//
//  NCShareExtension.swift
//  Share
//
//  Created by Marino Faggiana on 20/04/2021.
//  Copyright © 2021 Marino Faggiana. All rights reserved.
//  Copyright © 2021 Henrik Storch. All rights reserved.
//
//  Author Marino Faggiana <marino.faggiana@nextcloud.com>
//  Author Henrik Storch <henrik.storch@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 UIKit
import NextcloudKit

enum NCShareExtensionError: Error {
    case cancel, fileUpload, noAccount, noFiles
}

class NCShareExtension: UIViewController {
    @IBOutlet weak var collectionView: UICollectionView!
    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var cancelButton: UIBarButtonItem!
    @IBOutlet weak var separatorView: UIView!
    @IBOutlet weak var commandView: UIView!
    @IBOutlet weak var separatorHeightConstraint: NSLayoutConstraint!
    @IBOutlet weak var commandViewHeightConstraint: NSLayoutConstraint!

    @IBOutlet weak var createFolderView: UIView!
    @IBOutlet weak var createFolderImage: UIImageView!
    @IBOutlet weak var createFolderLabel: UILabel!
    @IBOutlet weak var uploadView: UIView!
    @IBOutlet weak var uploadImage: UIImageView!
    @IBOutlet weak var uploadLabel: UILabel!

    // -------------------------------------------------------------
    var serverUrl = ""
    var filesName: [String] = []
    // -------------------------------------------------------------

    let keyLayout = NCGlobal.shared.layoutViewShareExtension
    var metadataFolder: tableMetadata?
    var dataSourceTask: URLSessionTask?
    var dataSource = NCCollectionViewDataSource()
    let heightRowTableView: CGFloat = 50
    let heightCommandView: CGFloat = 170
    var autoUploadFileName = ""
    var autoUploadDirectory = ""
    let refreshControl = UIRefreshControl()
    var progress: CGFloat = 0
    var counterUploaded: Int = 0
    var uploadErrors: [tableMetadata] = []
    var uploadMetadata: [tableMetadata] = []
    var uploadStarted = false
    let hud = NCHud()
    let utilityFileSystem = NCUtilityFileSystem()
    let utility = NCUtility()
    let database = NCManageDatabase.shared
    var account: String = ""
    var session: NCSession.Session {
        if !account.isEmpty,
           let tableAccount = self.database.getTableAccount(account: account) {
            return NCSession.Session(account: tableAccount.account, urlBase: tableAccount.urlBase, user: tableAccount.user, userId: tableAccount.userId)
        } else if let activeTableAccount = self.database.getActiveTableAccount() {
            self.account = activeTableAccount.account
            return NCSession.Session(account: activeTableAccount.account, urlBase: activeTableAccount.urlBase, user: activeTableAccount.user, userId: activeTableAccount.userId)
        } else {
            return NCSession.Session(account: "", urlBase: "", user: "", userId: "")
        }
    }

    // MARK: - View Life Cycle

    override func viewDidLoad() {
        super.viewDidLoad()

        self.navigationController?.navigationBar.prefersLargeTitles = false

        collectionView.register(UINib(nibName: "NCSectionFirstHeaderEmptyData", bundle: nil), forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "sectionFirstHeaderEmptyData")
        collectionView.register(UINib(nibName: "NCListCell", bundle: nil), forCellWithReuseIdentifier: "listCell")
        collectionView.collectionViewLayout = NCListLayout()

        collectionView.refreshControl = refreshControl
        refreshControl.tintColor = NCBrandColor.shared.iconImageColor
        refreshControl.backgroundColor = .systemBackground
        refreshControl.addTarget(self, action: #selector(reloadDatasource), for: .valueChanged)

        commandView.backgroundColor = .secondarySystemBackground
        separatorView.backgroundColor = .separator
        separatorHeightConstraint.constant = 0.5

        tableView.separatorColor = .separator
        tableView.layer.cornerRadius = 10
        tableView.tableFooterView = UIView(frame: CGRect(origin: .zero, size: CGSize(width: 0, height: 1)))
        commandViewHeightConstraint.constant = heightCommandView

        createFolderView.layer.cornerRadius = 10
        createFolderImage.image = utility.loadImage(named: "folder.badge.plus", colors: [NCBrandColor.shared.iconImageColor])
        createFolderLabel.text = NSLocalizedString("_create_folder_", comment: "")
        let createFolderGesture = UITapGestureRecognizer(target: self, action: #selector(actionCreateFolder))
        createFolderView.addGestureRecognizer(createFolderGesture)

        uploadView.layer.cornerRadius = 10

        uploadLabel.text = NSLocalizedString("_upload_", comment: "")
        uploadLabel.textColor = .systemBlue
        let uploadGesture = UITapGestureRecognizer(target: self, action: #selector(actionUpload))
        uploadView.addGestureRecognizer(uploadGesture)

        // LOG
        let levelLog = NCKeychain().logLevel
        let isSimulatorOrTestFlight = utility.isSimulatorOrTestFlight()
        let versionNextcloudiOS = String(format: NCBrandOptions.shared.textCopyrightNextcloudiOS, utility.getVersionApp())

        NextcloudKit.shared.nkCommonInstance.levelLog = levelLog
        NextcloudKit.shared.nkCommonInstance.pathLog = utilityFileSystem.directoryGroup
        if isSimulatorOrTestFlight {
            NextcloudKit.shared.nkCommonInstance.writeLog("[INFO] Start Share session with level \(levelLog) " + versionNextcloudiOS + " (Simulator / TestFlight)")
        } else {
            NextcloudKit.shared.nkCommonInstance.writeLog("[INFO] Start Share session with level \(levelLog) " + versionNextcloudiOS)
        }

        NCBrandColor.shared.createUserColors()

        NotificationCenter.default.addObserver(self, selector: #selector(didCreateFolder(_:)), name: NSNotification.Name(rawValue: NCGlobal.shared.notificationCenterCreateFolder), object: nil)
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        guard !session.account.isEmpty,
              !NCPasscode.shared.isPasscodeReset else {
            return showAlert(description: "_no_active_account_") {
                self.cancel(with: .noAccount)
            }
        }
        accountRequestChangeAccount(account: account, controller: nil)
        guard let inputItems = extensionContext?.inputItems as? [NSExtensionItem] else {
            cancel(with: .noFiles)
            return
        }
        NCFilesExtensionHandler(items: inputItems) { fileNames in
            self.filesName = fileNames
            DispatchQueue.main.async { self.setCommandView() }
        }
        if NCKeychain().presentPasscode {
            NCPasscode.shared.presentPasscode(viewController: self, delegate: self) {
                NCPasscode.shared.enableTouchFaceID()
            }
        }
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)
        coordinator.animate(alongsideTransition: nil) { _ in
            self.collectionView?.collectionViewLayout.invalidateLayout()
        }
    }

    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        super.traitCollectionDidChange(previousTraitCollection)
        collectionView.reloadData()
        tableView.reloadData()
    }

    // MARK: -

    func cancel(with error: NCShareExtensionError) {
        // make sure no uploads are continued
        uploadStarted = false
        extensionContext?.cancelRequest(withError: error)
    }

    func showAlert(title: String = "_error_", description: String, onDismiss: (() -> Void)? = nil) {
        let description = description.replacingOccurrences(of: "\t", with: "\n")
        let alertController = UIAlertController(title: NSLocalizedString(title, comment: ""), message: NSLocalizedString(description, comment: ""), preferredStyle: .alert)
        alertController.addAction(UIAlertAction(title: NSLocalizedString("_ok_", comment: ""), style: .default, handler: { _ in
            onDismiss?()
        }))
        self.present(alertController, animated: true)
    }

    func setNavigationBar(navigationTitle: String) {
        navigationItem.title = navigationTitle
        cancelButton.title = NSLocalizedString("_cancel_", comment: "")

        // BACK BUTTON
        let backButton = UIButton(type: .custom)
        backButton.setImage(UIImage(named: "back"), for: .normal)
        backButton.tintColor = .systemBlue
        backButton.semanticContentAttribute = .forceLeftToRight
        backButton.setTitle(" " + NSLocalizedString("_back_", comment: ""), for: .normal)
        backButton.setTitleColor(.systemBlue, for: .normal)
        backButton.action(for: .touchUpInside) { _ in
            if !self.uploadStarted {
                while self.serverUrl.last != "/" { self.serverUrl.removeLast() }
                self.serverUrl.removeLast()
                self.reloadDatasource(withLoadFolder: true)
                var navigationTitle = (self.serverUrl as NSString).lastPathComponent
                if self.utilityFileSystem.getHomeServer(session: self.session) == self.serverUrl {
                    navigationTitle = NCBrandOptions.shared.brand
                }
                self.setNavigationBar(navigationTitle: navigationTitle)
            }
        }

        let tableAccount = self.database.getTableAccount(account: session.account)
        let image = utility.loadUserImage(for: session.user, displayName: tableAccount?.displayName, urlBase: session.urlBase)
        let profileButton = UIButton(type: .custom)
        profileButton.setImage(image, for: .normal)

        if serverUrl == utilityFileSystem.getHomeServer(session: self.session) {
            var title = "  "
            if let userAlias = tableAccount?.alias, !userAlias.isEmpty {
                title += userAlias
            } else {
                title += tableAccount?.displayName ?? ""
            }

            profileButton.setTitle(title, for: .normal)
            profileButton.setTitleColor(.systemBlue, for: .normal)
        }

        profileButton.semanticContentAttribute = .forceLeftToRight
        profileButton.sizeToFit()
        profileButton.action(for: .touchUpInside) { _ in
            if !self.uploadStarted {
                self.showAccountPicker()
            }
        }
        var navItems = [UIBarButtonItem(customView: profileButton)]
        if serverUrl != utilityFileSystem.getHomeServer(session: self.session) {
            let space = UIBarButtonItem(barButtonSystemItem: .fixedSpace, target: nil, action: nil)
            space.width = 20
            navItems.append(contentsOf: [UIBarButtonItem(customView: backButton), space])
        }
        navigationItem.setLeftBarButtonItems(navItems, animated: true)
    }

    func setCommandView() {
        guard !filesName.isEmpty else {
            cancel(with: .noFiles)
            return
        }
        let counter = min(CGFloat(filesName.count), 3)
        self.commandViewHeightConstraint.constant = heightCommandView + (self.heightRowTableView * counter)

        if filesName.count <= 3 {
            self.tableView.isScrollEnabled = false
        }
        uploadLabel.text = NSLocalizedString("_upload_", comment: "") + " \(filesName.count) " + NSLocalizedString("_files_", comment: "")
        self.tableView.reloadData()
    }

    // MARK: ACTION

    @IBAction func actionCancel(_ sender: UIBarButtonItem) {
        cancel(with: .cancel)
    }

    @objc func actionCreateFolder() {
        let alertController = UIAlertController.createFolder(serverUrl: serverUrl, session: session) { error in
            guard error != .success else { return }
            self.showAlert(title: "_error_createsubfolders_upload_", description: error.errorDescription)
        }
        self.present(alertController, animated: true)
    }
}

// MARK: - Upload
extension NCShareExtension {
    @objc func actionUpload() {
        guard !uploadStarted else { return }
        guard !filesName.isEmpty else { return showAlert(description: "_files_no_files_") }

        counterUploaded = 0
        uploadErrors = []
        var dismissAfterUpload = true

        var conflicts: [tableMetadata] = []
        var invalidNameIndexes: [Int] = []

        for (index, fileName) in filesName.enumerated() {
            let newFileName = FileAutoRenamer.shared.rename(fileName, account: session.account)

            if fileName != newFileName {
                renameFile(oldName: fileName, newName: newFileName, account: session.account)
            }

            if let fileNameError = FileNameValidator.shared.checkFileName(newFileName, account: session.account) {
                if filesName.count == 1 {
                    showRenameFileDialog(named: fileName, account: account)
                    return
                } else {
                    present(UIAlertController.warning(message: "\(fileNameError.errorDescription) \(NSLocalizedString("_please_rename_file_", comment: ""))") {
                        self.extensionContext?.completeRequest(returningItems: self.extensionContext?.inputItems, completionHandler: nil)
                    }, animated: true)

                    invalidNameIndexes.append(index)
                    dismissAfterUpload = false
                    continue
                }

            }
        }

        for index in invalidNameIndexes.reversed() {
            filesName.remove(at: index)
        }

        for fileName in filesName {
            let ocId = NSUUID().uuidString
            let toPath = utilityFileSystem.getDirectoryProviderStorageOcId(ocId, fileNameView: fileName)
            guard utilityFileSystem.copyFile(atPath: (NSTemporaryDirectory() + fileName), toPath: toPath) else { continue }
            let metadataForUpload = self.database.createMetadata(fileName: fileName,
                                                                 fileNameView: fileName,
                                                                 ocId: ocId,
                                                                 serverUrl: serverUrl,
                                                                 url: "",
                                                                 contentType: "",
                                                                 session: session,
                                                                 sceneIdentifier: nil)

            metadataForUpload.session = NCNetworking.shared.sessionUpload
            metadataForUpload.sessionSelector = NCGlobal.shared.selectorUploadFileShareExtension
            metadataForUpload.size = utilityFileSystem.getFileSize(filePath: toPath)
            metadataForUpload.status = NCGlobal.shared.metadataStatusWaitUpload
            metadataForUpload.sessionDate = Date()
            if self.database.getMetadataConflict(account: session.account, serverUrl: serverUrl, fileNameView: fileName) != nil {
                conflicts.append(metadataForUpload)
            } else {
                uploadMetadata.append(metadataForUpload)
            }
        }

        tableView.reloadData()

        if !conflicts.isEmpty {
            guard let conflict = UIStoryboard(name: "NCCreateFormUploadConflict", bundle: nil).instantiateInitialViewController() as? NCCreateFormUploadConflict
            else { return }

            conflict.account = session.account
            conflict.serverUrl = self.serverUrl
            conflict.metadatasUploadInConflict = conflicts
            conflict.delegate = self
            self.present(conflict, animated: true, completion: nil)
        } else {
            uploadStarted = true
            upload(dismissAfterUpload: dismissAfterUpload)
        }
    }

    func upload(dismissAfterUpload: Bool = true) {
        guard uploadStarted else { return }
        guard uploadMetadata.count > counterUploaded else { return DispatchQueue.main.async { self.finishedUploading(dismissAfterUpload: dismissAfterUpload) } }
        let metadata = uploadMetadata[counterUploaded]
        let results = NextcloudKit.shared.nkCommonInstance.getInternalType(fileName: metadata.fileNameView, mimeType: metadata.contentType, directory: false, account: session.account)

        metadata.contentType = results.mimeType
        metadata.iconName = results.iconName
        metadata.classFile = results.classFile
        // CHUNK
        var chunkSize = NCGlobal.shared.chunkSizeMBCellular
        if NCNetworking.shared.networkReachability == NKCommon.TypeReachability.reachableEthernetOrWiFi {
            chunkSize = NCGlobal.shared.chunkSizeMBEthernetOrWiFi
        }
        if metadata.size > chunkSize {
            metadata.chunk = chunkSize
        } else {
            metadata.chunk = 0
        }
        // E2EE
        metadata.e2eEncrypted = metadata.isDirectoryE2EE

        hud.initHudRing(view: self.view,
                        text: NSLocalizedString("_upload_file_", comment: "") + " \(self.counterUploaded + 1) " + NSLocalizedString("_of_", comment: "") + " \(self.filesName.count)")

        NCNetworking.shared.upload(metadata: metadata, uploadE2EEDelegate: self, controller: self) {
            self.hud.progress(0)
        } progressHandler: { _, _, fractionCompleted in
            self.hud.progress(fractionCompleted)
        } completion: { _, error in
            if error != .success {
                self.database.deleteMetadataOcId(metadata.ocId)
                self.utilityFileSystem.removeFile(atPath: self.utilityFileSystem.getDirectoryProviderStorageOcId(metadata.ocId))
                self.uploadErrors.append(metadata)
            }
            self.counterUploaded += 1
            self.upload()
        }
    }

    func finishedUploading(dismissAfterUpload: Bool = true) {
        uploadStarted = false
        if !uploadErrors.isEmpty {
            let fileList = "- " + uploadErrors.map({ $0.fileName }).joined(separator: "\n  - ")
            showAlert(title: "_error_files_upload_", description: fileList) {
                self.extensionContext?.cancelRequest(withError: NCShareExtensionError.fileUpload)
            }
        } else {
            hud.success()
            DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
                self.extensionContext?.completeRequest(returningItems: self.extensionContext?.inputItems, completionHandler: nil)
            }
        }
    }
}

extension NCShareExtension: uploadE2EEDelegate {
    func start() {
        self.hud.progress(0)
    }

    func uploadE2EEProgress(_ totalBytesExpected: Int64, _ totalBytes: Int64, _ fractionCompleted: Double) {
        self.hud.progress(fractionCompleted)
    }
}

extension NCShareExtension: NCPasscodeDelegate {
    func passcodeReset(_ passcodeViewController: TOPasscodeViewController) {
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
            passcodeViewController.dismiss(animated: false)
            self.cancel(with: .noAccount)
        }
    }

    func evaluatePolicy(_ passcodeViewController: TOPasscodeViewController, isCorrectCode: Bool) {
        if !isCorrectCode {
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
                passcodeViewController.dismiss(animated: false)
                self.cancel(with: .noAccount)
            }
        }
    }
}