[REST API] Use case to generate and delete Application password

Networking/Networking.xcodeproj/project.pbxproj

@@ -729,7 +729,9 @@
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 		E1BAB2C52913FB1800C3982B /* WordPressApiValidator.swift in Sources */ = {isa = PBXBuildFile; fileRef = E1BAB2C42913FB1800C3982B /* WordPressApiValidator.swift */; };
 		E1BAB2C72913FB5800C3982B /* WordPressApiError.swift in Sources */ = {isa = PBXBuildFile; fileRef = E1BAB2C62913FB5800C3982B /* WordPressApiError.swift */; };
-		EE54C8942947229800A9BF61 /* ApplicationPasswordUseCase.swift in Sources */ = {isa = PBXBuildFile; fileRef = EE54C8932947229800A9BF61 /* ApplicationPasswordUseCase.swift */; };
+		EE54C89F2947782E00A9BF61 /* ApplicationPasswordUseCase.swift in Sources */ = {isa = PBXBuildFile; fileRef = EE54C89E2947782E00A9BF61 /* ApplicationPasswordUseCase.swift */; };
+		EE54C8A5294859D200A9BF61 /* ApplicationPasswordNetwork.swift in Sources */ = {isa = PBXBuildFile; fileRef = EE54C8A4294859D200A9BF61 /* ApplicationPasswordNetwork.swift */; };
+		EE54C8A729486B6800A9BF61 /* ApplicationPasswordMapper.swift in Sources */ = {isa = PBXBuildFile; fileRef = EE54C8A629486B6800A9BF61 /* ApplicationPasswordMapper.swift */; };
 		EE8A86F1286C5226003E8AA4 /* media-update-product-id-in-wordpress-site.json in Resources */ = {isa = PBXBuildFile; fileRef = EE8A86F0286C5226003E8AA4 /* media-update-product-id-in-wordpress-site.json */; };
 		EECB7EE8286555180028C888 /* media-update-product-id.json in Resources */ = {isa = PBXBuildFile; fileRef = EECB7EE7286555180028C888 /* media-update-product-id.json */; };
 		FE28F6E226840DED004465C7 /* User.swift in Sources */ = {isa = PBXBuildFile; fileRef = FE28F6E126840DED004465C7 /* User.swift */; };
@@ -1491,7 +1493,9 @@
 		E1BAB2C22913FA6400C3982B /* ResponseDataValidator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ResponseDataValidator.swift; sourceTree = "<group>"; };
 		E1BAB2C42913FB1800C3982B /* WordPressApiValidator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WordPressApiValidator.swift; sourceTree = "<group>"; };
 		E1BAB2C62913FB5800C3982B /* WordPressApiError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WordPressApiError.swift; sourceTree = "<group>"; };
-		EE54C8932947229800A9BF61 /* ApplicationPasswordUseCase.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ApplicationPasswordUseCase.swift; sourceTree = "<group>"; };
+		EE54C89E2947782E00A9BF61 /* ApplicationPasswordUseCase.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ApplicationPasswordUseCase.swift; sourceTree = "<group>"; };
+		EE54C8A4294859D200A9BF61 /* ApplicationPasswordNetwork.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ApplicationPasswordNetwork.swift; sourceTree = "<group>"; };
+		EE54C8A629486B6800A9BF61 /* ApplicationPasswordMapper.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ApplicationPasswordMapper.swift; sourceTree = "<group>"; };
 		EE8A86F0286C5226003E8AA4 /* media-update-product-id-in-wordpress-site.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = "media-update-product-id-in-wordpress-site.json"; sourceTree = "<group>"; };
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 		F3F25DC15EC1D7C631169CB5 /* Pods_Networking.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_Networking.framework; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -1704,6 +1708,7 @@
 				B518662320A099BF00037A38 /* AlamofireNetwork.swift */,
 				B518662620A09BCC00037A38 /* MockNetwork.swift */,
 				D87F6150226591E10031A13B /* NullNetwork.swift */,
+				EE54C8A4294859D200A9BF61 /* ApplicationPasswordNetwork.swift */,
 			);
 			path = Network;
 			sourceTree = "<group>";
@@ -1816,7 +1821,7 @@
 		B557D9E5209753AA005962F4 /* Networking */ = {
 			isa = PBXGroup;
 			children = (
-				EE54C8922947227900A9BF61 /* ApplicationPassword */,
+				EE54C899294777D000A9BF61 /* ApplicationPassword */,
 				B5A0369F214C0F4C00774E2C /* Internal */,
 				B5BB1D0A20A204F400112D92 /* Extensions */,
 				B567AF2720A0FA0A00AB6C62 /* Mapper */,
@@ -2376,6 +2381,7 @@
 				DE34051828BDEE6A00CF0D97 /* JetpackConnectionURLMapper.swift */,
 				68CB800D28D8901B00E169F8 /* CustomerMapper.swift */,
 				68F48B0C28E3B2E80045C15B /* WCAnalyticsCustomerMapper.swift */,
+				EE54C8A629486B6800A9BF61 /* ApplicationPasswordMapper.swift */,
 			);
 			path = Mapper;
 			sourceTree = "<group>";
@@ -2578,10 +2584,10 @@
 			path = SystemStatusDetails;
 			sourceTree = "<group>";
 		};
-		EE54C8922947227900A9BF61 /* ApplicationPassword */ = {
+		EE54C899294777D000A9BF61 /* ApplicationPassword */ = {
 			isa = PBXGroup;
 			children = (
-				EE54C8932947229800A9BF61 /* ApplicationPasswordUseCase.swift */,
+				EE54C89E2947782E00A9BF61 /* ApplicationPasswordUseCase.swift */,
 			);
 			path = ApplicationPassword;
 			sourceTree = "<group>";
@@ -3022,6 +3028,7 @@
 				FE28F6E6268429B6004465C7 /* UserRemote.swift in Sources */,
 				7452387421124B7700A973CD /* AnyDecodable.swift in Sources */,
 				CEF88DAD233E95B000BED485 /* OrderRefundCondensed.swift in Sources */,
+				EE54C8A729486B6800A9BF61 /* ApplicationPasswordMapper.swift in Sources */,
 				FE28F6E426842848004465C7 /* UserMapper.swift in Sources */,
 				CE430670234B99F50073CBFF /* RefundsRemote.swift in Sources */,
 				B56C1EB620EA757B00D749F9 /* SiteListMapper.swift in Sources */,
@@ -3072,7 +3079,7 @@
 				743E84EE2217244C00FAC9D7 /* ShipmentTrackingListMapper.swift in Sources */,
 				451A97E5260B631E0059D135 /* ShippingLabelPredefinedPackage.swift in Sources */,
 				BAB373722795A1FB00837B4A /* OrderTaxLine.swift in Sources */,
-				EE54C8942947229800A9BF61 /* ApplicationPasswordUseCase.swift in Sources */,
+				EE54C89F2947782E00A9BF61 /* ApplicationPasswordUseCase.swift in Sources */,
 				B567AF2520A0CCA300AB6C62 /* AuthenticatedRequest.swift in Sources */,
 				453305E92459DF2100264E50 /* PostMapper.swift in Sources */,
 				E12552C526385B05001CEE70 /* ShippingLabelAddressValidationSuccess.swift in Sources */,
@@ -3222,6 +3229,7 @@
 				93D8BBFD226BBEE800AD2EB3 /* AccountSettingsMapper.swift in Sources */,
 				31D27C8726028CE9002EDB1D /* SitePluginsMapper.swift in Sources */,
 				74D522B62113607F00042831 /* StatGranularity.swift in Sources */,
+				EE54C8A5294859D200A9BF61 /* ApplicationPasswordNetwork.swift in Sources */,
 				02C2549A25636E1500A04423 /* ShippingLabelAddress.swift in Sources */,
 				03DCB786262739D200C8953D /* CouponMapper.swift in Sources */,
 				B518662220A097C200037A38 /* Network.swift in Sources */,

Networking/Networking/ApplicationPassword/ApplicationPasswordUseCase.swift

@@ -1,5 +1,11 @@
 import Foundation
 import WordPressShared
+import KeychainAccess
+
+enum ApplicationPasswordUseCaseError: Error {
+    case duplicateName
+    case applicationPasswordsDisabled
+}
 
 struct ApplicationPassword {
     /// WordPress org username that the application password belongs to
@@ -28,3 +34,235 @@ protocol ApplicationPasswordUseCase {
     ///
     func deletePassword() async throws
 }
+
+final class DefaultApplicationPasswordUseCase: ApplicationPasswordUseCase {
+    /// WordPress.com Credentials.
+    ///
+    private let credentials: Credentials
+
+    /// SiteID needed when using WPCOM credentials
+    ///
+    private let siteID: Int64
+
+    /// To generate and delete application password
+    ///
+    private let network: Network
+
+    /// Stores the application password
+    ///
+    private let keychain: Keychain
+
+    /// Used to name the password in wpadmin.
+    ///
+    private var applicationPasswordName: String {
+        get async {
+            let bundleIdentifier = Bundle.main.bundleIdentifier ?? "Unknown"
+            let model = await UIDevice.current.model
+            return bundleIdentifier + ".ios-app-client." + model
+        }
+    }
+
+    init(siteID: Int64,
+         networkcredentials: Credentials,
+         network: Network? = nil,
+         keychain: Keychain = Keychain(service: KeychainServiceName.name)) {
+        self.siteID = siteID
+        self.credentials = networkcredentials
+        self.keychain = keychain
+
+        if let network {
+            self.network = network
+        } else {
+            self.network = ApplicationPasswordNetwork(credentials: networkcredentials)
+        }
+    }
+
+    /// Returns the locally saved ApplicationPassword if available
+    ///
+    var applicationPassword: ApplicationPassword? {
+        guard let password = keychain.applicationPassword,
+              let username = keychain.applicationPasswordUsername else {
+            return nil
+        }
+        return ApplicationPassword(wpOrgUsername: username, password: Secret(password))
+    }
+
+    /// Generates new ApplicationPassword
+    ///
+    /// When `duplicateName` error occurs this method will delete the password and try generating again
+    ///
+    /// - Returns: Generated `ApplicationPassword` instance
+    ///
+    func generateNewPassword() async throws -> ApplicationPassword {
+        let password = try await {
+            do {
+                return try await createApplicationPasswordUsingWPCOMAuthToken()
+            } catch ApplicationPasswordUseCaseError.duplicateName {
+                try await deletePassword()
+                return try await createApplicationPasswordUsingWPCOMAuthToken()
+            }
+        }()
+        let username = try await fetchWPAdminUsername()
+
+        let applicationPassword = ApplicationPassword(wpOrgUsername: username, password: Secret(password))
+        saveApplicationPassword(applicationPassword)
+        return applicationPassword
+    }
+
+    /// Deletes the application password
+    ///
+    ///  Deletes locally and also sends an API request to delete it from the site
+    ///
+    func deletePassword() async throws {
+        try await deleteApplicationPasswordUsingWPCOMAuthToken()
+    }
+}
+
+private extension DefaultApplicationPasswordUseCase {
+    /// Creates application password using WordPress.com authentication token
+    ///
+    /// - Returns: Application password as `String`
+    ///
+    func createApplicationPasswordUsingWPCOMAuthToken() async throws -> String {
+        let passwordName = await applicationPasswordName
+
+        let parameters = [ParameterKey.name: passwordName]
+        let request = JetpackRequest(wooApiVersion: .none, method: .post, siteID: siteID, path: Path.applicationPasswords, parameters: parameters)
+
+        return try await withCheckedThrowingContinuation { continuation in
+            network.responseData(for: request) { result in
+                switch result {
+                case .success(let data):
+                    do {
+                        let validator = request.responseDataValidator()
+                        try validator.validate(data: data)
+                        let mapper = ApplicationPasswordMapper()
+                        let password = try mapper.map(response: data)
+                        continuation.resume(returning: password)
+                    } catch let DotcomError.unknown(code, _) where code == ErrorCode.applicationPasswordsDisabledErrorCode {
+                        continuation.resume(throwing: ApplicationPasswordUseCaseError.applicationPasswordsDisabled)
+                    } catch let DotcomError.unknown(code, _) where code == ErrorCode.duplicateNameErrorCode {
+                        continuation.resume(throwing: ApplicationPasswordUseCaseError.duplicateName)
+                    } catch {
+                        continuation.resume(throwing: error)
+                    }
+                case .failure(let error):
+                    continuation.resume(throwing: error)
+                }
+            }
+        }
+    }
+
+    /// Fetches wpadmin username using WordPress.com authentication token
+    ///
+    /// - Returns: wpadmin username
+    ///
+    func fetchWPAdminUsername() async throws -> String {
+        let parameters = [
+            "context": "edit",
+            "fields": "id,username,id_wpcom,email,first_name,last_name,nickname,roles"
+        ]
+        let request = JetpackRequest(wooApiVersion: .none, method: .get, siteID: siteID, path: Path.users, parameters: parameters)
+
+        return try await withCheckedThrowingContinuation { continuation in
+            network.responseData(for: request) { [weak self] result in
+                guard let self else { return }
+
+                switch result {
+                case .success(let data):
+                    do {
+                        let validator = request.responseDataValidator()
+                        try validator.validate(data: data)
+                        let mapper = UserMapper(siteID: self.siteID)
+                        let username =  try mapper.map(response: data).username
+                        continuation.resume(returning: username)
+                    } catch {
+                        continuation.resume(throwing: error)
+                    }
+                case .failure(let error):
+                    continuation.resume(throwing: error)
+                }
+            }
+        }
+    }
+
+    /// Deletes application password using WordPress.com authentication token
+    ///
+    func deleteApplicationPasswordUsingWPCOMAuthToken() async throws {
+        // Delete password from keychain
+        keychain.applicationPassword = nil
+        keychain.applicationPasswordUsername = nil
+
+        let passwordName = await applicationPasswordName
+
+        let parameters = [ParameterKey.name: passwordName]
+        let request = JetpackRequest(wooApiVersion: .none, method: .delete, siteID: siteID, path: Path.applicationPasswords, parameters: parameters)
+
+        try await withCheckedThrowingContinuation { continuation in
+            network.responseData(for: request) { result in
+                switch result {
+                case .success(let data):
+                    do {
+                        let validator = request.responseDataValidator()
+                        try validator.validate(data: data)
+                        continuation.resume()
+                    } catch {
+                        continuation.resume(throwing: error)
+                    }
+                case .failure(let error):
+                    continuation.resume(throwing: error)
+                }
+            }
+        }
+    }
+
+    /// Saves application password into keychain
+    ///
+    /// - Parameter password: `ApplicationPasword` to be saved
+    ///
+    func saveApplicationPassword(_ password: ApplicationPassword) {
+        keychain.applicationPassword = password.wpOrgUsername
+        keychain.applicationPasswordUsername = password.password.secretValue
+    }
+}
+
+// MARK: - Constants
+//
+private extension DefaultApplicationPasswordUseCase {
+    enum KeychainServiceName {
+        /// Matching `WooConstants.keychainServiceName`
+        ///
+        static let name = "com.automattic.woocommerce"
+    }
+
+    enum Path {
+        static let applicationPasswords = "wp/v2/users/me/application-passwords"
+        static let users = "wp/v2/users/me"
+    }
+
+    enum ParameterKey {
+        static let name = "name"
+    }
+
+    enum ErrorCode {
+        static let applicationPasswordsDisabledErrorCode = "application_passwords_disabled"
+        static let duplicateNameErrorCode = "application_password_duplicate_name"
+    }
+}
+
+// MARK: - For storing the application password in keychain
+//
+private extension Keychain {
+    private static let keychainApplicationPassword = "ApplicationPassword"
+    private static let keychainApplicationPasswordUsername = "ApplicationPasswordUsername"
+
+    var applicationPassword: String? {
+        get { self[Keychain.keychainApplicationPassword] }
+        set { self[Keychain.keychainApplicationPassword] = newValue }
+    }
+
+    var applicationPasswordUsername: String? {
+        get { self[Keychain.keychainApplicationPasswordUsername] }
+        set { self[Keychain.keychainApplicationPasswordUsername] = newValue }
+    }
+}

Networking/Networking/Mapper/ApplicationPasswordMapper.swift

@@ -0,0 +1,20 @@
+import Foundation
+
+struct ApplicationPasswordMapper: Mapper {
+    private struct ApplicationPassword: Decodable {
+        let password: String
+    }
+
+    private struct ApplicationPasswordEnvelope: Decodable {
+        let password: ApplicationPassword
+
+        private enum CodingKeys: String, CodingKey {
+            case password = "data"
+        }
+    }
+
+    func map(response: Data) throws -> String {
+        let decoder = JSONDecoder()
+        return try decoder.decode(ApplicationPasswordEnvelope.self, from: response).password.password
+    }
+}