/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * 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.
 */

namespace cpp2 example.chatroom
namespace go example.if.chatroom
namespace py3 example

struct Message {
  1: string message;
  2: string sender;
  3: i64 timestamp;
}

struct IndexToken {
  1: i64 index;
}

struct GetMessagesRequest {
  // This token is a pointer into the messages queue that the server maintains,
  // and it marks a particular client's place in the queue. Hence, if you have
  // 10 messages in the queue, and the token's index is 5, then the client
  // has already received messages 0-5.
  1: optional IndexToken token;
}

struct GetMessagesResponse {
  1: list<Message> messages;
  2: IndexToken token;
}

struct SendMessageRequest {
  1: string message;
  2: string sender;
}

exception Exception {
  1: string message;
}

service ChatRoomService {
  /**
   * Initialize the service
   */
  void initialize() throws (1: Exception e);

  /**
   * Get the last few chat messages
   */
  GetMessagesResponse getMessages(1: GetMessagesRequest req) throws (
    1: Exception e,
  );

  /**
   * Send a message
   */
  void sendMessage(1: SendMessageRequest req) throws (1: Exception e);
}

service Echo {
  /**
  * Echo back the message
  */
  string echo(1: string message);
}