Event.scala

import ObjectMapper

enum Event {
    case ringing
    case incomingSound(instant: Int64, samples: Data)
    case outgoingSound(instant: Int64, samples: Data)
    case hangUp
}

extension Event : ImmutableMappable {
    
    init(map: Map) throws {
        switch try map.value("kind") as String {
        case "ringing":
            self = .ringing
        case "hangUp":
            self = .hangUp
        case "incomingSound":
            self = .incomingSound(
                instant: try map.value("instant"),
                samples: try map.value("samples")
            )
        case "outgoingSound":
            self = .outgoingSound(
                instant: try map.value("instant"),
                samples: try map.value("samples")
            )
        default:
            throw NSError()
        }
    }
    
    mutating func mapping(map: Map) {
        switch self {
        case .ringing:
            "ringing" >>> map["kind"]
            
        case .hangUp:
            "hangUp" >>> map["kind"]
        
        case let .incomingSound(instant: instant, samples: samples):
            "incomingSound" >>> map["kind"]
            instant >>> map["instant"]
            samples >>> map["samples"]
            
        case let .outgoingSound(instant: instant, samples: samples):
            "outgoingSound" >>> map["kind"]
            instant >>> map["instant"]
            samples >>> map["samples"]
        }
    }
}