AllCoursesViewController

//
//  AllCoursesViewController.swift
//  AeroBuddy
//
//  Created by Luke Collister on 01/09/2019.
//  Copyright © 2019 Luke Collister. All rights reserved.
//

import UIKit
import StoreKit

class AllCoursesViewController: UITableViewController, SKProductsRequestDelegate, SKPaymentTransactionObserver, CourseCellDelegate {

    // MARK: - Variable Declarations
    var tempData = [Course]()

    var allCourses = [Course]()
    var ownedCourses = [Course]()
    var displayCourses = [Course]()
    var mycourse: Course!

    let workingDG = DispatchGroup()

    var productsSet = Set<String>()


    // MARK: - IAP Methods
    var product_identifier: String?

    func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
        let count: Int = response.products.count
        if (count > 0) {
            let validProduct: SKProduct = response.products[0] as SKProduct
            print(validProduct.localizedTitle)
            print(validProduct.localizedDescription)
            print(validProduct.price)
            buyProduct(product: validProduct)
        } else {
            print("nothing")
        }
    }

    func buyProduct(product: SKProduct) {
        print("Sending the Payment Request to Apple")
        let payment = SKPayment(product: product)
        SKPaymentQueue.default().add(payment)
    }

    func request(_ request: SKRequest, didFailWithError error: Error) {
        print("Error Fetching product information")
    }

    func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
        print("Received Payment Transaction Response from Apple")

        print("Transactions: ", transactions)

        for transaction: AnyObject in transactions {
            if let trans:SKPaymentTransaction = transaction as? SKPaymentTransaction {
                switch trans.transactionState {
                case .purchased:
                    print("Product Purchased")
                    SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)
                    // Handle the purchase
                    UserDefaults.standard.set(true , forKey: "purchased")
                    // Get the receipt if it's available
                    if let appStoreReceiptURL = Bundle.main.appStoreReceiptURL, FileManager.default.fileExists(atPath: appStoreReceiptURL.path) {

                        do {
                            let receiptData = try Data(contentsOf: appStoreReceiptURL, options: .alwaysMapped)
                            print("RECEIPT DATA: ", receiptData)

                            let receiptString = receiptData.base64EncodedString(options: [])
                            print("RECEIPT STRING: ", receiptString)

                            // Read receiptData
                            // Create POST request
                            let url = URL(string: "http://fe01.kilosierracharlie.me/verifypayment")!
                            var request = URLRequest(url: url)
                            request.httpMethod = "POST"
                            request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
                            let parameters: [String: Any] = [
                                "receipt": receiptString
                            ]
                            request.httpBody = parameters.percentEncoded()

                            // Send the data
                            print("Before URLSession")
                            let task = URLSession.shared.dataTask(with: request) { data, response, error in
                                guard let data = data, error == nil else {
                                    print(error?.localizedDescription ?? "No data")
                                    print("No data could be sent to the server. Please contact us.")
                                    return
                                }
                                let responseJSON = try? JSONSerialization.jsonObject(with: data, options: [])
                                if let responseJSON = responseJSON as? [String: Any] {
                                    print(responseJSON)
                                    //TO DO: Refresh if error false, else throw error
                                }
                                print("DATA: ", data)
                            }
                            print("Here")
                            task.resume()
                        }
                        catch {
                            print("Couldn't read receipt data with error: " + error.localizedDescription)
                        }
                    }
                    break;

                case .failed:
                    print("Purchased Failed")
                    SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)
                    break;

                case .restored:
                    print("Already Purchased")
                    SKPaymentQueue.default().restoreCompletedTransactions()

                    // Handle the purchase
                    UserDefaults.standard.set(true , forKey: "purchased")
                    //adView.hidden = true
                    break;
                default:
                    print("In default")
                    break;
                }
            }
        }
    }



    // MARK: - Default Methods
    override func viewDidLoad() {
        super.viewDidLoad()

        // Set Activity Indicator and show
        let activityIndicator = MyIndicator(frame: CGRect(x: UIScreen.main.bounds.size.width/2 - 75, y: UIScreen.main.bounds.size.height/2 - 150, width: 150, height: 150), image: UIImage(named: "LOADING.png")!)
        view.addSubview(activityIndicator)
        activityIndicator.startAnimating()

        // Clear the arrays in case of refresh
        displayCourses.removeAll()
        ownedCourses.removeAll()
        allCourses.removeAll()
        self.tableView.reloadData()

        // Provide an empty backBarButton to hide the 'Back' text present by default in the back button.
        self.navigationItem.setHidesBackButton(true, animated:true)

        // Add a right navigation bar button to allow refreshing of JSON
        navigationItem.rightBarButtonItem = UIBarButtonItem(image: UIImage(systemName: "arrow.clockwise"), style: .plain, target: self, action: #selector(viewDidLoad))

        // IAP Code
        SKPaymentQueue.default().add(self)

        // Display the content
        DispatchQueue.global(qos: .background).async {
            self.workingDG.enter()
            self.getAllCourses(endpoint: "courses")
            self.workingDG.enter()
            self.getAllCourses(endpoint: "courses/my")

            self.workingDG.notify(queue: .main) {
                for i in 0 ..< self.ownedCourses.count {
                    self.ownedCourses[i].owned = true
                }

                var idArray = [Int]()
                for course in self.ownedCourses {
                    idArray.append(course.id)
                }
                for course in self.allCourses {
                    course.owned = idArray.contains(course.id)
                    self.displayCourses.append(course)
                }
                self.tableView.reloadData()

                // Stop the activity indicator
                DispatchQueue.main.async {
                    activityIndicator.stopAnimating()
                }
            }
        }
    }


    // MARK: - JSON Methods
    func getAllCourses(endpoint: String) {
        let url = URL(string: "\(ServHandler.connectProtocol)://\(ServHandler.baseURL)/\(endpoint)")
        let task = URLSession.shared.dataTask(with: url!) {(data, response, error) in
            guard error == nil else {
                print("Error!")
                return
            }
            guard let content = data else {
                print("There is no data!")
                return
            }

            let decoder = JSONDecoder()
            do {
                for course in try decoder.decode([Course].self, from: content) {
                    if (endpoint == "courses") {
                        course.product_identifier = "com.aerobuddy.course.\(course.id)"
                        self.allCourses.append(course)
                    }
                    else {
                        self.ownedCourses.append(course)
                    }
                }
                self.workingDG.leave()
                return
            }
            catch {
                print(error.localizedDescription)
                print(error)
                return
            }
        }
        task.resume()
    }


    // MARK: - UITableViewMethods
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.displayCourses.count
    }


    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "CourseCell", for: indexPath) as! CourseCell
        cell.course = displayCourses[indexPath.row]
        if (cell.course?.owned == false) {
            cell.backgroundColor = UIColor(red: 90/255, green: 90/255, blue: 90/255, alpha: 1)
        } else {
            //cell.backgroundColor = default
        }
        cell.delegate = self
        return cell
    }


    // When the cell is pressed
    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        // Determine which Course was selected
        let selectedCourse = displayCourses[indexPath.row]
        mycourse = selectedCourse
        print("Selected course: ", displayCourses[indexPath.row])

        // Load the subjects for this course
        performSegue(withIdentifier: "courseToSubjectSegue", sender: self)
    }


    func cellButtonTapped(cell: CourseCell) {
        // Trigger an alert to buy the course
        let alert = UIAlertController(title: "Purchase Course?", message: "You do not own this course. Do you wish to purchase it? Pressing \"Yes\" will purchase *all* subjects and topics within the course.", preferredStyle: .alert)

        // Add the course product identifier to the set
        let buttonPosition: CGPoint = cell.convert(CGPoint.zero, to: self.tableView)
        let indexPath = self.tableView.indexPathForRow(at: buttonPosition)
        productsSet.insert(displayCourses[indexPath!.row].product_identifier!)
        print("PRODUCTS SET: ", productsSet)

        // Yes option
        alert.addAction(UIAlertAction(title: "Yes", style: .default, handler: { action in
           // IAP Code Here
           if (SKPaymentQueue.canMakePayments())
           {
               let productsRequest: SKProductsRequest = SKProductsRequest(productIdentifiers: self.productsSet)
               productsRequest.delegate = self
               productsRequest.start()
               print("Fetching Products")
           } else {
               print("Can't make purchases")
           }
        }))
        // No option
        alert.addAction(UIAlertAction(title: "No", style: .cancel, handler: { action in
            self.productsSet.removeAll()
        }))

        self.present(alert, animated: true)
        print("The course with product identifier ", productsSet, " was selected!")
    }


    // MARK: - Segue Methods
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "courseToSubjectSegue" {
            if let destinationVC = segue.destination as? SubjectsViewController {
                destinationVC.courseVar = mycourse
            }
        }
    }
}


// MARK: - Extensions
extension Dictionary {
    func percentEncoded() -> Data? {
        return map { key, value in
            let escapedKey = "\(key)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
            let escapedValue = "\(value)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
            print("In percentEncoded function")
            return escapedKey + "=" + escapedValue
        }
        .joined(separator: "&")
        .data(using: .utf8)
    }
}

extension CharacterSet {
    static let urlQueryValueAllowed: CharacterSet = {
        let generalDelimitersToEncode = ":#[]@" // does not include "?" or "/" due to RFC 3986 - Section 3.4
        let subDelimitersToEncode = "!$&'()*+,;="

        var allowed = CharacterSet.urlQueryAllowed
        allowed.remove(charactersIn: "\(generalDelimitersToEncode)\(subDelimitersToEncode)")
        print("In CharacterSet function")
        return allowed
    }()
}