/*

 * Copyright 2018, 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

import NIOCore

import SwiftProtobuf

public class EchoProvider: Echo_EchoProvider {

  public let interceptors: Echo_EchoServerInterceptorFactoryProtocol?

  public init(interceptors: Echo_EchoServerInterceptorFactoryProtocol? = nil) {

    self.interceptors = interceptors

  }

  public func get(

    request: Echo_EchoRequest,

    context: StatusOnlyCallContext

  ) -> EventLoopFuture<Echo_EchoResponse> {

    let response = Echo_EchoResponse.with {

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

    }

    return context.eventLoop.makeSucceededFuture(response)

  }

  public func expand(

    request: Echo_EchoRequest,

    context: StreamingResponseCallContext<Echo_EchoResponse>

  ) -> EventLoopFuture<GRPCStatus> {

    let responses = request.text.components(separatedBy: " ").lazy.enumerated().map { i, part in

      Echo_EchoResponse.with {

        $0.text = "Swift echo expand (\(i)): \(part)"

      }

    }

    context.sendResponses(responses, promise: nil)

    return context.eventLoop.makeSucceededFuture(.ok)

  }

  public func collect(

    context: UnaryResponseCallContext<Echo_EchoResponse>

  ) -> EventLoopFuture<(StreamEvent<Echo_EchoRequest>) -> Void> {

    var parts: [String] = []

    return context.eventLoop.makeSucceededFuture({ event in

      switch event {

      case let .message(message):

        parts.append(message.text)

      case .end:

        let response = Echo_EchoResponse.with {

          $0.text = "Swift echo collect: " + parts.joined(separator: " ")

        }

        context.responsePromise.succeed(response)

      }

    })

  }

  public func update(

    context: StreamingResponseCallContext<Echo_EchoResponse>

  ) -> EventLoopFuture<(StreamEvent<Echo_EchoRequest>) -> Void> {

    var count = 0

    return context.eventLoop.makeSucceededFuture({ event in

      switch event {

      case let .message(message):

        let response = Echo_EchoResponse.with {

          $0.text = "Swift echo update (\(count)): \(message.text)"

        }

        count += 1

        context.sendResponse(response, promise: nil)

      case .end:

        context.statusPromise.succeed(.ok)

      }

    })

  }

}