The game idea is based on RNG and is really simple:

The client sends the message to the server where it specifies the amount of players for each round. The server uses Akka actors for intercommunication. The game engine is simple:

• The engine generates a random number for each player and the bot
• it then applies some business logic and calculates the result for each player
• then drops all players who were outperformed by bot
• and finally sorts the results in descending order.

Let's see the flow:

• The client sends a simple JSON via WebSocket to initialize the game

  The JSON looks like this:

    {
      "messageType": "request.play",
      "players": 10
    }

• The server uses Akka Actors for intercommunication which looks like this:

  • Server receives the JSON, parses it, initializes the GameActor and sends InitializeGame to it.
  • GameActor spawns N amount of PlayerActor-s and sends Play message to each.
  • each PlayerActor sends GenerateRandomNumber to RNGActor.
  • RNGActor generates the random number and replies back to PlayerActor with PlayerUpdated message.
  • PlayerActor then replies GameActor with PlayerReply message.
  • Once all messages received, GameActor creates GameAggregatorActor and sends AggregateResults message to it.
  • GameAggregatorActor applies the business logic to the game and responds back with GameAggregatorReply.
  • GameActor responds back with the GameResult message which holds the final outcome for the round.
  • And finally the result gets parsed and delivered as a WebSocket response.

The typical response looks like:

[
  {
    "number": 100400,
    "player": "player_82d7f47f-84b1-48c0-a026-635d87020abe",
    "position": 1,
    "result": 1002
  },
  {
    "number": 616186,
    "player": "player_b5811f05-9884-470c-b4d4-6b389fb513f8",
    "position": 2,
    "result": 111
  },
  {
    "number": 542540,
    "player": "player_b700dec7-751f-406a-86a3-5ef1c72c2eea",
    "position": 3,
    "result": 22
  },
  {
    "number": 325584,
    "player": "player_874b306a-584a-4f7e-b7f1-81ce1a67b322",
    "position": 4,
    "result": 14
  },
  {
    "number": 691235,
    "player": "bot",
    "position": 5,
    "result": 6
  }
]

Setup instructions:

• clone the repo
• cd into ~/onair-game-simulation
• run test to make sure unit and actor tests pass
• run run to see the options, let's run the most interesting one (AkkaHttpApp) or you may also run AkkaConsoleApp or ScalaConsoleApp
• in case of running AkkaHttpApp you need to start second sbt server and run GameWebsocketClient for making randomized requests, please pay attention to periodical sorted json responses in terminal
• in case of running AkkaHttpApp you need to start third sbt server and run run PingPongWebsocketClient for making randomized requests, please pay attention to periodical json responses in terminal

The app can also be very simply set up with the help of IntelliJ IDEA.

Enjoy!