/*

 * Copyright 2021, gRPC Authors All rights reserved.

 *

 * 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.

 */

import EchoModel

import GRPC

@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)

public final class EchoAsyncProvider: Echo_EchoAsyncProvider {

  public let interceptors: Echo_EchoServerInterceptorFactoryProtocol?

  public init(interceptors: Echo_EchoServerInterceptorFactoryProtocol? = nil) {

    self.interceptors = interceptors

  }

  public func get(

    request: Echo_EchoRequest,

    context: GRPCAsyncServerCallContext

  ) async throws -> Echo_EchoResponse {

    return .with {

      $0.text = "Swift echo get: " + request.text

    }

  }

  public func expand(

    request: Echo_EchoRequest,

    responseStream: GRPCAsyncResponseStreamWriter<Echo_EchoResponse>,

    context: GRPCAsyncServerCallContext

  ) async throws {

    for (i, part) in request.text.components(separatedBy: " ").lazy.enumerated() {

      try await responseStream.send(.with { $0.text = "Swift echo expand (\(i)): \(part)" })

    }

  }

  public func collect(

    requestStream: GRPCAsyncRequestStream<Echo_EchoRequest>,

    context: GRPCAsyncServerCallContext

  ) async throws -> Echo_EchoResponse {

    let text = try await requestStream.reduce(into: "Swift echo collect:") { result, request in

      result += " \(request.text)"

    }

    return .with { $0.text = text }

  }

  public func update(

    requestStream: GRPCAsyncRequestStream<Echo_EchoRequest>,

    responseStream: GRPCAsyncResponseStreamWriter<Echo_EchoResponse>,

    context: GRPCAsyncServerCallContext

  ) async throws {

    var counter = 0

    for try await request in requestStream {

      let text = "Swift echo update (\(counter)): \(request.text)"

      try await responseStream.send(.with { $0.text = text })

      counter += 1

    }

  }

}