Bulk Editing: Add price picker

WooCommerce/Classes/ViewRelated/Products/PriceInputViewController.swift

@@ -0,0 +1,165 @@
+import UIKit
+import Yosemite
+import Combine
+
+final class PriceInputViewController: UIViewController {
+
+    let tableView: UITableView = UITableView(frame: .zero, style: .grouped)
+
+    private var viewModel: PriceInputViewModel
+    private var subscriptions = Set<AnyCancellable>()
+
+    private lazy var noticePresenter: NoticePresenter = {
+        let noticePresenter = DefaultNoticePresenter()
+        noticePresenter.presentingViewController = self
+        return noticePresenter
+    }()
+
+    init(viewModel: PriceInputViewModel, noticePresenter: NoticePresenter? = nil) {
+        self.viewModel = viewModel
+        super.init(nibName: nil, bundle: nil)
+
+        if let noticePresenter {
+            self.noticePresenter = noticePresenter
+        }
+    }
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        configureTitleAndBackground()
+        configureTableView()
+        configureViewModel()
+    }
+}
+
+private extension PriceInputViewController {
+    func configureTitleAndBackground() {
+        title = viewModel.screenTitle()
+        view.backgroundColor = .listBackground
+
+        navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .cancel,
+                                                           target: self,
+                                                           action: #selector(cancelButtonTapped))
+        navigationItem.rightBarButtonItem = UIBarButtonItem(title: Localization.bulkEditingApply,
+                                                            style: .plain,
+                                                            target: self,
+                                                            action: #selector(applyButtonTapped))
+    }
+
+    func configureViewModel() {
+        viewModel.$applyButtonEnabled
+            .sink { [weak self] enabled in
+                self?.navigationItem.rightBarButtonItem?.isEnabled = enabled
+            }.store(in: &subscriptions)
+
+        viewModel.$inputValidationError.sink { [weak self] error in
+            guard let error = error else {
+                return
+            }
+            self?.displayNoticeForError(error)
+        }.store(in: &subscriptions)
+    }
+
+    func configureTableView() {
+        tableView.translatesAutoresizingMaskIntoConstraints = false
+        view.addSubview(tableView)
+        view.pinSubviewToAllEdges(tableView)
+
+        tableView.rowHeight = UITableView.automaticDimension
+        tableView.backgroundColor = .listBackground
+
+        tableView.registerNib(for: UnitInputTableViewCell.self)
+
+        tableView.dataSource = self
+    }
+
+    /// Called when the cancel button is tapped
+    ///
+    @objc func cancelButtonTapped() {
+        viewModel.cancelButtonTapped()
+    }
+
+    /// Called when the save button is tapped to update the price for all products
+    ///
+    @objc func applyButtonTapped() {
+        // Dismiss the keyboard before triggering the update
+        view.endEditing(true)
+        viewModel.applyButtonTapped()
+    }
+
+    func displayNoticeForError(_ productPriceSettingsError: ProductPriceSettingsError) {
+        switch productPriceSettingsError {
+        case .salePriceWithoutRegularPrice:
+            displayNotice(for: Localization.salePriceWithoutRegularPriceError)
+        case .salePriceHigherThanRegularPrice:
+            displayNotice(for: Localization.displaySalePriceError)
+        case .newSaleWithEmptySalePrice:
+            displayNotice(for: Localization.displayMissingSalePriceError)
+        }
+    }
+
+    /// Displays a Notice onscreen for a given message
+    ///
+    func displayNotice(for message: String) {
+        view.endEditing(true)
+        let notice = Notice(title: message, feedbackType: .error)
+        noticePresenter.enqueue(notice: notice)
+    }
+}
+
+// MARK: - UITableViewDataSource Conformance
+//
+extension PriceInputViewController: UITableViewDataSource {
+
+    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        return 1
+    }
+
+    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: UnitInputTableViewCell.self.reuseIdentifier, for: indexPath)
+        configure(cell, at: indexPath)
+
+        return cell
+    }
+
+    func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
+        return UITableView.automaticDimension
+    }
+
+    func tableView(_ tableView: UITableView, titleForFooterInSection section: Int) -> String? {
+        return viewModel.footerText
+    }
+
+    private func configure(_ cell: UITableViewCell, at indexPath: IndexPath) {
+        switch cell {
+        case let cell as UnitInputTableViewCell:
+            let cellViewModel = UnitInputViewModel.createBulkPriceViewModel(using: ServiceLocator.currencySettings) { [weak self] value in
+                self?.viewModel.handlePriceChange(value)
+            }
+            cell.selectionStyle = .none
+            cell.configure(viewModel: cellViewModel)
+        default:
+            fatalError("Unidentified bulk update row type")
+            break
+        }
+    }
+}
+
+private extension PriceInputViewController {
+    enum Localization {
+        static let bulkEditingApply = NSLocalizedString("Apply", comment: "Title for the button to apply bulk editing changes to selected products.")
+
+        static let salePriceWithoutRegularPriceError = NSLocalizedString("The sale price can't be added without the regular price.",
+                                                                         comment: "Bulk price update error message, when the sale price is added but the"
+                                                                            + " regular price is not")
+        static let displaySalePriceError = NSLocalizedString("The sale price should be lower than the regular price.",
+                                                             comment: "Bulk price update error, when the sale price is higher than the regular"
+                                                                + " price")
+        static let displayMissingSalePriceError = NSLocalizedString("Please enter a sale price for the scheduled sale",
+                                                                    comment: "Bulk price update error, when the sale price is empty")
+    }
+}

WooCommerce/Classes/ViewRelated/Products/PriceInputViewModel.swift

@@ -0,0 +1,138 @@
+import Foundation
+import Yosemite
+import WooFoundation
+
+/// View Model logic for the bulk price setting screen
+///
+final class PriceInputViewModel {
+
+    @Published private(set) var applyButtonEnabled: Bool = false
+
+    @Published private(set) var inputValidationError: ProductPriceSettingsError? = nil
+
+    /// This holds the latest entered price. It is used to perform validations when the user taps the apply button
+    /// and for creating a products array with the new price for the bulk update Action
+    private var currentPrice: String = ""
+
+    private let productListViewModel: ProductListViewModel
+
+    private let priceSettingsValidator: ProductPriceSettingsValidator
+    private let currencySettings: CurrencySettings
+    private let currencyFormatter: CurrencyFormatter
+
+    var cancelClosure: () -> Void = {}
+    var applyClosure: (String) -> Void = { _ in }
+
+    init(productListViewModel: ProductListViewModel,
+         currencySettings: CurrencySettings = ServiceLocator.currencySettings) {
+        self.productListViewModel = productListViewModel
+        self.priceSettingsValidator = ProductPriceSettingsValidator(currencySettings: currencySettings)
+        self.currencySettings = currencySettings
+        self.currencyFormatter = CurrencyFormatter(currencySettings: currencySettings)
+    }
+
+    /// Called when the cancel button is tapped
+    ///
+    func cancelButtonTapped() {
+        cancelClosure()
+    }
+
+    /// Called when the save button is tapped
+    ///
+    func applyButtonTapped() {
+        inputValidationError = validatePrice()
+        guard inputValidationError == nil else {
+            return
+        }
+
+        applyClosure(currentPrice)
+    }
+
+    /// Called when price changes
+    ///
+    func handlePriceChange(_ price: String?) {
+        currentPrice = price ?? ""
+        updateButtonStateBasedOnCurrentPrice()
+    }
+
+    /// Update the button state to enable/disable based on price value
+    ///
+    private func updateButtonStateBasedOnCurrentPrice() {
+        if currentPrice.isNotEmpty {
+            applyButtonEnabled = true
+        } else {
+            applyButtonEnabled = false
+        }
+    }
+
+    /// Validates if the currently selected price is valid for all products
+    ///
+    private func validatePrice() -> ProductPriceSettingsError? {
+        for product in productListViewModel.selectedProducts {
+            let regularPrice = currentPrice
+            let salePrice = product.salePrice
+
+            if let error = priceSettingsValidator.validate(regularPrice: regularPrice,
+                                                           salePrice: salePrice,
+                                                           dateOnSaleStart: product.dateOnSaleStart,
+                                                           dateOnSaleEnd: product.dateOnSaleEnd) {
+                return error
+            }
+        }
+
+        return nil
+    }
+
+    /// Returns the footer text to be displayed with information about the current bulk price and how many products will be updated.
+    ///
+    var footerText: String {
+        let numberOfProducts = productListViewModel.selectedProductsCount
+        let numberOfProductsText = String.pluralize(numberOfProducts,
+                                                      singular: Localization.productsNumberSingularFooter,
+                                                      plural: Localization.productsNumberPluralFooter)
+
+        switch productListViewModel.commonPriceForSelectedProducts {
+        case .none:
+            return [Localization.currentPriceNoneFooter, numberOfProductsText].joined(separator: " ")
+        case .mixed:
+            return [Localization.currentPriceMixedFooter, numberOfProductsText].joined(separator: " ")
+        case let .value(price):
+            let currentPriceText = String.localizedStringWithFormat(Localization.currentPriceFooter, formatPriceString(price))
+            return [currentPriceText, numberOfProductsText].joined(separator: " ")
+        }
+    }
+
+    /// It formats a price `String` according to the current price settings.
+    ///
+    private func formatPriceString(_ price: String) -> String {
+        let currencyCode = currencySettings.currencyCode
+        let currency = currencySettings.symbol(from: currencyCode)
+
+        return currencyFormatter.formatAmount(price, with: currency) ?? ""
+    }
+
+    /// Returns the title to be displayed in the top of bulk update screen
+    ///
+    func screenTitle() -> String {
+        return Localization.screenTitle
+    }
+}
+
+private extension PriceInputViewModel {
+    enum Localization {
+        static let screenTitle = NSLocalizedString("Update Regular Price", comment: "Title that appears on top of the of bulk price setting screen")
+        static let productsNumberSingularFooter = NSLocalizedString("The price will be updated for %d product.",
+                                                                    comment: "Message in the footer of bulk price setting screen (singular).")
+        static let productsNumberPluralFooter = NSLocalizedString("The price will be updated for %d products.",
+                                                                  comment: "Message in the footer of bulk price setting screen (plurar).")
+        static let currentPriceFooter = NSLocalizedString("Current price is %@.",
+                                                          comment: "Message in the footer of bulk price setting screen"
+                                                          + " with the current price, when it is the same for all products")
+        static let currentPriceMixedFooter = NSLocalizedString("Current prices are mixed.",
+                                                               comment: "Message in the footer of bulk price setting screen, when products have"
+                                                               + " different price values.")
+        static let currentPriceNoneFooter = NSLocalizedString("Current price is not set.",
+                                                              comment: "Message in the footer of bulk price setting screen, when none of the"
+                                                              + " products have price value.")
+    }
+}

WooCommerce/Classes/ViewRelated/Products/ProductsListViewModel.swift

@@ -12,7 +12,7 @@ class ProductListViewModel {
     let siteID: Int64
     private let stores: StoresManager
 
-    private var selectedProducts: Set<Product> = .init()
+    private(set) var selectedProducts: Set<Product> = .init()
 
     init(siteID: Int64, stores: StoresManager) {
         self.siteID = siteID
@@ -43,6 +43,17 @@ class ProductListViewModel {
         selectedProducts.removeAll()
     }
 
+    /// Represents if a property in a collection of `Product`  has the same value or different values or is missing.
+    ///
+    enum BulkValue: Equatable {
+        /// All variations have the same value
+        case value(String)
+        /// When variations have mixed values.
+        case mixed
+        /// None of the variation has a value
+        case none
+    }
+
     /// Check if selected products share the same common ProductStatus. Returns `nil` otherwise.
     ///
     var commonStatusForSelectedProducts: ProductStatus? {
@@ -54,6 +65,18 @@ class ProductListViewModel {
         }
     }
 
+    /// Check if selected products share the same common ProductStatus. Returns `nil` otherwise.
+    ///
+    var commonPriceForSelectedProducts: BulkValue {
+        if selectedProducts.allSatisfy({ $0.regularPrice?.isEmpty != false }) {
+            return .none
+        } else if let price = selectedProducts.first?.regularPrice, selectedProducts.allSatisfy({ $0.regularPrice == price }) {
+            return .value(price)
+        } else {
+            return .mixed
+        }
+    }
+
     /// Update selected products with new ProductStatus and trigger Network action to save the change remotely.
     ///
     func updateSelectedProducts(with newStatus: ProductStatus, completion: @escaping (Result<Void, Error>) -> Void ) {
@@ -73,4 +96,24 @@ class ProductListViewModel {
         }
         stores.dispatch(batchAction)
     }
+
+    /// Update selected products with new price and trigger Network action to save the change remotely.
+    ///
+    func updateSelectedProducts(with newPrice: String, completion: @escaping (Result<Void, Error>) -> Void ) {
+        guard selectedProductsCount > 0 else {
+            completion(.failure(BulkEditError.noProductsSelected))
+            return
+        }
+
+        let updatedProducts = selectedProducts.map({ $0.copy(regularPrice: newPrice) })
+        let batchAction = ProductAction.updateProducts(siteID: siteID, products: updatedProducts) { result in
+            switch result {
+            case .success:
+                completion(.success(()))
+            case .failure(let error):
+                completion(.failure(error))
+            }
+        }
+        stores.dispatch(batchAction)
+    }
 }