Merge pull request #4949 from woocommerce/issue/4780-fetch-country-data

Author: Ecarrion

WooCommerce/Classes/ViewRelated/ListSelector/ListSelector.swift

@@ -1,12 +1,16 @@
 import SwiftUI
 
+/// Protocol required to re-render the view when the command updates any of it's content.
+///
+protocol ObservableListSelectorCommand: ListSelectorCommand, ObservableObject {}
+
 /// `SwiftUI` wrapper for `ListSelectorViewController`
 ///
-struct ListSelector<Command: ListSelectorCommand>: UIViewControllerRepresentable {
+struct ListSelector<Command: ObservableListSelectorCommand>: UIViewControllerRepresentable {
 
     /// Command that defines cell style and provide data.
     ///
-    let command: Command
+    @ObservedObject var command: Command
 
     /// Table view style.
     ///

WooCommerce/Classes/ViewRelated/Orders/Order Details/Address Edit/CountrySelectorCommand.swift

@@ -3,17 +3,17 @@ import Yosemite
 
 /// Command to be used to select a country when editing addresses.
 ///
-final class CountrySelectorCommand: ListSelectorCommand {
+final class CountrySelectorCommand: ObservableListSelectorCommand {
     typealias Model = Country
     typealias Cell = BasicTableViewCell
 
     /// Original array of countries.
     ///
-    private let countries: [Country]
+    private var countries: [Country]
 
     /// Data to display
     ///
-    private(set) var data: [Country]
+    @Published private(set) var data: [Country]
 
     /// Current selected country
     ///
@@ -23,7 +23,7 @@ final class CountrySelectorCommand: ListSelectorCommand {
     ///
     let navigationBarTitle: String? = ""
 
-    init(countries: [Country] = temporaryCountries, selected: Country? = nil) {
+    init(countries: [Country], selected: Country? = nil) {
         self.countries = countries
         self.data = countries
         self.selected = selected
@@ -41,6 +41,13 @@ final class CountrySelectorCommand: ListSelectorCommand {
         cell.textLabel?.text = model.name
     }
 
+    /// Resets countries data.
+    ///
+    func resetCountries(_ countries: [Country]) {
+        self.countries = countries
+        self.data = countries
+    }
+
     /// Filter available countries that contains a given search term.
     ///
     func filterCountries(term: String) {
@@ -51,16 +58,3 @@ final class CountrySelectorCommand: ListSelectorCommand {
         data = countries.filter { $0.name.localizedCaseInsensitiveContains(term) }
     }
 }
-
-// MARK: Temporary Methods
-extension CountrySelectorCommand {
-
-    // Supported countries will come from the view model later.
-    //
-    private static let temporaryCountries: [Country] = {
-        return Locale.isoRegionCodes.map { regionCode in
-            let name = Locale.current.localizedString(forRegionCode: regionCode) ?? ""
-            return Country(code: regionCode, name: name, states: [])
-        }
-    }()
-}

WooCommerce/Classes/ViewRelated/Orders/Order Details/Address Edit/CountrySelectorViewModel.swift

@@ -1,5 +1,7 @@
 import Combine
 import SwiftUI
+import Yosemite
+import protocol Storage.StorageManagerType
 
 /// View Model for the `CountrySelector` view.
 ///
@@ -10,13 +12,12 @@ final class CountrySelectorViewModel: FilterListSelectorViewModelable, Observabl
     var searchTerm: String = "" {
         didSet {
             command.filterCountries(term: searchTerm)
-            objectWillChange.send()
         }
     }
 
     /// Command that powers the `ListSelector` view.
     ///
-    let command = CountrySelectorCommand()
+    let command = CountrySelectorCommand(countries: [])
 
     /// Navigation title
     ///
@@ -25,6 +26,56 @@ final class CountrySelectorViewModel: FilterListSelectorViewModelable, Observabl
     /// Filter text field placeholder
     ///
     let filterPlaceholder = Localization.placeholder
+
+    /// ResultsController for stored countries.
+    ///
+    private lazy var countriesResultsController: ResultsController<StorageCountry> = {
+        let countriesDescriptor = NSSortDescriptor(key: "name", ascending: true)
+        return ResultsController<StorageCountry>(storageManager: storageManager, sortedBy: [countriesDescriptor])
+    }()
+
+    /// Storage to fetch countries
+    ///
+    private let storageManager: StorageManagerType
+
+    /// Stores to sync countries
+    ///
+    private let stores: StoresManager
+
+    /// Current `SiteID`, needed to sync countries from a remote source.
+    ///
+    private let siteID: Int64
+
+    init(siteID: Int64, storageManager: StorageManagerType = ServiceLocator.storageManager, stores: StoresManager = ServiceLocator.stores) {
+        self.siteID = siteID
+        self.storageManager = storageManager
+        self.stores = stores
+        fetchAndBindCountries()
+    }
+}
+
+// MARK: Helpers
+private extension CountrySelectorViewModel {
+    /// Fetches & Binds countries from storage, If there are no stored countries, sync them from a remote source.
+    ///
+    func fetchAndBindCountries() {
+        // Bind stored countries & command
+        countriesResultsController.onDidChangeContent = { [weak self] in
+            guard let self = self else { return }
+            self.command.resetCountries(self.countriesResultsController.fetchedObjects)
+        }
+
+        // Initial fetch
+        try? countriesResultsController.performFetch()
+
+        // Reset countries with fetched data or sync countries if needed.
+        if !countriesResultsController.isEmpty {
+            command.resetCountries(countriesResultsController.fetchedObjects)
+        } else {
+            let action = DataAction.synchronizeCountries(siteID: siteID, onCompletion: { _ in })
+            stores.dispatch(action)
+        }
+    }
 }
 
 // MARK: Constants

WooCommerce/Classes/ViewRelated/Orders/Order Details/Address Edit/EditAddressForm.swift

@@ -136,8 +136,7 @@ struct EditAddressForm: View {
         .disabled(!viewModel.isDoneButtonEnabled))
 
         // Go to edit country
-        // TODO: Move `CountrySelectorViewModel` creation to the VM when it exists.
-        NavigationLink(destination: FilterListSelector(viewModel: CountrySelectorViewModel()), isActive: $showCountrySelector) {
+        NavigationLink(destination: FilterListSelector(viewModel: viewModel.createCountryViewModel()), isActive: $showCountrySelector) {
             EmptyView()
         }
 
@@ -197,7 +196,7 @@ struct EditAddressForm_Previews: PreviewProvider {
                                        country: "US",
                                        phone: "333-333-3333",
                                        email: "[email protected]")
-    static let sampleViewModel = EditAddressFormViewModel(address: sampleAddress)
+    static let sampleViewModel = EditAddressFormViewModel(siteID: 123, address: sampleAddress)
 
     static var previews: some View {
         NavigationView {

WooCommerce/Classes/ViewRelated/Orders/Order Details/Address Edit/EditAddressFormViewModel.swift

@@ -2,7 +2,12 @@ import Yosemite
 
 final class EditAddressFormViewModel: ObservableObject {
 
-    init(address: Address?) {
+    /// Current site ID
+    ///
+    private let siteID: Int64
+
+    init(siteID: Int64, address: Address?) {
+        self.siteID = siteID
         self.originalAddress = address ?? .empty
         updateFieldsWithOriginalAddress()
     }
@@ -33,6 +38,12 @@ final class EditAddressFormViewModel: ObservableObject {
     var isDoneButtonEnabled: Bool {
         return originalAddress != addressFromFields
     }
+
+    /// Creates a view model to be used when selecting a country
+    ///
+    func createCountryViewModel() -> CountrySelectorViewModel {
+        CountrySelectorViewModel(siteID: siteID)
+    }
 }
 
 private extension EditAddressFormViewModel {

WooCommerce/Classes/ViewRelated/Orders/Order Details/Address Edit/FilterListSelector.swift

@@ -2,7 +2,7 @@ import SwiftUI
 
 protocol FilterListSelectorViewModelable: ObservableObject {
 
-    associatedtype Command: ListSelectorCommand
+    associatedtype Command: ObservableListSelectorCommand
 
     /// Binding variable for the filter search term
     ///
@@ -85,11 +85,3 @@ private extension SearchHeader {
         static let externalPadding = EdgeInsets(top: 10, leading: 16, bottom: 10, trailing: 16)
     }
 }
-
-struct FilterListSelector_Previews: PreviewProvider {
-    static var previews: some View {
-        NavigationView {
-            FilterListSelector(viewModel: CountrySelectorViewModel())
-        }
-    }
-}

WooCommerce/Classes/ViewRelated/Orders/Order Details/Address Edit/StateSelectorCommand.swift

@@ -3,7 +3,7 @@ import Yosemite
 
 /// Command to be used to select a state when editing addresses.
 ///
-final class StateSelectorCommand: ListSelectorCommand {
+final class StateSelectorCommand: ObservableListSelectorCommand {
     typealias Model = StateOfACountry
     typealias Cell = BasicTableViewCell
 

WooCommerce/Classes/ViewRelated/Orders/Order Details/OrderDetailsViewController.swift

@@ -661,7 +661,7 @@ private extension OrderDetailsViewController {
     }
 
     func editShippingAddressTapped() {
-        let viewModel = EditAddressFormViewModel(address: viewModel.order.shippingAddress)
+        let viewModel = EditAddressFormViewModel(siteID: viewModel.order.siteID, address: viewModel.order.shippingAddress)
         let editAddressViewController = EditAddressHostingController(viewModel: viewModel)
         show(editAddressViewController, sender: self)
     }

WooCommerce/WooCommerceTests/ViewRelated/Orders/Order Details/Addresses/CountrySelector/CountrySelectorViewModelTests.swift

@@ -5,57 +5,69 @@ import TestKit
 
 final class CountrySelectorViewModelTests: XCTestCase {
 
+    let sampleSiteID: Int64 = 123
+    let testingStorage = MockStorageManager()
+
+    override func setUp () {
+        super.setUp()
+
+        testingStorage.reset()
+        testingStorage.insertSampleCountries(readOnlyCountries: Self.sampleCountries)
+    }
+
     func test_filter_countries_return_expected_results() {
         // Given
-        let viewModel = CountrySelectorViewModel()
+        let viewModel = CountrySelectorViewModel(siteID: sampleSiteID, storageManager: testingStorage)
 
         // When
         viewModel.searchTerm = "Co"
         let countries = viewModel.command.data.map { $0.name }
+
         // Then
         assertEqual(countries, [
             "Cocos (Keeling) Islands",
-            "Congo - Kinshasa",
+            "Colombia",
+            "Comoros",
             "Congo - Brazzaville",
+            "Congo - Kinshasa",
             "Cook Islands",
-            "Colombia",
             "Costa Rica",
-            "Comoros",
-            "Morocco",
-            "Monaco",
             "Mexico",
+            "Monaco",
+            "Morocco",
             "Puerto Rico",
             "Turks & Caicos Islands"
         ])
     }
 
     func test_filter_countries_with_uppercase_letters_return_expected_results() {
         // Given
-        let viewModel = CountrySelectorViewModel()
+        let viewModel = CountrySelectorViewModel(siteID: sampleSiteID, storageManager: testingStorage)
 
         // When
         viewModel.searchTerm = "CO"
         let countries = viewModel.command.data.map { $0.name }
+
         // Then
         assertEqual(countries, [
             "Cocos (Keeling) Islands",
-            "Congo - Kinshasa",
+            "Colombia",
+            "Comoros",
             "Congo - Brazzaville",
+            "Congo - Kinshasa",
             "Cook Islands",
-            "Colombia",
             "Costa Rica",
-            "Comoros",
-            "Morocco",
-            "Monaco",
             "Mexico",
+            "Monaco",
+            "Morocco",
             "Puerto Rico",
             "Turks & Caicos Islands"
         ])
     }
 
     func test_cleaning_search_terms_return_all_countries() {
         // Given
-        let viewModel = CountrySelectorViewModel()
+        let viewModel = CountrySelectorViewModel(siteID: sampleSiteID, storageManager: testingStorage)
         let totalNumberOfCountries = viewModel.command.data.count
 
         // When
@@ -66,4 +78,36 @@ final class CountrySelectorViewModelTests: XCTestCase {
         // Then
         XCTAssertEqual(viewModel.command.data.count, totalNumberOfCountries)
     }
+
+    func test_starting_view_model_without_stored_countries_fetches_them_remotely() {
+        // Given
+        testingStorage.reset()
+        let testingStores = MockStoresManager(sessionManager: .testingInstance)
+
+
+        // When
+        let countriesFetched: Bool = waitFor { promise in
+            testingStores.whenReceivingAction(ofType: DataAction.self) { action in
+                switch action {
+                case .synchronizeCountries:
+                    promise(true)
+                }
+            }
+
+            _ = CountrySelectorViewModel(siteID: self.sampleSiteID, storageManager: self.testingStorage, stores: testingStores)
+        }
+
+        // Then
+        XCTAssertTrue(countriesFetched)
+    }
+}
+
+// MARK: Helpers
+private extension CountrySelectorViewModelTests {
+    static let sampleCountries: [Country] = {
+        return Locale.isoRegionCodes.map { regionCode in
+            let name = Locale.current.localizedString(forRegionCode: regionCode) ?? ""
+            return Country(code: regionCode, name: name, states: [])
+        }
+    }()
 }