FirebaseInstallationsPlugin.swift

// Copyright 2021 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if canImport(FlutterMacOS)
  import FlutterMacOS
#else
  import Flutter
#endif

import firebase_core
import FirebaseInstallations

let kFLTFirebaseInstallationsChannelName = "plugins.flutter.io/firebase_app_installations"

public class FirebaseInstallationsPluginSwift: FLTFirebasePlugin, FlutterPlugin {
  private var eventSink: FlutterEventSink?
  private var messenger: FlutterBinaryMessenger

  var result: FLTFirebaseMethodCallResult?
  var streamHandler = [String: IdChangedStreamHandler?]()

  var args = NSDictionary()

  init(messenger: FlutterBinaryMessenger) {
    self.messenger = messenger
  }

  public static func register(with registrar: FlutterPluginRegistrar) {
    let binaryMessenger: FlutterBinaryMessenger

    #if os(macOS)
      binaryMessenger = registrar.messenger
    #elseif os(iOS)
      binaryMessenger = registrar.messenger()
    #endif

    let channel = FlutterMethodChannel(
      name: kFLTFirebaseInstallationsChannelName,
      binaryMessenger: binaryMessenger
    )
    let instance = FirebaseInstallationsPluginSwift(messenger: binaryMessenger)
    registrar.addMethodCallDelegate(instance, channel: channel)
  }

  /// Gets Installations instance for a Firebase App.
  /// - Returns: a Firebase Installations instance for the passed app from Dart
  internal func getInstallations() -> Installations {
    let app: FirebaseApp = FLTFirebasePlugin.firebaseAppNamed(args["appName"] as! String)!
    return Installations.installations(app: app)
  }

  /// Gets Installations Id for an instance.
  /// - Parameter arguments: the arguments passed by the Dart calling method
  /// - Parameter result: the result instance used to send the result to Dart.
  internal func getId() {
    let instance: Installations = getInstallations()
    instance.installationID { (id: String?, error: Error?) in
      if error != nil {
        self.result!.error(nil, nil, nil, error)
      } else {
        self.result!.success(id)
      }
    }
  }

  /// Deletes Installations Id for an instance.
  internal func deleteId() {
    let instance: Installations = getInstallations()
    instance.delete { (error: Error?) in
      if error != nil {
        self.result!.error(nil, nil, nil, error)
      } else {
        self.result!.success(nil)
      }
    }
  }

  /// Gets the token Id for an instance.
  internal func getToken() {
    let instance: Installations = getInstallations()
    let forceRefresh: Bool = (args["forceRefresh"] as? Bool) ?? false

    instance.authTokenForcingRefresh(
      forceRefresh,
      completion: { (tokenResult: InstallationsAuthTokenResult?, error: Error?) in
        if error != nil {
          self.result!.error(nil, nil, nil, error)
        } else {
          self.result!.success(tokenResult?.authToken)
        }
      }
    )
  }

  /// Starts listening to Installation ID events for an instance.
  internal func registerIdChangeListener() {
    let instance: Installations = getInstallations()

    let appName = (args["appName"] as! String)
    let eventChannelName: String = kFLTFirebaseInstallationsChannelName + "/token/" + appName

    let eventChannel = FlutterEventChannel(name: eventChannelName, binaryMessenger: messenger)

    if streamHandler[eventChannelName] == nil {
      streamHandler[eventChannelName] = IdChangedStreamHandler(instance: instance)
    }

    eventChannel.setStreamHandler(streamHandler[eventChannelName]!)

    result?.success(eventChannelName)
  }

  internal func mapInstallationsErrorCodes(code: UInt) -> NSString {
    let error = InstallationsErrorCode(InstallationsErrorCode
      .Code(rawValue: Int(code)) ?? InstallationsErrorCode.unknown)

    switch error {
    case InstallationsErrorCode.invalidConfiguration:
      return "invalid-configuration"
    case InstallationsErrorCode.keychain:
      return "invalid-keychain"
    case InstallationsErrorCode.serverUnreachable:
      return "server-unreachable"
    case InstallationsErrorCode.unknown:
      return "unknown"
    default:
      return "unknown"
    }
  }

  public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
    let args = call.arguments as! NSDictionary

    let errorBlock: FLTFirebaseMethodCallErrorBlock = { (code, message, details, error: Error?) in
      var errorDetails = [String: Any?]()

      errorDetails["code"] = code ?? self
        .mapInstallationsErrorCodes(code: UInt((error! as NSError).code))
      errorDetails["message"] = message ?? error?
        .localizedDescription ?? "An unknown error has occurred."
      errorDetails["additionalData"] = details

      if code == "unknown" {
        NSLog(
          "FLTFirebaseInstallations: An error occurred while calling method %@",
          call.method
        )
      }

      result(FLTFirebasePlugin.createFlutterError(fromCode: errorDetails["code"] as! String,
                                                  message: errorDetails["message"] as! String,
                                                  optionalDetails: errorDetails[
                                                    "additionalData"
                                                  ] as? [AnyHashable: Any],
                                                  andOptionalNSError: error))
    }

    self.result = .create(success: result, andErrorBlock: errorBlock)
    self.args = args

    switch call.method {
    case "FirebaseInstallations#getId":
      getId()
    case "FirebaseInstallations#delete":
      deleteId()
    case "FirebaseInstallations#getToken":
      getToken()
    case "FirebaseInstallations#registerIdChangeListener":
      registerIdChangeListener()
    default:
      result(FlutterMethodNotImplemented)
    }
  }
}