
    }
    
    @objc func passcodeViewCloseButtonPressed(_ sender: Any) {
        self.dismiss(animated: true, completion: nil)
    }

    // MARK: TAP EVENT
    
    func tapSwitchHeader(sender: Any) {
        
        if collectionView.collectionViewLayout == gridLayout {
            // list layout
            UIView.animate(withDuration: 0.0, animations: {
                self.collectionView.collectionViewLayout.invalidateLayout()
                self.collectionView.setCollectionViewLayout(self.listLayout, animated: false, completion: { (_) in
                    self.collectionView.reloadData()
                    self.collectionView.setContentOffset(CGPoint(x:0,y:0), animated: false)
                })
            })
            typeLayout = k_layout_list
            NCUtility.sharedInstance.setLayoutForView(key: k_layout_view_offline, layout: typeLayout, sort: datasourceSorted, ascending: datasourceAscending, groupBy: datasourceGroupBy, directoryOnTop: datasourceDirectoryOnTop)
        } else {
            // grid layout
            UIView.animate(withDuration: 0.0, animations: {
                self.collectionView.collectionViewLayout.invalidateLayout()
                self.collectionView.setCollectionViewLayout(self.gridLayout, animated: false, completion: { (_) in
                    self.collectionView.reloadData()
                    self.collectionView.setContentOffset(CGPoint(x:0,y:0), animated: false)
                })
            })
            typeLayout = k_layout_grid
            NCUtility.sharedInstance.setLayoutForView(key: k_layout_view_offline, layout: typeLayout, sort: datasourceSorted, ascending: datasourceAscending, groupBy: datasourceGroupBy, directoryOnTop: datasourceDirectoryOnTop)
        }
    }
    
    func tapOrderHeader(sender: Any) {
        
        var menuView: DropdownMenu?
        var selectedIndexPath = [IndexPath()]
        
        let item1 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "sortFileNameAZ"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_order_by_name_a_z_", comment: ""))
        let item2 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "sortFileNameZA"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_order_by_name_z_a_", comment: ""))
        let item3 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "sortDateMoreRecent"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_order_by_date_more_recent_", comment: ""))
        let item4 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "sortDateLessRecent"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_order_by_date_less_recent_", comment: ""))
        let item5 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "sortSmallest"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_order_by_size_smallest_", comment: ""))
        let item6 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "sortLargest"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_order_by_size_largest_", comment: ""))
        
        switch datasourceSorted {
        case "fileName":
            if datasourceAscending == true { item1.style = .highlight; selectedIndexPath.append(IndexPath(row: 0, section: 0)) }
            if datasourceAscending == false { item2.style = .highlight; selectedIndexPath.append(IndexPath(row: 1, section: 0)) }
        case "date":
            if datasourceAscending == false { item3.style = .highlight; selectedIndexPath.append(IndexPath(row: 2, section: 0)) }
            if datasourceAscending == true { item4.style = .highlight; selectedIndexPath.append(IndexPath(row: 3, section: 0)) }
        case "size":
            if datasourceAscending == true { item5.style = .highlight; selectedIndexPath.append(IndexPath(row: 4, section: 0)) }
            if datasourceAscending == false { item6.style = .highlight; selectedIndexPath.append(IndexPath(row: 5, section: 0)) }
        default:
            ()
        }
        
        let item7 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "MenuGroupByAlphabetic"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_group_alphabetic_no_", comment: ""))
        let item8 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "MenuGroupByFile"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_group_typefile_no_", comment: ""))
        let item9 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "MenuGroupByDate"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_group_date_no_", comment: ""))
        
        switch datasourceGroupBy {
        case "alphabetic":
            item7.style = .highlight; selectedIndexPath.append(IndexPath(row: 0, section: 1))
        case "typefile":
            item8.style = .highlight; selectedIndexPath.append(IndexPath(row: 1, section: 1))
        case "date":
            item9.style = .highlight; selectedIndexPath.append(IndexPath(row: 2, section: 1))
        default:
            ()
        }
        
        let item10 = DropdownItem(image: CCGraphics.changeThemingColorImage(UIImage.init(named: "foldersOnTop"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), title: NSLocalizedString("_directory_on_top_no_", comment: ""))
        
        if datasourceDirectoryOnTop {
            item10.style = .highlight; selectedIndexPath.append(IndexPath(row: 0, section: 2))
        }
        
        let sectionOrder = DropdownSection(sectionIdentifier: "", items: [item1, item2, item3, item4, item5, item6])
        let sectionGroupBy = DropdownSection(sectionIdentifier: "", items: [item7, item8, item9])
        let sectionFolderOnTop = DropdownSection(sectionIdentifier: "", items: [item10])
        
        menuView = DropdownMenu(navigationController: self.navigationController!, sections: [sectionOrder, sectionGroupBy, sectionFolderOnTop], selectedIndexPath: selectedIndexPath)
        menuView?.token = "tapOrderHeaderMenu"
        menuView?.delegate = self
        menuView?.rowHeight = 45
        menuView?.sectionHeaderHeight = 8
        menuView?.highlightColor = NCBrandColor.sharedInstance.brand
        menuView?.tableView.alwaysBounceVertical = false
        menuView?.tableViewBackgroundColor = UIColor.white
        
        let header = (sender as? UIButton)?.superview
        let headerRect = self.collectionView.convert(header!.bounds, from: self.view)
        let menuOffsetY =  headerRect.height - headerRect.origin.y - 2
        menuView?.topOffsetY = CGFloat(menuOffsetY)
        
        menuView?.showMenu()
    }
    
    func tapMoreHeader(sender: Any) {
        
    }
    
    func tapMoreListItem(with fileID: String, sender: Any) {
        tapMoreGridItem(with: fileID, sender: sender)
    }
    
    func tapMoreGridItem(with fileID: String, sender: Any) {
        
        guard let metadata = NCManageDatabase.sharedInstance.getMetadata(predicate: NSPredicate(format: "fileID == %@", fileID)) else {
            return
        }
        
        if !isEditMode {
            
            var items = [ActionSheetItem]()
            let appearanceDelete = ActionSheetItemAppearance.init()
            appearanceDelete.textColor = UIColor.red
            
            // 0 == CCMore, 1 = first NCOffline ....
            if (self == self.navigationController?.viewControllers[1]) {
                items.append(ActionSheetItem(title: NSLocalizedString("_remove_available_offline_", comment: ""), value: 0, image: CCGraphics.changeThemingColorImage(UIImage.init(named: "offline"), multiplier: 2, color: NCBrandColor.sharedInstance.icon)))
            }
            items.append(ActionSheetItem(title: NSLocalizedString("_share_", comment: ""), value: 1, image: CCGraphics.changeThemingColorImage(UIImage.init(named: "share"), width: 50, height: 50, color: NCBrandColor.sharedInstance.icon)))

            let itemDelete = ActionSheetItem(title: NSLocalizedString("_delete_", comment: ""), value: 2, image: CCGraphics.changeThemingColorImage(UIImage.init(named: "trash"), width: 50, height: 50, color: .red))
            itemDelete.customAppearance = appearanceDelete
            items.append(itemDelete)
            items.append(ActionSheetCancelButton(title: NSLocalizedString("_cancel_", comment: "")))
            
            actionSheet = ActionSheet(items: items) { sheet, item in
                if item.value as? Int == 0 {
                    if metadata.directory {
                        NCManageDatabase.sharedInstance.setDirectory(serverUrl: CCUtility.stringAppendServerUrl(metadata.serverUrl, addFileName: metadata.fileName)!, offline: false, account: self.appDelegate.activeAccount)
                    } else {
                        NCManageDatabase.sharedInstance.setLocalFile(fileID: metadata.fileID, offline: false)
                    }
                    self.loadDatasource()
                }
                if item.value as? Int == 1 { self.appDelegate.activeMain.readShare(withAccount: self.appDelegate.activeAccount, openWindow: true, metadata: metadata) }
                if item.value as? Int == 2 { self.deleteItem(with: metadata, sender: sender) }
                if item is ActionSheetCancelButton { print("Cancel buttons has the value `true`") }
            }
            
            let headerView = NCActionSheetHeader.sharedInstance.actionSheetHeader(isDirectory: metadata.directory, iconName: metadata.iconName, fileID: metadata.fileID, fileNameView: metadata.fileNameView, text: metadata.fileNameView)
            actionSheet?.headerView = headerView
            actionSheet?.headerView?.frame.size.height = 50
            
            actionSheet?.present(in: self, from: sender as! UIButton)
        } else {
            
            let buttonPosition:CGPoint = (sender as! UIButton).convert(CGPoint.zero, to:collectionView)
            let indexPath = collectionView.indexPathForItem(at: buttonPosition)
            collectionView(self.collectionView, didSelectItemAt: indexPath!)
        }
    }
    
    // MARK: DROP-DOWN-MENU

    func dropdownMenu(_ dropdownMenu: DropdownMenu, didSelectRowAt indexPath: IndexPath) {
        
        if dropdownMenu.token == "tapOrderHeaderMenu" {
            
            switch indexPath.section {
            
                    case 0: switch indexPath.row {
                        
                    case 0: datasourceSorted = "fileName"; datasourceAscending = true
                    case 1: datasourceSorted = "fileName"; datasourceAscending = false
                        
                    case 2: datasourceSorted = "date"; datasourceAscending = false
                    case 3: datasourceSorted = "date"; datasourceAscending = true
                        
                    case 4: datasourceSorted = "size"; datasourceAscending = true
                    case 5: datasourceSorted = "size"; datasourceAscending = false
                
                    default: ()
                    }
                
            case 1: switch indexPath.row {
                
                    case 0:
                        if datasourceGroupBy == "alphabetic" {
                            datasourceGroupBy = "none"
                        } else {
                            datasourceGroupBy = "alphabetic"
                        }
                    case 1:
                        if datasourceGroupBy == "typefile" {
                            datasourceGroupBy = "none"
                        } else {
                            datasourceGroupBy = "typefile"
                        }
                    case 2:
                        if datasourceGroupBy == "date" {
                            datasourceGroupBy = "none"
                        } else {
                            datasourceGroupBy = "date"
                        }
                
                    default: ()
                        }
                    case 2:
                        if datasourceDirectoryOnTop {
                            datasourceDirectoryOnTop = false
                        } else {
                            datasourceDirectoryOnTop = true
                        }
                    default: ()
                    }
            
            NCUtility.sharedInstance.setLayoutForView(key: k_layout_view_offline, layout: typeLayout, sort: datasourceSorted, ascending: datasourceAscending, groupBy: datasourceGroupBy, directoryOnTop: datasourceDirectoryOnTop)

            loadDatasource()
        }
        
        if dropdownMenu.token == "tapMoreHeaderMenu" {
        
        }
        
        if dropdownMenu.token == "tapMoreHeaderMenuSelect" {
            
        }
    }
    
    // MARK: SEGUE
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        
        let photoDataSource: NSMutableArray = []
        
        for fileID: String in sectionDatasource.allFileID as! [String] {
            let metadata = sectionDatasource.allRecordsDataSource.object(forKey: fileID) as! tableMetadata
            if metadata.typeFile == k_metadataTypeFile_image {
                photoDataSource.add(metadata)
            }
        }
        
        if let segueNavigationController = segue.destination as? UINavigationController {
            if let segueViewController = segueNavigationController.topViewController as? CCDetail {
            
                segueViewController.metadataDetail = metadataPush
                segueViewController.dateFilterQuery = nil
                segueViewController.photoDataSource = photoDataSource
                segueViewController.title = metadataPush!.fileNameView
            }
        }
    }
    
    // MARK: NAVIGATION
    
    private func performSegueDirectoryWithControlPasscode(controlPasscode: Bool) {
        
        guard let serverUrlPush = CCUtility.stringAppendServerUrl(metadataPush!.serverUrl, addFileName: metadataPush!.fileName) else {
            return
        }
        guard let directoryPush = NCManageDatabase.sharedInstance.getTableDirectory(predicate: NSPredicate(format: "account == %@ AND serverUrl == %@", appDelegate.activeAccount, serverUrlPush))  else {
            return
        }
        
        if directoryPush.lock == true && CCUtility.getBlockCode() != nil && (CCUtility.getBlockCode()?.count)! > 0 && controlPasscode {
            
            let viewController = CCBKPasscode.init(nibName: nil, bundle: nil)
            guard let touchIDManager = BKTouchIDManager.init(keychainServiceName: k_serviceShareKeyChain) else {
                return
            }
            touchIDManager.promptText = NSLocalizedString("_scan_fingerprint_", comment: "")
            
            viewController.delegate = self
            viewController.type = BKPasscodeViewControllerCheckPasscodeType
            viewController.inputViewTitlePassword = true
            if CCUtility.getSimplyBlockCode() {
                viewController.passcodeStyle = BKPasscodeInputViewNumericPasscodeStyle
                viewController.passcodeInputView.maximumLength = 6
            } else {
                viewController.passcodeStyle = BKPasscodeInputViewNormalPasscodeStyle
                viewController.passcodeInputView.maximumLength = 64
            }
            viewController.touchIDManager = touchIDManager
            viewController.title = NSLocalizedString("_folder_blocked_", comment: "")
            viewController.navigationItem.leftBarButtonItem = UIBarButtonItem.init(barButtonSystemItem: UIBarButtonItem.SystemItem.cancel, target: self, action: #selector(passcodeViewCloseButtonPressed(_:)))
            viewController.navigationItem.leftBarButtonItem?.tintColor = UIColor.black
            
            let navigationController = UINavigationController.init(rootViewController: viewController)
            self.present(navigationController, animated: true, completion: nil)
            
            return
        }
        
        let ncOffline:NCOffline = UIStoryboard(name: "NCOffline", bundle: nil).instantiateInitialViewController() as! NCOffline
        
        ncOffline.serverUrl = serverUrlPush
        ncOffline.titleCurrentFolder = metadataPush!.fileNameView
        
        self.navigationController?.pushViewController(ncOffline, animated: true)
    }
}

// MARK: - 3D Touch peek and pop

extension NCOffline: UIViewControllerPreviewingDelegate {
    
    func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
        
        guard let point = collectionView?.convert(location, from: collectionView?.superview) else { return nil }
        guard let indexPath = collectionView?.indexPathForItem(at: point) else { return nil }
        guard let metadata = NCMainCommon.sharedInstance.getMetadataFromSectionDataSourceIndexPath(indexPath, sectionDataSource: sectionDatasource) else { return nil }
        guard let viewController = UIStoryboard(name: "CCPeekPop", bundle: nil).instantiateViewController(withIdentifier: "PeekPopImagePreview") as? CCPeekPop else { return nil }

        viewController.metadata = metadata

        if typeLayout == k_layout_grid {
            guard let cell = collectionView?.cellForItem(at: indexPath) as? NCGridCell else { return nil }
            previewingContext.sourceRect = cell.frame
            viewController.imageFile = cell.imageItem.image
        } else {
            guard let cell = collectionView?.cellForItem(at: indexPath) as? NCListCell else { return nil }
            previewingContext.sourceRect = cell.frame
            viewController.imageFile = cell.imageItem.image
        }
        
        viewController.showOpenIn = true
        viewController.showShare = false
        
        return viewController
    }
    
    func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
        
        guard let indexPath = collectionView?.indexPathForItem(at: previewingContext.sourceRect.origin) else { return }
        
        collectionView(collectionView, didSelectItemAt: indexPath)
    }
}

// MARK: - Collection View

extension NCOffline: UICollectionViewDelegate {

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        
        guard let metadata = NCMainCommon.sharedInstance.getMetadataFromSectionDataSourceIndexPath(indexPath, sectionDataSource: sectionDatasource) else {
            return
        }
        metadataPush = metadata
        
        if isEditMode {
            if let index = selectFileID.firstIndex(of: metadata.fileID) {
                selectFileID.remove(at: index)
            } else {
                selectFileID.append(metadata.fileID)
            }
            collectionView.reloadItems(at: [indexPath])
            return
        }
        
        if metadata.directory {
            
            performSegueDirectoryWithControlPasscode(controlPasscode: true)
            
        } else {
            
            
            performSegue(withIdentifier: "segueDetail", sender: self)
        }
    }
}

extension NCOffline: UICollectionViewDataSource {

    func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
        
        if (indexPath.section == 0) {
            
            if kind == UICollectionView.elementKindSectionHeader {
                
                let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "sectionHeaderMenu", for: indexPath) as! NCSectionHeaderMenu
                
                if collectionView.collectionViewLayout == gridLayout {
                    header.buttonSwitch.setImage(CCGraphics.changeThemingColorImage(UIImage.init(named: "switchList"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), for: .normal)
                } else {
                    header.buttonSwitch.setImage(CCGraphics.changeThemingColorImage(UIImage.init(named: "switchGrid"), multiplier: 2, color: NCBrandColor.sharedInstance.icon), for: .normal)
                }
                
                header.delegate = self
                
                header.setStatusButton(count: sectionDatasource.allFileID.count)
                header.setTitleOrder(datasourceSorted: datasourceSorted, datasourceAscending: datasourceAscending)
                
                if datasourceGroupBy == "none" {
                    header.labelSection.isHidden = true
                    header.labelSectionHeightConstraint.constant = 0
                } else {
                    header.labelSection.isHidden = false
                    header.setTitleLabel(sectionDatasource: sectionDatasource, section: indexPath.section)
                    header.labelSectionHeightConstraint.constant = sectionHeaderHeight
                }
                
                return header
                
            } else {
                
                let footer = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "sectionFooter", for: indexPath) as! NCSectionFooter
                
                footer.setTitleLabel(sectionDatasource: sectionDatasource)
                
                return footer
            }
            
        } else {
            
            if kind == UICollectionView.elementKindSectionHeader {
                
                let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "sectionHeader", for: indexPath) as! NCSectionHeader
                
                header.setTitleLabel(sectionDatasource: sectionDatasource, section: indexPath.section)
                
                return header
                
            } else {
                
                let footer = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "sectionFooter", for: indexPath) as! NCSectionFooter
                
                footer.setTitleLabel(sectionDatasource: sectionDatasource)
                
                return footer
            }
        }
    }
    
    func numberOfSections(in collectionView: UICollectionView) -> Int {
        let sections = sectionDatasource.sectionArrayRow.allKeys.count
        return sections
    }
    
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        let key = sectionDatasource.sections.object(at: section)
        let datasource = sectionDatasource.sectionArrayRow.object(forKey: key) as! [tableMetadata]
        return datasource.count
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        let cell: UICollectionViewCell
        
        guard let metadata = NCMainCommon.sharedInstance.getMetadataFromSectionDataSourceIndexPath(indexPath, sectionDataSource: sectionDatasource) else {
            return collectionView.dequeueReusableCell(withReuseIdentifier: "listCell", for: indexPath) as! NCListCell
        }
        
        if typeLayout == k_layout_grid {
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "gridCell", for: indexPath) as! NCGridCell
        } else {
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "listCell", for: indexPath) as! NCListCell
        }
        
        NCMainCommon.sharedInstance.collectionViewCellForItemAt(indexPath, collectionView: collectionView, cell: cell, metadata: metadata, metadataFolder: nil, serverUrl: metadata.serverUrl, isEditMode: isEditMode, selectFileID: selectFileID, autoUploadFileName: autoUploadFileName, autoUploadDirectory: autoUploadDirectory, hideButtonMore: false, downloadThumbnail: true, source: self)
        
        return cell
    }
}

extension NCOffline: UICollectionViewDelegateFlowLayout {

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
        if section == 0 {
            if datasourceGroupBy == "none" {
                return CGSize(width: collectionView.frame.width, height: headerMenuHeight)
            } else {
                return CGSize(width: collectionView.frame.width, height: headerMenuHeight + sectionHeaderHeight)
            }
        } else {
            return CGSize(width: collectionView.frame.width, height: sectionHeaderHeight)
        }
    }
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize {
        let sections = sectionDatasource.sectionArrayRow.allKeys.count
        if (section == sections - 1) {
            return CGSize(width: collectionView.frame.width, height: footerHeight)
        } else {
            return CGSize(width: collectionView.frame.width, height: 0)
        }
    }
}

// MARK: - NC API & Algorithm

extension NCOffline {

    @objc func loadDatasource() {
        
        var fileIDs = [String]()
        sectionDatasource = CCSectionDataSourceMetadata()
        
        if serverUrl == "" {
            
            if let directories = NCManageDatabase.sharedInstance.getTablesDirectory(predicate: NSPredicate(format: "account == %@ AND offline == true", appDelegate.activeAccount), sorted: "serverUrl", ascending: true) {
                for directory: tableDirectory in directories {
                    fileIDs.append(directory.fileID)
                }
            }
            
            if let files = NCManageDatabase.sharedInstance.getTableLocalFiles(predicate: NSPredicate(format: "account == %@ AND offline == true", appDelegate.activeAccount), sorted: "fileName", ascending: true) {
                for file: tableLocalFile in files {
                    fileIDs.append(file.fileID)
                }
            }
            
            if let metadatas = NCManageDatabase.sharedInstance.getMetadatas(predicate: NSPredicate(format: "account == %@ AND fileID IN %@", appDelegate.activeAccount, fileIDs), sorted: nil, ascending: false)  {
                
                sectionDatasource = CCSectionMetadata.creataDataSourseSectionMetadata(metadatas, listProgressMetadata: nil, groupByField: datasourceGroupBy, filterFileID: nil, filterTypeFileImage: false, filterTypeFileVideo: false, sorted: datasourceSorted, ascending: datasourceAscending, activeAccount: appDelegate.activeAccount)
            }
            
        } else {
            
            if let metadatas = NCManageDatabase.sharedInstance.getMetadatas(predicate: NSPredicate(format: "account == %@ AND serverUrl == %@", appDelegate.activeAccount, serverUrl), sorted: nil, ascending: false)  {
                
                sectionDatasource = CCSectionMetadata.creataDataSourseSectionMetadata(metadatas, listProgressMetadata: nil, groupByField: datasourceGroupBy, filterFileID: nil, filterTypeFileImage: false, filterTypeFileVideo: false, sorted: datasourceSorted, ascending: datasourceAscending, activeAccount: appDelegate.activeAccount)
            }
        }
        
        self.refreshControl.endRefreshing()
        
        collectionView.reloadData()
    }
    
    func deleteItem(with metadata: tableMetadata, sender: Any) {
        
        var items = [ActionSheetItem]()
        
        guard let tableDirectory = NCManageDatabase.sharedInstance.getTableDirectory(predicate: NSPredicate(format: "account == %@ AND serverUrl == serverUrl", appDelegate.activeAccount, metadata.serverUrl)) else {
            return
        }
        
        items.append(ActionSheetDangerButton(title: NSLocalizedString("_delete_", comment: "")))
        items.append(ActionSheetCancelButton(title: NSLocalizedString("_cancel_", comment: "")))
        
        actionSheet = ActionSheet(items: items) { sheet, item in
            if item is ActionSheetDangerButton {
                NCMainCommon.sharedInstance.deleteFile(metadatas: [metadata], e2ee: tableDirectory.e2eEncrypted, serverUrl: tableDirectory.serverUrl, folderFileID: tableDirectory.fileID) { (errorCode, message) in
                    self.loadDatasource()
                }
            }
            if item is ActionSheetCancelButton { print("Cancel buttons has the value `true`") }
        }
        
        let headerView = NCActionSheetHeader.sharedInstance.actionSheetHeader(isDirectory: metadata.directory, iconName: metadata.iconName, fileID: metadata.fileID, fileNameView: metadata.fileNameView, text: metadata.fileNameView)
        actionSheet?.headerView = headerView
        actionSheet?.headerView?.frame.size.height = 50
        
        actionSheet?.present(in: self, from: sender as! UIButton)
    }
}