Models.scala

case class FacebookPostingMessages(`object`: String, entry: Seq[MessagePostEntry]) {
  def messages(): Seq[Message] = {
    entry.flatMap(_.messaging).map(_.message)
  }
}
case class Correspondent(id: String)
case class MessagePostEntry(id: String, time: Long, messaging: Seq[Messaging])
case class Messaging(sender: Correspondent, recipient: Correspondent, timestamp: Long, message: Message)
case class Message(mid: String, seq: Long, text: String)

object MessageFormats {
  implicit val messageFormat = Json.format[Message]
  implicit val messageReads = Json.reads[Message]

  implicit val correspondentFormat = Json.format[Correspondent]
  implicit val correspondentReads = Json.reads[Correspondent]

  implicit val messagingFormat = Json.format[Messaging]
  implicit val messagingReads = Json.reads[Messaging]

  implicit val entryFormat = Json.format[MessagePostEntry]
  implicit val entryReads = Json.reads[MessagePostEntry]

  implicit val facebookPostingMessagesFormats = Json.format[FacebookPostingMessages]
  implicit val facebookPostingMessagesReads = Json.reads[FacebookPostingMessages]
}