Hinduja-LMS/LMS/View Controller/OfflineAssessmentViewController.swift

//
//  OfflineAssessmentViewController.swift
//  LMS
//
//  Created by Suraj Kumar Mandal on 11/01/23.
//

import UIKit
import Toast_Swift
import SideMenu
import MobileCoreServices
import UniformTypeIdentifiers

class OfflineAssessmentViewController: UIViewController {
    
    @IBOutlet var downloadView: UIView!
    @IBOutlet var downloadImageView: UIImageView!
    @IBOutlet var downloadLabel: UILabel!
    
    @IBOutlet var uploadView: UIView!
    @IBOutlet var uploadImageView: UIImageView!
    @IBOutlet var uploadLabel: UILabel!
    
    var viewModel = OfflineAssessmentViewModel()
    
    let userData = DBManager.sharedInstance.database.objects(UserDetailsModel.self)
    
    var assessmentName = String()
    var assessmentId = Int()
    var fileExtension = String()
    var fileId = String()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Do any additional setup after loading the view.
        viewModel.delegate = self
        setupUI()
        // Add touch gesture to download view
        let downloadGesture = UITapGestureRecognizer(target: self, action:  #selector(self.downloadPDF(sender:)))
        self.downloadView.addGestureRecognizer(downloadGesture)
        
        // Add touch gesture to upload view
        let uploadGesture = UITapGestureRecognizer(target: self, action:  #selector(self.upload(sender:)))
        self.uploadView.addGestureRecognizer(uploadGesture)
    }
    
    func setupUI() {
        downloadView.layer.cornerRadius = 20
        downloadView.layer.borderWidth = 3
        downloadView.layer.borderColor = #colorLiteral(red: 0.00400000019, green: 0.200000003, blue: 0.3919999897, alpha: 1)
        
        uploadView.layer.cornerRadius = 20
        uploadView.layer.borderWidth = 3
        uploadView.layer.borderColor = #colorLiteral(red: 0.00400000019, green: 0.200000003, blue: 0.3919999897, alpha: 1)
    }
    
    @objc func downloadPDF(sender : UITapGestureRecognizer) {
        if Reachability.isConnectedToNetwork() {
            viewModel.downloadAssessment(fileId: fileId)
        } else {
            Alert.showInternetFailureAlert(on: self)
        }
    }
    
    // This will creates a PDF file
    func createPDF(with base64Info: String) {
        let base64Data = Data(base64Encoded: base64Info, options: .ignoreUnknownCharacters)
        let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
        let docName = "QuestionPaper-\(assessmentName)\(assessmentId).\(fileExtension)"
        let filePath = "\(documentsPath)/\(docName)"
        if FileManager.default.fileExists(atPath: filePath) {
            self.view.makeToast("File already exist!")
        } else {
            let url = URL(fileURLWithPath: filePath)
            do {
                try base64Data?.write(to: url, options: .atomic)
                self.view.makeToast("Download successful.")
            } catch let failedError {
                print("Failed to write the pdf data due to \(failedError.localizedDescription)")
            }
        }
    }
    
    @objc func upload(sender : UITapGestureRecognizer) {
        var documentPicker: UIDocumentPickerViewController!
        if #available(iOS 14, *) {
            // iOS 14 & later
            let supportedTypes: [UTType] = [UTType.pdf]
            documentPicker = UIDocumentPickerViewController(forOpeningContentTypes: supportedTypes)
        } else {
            // iOS 13 or older code
            let supportedTypes: [String] = [kUTTypePDF as String]
            documentPicker = UIDocumentPickerViewController(documentTypes: supportedTypes, in: .import)
        }
        documentPicker.delegate = self
        documentPicker.allowsMultipleSelection = true
        documentPicker.modalPresentationStyle = .formSheet
        self.present(documentPicker, animated: true)
    }
    
    
    /*
     // MARK: - Navigation
     
     // In a storyboard-based application, you will often want to do a little preparation before navigation
     override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
     // Get the new view controller using segue.destination.
     // Pass the selected object to the new view controller.
     }
     */
    
    @IBAction func sideMenuAction(_ sender: UIBarButtonItem) {
        let menu = storyboard!.instantiateViewController(withIdentifier: "SideMenuNavigationController") as! SideMenuNavigationController
        present(menu, animated: true, completion: nil)
    }
    
}

extension OfflineAssessmentViewController: OfflineAssessmentProtocol {
    func startLoader() {
        ActivityIndicator.start()
    }
    
    func stopLoader() {
        ActivityIndicator.stop()
    }
    
    func showError(error: String) {
        self.view.makeToast(error)
    }
    
    func getDownloadedFile(base64:String) {
        self.createPDF(with: base64)
    }
    
    func moveToAssessment() {
        let vc = self.storyboard?.instantiateViewController(withIdentifier: "AssessmentBeneficiaryViewController") as! AssessmentBeneficiaryViewController
        self.navigationController?.pushViewController(vc, animated: true)
    }
}

extension OfflineAssessmentViewController: UIDocumentPickerDelegate {
    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        
        for url in urls {
            
            // Start accessing a security-scoped resource.
            guard url.startAccessingSecurityScopedResource() else {
                // Handle the failure here.
                return
            }
            
            do {
                let data = try Data.init(contentsOf: url)
                print("url: \(url)")
                if Reachability.isConnectedToNetwork() {
                    // You will have data of the selected file
                    viewModel.uploadAssessment(assessmentId: assessmentId, userId: userData[0].id, fileType: "pdf", docData: data)
                } else {
                    Alert.showInternetFailureAlert(on: self)
                }
                
            }
            catch {
                print(error.localizedDescription)
            }
            
            // Make sure you release the security-scoped resource when you finish.
            do { url.stopAccessingSecurityScopedResource() }
        }
    }
    
    func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
        controller.dismiss(animated: true, completion: nil)
    }
}