// Copyright 2021 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#if canImport(Combine) && swift(>=5.0)

  #if os(iOS) || targetEnvironment(macCatalyst)

    import Combine
    import FirebaseAuth

    @available(swift 5.0)
    @available(iOS 13.0, macCatalyst 13.0, *)
    @available(macOS, unavailable)
    @available(tvOS, unavailable)
    @available(watchOS, unavailable)
    public extension OAuthProvider {
      /// Used to obtain an auth credential via a mobile web flow.
      ///
      /// The publisher will emit events on the **main** thread.
      ///
      /// - Parameter uiDelegate: An optional UI delegate used to presenet the mobile web flow.
      /// - Returns: A publisher that emits an `AuthCredential` when the credential is obtained
      ///   successfully, or an error otherwise. The publisher will emit on the *main* thread.
      func getCredentialWith(_ uiDelegate: AuthUIDelegate?)
        -> Future<AuthCredential, Error> {
        Future<AuthCredential, Error> { promise in
          self.getCredentialWith(uiDelegate) { authCredential, error in
            if let error = error {
              promise(.failure(error))
            } else if let authCredential = authCredential {
              promise(.success(authCredential))
            }
          }
        }
      }
    }

  #endif // os(iOS) || targetEnvironment(macCatalyst)

#endif // canImport(Combine) && swift(>=5.0)
